Fibrillization endows food proteins with anisotropic nanostructures,significantly enhancing their functional properties.The resultant food protein fibrils(FPFs)have garnered attention for their diverse applications ac...Fibrillization endows food proteins with anisotropic nanostructures,significantly enhancing their functional properties.The resultant food protein fibrils(FPFs)have garnered attention for their diverse applications across the food industry.However,the full potential of FPFs is hindered by inherent challenges,particularly their limited stability.This review critically examines the formation of FPFs in food processing,the new protein sources,and on the modification strategies of FPFs,thereby unlocking new avenues for FPF utilization in food processing.In particular,the strategies during and after fibrillization are highlighted.The first strategy is to modify the structure and function of protein fibrils by influencing fibrillization,such as through pretreatment,incubation conditions,nuclei induction,and ingredient interactions.The second strategy is to modify the mature FPFs by regulating their properties and interactions with other components.The review also discusses the potential applications and challenges of FPFs in food systems,such as food preservation,functional food design,and novel delivery carriers.展开更多
Amidst the ever-growing interest in high-mass-loading Li battery electrodes,a persistent challenge has been the insufficient continuity of their ion/electron conduction pathways.Here,we propose cellulose elementary fi...Amidst the ever-growing interest in high-mass-loading Li battery electrodes,a persistent challenge has been the insufficient continuity of their ion/electron conduction pathways.Here,we propose cellulose elementary fibrils(CEFs)as a class of deagglomerated binder for high-mass-loading electrodes.Derived from natural wood,CEF represents the most fundamental unit of cellulose with nanoscale diameter.The preparation of the CEFs involves the modulation of intermolecular hydrogen bonding by the treatment with a proton acceptor and a hydrotropic agent.This elementary deagglomeration of the cellulose fibers increases surface area and anionic charge density,thus promoting uniform dispersion with carbon conductive additives and suppressing interfacial side reactions at electrodes.Consequently,a homogeneous redox reaction is achieved throughout the electrodes.The resulting CEF-based cathode(overlithiated layered oxide(OLO)is chosen as a benchmark electrode active material)exhibits a high areal-mass-loading(50 mg cm^(-2),equivalent to an areal capacity of 12.5 mAh cm^(-2))and a high specific energy density(445.4 Wh kg–1)of a cell,which far exceeds those of previously reported OLO cathodes.This study highlights the viability of the deagglomerated binder in enabling sustainable high-mass-loading electrodes that are difficult to achieve with conventional synthetic polymer binders.展开更多
Experimental X-ray crystallography, NMR (Nuclear Magnetic Resonance) spectroscopy, dual polarization interferometry, etc. are indeed very powerful tools to determine the 3-Dimensional structure of a protein (including...Experimental X-ray crystallography, NMR (Nuclear Magnetic Resonance) spectroscopy, dual polarization interferometry, etc. are indeed very powerful tools to determine the 3-Dimensional structure of a protein (including the membrane protein);theoretical mathematical and physical computational approaches can also allow us to obtain a description of the protein 3D structure at a submicroscopic level for some unstable, noncrystalline and insoluble proteins. X-ray crystallography finds the X-ray final structure of a protein, which usually need refinements using theoretical protocols in order to produce a better structure. This means theoretical methods are also important in determinations of protein structures. Optimization is always needed in the computer-aided drug design, structure-based drug design, molecular dynamics, and quantum and molecular mechanics. This paper introduces some optimization algorithms used in these research fields and presents a new theoretical computational method—an improved LBFGS Quasi-Newtonian mathematical optimization method—to produce 3D structures of prion AGAAAAGA amyloid fibrils (which are unstable, noncrystalline and insoluble), from the potential energy minimization point of view. Because the NMR or X-ray structure of the hydrophobic region AGAAAAGA of prion proteins has not yet been determined, the model constructed by this paper can be used as a reference for experimental studies on this region, and may be useful in furthering the goals of medicinal chemistry in this field.展开更多
The assessment of nanomechanical properties of a single amyloid fibril in a confined space provides important information for understanding the role of fibrils in a cell microenvironment. In this study, the structure ...The assessment of nanomechanical properties of a single amyloid fibril in a confined space provides important information for understanding the role of fibrils in a cell microenvironment. In this study, the structure and nanomechanical properties of different fibrils formed in water nanofilms on mica surface are carefully investigated by using the new atomic force microscopy imaging mode-peak force quantitative nanomechanics （PF-QNM）. We find that two types of fibrils with different morphologies are formed in water nanofilm on mica. The compression elasticities of these two types of fibrils are 3.9±0.9 and 2.5±0.6 GPa, respectively. The remarkable difference is possibly due to the structural discrepancy in two types of fibrils.展开更多
Amyloid fibrils are widely recognized as a cause of serious amyloidosis such as Alzheimer’s disease. Although dissociation of amyloid fibril aggregates is expected to lead to a decrease in the toxicity of the fibrils...Amyloid fibrils are widely recognized as a cause of serious amyloidosis such as Alzheimer’s disease. Although dissociation of amyloid fibril aggregates is expected to lead to a decrease in the toxicity of the fibrils in cells, the fibril structure is robust under physiological conditions. We have irradiated amyloid fibrils with a free-electron laser (FEL) tuned to mid-infrared frequencies to induce dissociation of the aggregates into monomer forms. We have previously succeeded in dissociating fibril structures of a short peptide of the thyroid hormone by tuning the oscillation frequency to the amide I band, but the detailed structural changes of the peptide have not yet been determined at a high spatial resolution. Synchrotron-radiation infrared microscopy (SR-IRM) is a powerful tool for in situ analysis of minute structural changes of various materials, and in this study, the feasibility of SR-IRM for analyzing the microscopic conformational changes of amyloid fibrils after FEL irradiation was investigated. Reflection spectra of the amyloid fibril surface showed that the amide I peaks shifted to higher wave numbers after the FEL irradiation, indicating that the initial β-sheet-rich structure transformed into a mixture of non-ordered and turn-like peptide conformations. This result demonstrates that conformational changes of the fibril structure after the FEL irradiation can be observed at a high spatial resolution using SR-IRM analysis and the FEL irradiation system can be useful for dissociation of amyloid aggregates.展开更多
According to current knowledge on collagen fibril-logenesis, collagen fibrils are formed by a cooperative process involving lateral fusion of small protofibrils. Almost all the experimental research, however, was carr...According to current knowledge on collagen fibril-logenesis, collagen fibrils are formed by a cooperative process involving lateral fusion of small protofibrils. Almost all the experimental research, however, was carried out on tendon collagen, whose fibrils are characterized by approximately straight subfibrils. By contrast, in most tissues the collagen fibril sub-units follow a helical course in which geometrical constraints prevent lateral fusions, thereby implying a different mechanism where collagen fibrils grow by addition of individual microfibrils rather than by lateral fusion of pre-assembled subfibrils. The proc-ess at the origin of these fibrils may provide a simple, automatic explanation for the remarkable uniformity in fibrils size observed in most tissues without re-quiring the intervention of unknown mechanisms of diameter control. Other mechanisms of growth con-trol remain indispensable to terminate the fibril-logenesis process in tendons and ligaments.展开更多
Amyloid fibrils derived from different proteins have been proved as a promising material for adsorption of various pollutants from wastewater,which showed advantages of low cost and eco-friendliness.However,most of th...Amyloid fibrils derived from different proteins have been proved as a promising material for adsorption of various pollutants from wastewater,which showed advantages of low cost and eco-friendliness.However,most of the amyloid fibrils derived from animal-based proteins with high environmental footprint,while more sustainable amyloid fibrils derived from plant materials are desirable.In this study,a plant-derived amyloid fibril was extracted from the commonly used wheat flour with a simple and scalable protein purification and fibrillization process.Interestingly,the amyloid fibrils showed good adsorption capacity towards typical organic dyes(Eosin Y(EY)and Congo red(CR))from contaminated water.Adsorption kinetic analysis indicated the adsorption process to EY or CR by wheat flour amyloid well fitted with a pseudo-second-order model.The adsorption also followed a Langmuir isothermal model with adsorption capacities of 333 mg/g and 138 mg/g towards CR and EY,respectively.This work demonstrated the feasibility to utilize the plant-based amyloid fibril for organic dyes removal from contaminated water,which provided an affordable,sustainable and scalable tool for organic dyes removal from wastewater.展开更多
The cornea is a soft tissue located at the front of the eye with the principal function of transmitting and refracting light rays to precisely sense visual information. Corneal shape, refraction, and stromal stiffness...The cornea is a soft tissue located at the front of the eye with the principal function of transmitting and refracting light rays to precisely sense visual information. Corneal shape, refraction, and stromal stiffness are to a large part determined by corneal fibrils, the arrangements of which define the corneal cells and their functional behaviour. However, the modality and alignment of native corneal collagen lamellae are altered in various corneal pathological states such as infection, injury, keratoconus, corneal scar formation, and keratoprosthesis. Furthermore, corneal recuperation after corneal pathological change is dependent on the balance of corneal collagen degradation and contraction. A thorough understanding of the characteristics of corneal collagen is thus necessary to develop viable therapies using the outcome of strategies using engineered corneas. In this review, we discuss the composition and distribution of corneal collagens as well as their degradation and contraction, and address the current status of corneal tissue engineering and the progress of corneal cross-linking.展开更多
in situ Fibril formation of polyamide-6 （PA6） in isotropic polypropylene （iPP） was first fabricated using a slit die extrusion and hot stretching process. Then the prepared materials were subjected to injection mo...in situ Fibril formation of polyamide-6 （PA6） in isotropic polypropylene （iPP） was first fabricated using a slit die extrusion and hot stretching process. Then the prepared materials were subjected to injection molding in the temperature range higher than the melting temperature of iPP but lower than that of PA6. The obtained injection-molded samples were characterized via scanning electron microscopy （SEM）, differential scanning calorimetry （DSC） and two-dimensional wide- angle X-ray scattering （2D-WAXS）. Mechanical properties were also investigated. The SEM result shows that the optimum fibril formation could be only achieved in the range of 20 wt% to 30 wt% of PA6 content for the studied system. The fibril morphology changes along the sample thickness in the injection-molded bars. The fibril morphology in the skin layer was better than that in the core layer. 2D-WAXS results showed that the orientation of PP decreased with the increase of PA6 content, which indicated that the orientation of PP was confined by PA6 fibrils. Combined consideration of mechanical properties and morphology indicates that only PP/PA6 composites with 20 wt% of PA6 content show better properties because of the better fibril morphology and PP chain orientation.展开更多
α-Synuclein(α-syn)forms structurally distinct fibril polymorphs with various pathological activities in different subtypes of synucleinopathies,such as Parkinson's disease(PD).As a unique proteinaceous polymer,t...α-Synuclein(α-syn)forms structurally distinct fibril polymorphs with various pathological activities in different subtypes of synucleinopathies,such as Parkinson's disease(PD).As a unique proteinaceous polymer,the mechanical property ofα-syn fibril is a primary determinant of its neurotoxicity,immunogenicity,and seeding and transmission capacity.Nevertheless,how genetic mutations inα-syn fibrils cause varied polymer behaviors remains largely unknown.Using optical tweezers,we quantitatively characterize the mechanical properties of threeα-syn fibril variants at the single-molecule level.We find that wild-typeα-syn fibrils are generally more sustainable to an axial disruption force than those formed by the disease-causing E46K and A53Tα-syn mutants,whereas their heterogeneous elastic properties manifest similarity.Based on the molecular dynamics simulations,theβ-sheet motif and the interface between the two protofilaments dominate in stabilizing the fibril structure.Additionally,single-molecule and simulation analysis consistently reveal the force-drivenα-syn protein unfolding without a fibril break.Due to the flexible periphery,these subtle structural changes become more pronounced with the E46K fibril.The structure–mechanics relationship ofα-syn fibrils built in this work sheds new light on the fibril assembly and disassembly mechanism and the mutant-associated pathogenesis in PD.展开更多
Polyacrylonitrile (PAN) fiber is an important precursor fiber for high performance carbon fiber.The properties of the final carbon fiber depend strongly on the nature of the PAN fibers.The PAN fibrils were separated s...Polyacrylonitrile (PAN) fiber is an important precursor fiber for high performance carbon fiber.The properties of the final carbon fiber depend strongly on the nature of the PAN fibers.The PAN fibrils were separated successfully from fibers by ultrasonic etching and were systematically investigated by field emission scanning electron microscopy (FESEM) and high resolution transmission electron microscopy (HRTEM).It is found that in certain ultrasonic etching conditions (at 75±2oC for 6 h with a frequency of 40 kHz) the PAN fibers are dissolved in the 95 wt.% aqueous dimethylsulphoxide (DMSO) solution;the fibrils consisting of numerous periodic lamellae with thickness of 30-45 nm and perpendicular to the fiber axis are separated in the 90 wt.% aqueous DMSO solution;and the fibrils with smooth surface exfoliated from the PAN fibers are obtained in the 70-90 wt.% aqueous DMSO solutions.Inner periodical structure of fibrils was observed in HRTEM,which indicates that there are different densities and two phases in fibrils.The PAN fibers are dissolved layer by layer with increasing ultrasonic etching time.The fiber surface experiences ultrasonic cleaning,selective etching,excessive etching and dissolution,and then the sublayer experiences the same process.There are numerous periodic lamellae in fibrils of nascent fibers.This means that the fibrils with lamellae are formed by orientation and crystallization in shearing field of spinning pipe and drawing stress field of coagulation bath.展开更多
Collagen,one of the major components in the mammalian connective tissues,plays an essential role in many vital physiological processes.Many common diseases,such as fibrosis,overuse injuries,and bone fracture,are assoc...Collagen,one of the major components in the mammalian connective tissues,plays an essential role in many vital physiological processes.Many common diseases,such as fibrosis,overuse injuries,and bone fracture,are associated with collagen arrangement defects.However,the underlying mechanism of collagen arrangement defects remains elusive.In this study,we applied infrared scattering-type scanning near-field optical microscopy to study collagen fibrils’structural properties.Experimentally,we observed two types of collagen fibrils’arrangement with different periodic characteristics.A crystal sliding model was employed to explain this observation qualitatively.Our results suggest that the collagen dislocation propagates in collagen fibrils,which may shed light on many collagen diseases’pathogenesis.These findings help to understand the regulation mechanism of hierarchical biological structure.展开更多
The modification of amyloid fibrils cytotoxicity through exogenous nanomaterials is crucial to understand the processes controlling the role of protein aggregation in the related diseases.The influence of nanoparticle...The modification of amyloid fibrils cytotoxicity through exogenous nanomaterials is crucial to understand the processes controlling the role of protein aggregation in the related diseases.The influence of nanoparticles on amyloid stability yields great interest due to the small size and high surface area-to-volume ratio of nanoparticles.Various physico-chemical parameters play a role in the interaction of proteins and nanoparticles in solution,thus influencing the disaggregation of preformed fibrils.We have examined the influence of two kinds of metallic nanoparticles on lysozyme amyloid fibrils using a multi-technique approach and focalized their impact on cytotoxicity on human neuroblastoma cells(SH-SY5Y).In particular,fluorescence,infrared and circular dichroism spectroscopies,optical and atomic force microscopy experiments have been carried out;the results are analyzed to rationalize the effects of these complexes on neural cell viability.It is remarkable,that the fibrils in the presence of AuNPs,unlike fibrils alone or with AgNPs,do not generate a significant cytotoxic effect even at high concentration and an amyloid degradation effect is visible.展开更多
The formation of amyloid plaques usually occurs in the early-stage of Alzheimer’s disease(AD).Stimulated emission depletion(STED)imaging provided a powerful tool for visualizing amyloid structures on the nanometer sc...The formation of amyloid plaques usually occurs in the early-stage of Alzheimer’s disease(AD).Stimulated emission depletion(STED)imaging provided a powerful tool for visualizing amyloid structures on the nanometer scale.However,many commercial probes adopted in detecting amyloid fibrils are inapplicable to STED imaging,owing to their unmatched absorption and emission wavelengths,small Stokes'shift,easy photo-bleaching,etc.Herein,we demonstrated a polarity-activated STED probe based on an intramolecular charge transfer donor(D)-7c-acceptor(A)compound.The electron-rich carbazole group and the electron-poor pyridinium bromide group,linked by 7i-conjugated thiophen-bridge,ensure strong near infrared(NIR)emission with a Stokes'shift larger than 200 nm.The tiny change in polarity before and after binding with amyloid plaques leads to a transition from weakly emission charge-transfer(CT)state(Φ<0.04)to highly emissive locally-excited(LE)state(Φ=0.57),giving rise to a fluorescence Turn-On probe.Together with large Stokes'shift,good photostability and high depletion efficiency,the super-resolution imaging of the formation and morphology of amyloid fibrils in vitro based on this probe was realized with a lateral spatial resolution better than 33 nm at an extremely low depletion power.Moreover,the ex-vivo super-resolution imaging of(E)-1-butyl-4(2-(5-(9-ethyl-9Hcarbazol-3-yl)thiophen-2-yl)vinyl)pyridinium bromide(CTPB)probe in Aβ plaques in the brain slices of a Tg mouse was demonstrated.This research provides a demonstration of the super resolution imaging probe of amyloid fibrils based on polarity-response mechanism,providing a new approach to the development of future amyloid probes.展开更多
The deposition of highly ordered amyloid fibrils is recognized as a hallmark of amyloidosis diseases such as Alzheimer’s disease and Parkinson’s disease.Disaggregating the amyloid fibrils is considered as one of the...The deposition of highly ordered amyloid fibrils is recognized as a hallmark of amyloidosis diseases such as Alzheimer’s disease and Parkinson’s disease.Disaggregating the amyloid fibrils is considered as one of the effective strategies for the control and treatment of amyloidosis diseases.In this article,by simulating the function of natural molecular chaperones,co-assembled block copolymer micelles with coordination groups of nitrilotriacetic acid(NTA)and hydrophobic microdomains of poly(Nisopropylacrylamide)(PNIPAM)on the surface were used as nanochaperones(n Chaps)to disaggregate amyloid insulin fibrils.Zinc ions chelated by NTA can bind the histidine imidazole residues while the PNIPAM microdomains can interact with the exposed hydrophobic sites on the amyloid insulin fibrils,which synergistically perturb the stability of amyloid insulin fibrils,loosen their structure,and finally promote their disaggregation.A combination of characterizations with fluorescence spectroscopy,transmission electron microscopy(TEM),dynamic hight scattering(DLS),and quartz crystal microbalance(QCM)demonstrated that mature amyloid insulin fibrils were completely disaggregated after incubating with n Chaps for 90 h.This study may provide a promising strategy for the development of n Chaps for the treatment of amyloidosis diseases.展开更多
Chlamydomonas is a primitive unicellar eukaryote with two flagella of equal length at its anterior end. At the root of flagella is the organella called the basal body which consists of nine triple sets of microtubules...Chlamydomonas is a primitive unicellar eukaryote with two flagella of equal length at its anterior end. At the root of flagella is the organella called the basal body which consists of nine triple sets of microtubules. The basal bodies are homologous to the centriole, and are the center of organizing microtubule in flagellum展开更多
Amyloid peptides are renowned to be related to neurodegenerative diseases, however, a fruitful avenue is to employ them as high-performance nanomaterials. These materials benefit from the intrinsic outstanding mechani...Amyloid peptides are renowned to be related to neurodegenerative diseases, however, a fruitful avenue is to employ them as high-performance nanomaterials. These materials benefit from the intrinsic outstanding mechanical robustness of the amyloid backbone made of r-strands. In this work, we exploited amyloid-like fibrils as functional material to attach pristine L-cysteine aggregates （cystine oligomers） and gold nanoparticles, without the need of templating compounds. This work will open new avenues on functional materials design and their realisation.展开更多
In artificial photosynthesis systems,synthetic diiron complexes are popular[FeFe]-hydrogenase mimics,which are attractive for the fabrication of photocatalyst-protein hybrid structures to amplify hydrogen(H2)generatio...In artificial photosynthesis systems,synthetic diiron complexes are popular[FeFe]-hydrogenase mimics,which are attractive for the fabrication of photocatalyst-protein hybrid structures to amplify hydrogen(H2)generation capability.However,constructing a highly bionic and efficient catalytic hybrid system is a major challenge.Notably,we designed an ideal hybrid nanofibrils system that incorporates the crucial components:(1)a[FeFe]-H2ase mimic,which has a three-arm architecture(named triFeFe)for more interaction sites and higher catalytic activity and(2)uniform hybrid nanofibrils as the biological environment in which cysteine-catalyst coordination and the hydrogen-bonding network play a vital role in both catalyst binding and hydrogen evolution reaction activity.The assembled hybrid nanofibrils achieve efficient H2 generation with a turnover number of 2.3×103,outperforming previously reported diiron catalyst-protein hybrid systems.Additionally,the hybrid nanofibrils work with photosynthetic thylakoids to produce H2,without extra photosensitizers or electron shuttle proteins,which advances the bioengineering of living systems for solar-driven biofuel production.展开更多
Optimizing the components and morphology within the photoactive layer of organic solar cells(OSCs)can significantly enhance their power conversion efficiency(PCE).A new A-D-A type non-fullerene acceptor IDMIC-4F is de...Optimizing the components and morphology within the photoactive layer of organic solar cells(OSCs)can significantly enhance their power conversion efficiency(PCE).A new A-D-A type non-fullerene acceptor IDMIC-4F is designed and synthesized in this work,and is employed as the third component to prepare high performance ternary solar cells.IDMIC-4F can form fibrils after solution casting,and the presence of this fibrillar structure in the PBDB-T-2F:BTP-4F host confines the growth of donors and acceptors into fine domains,as well as acting as transport channels to enhance electron mobility.Single junction ternary devices incorporating 10 wt%IDMIC-4F exhibit enhanced light absorption and balanced carrier mobility,and achieve a maximum PCE of 16.6%compared to 15.7%for the binary device,which is a remarkable efficiency for OSCs reported in literature.This non-fullerene acceptor fibril network strategy is a promising method to improve the photovoltaic performance of ternary OSCs.展开更多
α-Synuclein accumulation and transmission are vital to the pathogenesis of Parkinson's disease,although the mechanisms underlying misfoldedα-synuclein accumulation and propagation have not been conclusively dete...α-Synuclein accumulation and transmission are vital to the pathogenesis of Parkinson's disease,although the mechanisms underlying misfoldedα-synuclein accumulation and propagation have not been conclusively determined.The expression of low-density lipoprotein receptor–related protein 1,which is abundantly expressed in neurons and considered to be a multifunctional endocytic receptor,is elevated in the neurons of patients with Parkinson's disease.However,whether there is a direct link between low-density lipoprotein receptor–related protein 1 andα-synuclein aggregation and propagation in Parkinson's disease remains unclear.Here,we established animal models of Parkinson's disease by inoculating monkeys and mice withα-synuclein pre-formed fibrils and observed elevated low-density lipoprotein receptor–related protein 1 levels in the striatum and substantia nigra,accompanied by dopaminergic neuron loss and increasedα-synuclein levels.However,low-density lipoprotein receptor–related protein 1 knockdown efficiently rescued dopaminergic neurodegeneration and inhibited the increase inα-synuclein levels in the nigrostriatal system.In HEK293A cells overexpressingα-synuclein fragments,low-density lipoprotein receptor–related protein 1 levels were upregulated only when the N-terminus ofα-synuclein was present,whereas anα-synuclein fragment lacking the N-terminus did not lead to low-density lipoprotein receptor–related protein 1 upregulation.Furthermore,the N-terminus ofα-synuclein was found to be rich in lysine residues,and blocking lysine residues in PC12 cells treated withα-synuclein pre-formed fibrils effectively reduced the elevated low-density lipoprotein receptor–related protein 1 andα-synuclein levels.These findings indicate that low-density lipoprotein receptor–related protein 1 regulates pathological transmission ofα-synuclein from the striatum to the substantia nigra in the nigrostriatal system via lysine residues in theα-synuclein N-terminus.展开更多
基金supported by the Natural Science Foundation of Jiangxi Province(20232BAB205075,20224ACB205014).
文摘Fibrillization endows food proteins with anisotropic nanostructures,significantly enhancing their functional properties.The resultant food protein fibrils(FPFs)have garnered attention for their diverse applications across the food industry.However,the full potential of FPFs is hindered by inherent challenges,particularly their limited stability.This review critically examines the formation of FPFs in food processing,the new protein sources,and on the modification strategies of FPFs,thereby unlocking new avenues for FPF utilization in food processing.In particular,the strategies during and after fibrillization are highlighted.The first strategy is to modify the structure and function of protein fibrils by influencing fibrillization,such as through pretreatment,incubation conditions,nuclei induction,and ingredient interactions.The second strategy is to modify the mature FPFs by regulating their properties and interactions with other components.The review also discusses the potential applications and challenges of FPFs in food systems,such as food preservation,functional food design,and novel delivery carriers.
基金supported by the Institute of Civil Military Technology Cooperation funded by the Defense Acquisition Program Administration and Ministry of Trade,Industry and Energy of Korean government under grant No 23-CM-AI-08.
文摘Amidst the ever-growing interest in high-mass-loading Li battery electrodes,a persistent challenge has been the insufficient continuity of their ion/electron conduction pathways.Here,we propose cellulose elementary fibrils(CEFs)as a class of deagglomerated binder for high-mass-loading electrodes.Derived from natural wood,CEF represents the most fundamental unit of cellulose with nanoscale diameter.The preparation of the CEFs involves the modulation of intermolecular hydrogen bonding by the treatment with a proton acceptor and a hydrotropic agent.This elementary deagglomeration of the cellulose fibers increases surface area and anionic charge density,thus promoting uniform dispersion with carbon conductive additives and suppressing interfacial side reactions at electrodes.Consequently,a homogeneous redox reaction is achieved throughout the electrodes.The resulting CEF-based cathode(overlithiated layered oxide(OLO)is chosen as a benchmark electrode active material)exhibits a high areal-mass-loading(50 mg cm^(-2),equivalent to an areal capacity of 12.5 mAh cm^(-2))and a high specific energy density(445.4 Wh kg–1)of a cell,which far exceeds those of previously reported OLO cathodes.This study highlights the viability of the deagglomerated binder in enabling sustainable high-mass-loading electrodes that are difficult to achieve with conventional synthetic polymer binders.
文摘Experimental X-ray crystallography, NMR (Nuclear Magnetic Resonance) spectroscopy, dual polarization interferometry, etc. are indeed very powerful tools to determine the 3-Dimensional structure of a protein (including the membrane protein);theoretical mathematical and physical computational approaches can also allow us to obtain a description of the protein 3D structure at a submicroscopic level for some unstable, noncrystalline and insoluble proteins. X-ray crystallography finds the X-ray final structure of a protein, which usually need refinements using theoretical protocols in order to produce a better structure. This means theoretical methods are also important in determinations of protein structures. Optimization is always needed in the computer-aided drug design, structure-based drug design, molecular dynamics, and quantum and molecular mechanics. This paper introduces some optimization algorithms used in these research fields and presents a new theoretical computational method—an improved LBFGS Quasi-Newtonian mathematical optimization method—to produce 3D structures of prion AGAAAAGA amyloid fibrils (which are unstable, noncrystalline and insoluble), from the potential energy minimization point of view. Because the NMR or X-ray structure of the hydrophobic region AGAAAAGA of prion proteins has not yet been determined, the model constructed by this paper can be used as a reference for experimental studies on this region, and may be useful in furthering the goals of medicinal chemistry in this field.
基金Supported by the National Natural Science Foundation of China under Grant No 11474173the Natural Science Foundation of Zhejiang Province under Grant Nos LY14A040006 and LQ14F040002+1 种基金the Ningbo Natural Science Foundation under Grant Nos2014A610202 and 2014A610149the K.C.Wong Magna Fund in Ningbo University
文摘The assessment of nanomechanical properties of a single amyloid fibril in a confined space provides important information for understanding the role of fibrils in a cell microenvironment. In this study, the structure and nanomechanical properties of different fibrils formed in water nanofilms on mica surface are carefully investigated by using the new atomic force microscopy imaging mode-peak force quantitative nanomechanics （PF-QNM）. We find that two types of fibrils with different morphologies are formed in water nanofilm on mica. The compression elasticities of these two types of fibrils are 3.9±0.9 and 2.5±0.6 GPa, respectively. The remarkable difference is possibly due to the structural discrepancy in two types of fibrils.
文摘Amyloid fibrils are widely recognized as a cause of serious amyloidosis such as Alzheimer’s disease. Although dissociation of amyloid fibril aggregates is expected to lead to a decrease in the toxicity of the fibrils in cells, the fibril structure is robust under physiological conditions. We have irradiated amyloid fibrils with a free-electron laser (FEL) tuned to mid-infrared frequencies to induce dissociation of the aggregates into monomer forms. We have previously succeeded in dissociating fibril structures of a short peptide of the thyroid hormone by tuning the oscillation frequency to the amide I band, but the detailed structural changes of the peptide have not yet been determined at a high spatial resolution. Synchrotron-radiation infrared microscopy (SR-IRM) is a powerful tool for in situ analysis of minute structural changes of various materials, and in this study, the feasibility of SR-IRM for analyzing the microscopic conformational changes of amyloid fibrils after FEL irradiation was investigated. Reflection spectra of the amyloid fibril surface showed that the amide I peaks shifted to higher wave numbers after the FEL irradiation, indicating that the initial β-sheet-rich structure transformed into a mixture of non-ordered and turn-like peptide conformations. This result demonstrates that conformational changes of the fibril structure after the FEL irradiation can be observed at a high spatial resolution using SR-IRM analysis and the FEL irradiation system can be useful for dissociation of amyloid aggregates.
文摘According to current knowledge on collagen fibril-logenesis, collagen fibrils are formed by a cooperative process involving lateral fusion of small protofibrils. Almost all the experimental research, however, was carried out on tendon collagen, whose fibrils are characterized by approximately straight subfibrils. By contrast, in most tissues the collagen fibril sub-units follow a helical course in which geometrical constraints prevent lateral fusions, thereby implying a different mechanism where collagen fibrils grow by addition of individual microfibrils rather than by lateral fusion of pre-assembled subfibrils. The proc-ess at the origin of these fibrils may provide a simple, automatic explanation for the remarkable uniformity in fibrils size observed in most tissues without re-quiring the intervention of unknown mechanisms of diameter control. Other mechanisms of growth con-trol remain indispensable to terminate the fibril-logenesis process in tendons and ligaments.
基金Natural Science Foundation of Jiangsu Province(Carbon Neutralization,BK20220003)Special Scientific Research Project of School of Emergency Management,Jiangsu University(KY-B-02).
文摘Amyloid fibrils derived from different proteins have been proved as a promising material for adsorption of various pollutants from wastewater,which showed advantages of low cost and eco-friendliness.However,most of the amyloid fibrils derived from animal-based proteins with high environmental footprint,while more sustainable amyloid fibrils derived from plant materials are desirable.In this study,a plant-derived amyloid fibril was extracted from the commonly used wheat flour with a simple and scalable protein purification and fibrillization process.Interestingly,the amyloid fibrils showed good adsorption capacity towards typical organic dyes(Eosin Y(EY)and Congo red(CR))from contaminated water.Adsorption kinetic analysis indicated the adsorption process to EY or CR by wheat flour amyloid well fitted with a pseudo-second-order model.The adsorption also followed a Langmuir isothermal model with adsorption capacities of 333 mg/g and 138 mg/g towards CR and EY,respectively.This work demonstrated the feasibility to utilize the plant-based amyloid fibril for organic dyes removal from contaminated water,which provided an affordable,sustainable and scalable tool for organic dyes removal from wastewater.
基金Supported by Science and Technology Department of Jilin Province Research Fund(No.20160101011JC)Development and Reform Commission of Jilin Province(No.2016C044-1)
文摘The cornea is a soft tissue located at the front of the eye with the principal function of transmitting and refracting light rays to precisely sense visual information. Corneal shape, refraction, and stromal stiffness are to a large part determined by corneal fibrils, the arrangements of which define the corneal cells and their functional behaviour. However, the modality and alignment of native corneal collagen lamellae are altered in various corneal pathological states such as infection, injury, keratoconus, corneal scar formation, and keratoprosthesis. Furthermore, corneal recuperation after corneal pathological change is dependent on the balance of corneal collagen degradation and contraction. A thorough understanding of the characteristics of corneal collagen is thus necessary to develop viable therapies using the outcome of strategies using engineered corneas. In this review, we discuss the composition and distribution of corneal collagens as well as their degradation and contraction, and address the current status of corneal tissue engineering and the progress of corneal cross-linking.
基金This work was supported by the National Natural Science Foundation of China(Nos.50533050,20490220,20404008,and50373030)This work was subsidized by the Special Funds for Major State Basic Research Projects of China(No.2003CB615600)by the Ministry of Education of China(No.20050610030).
文摘in situ Fibril formation of polyamide-6 （PA6） in isotropic polypropylene （iPP） was first fabricated using a slit die extrusion and hot stretching process. Then the prepared materials were subjected to injection molding in the temperature range higher than the melting temperature of iPP but lower than that of PA6. The obtained injection-molded samples were characterized via scanning electron microscopy （SEM）, differential scanning calorimetry （DSC） and two-dimensional wide- angle X-ray scattering （2D-WAXS）. Mechanical properties were also investigated. The SEM result shows that the optimum fibril formation could be only achieved in the range of 20 wt% to 30 wt% of PA6 content for the studied system. The fibril morphology changes along the sample thickness in the injection-molded bars. The fibril morphology in the skin layer was better than that in the core layer. 2D-WAXS results showed that the orientation of PP decreased with the increase of PA6 content, which indicated that the orientation of PP was confined by PA6 fibrils. Combined consideration of mechanical properties and morphology indicates that only PP/PA6 composites with 20 wt% of PA6 content show better properties because of the better fibril morphology and PP chain orientation.
基金supported by the ShanghaiTech University School of Life Science and Technology Development Fund(SLST-YS2024004 to B.S.)the National Natural Science Foundation of China(32271505 and 32471508 to B.S.,32100993 to L.B.,32090040 to Z.H.,82188101,22425704 and 32171236 to C.L.,32494764,92353302 and 32170683 to D.L.)+4 种基金National Key R&D Program of China(2022YFA1303100 to Z.H.)the Science and Technology Commission of Shanghai Municipality(STCSM)(22ZR1441900 and 23ZR1442200 to B.S.,20XD1425000 and 22JC1410400 to C.L.)the Shanghai Pilot Program for Basic Research-Chinese Academy of Science,Shanghai Branch(CYJ-SHFY-2022-005 to C.L.)the CAS Project for Young Scientists in Basic Research(YSBR-095 to C.L.)Shanghai Basic Research Pioneer Project to C.L.,the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB1040000 and XDB1060000 to C.L.,XDB0450402 to Z.H.).
文摘α-Synuclein(α-syn)forms structurally distinct fibril polymorphs with various pathological activities in different subtypes of synucleinopathies,such as Parkinson's disease(PD).As a unique proteinaceous polymer,the mechanical property ofα-syn fibril is a primary determinant of its neurotoxicity,immunogenicity,and seeding and transmission capacity.Nevertheless,how genetic mutations inα-syn fibrils cause varied polymer behaviors remains largely unknown.Using optical tweezers,we quantitatively characterize the mechanical properties of threeα-syn fibril variants at the single-molecule level.We find that wild-typeα-syn fibrils are generally more sustainable to an axial disruption force than those formed by the disease-causing E46K and A53Tα-syn mutants,whereas their heterogeneous elastic properties manifest similarity.Based on the molecular dynamics simulations,theβ-sheet motif and the interface between the two protofilaments dominate in stabilizing the fibril structure.Additionally,single-molecule and simulation analysis consistently reveal the force-drivenα-syn protein unfolding without a fibril break.Due to the flexible periphery,these subtle structural changes become more pronounced with the E46K fibril.The structure–mechanics relationship ofα-syn fibrils built in this work sheds new light on the fibril assembly and disassembly mechanism and the mutant-associated pathogenesis in PD.
基金supported by the National Natural Science Foundation of China (Grant No.50673052)the Major State Basic Research Development Program of China (973 Program) (Grant No.2006CB605314)the Provincial Natural Science Foundation of Shandong Province (Grant No.Z2008F02)
文摘Polyacrylonitrile (PAN) fiber is an important precursor fiber for high performance carbon fiber.The properties of the final carbon fiber depend strongly on the nature of the PAN fibers.The PAN fibrils were separated successfully from fibers by ultrasonic etching and were systematically investigated by field emission scanning electron microscopy (FESEM) and high resolution transmission electron microscopy (HRTEM).It is found that in certain ultrasonic etching conditions (at 75±2oC for 6 h with a frequency of 40 kHz) the PAN fibers are dissolved in the 95 wt.% aqueous dimethylsulphoxide (DMSO) solution;the fibrils consisting of numerous periodic lamellae with thickness of 30-45 nm and perpendicular to the fiber axis are separated in the 90 wt.% aqueous DMSO solution;and the fibrils with smooth surface exfoliated from the PAN fibers are obtained in the 70-90 wt.% aqueous DMSO solutions.Inner periodical structure of fibrils was observed in HRTEM,which indicates that there are different densities and two phases in fibrils.The PAN fibers are dissolved layer by layer with increasing ultrasonic etching time.The fiber surface experiences ultrasonic cleaning,selective etching,excessive etching and dissolution,and then the sublayer experiences the same process.There are numerous periodic lamellae in fibrils of nascent fibers.This means that the fibrils with lamellae are formed by orientation and crystallization in shearing field of spinning pipe and drawing stress field of coagulation bath.
基金the National Key Research and Development Program of China(No.2016YFA0203500)the National Natural Science Foundation of China(No.11874407)Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB 30000000)。
文摘Collagen,one of the major components in the mammalian connective tissues,plays an essential role in many vital physiological processes.Many common diseases,such as fibrosis,overuse injuries,and bone fracture,are associated with collagen arrangement defects.However,the underlying mechanism of collagen arrangement defects remains elusive.In this study,we applied infrared scattering-type scanning near-field optical microscopy to study collagen fibrils’structural properties.Experimentally,we observed two types of collagen fibrils’arrangement with different periodic characteristics.A crystal sliding model was employed to explain this observation qualitatively.Our results suggest that the collagen dislocation propagates in collagen fibrils,which may shed light on many collagen diseases’pathogenesis.These findings help to understand the regulation mechanism of hierarchical biological structure.
基金This work was partially supported by Slovak grand agency VEGA 2/0145/17,APW-18-0284,Italian flagship NANOMAX,N-CHEM,Ministery o f Education,University and Research(PRIN grant 20173L7W8K).Microscopy was carried out at the SPM@ISMN facility.
文摘The modification of amyloid fibrils cytotoxicity through exogenous nanomaterials is crucial to understand the processes controlling the role of protein aggregation in the related diseases.The influence of nanoparticles on amyloid stability yields great interest due to the small size and high surface area-to-volume ratio of nanoparticles.Various physico-chemical parameters play a role in the interaction of proteins and nanoparticles in solution,thus influencing the disaggregation of preformed fibrils.We have examined the influence of two kinds of metallic nanoparticles on lysozyme amyloid fibrils using a multi-technique approach and focalized their impact on cytotoxicity on human neuroblastoma cells(SH-SY5Y).In particular,fluorescence,infrared and circular dichroism spectroscopies,optical and atomic force microscopy experiments have been carried out;the results are analyzed to rationalize the effects of these complexes on neural cell viability.It is remarkable,that the fibrils in the presence of AuNPs,unlike fibrils alone or with AgNPs,do not generate a significant cytotoxic effect even at high concentration and an amyloid degradation effect is visible.
基金This work was supported by the Ministry of Science and Technology of China(Nos.2017YFA0204503 and 2018YFA0704805)the National Natural Science Foundation of China(Nos.21503139,21573251,21673144,21873065,21833005,81970425 and 21790364)+5 种基金the Beijing Natural Science Foundation of China(No.2192011)the High-level Teachers in Bejing Municipal Universities in the Period of 13^th Five-year Plan(Nos.IDHT20180517 and CIT&TCD20180331)the Open Fund of the State Key Laboratory of Integrated Optoelectronics(No.IOSKL2019KF01)Capacity Building for Sci-Tech Innovation-Fundamental Scientific Research Funds(Nos.025185305000/210,009/19530050162 and 19530012018)Youth Innovative Research Team of Capital Normal University(No,009/19530050148)Beijing Advanced Innovation Center for Imaging Theory and Technology(No.009/19530011009).
文摘The formation of amyloid plaques usually occurs in the early-stage of Alzheimer’s disease(AD).Stimulated emission depletion(STED)imaging provided a powerful tool for visualizing amyloid structures on the nanometer scale.However,many commercial probes adopted in detecting amyloid fibrils are inapplicable to STED imaging,owing to their unmatched absorption and emission wavelengths,small Stokes'shift,easy photo-bleaching,etc.Herein,we demonstrated a polarity-activated STED probe based on an intramolecular charge transfer donor(D)-7c-acceptor(A)compound.The electron-rich carbazole group and the electron-poor pyridinium bromide group,linked by 7i-conjugated thiophen-bridge,ensure strong near infrared(NIR)emission with a Stokes'shift larger than 200 nm.The tiny change in polarity before and after binding with amyloid plaques leads to a transition from weakly emission charge-transfer(CT)state(Φ<0.04)to highly emissive locally-excited(LE)state(Φ=0.57),giving rise to a fluorescence Turn-On probe.Together with large Stokes'shift,good photostability and high depletion efficiency,the super-resolution imaging of the formation and morphology of amyloid fibrils in vitro based on this probe was realized with a lateral spatial resolution better than 33 nm at an extremely low depletion power.Moreover,the ex-vivo super-resolution imaging of(E)-1-butyl-4(2-(5-(9-ethyl-9Hcarbazol-3-yl)thiophen-2-yl)vinyl)pyridinium bromide(CTPB)probe in Aβ plaques in the brain slices of a Tg mouse was demonstrated.This research provides a demonstration of the super resolution imaging probe of amyloid fibrils based on polarity-response mechanism,providing a new approach to the development of future amyloid probes.
基金supported by the National Natural Science Foundation of China(51773099,51933006)。
文摘The deposition of highly ordered amyloid fibrils is recognized as a hallmark of amyloidosis diseases such as Alzheimer’s disease and Parkinson’s disease.Disaggregating the amyloid fibrils is considered as one of the effective strategies for the control and treatment of amyloidosis diseases.In this article,by simulating the function of natural molecular chaperones,co-assembled block copolymer micelles with coordination groups of nitrilotriacetic acid(NTA)and hydrophobic microdomains of poly(Nisopropylacrylamide)(PNIPAM)on the surface were used as nanochaperones(n Chaps)to disaggregate amyloid insulin fibrils.Zinc ions chelated by NTA can bind the histidine imidazole residues while the PNIPAM microdomains can interact with the exposed hydrophobic sites on the amyloid insulin fibrils,which synergistically perturb the stability of amyloid insulin fibrils,loosen their structure,and finally promote their disaggregation.A combination of characterizations with fluorescence spectroscopy,transmission electron microscopy(TEM),dynamic hight scattering(DLS),and quartz crystal microbalance(QCM)demonstrated that mature amyloid insulin fibrils were completely disaggregated after incubating with n Chaps for 90 h.This study may provide a promising strategy for the development of n Chaps for the treatment of amyloidosis diseases.
文摘Chlamydomonas is a primitive unicellar eukaryote with two flagella of equal length at its anterior end. At the root of flagella is the organella called the basal body which consists of nine triple sets of microtubules. The basal bodies are homologous to the centriole, and are the center of organizing microtubule in flagellum
文摘Amyloid peptides are renowned to be related to neurodegenerative diseases, however, a fruitful avenue is to employ them as high-performance nanomaterials. These materials benefit from the intrinsic outstanding mechanical robustness of the amyloid backbone made of r-strands. In this work, we exploited amyloid-like fibrils as functional material to attach pristine L-cysteine aggregates （cystine oligomers） and gold nanoparticles, without the need of templating compounds. This work will open new avenues on functional materials design and their realisation.
基金the National Natural Science Foundation of China(grant nos.22077065,22021002,and 22277054)the National Key R&D Program of China(grant no.2018YFE0200700)+1 种基金the China Postdoctoral Science Foundation(grant no.2021M703264)the Beijing National Laboratory for Molecular Sciences for financial support.
文摘In artificial photosynthesis systems,synthetic diiron complexes are popular[FeFe]-hydrogenase mimics,which are attractive for the fabrication of photocatalyst-protein hybrid structures to amplify hydrogen(H2)generation capability.However,constructing a highly bionic and efficient catalytic hybrid system is a major challenge.Notably,we designed an ideal hybrid nanofibrils system that incorporates the crucial components:(1)a[FeFe]-H2ase mimic,which has a three-arm architecture(named triFeFe)for more interaction sites and higher catalytic activity and(2)uniform hybrid nanofibrils as the biological environment in which cysteine-catalyst coordination and the hydrogen-bonding network play a vital role in both catalyst binding and hydrogen evolution reaction activity.The assembled hybrid nanofibrils achieve efficient H2 generation with a turnover number of 2.3×103,outperforming previously reported diiron catalyst-protein hybrid systems.Additionally,the hybrid nanofibrils work with photosynthetic thylakoids to produce H2,without extra photosensitizers or electron shuttle proteins,which advances the bioengineering of living systems for solar-driven biofuel production.
基金supported by the Natural Science Foundation of Hubei Province of China(2018CFA055)the National Natural Science Foundation of China(21774097)the 111 project(B18038)。
文摘Optimizing the components and morphology within the photoactive layer of organic solar cells(OSCs)can significantly enhance their power conversion efficiency(PCE).A new A-D-A type non-fullerene acceptor IDMIC-4F is designed and synthesized in this work,and is employed as the third component to prepare high performance ternary solar cells.IDMIC-4F can form fibrils after solution casting,and the presence of this fibrillar structure in the PBDB-T-2F:BTP-4F host confines the growth of donors and acceptors into fine domains,as well as acting as transport channels to enhance electron mobility.Single junction ternary devices incorporating 10 wt%IDMIC-4F exhibit enhanced light absorption and balanced carrier mobility,and achieve a maximum PCE of 16.6%compared to 15.7%for the binary device,which is a remarkable efficiency for OSCs reported in literature.This non-fullerene acceptor fibril network strategy is a promising method to improve the photovoltaic performance of ternary OSCs.
基金supported by the Natural Science Foundation of Guangxi Zhuang Automomous Region,Nos.2019GXNSFDA245015(to MC),2022GXNSFBA035654(to HL)the National Natural Science Foundation of China,Nos.82360241(to MC),82304876(to HL)+1 种基金Scientific Research and Technology Development Project of Guilin City,Nos.20220139-3(to MC),20210218-5(to HL)Guangxi Medical and Health Key Discipline Construction Project(to QL)。
文摘α-Synuclein accumulation and transmission are vital to the pathogenesis of Parkinson's disease,although the mechanisms underlying misfoldedα-synuclein accumulation and propagation have not been conclusively determined.The expression of low-density lipoprotein receptor–related protein 1,which is abundantly expressed in neurons and considered to be a multifunctional endocytic receptor,is elevated in the neurons of patients with Parkinson's disease.However,whether there is a direct link between low-density lipoprotein receptor–related protein 1 andα-synuclein aggregation and propagation in Parkinson's disease remains unclear.Here,we established animal models of Parkinson's disease by inoculating monkeys and mice withα-synuclein pre-formed fibrils and observed elevated low-density lipoprotein receptor–related protein 1 levels in the striatum and substantia nigra,accompanied by dopaminergic neuron loss and increasedα-synuclein levels.However,low-density lipoprotein receptor–related protein 1 knockdown efficiently rescued dopaminergic neurodegeneration and inhibited the increase inα-synuclein levels in the nigrostriatal system.In HEK293A cells overexpressingα-synuclein fragments,low-density lipoprotein receptor–related protein 1 levels were upregulated only when the N-terminus ofα-synuclein was present,whereas anα-synuclein fragment lacking the N-terminus did not lead to low-density lipoprotein receptor–related protein 1 upregulation.Furthermore,the N-terminus ofα-synuclein was found to be rich in lysine residues,and blocking lysine residues in PC12 cells treated withα-synuclein pre-formed fibrils effectively reduced the elevated low-density lipoprotein receptor–related protein 1 andα-synuclein levels.These findings indicate that low-density lipoprotein receptor–related protein 1 regulates pathological transmission ofα-synuclein from the striatum to the substantia nigra in the nigrostriatal system via lysine residues in theα-synuclein N-terminus.
