The unique structure of fluorescent proteins in which the fluorophore is encapsulated by the protein shell to restrict rotation and emit light inspired the screening of chromophores that selectively bind to biomolecul...The unique structure of fluorescent proteins in which the fluorophore is encapsulated by the protein shell to restrict rotation and emit light inspired the screening of chromophores that selectively bind to biomolecules to generate fluorescence. In this paper, we report a curcuminoid-BF2-like fluorescent dye NBF2containing 4-dimethylaniline as an electron-donating group. When this dye is combined with HSA or BSA, the fluorescence is enhanced 90/112-fold, and the fluorescence quantum yield increases from <0.001to 0.16/0.19. Such a large change in fluorescence enhancement is due to the encapsulation of N-BF2in the protein cavity by HSA/BSA, which inhibits the intramolecular rotation of the aniline moiety caused by charge transfer after the fluorophore is excited by light. N-BF2has fast and strong binding to HSA or BSA and was found to be reversible in solution and intracellularly. Since N-BF2also has the ability to target lipid droplets, the complex of N-BF2/HSA realizes the regulation of reversible lipid droplet staining in cells.展开更多
Apoptosis is an important process for maintaining tissue homeostasis and eliminating abnormal cells in multicellular organisms.Abnormality in apoptosis often leads to severe diseases such as cancers. Better understand...Apoptosis is an important process for maintaining tissue homeostasis and eliminating abnormal cells in multicellular organisms.Abnormality in apoptosis often leads to severe diseases such as cancers. Better understanding of its mechanisms and processes is therefore important. Accompanying molecular biology events of apoptosis is a series of cellular morphology changes: nucleus condensation, cell shrinkage and rounding, cell surface blebbing, dynamic blebbing, apoptotic membrane protrusions and nucleus fragmentations and finally, the formation and release of apoptotic bodies. It is difficult to detect cellular changes in the early phase of apoptosis due to the subtle changes at this phase. In the current study, we induced apoptosis in He La cells with H2 O2 and used nuclear dye Hoechst 33258, mitochondria, lysosome and cytoplasmic protein specific aggregation-induced emission fluorogens(AIEgens), TPE-Ph-In, 2 M-DABS and BSPOTPE to successfully perform live cell multiplexed imaging to investigate early apoptosis cellular events. We showed the gradual dissipation of mitochondria membrane potential until it is nondetectable by TPE-Ph-In. Increased mitophagy detected by TPE-Ph-In and 2 M-DABS, condensed nucleus detected by Hoechst33258, increased permeability and/or reduced integrity of nuclear membrane, and increased intracellular vesicles detected by2 M-DABS are some of the early events of apoptosis.展开更多
Over the past decade,aggregation-induced emission(AIE)molecules have played a pivotal role in bioimaging,anti-microbial,and photodynamic therapy,and have been at the forefront of several disciplines worldwide.When com...Over the past decade,aggregation-induced emission(AIE)molecules have played a pivotal role in bioimaging,anti-microbial,and photodynamic therapy,and have been at the forefront of several disciplines worldwide.When combined with chiral moieties,they can easily collide with dazzling sparks and exhibit exceptional and unique advantages.In the application of chiral recognition and measurement of enantiomeric excess,it can identify chi-ral molecules visually based on color change and precipitation reaction,quantitatively analyze chiral molecules while determining the enantiomeric composition based on the fluorescence intensity change at different wave-lengths,and obtain two parameters about chiral molecules from one measurement,thereby demonstrating its high selectivity,sensitivity and accuracy in chiral identification.In the field of organic circularly polarized lu-minescent(CPL)materials,the asymmetry(g lum)of common organic light emitting elements is usually between 10−5 and 10−2,whereas the CPL asymmetry factor(g lum)of chiral AIE fluorogens(AIEgens)can reach 1.42,which is very close to the theoretical value of 2.Therefore,the combination of chiral elements and luminescent groups promotes their adoption in the field of organic CPL materials.Herein we have summarized the recent applications of chiral AIEgens in both chiral molecule recognition and circularly polarized organic light-emitting diode(CP-OLED)in order to provide future researchers with a more comprehensive and detailed understanding of chiral AIEgens and to encourage more scientists to contribute to the development of AIEgens.展开更多
Polarity,as a crucial environmental characteristic,plays a significant role in numerous cellular physiological processes.Abnormal changes in polarity are closely associated with various diseases.However,existing tools...Polarity,as a crucial environmental characteristic,plays a significant role in numerous cellular physiological processes.Abnormal changes in polarity are closely associated with various diseases.However,existing tools still have certain limitations that hinder accurate detection of polarity.Therefore,there is a pressing need to develop powerful tools for precisely monitoring changes in polarity.In this study,we developed two dual-emissive fluorogenic dyes by innovatively introducing 1,3-dithio-2-heteroarsenic cyclopentane and 1,2-diselenocyclopentane respectively into the near-infrared(NIR)coumarin-benzopyranium skeleton to enhance their cellular uptake capability.Additionally,we synthesized the polarity-sensitive dual-emissive fluorogenic probe CSFNS,which exhibits high cellular uptake rate,by modifying the spironolactone(Aldactone)structure of CBA into spirolactam.CSFNS not only demonstrates excellent polarity sensitivity in vitro but is also successfully applied to visually monitor the polarity changes in various types of living cells,including healthy cells,cancer cells and drug-induced senescent cells.展开更多
Cytochrome P4501 A1(CYP1A1),a heme-containing monooxygenase,is of particular importance for human health because of its vital roles in the metabolic activation of pro-carcinogenic compounds to the carcinogens.Decipher...Cytochrome P4501 A1(CYP1A1),a heme-containing monooxygenase,is of particular importance for human health because of its vital roles in the metabolic activation of pro-carcinogenic compounds to the carcinogens.Deciphering the relevance of CYP1A1 to human diseases and screening of CYP1A1 modulators require reliable tool(s)for probing this key enzyme in complex biological matrices.Herein,a practical and ultrasensitive fluorescence-based assay for real-time sensing CYP1A1 activities in biological systems has been developed,via designing an isoform-specific fluorogenic sensor for CYP1A1(CHPO).The newly developed fluorogenic substrate for CYP1A1 has been carefully investigated in terms of specificity,sensitivity,precision,quantitative linear range and the anti-interference ability.The excellent selectivity,strong anti-interference ability and fast response kinetics,making the practicability of CHPObased CYP1A1 activity assay is better than that of most reported CYP1A1 activity assays.Furthermore,CHPO has been successfully used for imaging CYP1A1 activities in living cells and human tissues,as well as for high-throughput screening of CYP1A1 inhibitors using tissue preparations as enzyme sources.Collectively,this study provided a practical fluorogenic sensor for real-time sensing CYP1A1 in complex biological systems,which would strongly facilitate the investigations on the relevance of CYP1A1 to human diseases and promote high-throughput screening of CYP1A1 modulators for biomedical applications.展开更多
Monoamine oxidase is flavoenzymes, widely distributed in mammals. It is well recognized that MAOs serve an important role in metabolism that they have close relationship with health .Along with the discoveries between...Monoamine oxidase is flavoenzymes, widely distributed in mammals. It is well recognized that MAOs serve an important role in metabolism that they have close relationship with health .Along with the discoveries between MAOs and neurotic disease, more and more studies have been jumped in .In this paper, we design a new probe for assaying the activities of MAOs. The results showed that the probe [7-（3-aminopropoxy）coumarin] is simple, effective and sensitive for MAOB.展开更多
Porcine lipoprotein lipase （LPL） cDNA was cloned as the standard for real-time quantifying LPL mRNA and the TaqMan-fluorescence quantitative PCR assay for detection was established. The total RNA extracted from Long...Porcine lipoprotein lipase （LPL） cDNA was cloned as the standard for real-time quantifying LPL mRNA and the TaqMan-fluorescence quantitative PCR assay for detection was established. The total RNA extracted from Longissimus dorsi of porcine was reverse-transcribed to cDNA. LPL cDNA was ligated with pGM-T vector and transformed into Escherichia coli TOP10. Plasmid DNA extracted from positive clones was verified by PCR amplification and sequenced. LPL was amplified by real-time fluorescence quantitative PCR from the plasmid DNA. The concentration of DNA template purified was detected by analyzing absorbance in 260 nm and then the combined plasmid was diluted to series as standard for fluorescence quantitative PCR （FQ-PCR）. The method of LPL mRNA real-time PCR was well established, which detected as low as 103 with the linear range 10^3 to 10^10 copies. The standard curves showed high correlations （R2 = 0.9871）. A series of standards for real-time PCR analysis have been constructed successfially, and real-time TaqMan-fluorescence quantitative RT-PCR is reliable to quantitatively evaluate FQ-PCR mRNA in L. dorsi of porcine.展开更多
AIM: To establish a novel, sensitive and high-throughput gelatinolytic assay to define new inhibitors and compare domain deletion mutants of gelatinase B/matrix metalloproteinase (MMP)-9. METHODS: Fluorogenic Dye-quen...AIM: To establish a novel, sensitive and high-throughput gelatinolytic assay to define new inhibitors and compare domain deletion mutants of gelatinase B/matrix metalloproteinase (MMP)-9. METHODS: Fluorogenic Dye-quenched (DQ)TM-gelatin was used as a substrate and biochemical parameters (substrate and enzyme concentrations, DMSO solvent concentrations) were optimized to establish a highthroughput assay system. Various small-sized libraries (ChemDiv, InterBioScreen and ChemBridge) of hetero-cyclic, drug-like substances were tested and compared with prototypic inhibitors. RESULTS: First, we designed a test system with gelatin as a natural substrate. Second, the assay was validated by selecting a novel pyrimidine-2,4,6-trione (barbitu- rate) inhibitor. Third, and in line with present structural data on collagenolysis, it was found that deletion of the O-glycosylated region significantly decreased gelatinolytic activity (kcat/kM ± 40% less than full-length MMP-9). CONCLUSION: The DQTM-gelatin assay is useful in high-throughput drug screening and exosite targeting. We demonstrate that flexibility between the catalytic and hemopexin domain is functionally critical for gelatinolysis.展开更多
Fluorescence imaging has facilitated fluorescent probes to analyze the subcellular localization and dynamics of biological targets. In this paper, we reported a fluorogenic probe for bacteria imaging. The probe was an...Fluorescence imaging has facilitated fluorescent probes to analyze the subcellular localization and dynamics of biological targets. In this paper, we reported a fluorogenic probe for bacteria imaging. The probe was an imidazolium-derived pyrene compound, which self-assembled to form nano-particles and the pyrene fluorescence was quenched by the aggregation effects. When the self-assembly nanoparticles interacted with anionic bacteria surfaces, synergistic effects of electrostatic interaction and hydrophobic force caused competing binding between bacteria surfaces and imidazoliums. This binding resulted in the disassembly of the aggregates to give fluorescence turn-on signal. Meanwhile, the probe bound bacteria surfaces and displayed both pyrene-excimer and pyrene-monomer fluorescence, which gave ratiometric signal. Then, fluorescent labeling by the probe enabled the two-photo ratiometric imaging of bacteria.展开更多
Enzymes are macromolecular biological catalysts which can accelerate chemical reactions in living organisms. Almost all the physiological metabolism activities in the cell need enzymes to sustain life via rapid cataly...Enzymes are macromolecular biological catalysts which can accelerate chemical reactions in living organisms. Almost all the physiological metabolism activities in the cell need enzymes to sustain life via rapid catalysis. Currently, medical research has proved that abnormal enzyme activity is associated with numerous diseases, such as Parkinson’s disease(PD), Alzheimer’s disease(AD) and cancers. On the other hand, early diagnosis of those diseases is of great significance to improve the survival rate and cure rate.In the current diagnostic tools, two-photon fluorescent probes(TPFPs) are developing rapidly due to their unique advantages, such as higher spatial resolution, deeper imaging depth, and lower biotoxicity.Therefore, the design and synthesis of two-photon(TP) small molecule enzymatic probes have broad prospects for early diagnosis and treatment of diseases. As of now, scientists have developed many TP small molecule enzymatic probes. This review aims to summarize the TP small molecule enzymatic probes and expound the reaction mechanism.展开更多
Taking the advantage of reduced scattering and low autofluorescence background, the NIR fluorescence probes, such as fluorescence proteins, organic molecules and nanoparticles, not only hold the promise of in vivo ima...Taking the advantage of reduced scattering and low autofluorescence background, the NIR fluorescence probes, such as fluorescence proteins, organic molecules and nanoparticles, not only hold the promise of in vivo imaging of biological processes in physiology and pathology with high signal-to-noise ratio, but also for clinical diagnosis. In this review, we provide an overview of the recent progress on NIR probes,focusing on fundamental mechanisms of NIR dyes and nanoparticles, and protein engineering strategies for NIR proteins.展开更多
Protein self-labeling tags achieve selective fusion and labeling of target proteins through genetic coding technology,but require exogenous fluorescent probes with fluorogenicity for protein tag binding to have the pe...Protein self-labeling tags achieve selective fusion and labeling of target proteins through genetic coding technology,but require exogenous fluorescent probes with fluorogenicity for protein tag binding to have the performance of wash-free fluorescence imaging in live cells.In this paper,we reported a fluorogenic probe 1 capable of ratiometric fluorescence recognition of SNAP-tag proteins.In this probe,the O6-benzylguanine derivative of 3-hydroxy-1,8-naphthalimide underwent a selective covalent linkage reaction with SNAP-tag protein.The hydroxyl group on the naphthalimide fluorophore formed a hydrogen bond with the functional group near the protein cavity.The excited state proton transfer occurred after illumination,to obtain the ratio fluorescence signal from blue emission to red emission,realizing the wash-free fluorescence imaging of the target proteins.展开更多
Peroxynitrite(ONOO^(-))contributes to oxidative stress and neurodegeneration in Parkinson's disease(PD).Developing a peroxynitrite probe would enable in situ visualization of the overwhelming ONOO^(-)flux and unde...Peroxynitrite(ONOO^(-))contributes to oxidative stress and neurodegeneration in Parkinson's disease(PD).Developing a peroxynitrite probe would enable in situ visualization of the overwhelming ONOO^(-)flux and understanding of the ONOO^(-)stress-induced neuropathology of PD.Herein,a novelα-ketoamide-based fluorogenic probe(DFlu)was designed for ONOO^(-)monitoring in multiple PD models.The results demonstrated that DFlu exhibits a fluorescence turn-on response to ONOO^(-)with high specificity and sensitivity.The efficacy of DFlu for intracellular ONOO^(-)imaging was demonstrated systematically.The results showed that DFlu can successfully visualize endogenous and exogenous ONOO^(-)in cells derived from chemical and biochemical routes.More importantly,the two-photon excitation ability of DFlu has been well demonstrated by monitoring exogenous/endogenous ONOO^(-)production and scavenging in live zebraflsh PD models.This work provides a reliable and promisingα-ketoamide-based optical tool for identifying variations of ONOO^(-)in PD models.展开更多
H2S is an essential gas signal molecule in cells,and viscosity is a key internal environmental parameter.Recent studies have shown that H_(2)S acts as a cytoarchitecture agent and gas transmitter in many tissues,e.g.,...H2S is an essential gas signal molecule in cells,and viscosity is a key internal environmental parameter.Recent studies have shown that H_(2)S acts as a cytoarchitecture agent and gas transmitter in many tissues,e.g.,as a regulator of neuroendocrine in the brain for mediating vascular tone in blood vessels.Mitochondrial viscosity is an important parameter for judging whether mitochondrial function is normal.It has been reported that oxidative stress and mitochondrial dysfunction are connected with Parkinson’s disease(PD),and the protective role of H_(2)S in PD models has been extensively demonstrated.Herein,Mito-HS,a new two-photon fluorescent probe was demonstrated to detect cross-talk between the two channels of mitochondrial viscosity and H_(2)S content.Moreover,this probe could detect the relative amount of and changes in mitochondrial H2S in situ due to the reduced mitochondrial targeting ability after reaction with H_(2)S.The results show that H2S in mitochondria is inversely related to viscosity.The PD model has a lower H2S in mitochondria and a higher mitochondrial viscosity than did the normal.This result is important for our deep understanding of PD and its causes.展开更多
A new near-infrared fluorescent dye, 9-N-(2-hydroxyethyl)-N-methylamino-6-carbethoxy-5H-benzo[a]phenoxazin-5-one 1, was prepared from the reaction of N-(2-hydroxyethyl)-N-methyl-4-nitrosoaniline hydrochloride and ethy...A new near-infrared fluorescent dye, 9-N-(2-hydroxyethyl)-N-methylamino-6-carbethoxy-5H-benzo[a]phenoxazin-5-one 1, was prepared from the reaction of N-(2-hydroxyethyl)-N-methyl-4-nitrosoaniline hydrochloride and ethyl 1,3-dihydroxynaphthoate. Five more fluorescent compounds were synthesized by the reaction of the resulting dye 1 with appropriate amino acid or carboxylic acids.展开更多
Radical detection has attracted significant attention recently. Here we have developed a scaffold through covalent assembly principle（OR570）, which could facile applications in detection of oxidative radicals.The pr...Radical detection has attracted significant attention recently. Here we have developed a scaffold through covalent assembly principle（OR570）, which could facile applications in detection of oxidative radicals.The primary advantage of the assembly type probe lies at the turn-on fluorescence signal from a zero background and hence high fluorescence turn-on ratio for sensitive detection of weak signal.展开更多
Monitoring mitochondrial derived copper（Ⅱ） in live cells is highly demanded, but accurately detecting is unmet due to the interference with cytoplasmic copper（Ⅱ）. Herein, we have reported the design,synthesis an...Monitoring mitochondrial derived copper（Ⅱ） in live cells is highly demanded, but accurately detecting is unmet due to the interference with cytoplasmic copper（Ⅱ）. Herein, we have reported the design,synthesis and characterization of photocontrollable fluorogenic probe, MCu-3, which is equipped with a photo-labile group（nitrobenzyl group） and mitochondria targeting unit（triphenylphosphonium salt）.This novel probe showed an intense fluorescence enhancement in response to copper（Ⅱ） without interference from other metal cations in the biological condition（p H 6–9）. The detection limit is 1.7 ×10^（-7） mol/L in HEPES buffer. The confocal fluorescence imaging results demonstrated MCu-3 can visualize mitochondrial copper（Ⅱ） in live mammalian cells. The clear advantage of our photocontrollable method is successful to avoid the influence of cytoplasmic copper（Ⅱ） during mitochondria specific detection.展开更多
Imaging dynamics of membrane proteins of live cells in a wash-free and real-time manner has been a challenging task. Herein, we report unprecedented applications of malachite green(MG), an organic dye widely used in p...Imaging dynamics of membrane proteins of live cells in a wash-free and real-time manner has been a challenging task. Herein, we report unprecedented applications of malachite green(MG), an organic dye widely used in pigment industry, as a switchable fluorophore to monitor membrane enzymes or noncatalytic proteins in live cells. Conformationally flexible MG is non-fluorescent in aqueous solution, yet covalent binding with endogenous proteins of cells significantly enhances its fluorescence at 670 nm by restricting flexibility of dye. Integrating a phosphate-caged quinone methide precursor with MG yielded a covalent labeling fluorogenic probe, allowing real-time imaging of membrane alkaline phosphatase(ALP,a model catalytic protein) activity in live cells with over 100-fold enhancement of fluorescence intensity.Moreover, MG is also applicable to image non-catalytic protein by conjugation with protein-specific ligand. A fluorogenic probe consisted of c-RGDf K peptide and MG proved to be compatible with wash-free and real-time visualization of non-catalytic integrin α_(v)β_(3) in live cells with high contrast.展开更多
Herein we presented a general strategy for in situ assembly of intramolecular charge-transfer(ICT)-based light-up fluorophores via bioorthogonal Suzuki-Miyaura cross-coupling reaction.By introducing iodo group at the ...Herein we presented a general strategy for in situ assembly of intramolecular charge-transfer(ICT)-based light-up fluorophores via bioorthogonal Suzuki-Miyaura cross-coupling reaction.By introducing iodo group at the appropriate position,five fluorophores with different scaffolds including naphthalimide,coumarin,naphthalene sulfonate,nitrobenzoxadiazole,and acetonaphthone,were designed as bioorthogonal multicolor fluorogenic probes,which could produce significant fluorescence enhancement and high fluorescence quantum yield after Suzuki-Miyaura reaction with aryl boronic acid or boronate.Manipulating the substituents andπscaffold in the fluorophores allows fine-tuning of their photophysical properties.With this strategy,we succeeded in peptide conjugation,no-wash fluorogenic protein labeling,and mitochondria-selective bioorthogonal imaging in live cells.展开更多
Protein labeling by using a protein tag and tag-specific fluorescent probes is increasingly becoming a useful technique for the real-time imaging of proteins in living cells. SNAP-tag as one of the most prominent fusi...Protein labeling by using a protein tag and tag-specific fluorescent probes is increasingly becoming a useful technique for the real-time imaging of proteins in living cells. SNAP-tag as one of the most prominent fusion tags has been widely used and already commercially available. Recently, various fluorogenic probes for SNAP-tag based protein labeling were reported. Owing to turn-on fluorescence response, fluorogenic probes for SNAP-tag minimize the fluorescence background caused by unreacted or nonspecifically bound probes and allow for direct imaging in living cells without wash-out steps. Thus,real-time analysis of protein localization, dynamics and interactions has been made possible by SNAP-tag fluorogenic probes. In this review,we describe the design strategies of fluorogenic probes for SNAP-tag and their applications in cellular protein labeling.展开更多
基金supported by the National Natural Science Foundation of China (Nos. 22078314, 21878286, 21908216, 22078201, U1908202)。
文摘The unique structure of fluorescent proteins in which the fluorophore is encapsulated by the protein shell to restrict rotation and emit light inspired the screening of chromophores that selectively bind to biomolecules to generate fluorescence. In this paper, we report a curcuminoid-BF2-like fluorescent dye NBF2containing 4-dimethylaniline as an electron-donating group. When this dye is combined with HSA or BSA, the fluorescence is enhanced 90/112-fold, and the fluorescence quantum yield increases from <0.001to 0.16/0.19. Such a large change in fluorescence enhancement is due to the encapsulation of N-BF2in the protein cavity by HSA/BSA, which inhibits the intramolecular rotation of the aniline moiety caused by charge transfer after the fluorophore is excited by light. N-BF2has fast and strong binding to HSA or BSA and was found to be reversible in solution and intracellularly. Since N-BF2also has the ability to target lipid droplets, the complex of N-BF2/HSA realizes the regulation of reversible lipid droplet staining in cells.
基金supported by the Hong Kong Branch of Chinese National Engineering Research Centres for Tissue Restoration and Reconstruction
文摘Apoptosis is an important process for maintaining tissue homeostasis and eliminating abnormal cells in multicellular organisms.Abnormality in apoptosis often leads to severe diseases such as cancers. Better understanding of its mechanisms and processes is therefore important. Accompanying molecular biology events of apoptosis is a series of cellular morphology changes: nucleus condensation, cell shrinkage and rounding, cell surface blebbing, dynamic blebbing, apoptotic membrane protrusions and nucleus fragmentations and finally, the formation and release of apoptotic bodies. It is difficult to detect cellular changes in the early phase of apoptosis due to the subtle changes at this phase. In the current study, we induced apoptosis in He La cells with H2 O2 and used nuclear dye Hoechst 33258, mitochondria, lysosome and cytoplasmic protein specific aggregation-induced emission fluorogens(AIEgens), TPE-Ph-In, 2 M-DABS and BSPOTPE to successfully perform live cell multiplexed imaging to investigate early apoptosis cellular events. We showed the gradual dissipation of mitochondria membrane potential until it is nondetectable by TPE-Ph-In. Increased mitophagy detected by TPE-Ph-In and 2 M-DABS, condensed nucleus detected by Hoechst33258, increased permeability and/or reduced integrity of nuclear membrane, and increased intracellular vesicles detected by2 M-DABS are some of the early events of apoptosis.
文摘Over the past decade,aggregation-induced emission(AIE)molecules have played a pivotal role in bioimaging,anti-microbial,and photodynamic therapy,and have been at the forefront of several disciplines worldwide.When combined with chiral moieties,they can easily collide with dazzling sparks and exhibit exceptional and unique advantages.In the application of chiral recognition and measurement of enantiomeric excess,it can identify chi-ral molecules visually based on color change and precipitation reaction,quantitatively analyze chiral molecules while determining the enantiomeric composition based on the fluorescence intensity change at different wave-lengths,and obtain two parameters about chiral molecules from one measurement,thereby demonstrating its high selectivity,sensitivity and accuracy in chiral identification.In the field of organic circularly polarized lu-minescent(CPL)materials,the asymmetry(g lum)of common organic light emitting elements is usually between 10−5 and 10−2,whereas the CPL asymmetry factor(g lum)of chiral AIE fluorogens(AIEgens)can reach 1.42,which is very close to the theoretical value of 2.Therefore,the combination of chiral elements and luminescent groups promotes their adoption in the field of organic CPL materials.Herein we have summarized the recent applications of chiral AIEgens in both chiral molecule recognition and circularly polarized organic light-emitting diode(CP-OLED)in order to provide future researchers with a more comprehensive and detailed understanding of chiral AIEgens and to encourage more scientists to contribute to the development of AIEgens.
基金the financial support from the National Natural Science Foundation of China(Nos.22477101,22277098 and 22037002)the Natural Science Basic Research Plan for Distinguished Young Scholars in Shaanxi Province of China(No.2020JC-38)the Shaanxi Fundamental Science Research Project for Chemistry and Biology(No.22JHQ070)。
文摘Polarity,as a crucial environmental characteristic,plays a significant role in numerous cellular physiological processes.Abnormal changes in polarity are closely associated with various diseases.However,existing tools still have certain limitations that hinder accurate detection of polarity.Therefore,there is a pressing need to develop powerful tools for precisely monitoring changes in polarity.In this study,we developed two dual-emissive fluorogenic dyes by innovatively introducing 1,3-dithio-2-heteroarsenic cyclopentane and 1,2-diselenocyclopentane respectively into the near-infrared(NIR)coumarin-benzopyranium skeleton to enhance their cellular uptake capability.Additionally,we synthesized the polarity-sensitive dual-emissive fluorogenic probe CSFNS,which exhibits high cellular uptake rate,by modifying the spironolactone(Aldactone)structure of CBA into spirolactam.CSFNS not only demonstrates excellent polarity sensitivity in vitro but is also successfully applied to visually monitor the polarity changes in various types of living cells,including healthy cells,cancer cells and drug-induced senescent cells.
基金the National Natural Science Foundation of China(Nos.81922070,81973286,81803489,81773687 and 81703604)the National Key Research and Development Program of China(Nos.2016YFC1303900,2017YFC1700200 and 2017YFC1702000)+3 种基金the Three-year Action Plan of Shanghai TCM Development(No.ZY-(2018-2020)-CCCX5001)Drug Innovation Major Project(No.2018ZX09731016)Program of Shanghai Academic/Technology Research Leader(No.18XD1403600)Shuguang Program(No.18SG40)supported by Shanghai Education Development Foundation and Shanghai Municipal Education Commission。
文摘Cytochrome P4501 A1(CYP1A1),a heme-containing monooxygenase,is of particular importance for human health because of its vital roles in the metabolic activation of pro-carcinogenic compounds to the carcinogens.Deciphering the relevance of CYP1A1 to human diseases and screening of CYP1A1 modulators require reliable tool(s)for probing this key enzyme in complex biological matrices.Herein,a practical and ultrasensitive fluorescence-based assay for real-time sensing CYP1A1 activities in biological systems has been developed,via designing an isoform-specific fluorogenic sensor for CYP1A1(CHPO).The newly developed fluorogenic substrate for CYP1A1 has been carefully investigated in terms of specificity,sensitivity,precision,quantitative linear range and the anti-interference ability.The excellent selectivity,strong anti-interference ability and fast response kinetics,making the practicability of CHPObased CYP1A1 activity assay is better than that of most reported CYP1A1 activity assays.Furthermore,CHPO has been successfully used for imaging CYP1A1 activities in living cells and human tissues,as well as for high-throughput screening of CYP1A1 inhibitors using tissue preparations as enzyme sources.Collectively,this study provided a practical fluorogenic sensor for real-time sensing CYP1A1 in complex biological systems,which would strongly facilitate the investigations on the relevance of CYP1A1 to human diseases and promote high-throughput screening of CYP1A1 modulators for biomedical applications.
基金the project sponsored by the Scientific Research Foundation for the Returned Overseas Chinese Scholars Fund,Zhejiang Province(No.Z01105002)Returned Overseas Chinese Scholars Fund.
文摘Monoamine oxidase is flavoenzymes, widely distributed in mammals. It is well recognized that MAOs serve an important role in metabolism that they have close relationship with health .Along with the discoveries between MAOs and neurotic disease, more and more studies have been jumped in .In this paper, we design a new probe for assaying the activities of MAOs. The results showed that the probe [7-（3-aminopropoxy）coumarin] is simple, effective and sensitive for MAOB.
基金support provided by the 973 Program of China (2004CB117500)
文摘Porcine lipoprotein lipase （LPL） cDNA was cloned as the standard for real-time quantifying LPL mRNA and the TaqMan-fluorescence quantitative PCR assay for detection was established. The total RNA extracted from Longissimus dorsi of porcine was reverse-transcribed to cDNA. LPL cDNA was ligated with pGM-T vector and transformed into Escherichia coli TOP10. Plasmid DNA extracted from positive clones was verified by PCR amplification and sequenced. LPL was amplified by real-time fluorescence quantitative PCR from the plasmid DNA. The concentration of DNA template purified was detected by analyzing absorbance in 260 nm and then the combined plasmid was diluted to series as standard for fluorescence quantitative PCR （FQ-PCR）. The method of LPL mRNA real-time PCR was well established, which detected as low as 103 with the linear range 10^3 to 10^10 copies. The standard curves showed high correlations （R2 = 0.9871）. A series of standards for real-time PCR analysis have been constructed successfially, and real-time TaqMan-fluorescence quantitative RT-PCR is reliable to quantitatively evaluate FQ-PCR mRNA in L. dorsi of porcine.
基金Supported by A postdoctoral fellowship (Van den Steen PE) and a research assistantship (Geurts N) of the Fund for Scientific Research,Belgium (FWO-Vlaanderen)
文摘AIM: To establish a novel, sensitive and high-throughput gelatinolytic assay to define new inhibitors and compare domain deletion mutants of gelatinase B/matrix metalloproteinase (MMP)-9. METHODS: Fluorogenic Dye-quenched (DQ)TM-gelatin was used as a substrate and biochemical parameters (substrate and enzyme concentrations, DMSO solvent concentrations) were optimized to establish a highthroughput assay system. Various small-sized libraries (ChemDiv, InterBioScreen and ChemBridge) of hetero-cyclic, drug-like substances were tested and compared with prototypic inhibitors. RESULTS: First, we designed a test system with gelatin as a natural substrate. Second, the assay was validated by selecting a novel pyrimidine-2,4,6-trione (barbitu- rate) inhibitor. Third, and in line with present structural data on collagenolysis, it was found that deletion of the O-glycosylated region significantly decreased gelatinolytic activity (kcat/kM ± 40% less than full-length MMP-9). CONCLUSION: The DQTM-gelatin assay is useful in high-throughput drug screening and exosite targeting. We demonstrate that flexibility between the catalytic and hemopexin domain is functionally critical for gelatinolysis.
基金financially supported by the National Natural Science Foundation of China(Nos. 21878286, 21502189)DICP (Nos. DMT0201603, TMSR201601)
文摘Fluorescence imaging has facilitated fluorescent probes to analyze the subcellular localization and dynamics of biological targets. In this paper, we reported a fluorogenic probe for bacteria imaging. The probe was an imidazolium-derived pyrene compound, which self-assembled to form nano-particles and the pyrene fluorescence was quenched by the aggregation effects. When the self-assembly nanoparticles interacted with anionic bacteria surfaces, synergistic effects of electrostatic interaction and hydrophobic force caused competing binding between bacteria surfaces and imidazoliums. This binding resulted in the disassembly of the aggregates to give fluorescence turn-on signal. Meanwhile, the probe bound bacteria surfaces and displayed both pyrene-excimer and pyrene-monomer fluorescence, which gave ratiometric signal. Then, fluorescent labeling by the probe enabled the two-photo ratiometric imaging of bacteria.
基金financially supported by the National Natural Science Foundation of China (No. 81672508)Jiangsu Provincial Foundation for Distinguished Young Scholars (No. BK20170041)+2 种基金Natural Science Foundation of Shaanxi Province (No. 2019JM-016)China-Sweden Joint Mobility Project (No. 51811530018)Fundamental Research Funds for the Central Universities
文摘Enzymes are macromolecular biological catalysts which can accelerate chemical reactions in living organisms. Almost all the physiological metabolism activities in the cell need enzymes to sustain life via rapid catalysis. Currently, medical research has proved that abnormal enzyme activity is associated with numerous diseases, such as Parkinson’s disease(PD), Alzheimer’s disease(AD) and cancers. On the other hand, early diagnosis of those diseases is of great significance to improve the survival rate and cure rate.In the current diagnostic tools, two-photon fluorescent probes(TPFPs) are developing rapidly due to their unique advantages, such as higher spatial resolution, deeper imaging depth, and lower biotoxicity.Therefore, the design and synthesis of two-photon(TP) small molecule enzymatic probes have broad prospects for early diagnosis and treatment of diseases. As of now, scientists have developed many TP small molecule enzymatic probes. This review aims to summarize the TP small molecule enzymatic probes and expound the reaction mechanism.
基金financially supported by the National Key Research and Development Program of China (No. 2017YFA0700403)National Natural Science Foundation of China (Nos. 31670872, 21874145, 2018M633180, 21905296)+1 种基金Shenzhen Science and Technology Innovation Committee (Nos. KQJSCX20170331161420421, JCYJ20170818163925063, JCYJ20170818164040422, GJHS2017031 4160302802)Chinese Academy of Sciences (No. GJJSTD20180002)
文摘Taking the advantage of reduced scattering and low autofluorescence background, the NIR fluorescence probes, such as fluorescence proteins, organic molecules and nanoparticles, not only hold the promise of in vivo imaging of biological processes in physiology and pathology with high signal-to-noise ratio, but also for clinical diagnosis. In this review, we provide an overview of the recent progress on NIR probes,focusing on fundamental mechanisms of NIR dyes and nanoparticles, and protein engineering strategies for NIR proteins.
基金supported by the National Natural Science Foundation of China(Nos.22225806,22078314 and 22278394)Dalian Institute of Chemical Physics(Nos.DICPI202227 and DICPI202142)。
文摘Protein self-labeling tags achieve selective fusion and labeling of target proteins through genetic coding technology,but require exogenous fluorescent probes with fluorogenicity for protein tag binding to have the performance of wash-free fluorescence imaging in live cells.In this paper,we reported a fluorogenic probe 1 capable of ratiometric fluorescence recognition of SNAP-tag proteins.In this probe,the O6-benzylguanine derivative of 3-hydroxy-1,8-naphthalimide underwent a selective covalent linkage reaction with SNAP-tag protein.The hydroxyl group on the naphthalimide fluorophore formed a hydrogen bond with the functional group near the protein cavity.The excited state proton transfer occurred after illumination,to obtain the ratio fluorescence signal from blue emission to red emission,realizing the wash-free fluorescence imaging of the target proteins.
基金supported by the National Natural Science Foundation of China(22077101)the Open Project Program of Wuhan National Laboratory for Optoelectronics(No.2020WNLOKF023)+4 种基金Natural Science Foundation of Shaanxi Province(2022JM-130)the Joint Research Funds of Department of Science&Technology of Shaanxi Province and Northwestern Polytechnical University(2020GXLH-Z-008,2020GXLH-Z-021,2020GXLH-Z-023)the China Postdoctoral Science Foundation(2022M711595,2022M722595)Postdoctoral Research Funding Schemes of Jiangsu Province(2021K036A)The Natural Science Foundation of Ningbo(202003N4049,202003N4065).
文摘Peroxynitrite(ONOO^(-))contributes to oxidative stress and neurodegeneration in Parkinson's disease(PD).Developing a peroxynitrite probe would enable in situ visualization of the overwhelming ONOO^(-)flux and understanding of the ONOO^(-)stress-induced neuropathology of PD.Herein,a novelα-ketoamide-based fluorogenic probe(DFlu)was designed for ONOO^(-)monitoring in multiple PD models.The results demonstrated that DFlu exhibits a fluorescence turn-on response to ONOO^(-)with high specificity and sensitivity.The efficacy of DFlu for intracellular ONOO^(-)imaging was demonstrated systematically.The results showed that DFlu can successfully visualize endogenous and exogenous ONOO^(-)in cells derived from chemical and biochemical routes.More importantly,the two-photon excitation ability of DFlu has been well demonstrated by monitoring exogenous/endogenous ONOO^(-)production and scavenging in live zebraflsh PD models.This work provides a reliable and promisingα-ketoamide-based optical tool for identifying variations of ONOO^(-)in PD models.
基金the National Natural Science Foundation of China(Nos.81672508,21675085)Jiangsu Provincial Foundation for Distinguished Young Scholars(Nos.BK20170041,BK20170042)+2 种基金Natural Science Foundation of Shaanxi Province(No.2019JM-016)China-Sweden Joint Mobility Project(No.51811530018)Fundamental Research Funds for the Central Universities。
文摘H2S is an essential gas signal molecule in cells,and viscosity is a key internal environmental parameter.Recent studies have shown that H_(2)S acts as a cytoarchitecture agent and gas transmitter in many tissues,e.g.,as a regulator of neuroendocrine in the brain for mediating vascular tone in blood vessels.Mitochondrial viscosity is an important parameter for judging whether mitochondrial function is normal.It has been reported that oxidative stress and mitochondrial dysfunction are connected with Parkinson’s disease(PD),and the protective role of H_(2)S in PD models has been extensively demonstrated.Herein,Mito-HS,a new two-photon fluorescent probe was demonstrated to detect cross-talk between the two channels of mitochondrial viscosity and H_(2)S content.Moreover,this probe could detect the relative amount of and changes in mitochondrial H2S in situ due to the reduced mitochondrial targeting ability after reaction with H_(2)S.The results show that H2S in mitochondria is inversely related to viscosity.The PD model has a lower H2S in mitochondria and a higher mitochondrial viscosity than did the normal.This result is important for our deep understanding of PD and its causes.
文摘A new near-infrared fluorescent dye, 9-N-(2-hydroxyethyl)-N-methylamino-6-carbethoxy-5H-benzo[a]phenoxazin-5-one 1, was prepared from the reaction of N-(2-hydroxyethyl)-N-methyl-4-nitrosoaniline hydrochloride and ethyl 1,3-dihydroxynaphthoate. Five more fluorescent compounds were synthesized by the reaction of the resulting dye 1 with appropriate amino acid or carboxylic acids.
基金supported by the Fundamental Research Funds for the Central Universities (Nos. 1222201718004, WY1514053 and WY1516017)the National Natural Science Foundation of China (Nos. 21372080, 21572061, and 21236002)
文摘Radical detection has attracted significant attention recently. Here we have developed a scaffold through covalent assembly principle（OR570）, which could facile applications in detection of oxidative radicals.The primary advantage of the assembly type probe lies at the turn-on fluorescence signal from a zero background and hence high fluorescence turn-on ratio for sensitive detection of weak signal.
基金supported by the National Natural Science Foundation of China (Nos. 81672508, 61505076)Natural Science Foundation of Jiangsu Province (No. BK20140951)+1 种基金Key University Science Research Project of Jiangsu Province (No. 16KJA180004)SICAM Fellowship & Scholarship by Jiangsu National Synergetic Innovation Center for Advanced Materials
文摘Monitoring mitochondrial derived copper（Ⅱ） in live cells is highly demanded, but accurately detecting is unmet due to the interference with cytoplasmic copper（Ⅱ）. Herein, we have reported the design,synthesis and characterization of photocontrollable fluorogenic probe, MCu-3, which is equipped with a photo-labile group（nitrobenzyl group） and mitochondria targeting unit（triphenylphosphonium salt）.This novel probe showed an intense fluorescence enhancement in response to copper（Ⅱ） without interference from other metal cations in the biological condition（p H 6–9）. The detection limit is 1.7 ×10^（-7） mol/L in HEPES buffer. The confocal fluorescence imaging results demonstrated MCu-3 can visualize mitochondrial copper（Ⅱ） in live mammalian cells. The clear advantage of our photocontrollable method is successful to avoid the influence of cytoplasmic copper（Ⅱ） during mitochondria specific detection.
基金financially supported by the National Natural Science Foundation of China (No. 22077031)the Research Program of State Key Laboratory of Bioreactor Engineeringthe Fundamental Research Funds for the Central Universities。
文摘Imaging dynamics of membrane proteins of live cells in a wash-free and real-time manner has been a challenging task. Herein, we report unprecedented applications of malachite green(MG), an organic dye widely used in pigment industry, as a switchable fluorophore to monitor membrane enzymes or noncatalytic proteins in live cells. Conformationally flexible MG is non-fluorescent in aqueous solution, yet covalent binding with endogenous proteins of cells significantly enhances its fluorescence at 670 nm by restricting flexibility of dye. Integrating a phosphate-caged quinone methide precursor with MG yielded a covalent labeling fluorogenic probe, allowing real-time imaging of membrane alkaline phosphatase(ALP,a model catalytic protein) activity in live cells with over 100-fold enhancement of fluorescence intensity.Moreover, MG is also applicable to image non-catalytic protein by conjugation with protein-specific ligand. A fluorogenic probe consisted of c-RGDf K peptide and MG proved to be compatible with wash-free and real-time visualization of non-catalytic integrin α_(v)β_(3) in live cells with high contrast.
基金supported by the Beijing Nova Program(No.Z201100006820049)the National Natural Science Foundation of China(No.21907109)the CAMS Innovation Fund for Graduate Students(No.2019–1007–03)
文摘Herein we presented a general strategy for in situ assembly of intramolecular charge-transfer(ICT)-based light-up fluorophores via bioorthogonal Suzuki-Miyaura cross-coupling reaction.By introducing iodo group at the appropriate position,five fluorophores with different scaffolds including naphthalimide,coumarin,naphthalene sulfonate,nitrobenzoxadiazole,and acetonaphthone,were designed as bioorthogonal multicolor fluorogenic probes,which could produce significant fluorescence enhancement and high fluorescence quantum yield after Suzuki-Miyaura reaction with aryl boronic acid or boronate.Manipulating the substituents andπscaffold in the fluorophores allows fine-tuning of their photophysical properties.With this strategy,we succeeded in peptide conjugation,no-wash fluorogenic protein labeling,and mitochondria-selective bioorthogonal imaging in live cells.
基金supports from the National Natural Science Foundation of China (Nos. 21422606 and 21502189)Dalian Cultivation Fund for Distinguished Young Scholars (Nos. 2014J11JH130 and 2015J12JH205)
文摘Protein labeling by using a protein tag and tag-specific fluorescent probes is increasingly becoming a useful technique for the real-time imaging of proteins in living cells. SNAP-tag as one of the most prominent fusion tags has been widely used and already commercially available. Recently, various fluorogenic probes for SNAP-tag based protein labeling were reported. Owing to turn-on fluorescence response, fluorogenic probes for SNAP-tag minimize the fluorescence background caused by unreacted or nonspecifically bound probes and allow for direct imaging in living cells without wash-out steps. Thus,real-time analysis of protein localization, dynamics and interactions has been made possible by SNAP-tag fluorogenic probes. In this review,we describe the design strategies of fluorogenic probes for SNAP-tag and their applications in cellular protein labeling.
