Porcine epidemic diarrhea virus(PEDV),an enteric coronavirus,is widely spread worldwide and causes huge economic losses.The effective measure to control the viral infection is to develop ideal vaccines.Here,the collag...Porcine epidemic diarrhea virus(PEDV),an enteric coronavirus,is widely spread worldwide and causes huge economic losses.The effective measure to control the viral infection is to develop ideal vaccines.Here,the collagenase equivalent domain(COE)of PEDV was displayed on the surface of nanoparticles(NPs)in order to develop a newer,safer and more effective subunit vaccine against PEDV.The monomeric COE was displayed on the mi3 protein,which self-assembles into nanoparticles composed of 60 subunits,using the SpyTag/SpyCatcher system.The size,zeta potential,microstructure of the COE-mi3 virus-like particles(VLPs)were investigated.The COE-mi3 VLPs that possessed good security,stability and better retention can be more efficiently taken up by antigen-presenting cells(APCs)and help promote dendritic cells(DCs)maturation.Moreover,COE-mi3 VLPs could prominently improve specifc antibody levels including neutralizing antibodies(NAbs),and serum IgG,mucosal IgA.Moreover,COE-mi3 VLPs elicited more activation of CD4^(+)and CD8^(+)T cells and production of IFN-γand IL-4 cytokines.In particular,COE-mi3 VLPs is an effectual antigen-delivery platform to enhance germinal center(GC)B cell responses.This structure-based self-assembly of NP gives great potential to be developed as a new subunit vaccines attractive platform,and may also provide new ideas for the development of other enteric coronavirus vaccines.展开更多
The triggering receptor expressed on myeloid cells-1(TREM-1)is a receptor expressed on innate immune cells.By promoting the amplification of inflammatory signals that are initially triggered by Toll-like receptors(TLR...The triggering receptor expressed on myeloid cells-1(TREM-1)is a receptor expressed on innate immune cells.By promoting the amplification of inflammatory signals that are initially triggered by Toll-like receptors(TLRs),TREM-1 has been characterized as a major player in the pathophysiology of acute and chronic inflammatory diseases,such as septic shock,myocardial infarction,atherosclerosis,and inflammatory bowel diseases.However,the molecular events leading to the activation of TREM-1 in innate immune cells remain unknown.Here,we show that TREM-1 is activated by multimerization and that the levels of intracellular Ca 2+release,reactive oxygen species,and cytokine production correlate with the degree of TREM-1 aggregation.TREM-1 activation on primary human monocytes by LPS required a two-step process consisting of upregulation followed by clustering of TREM-1 at the cell surface,in contrast to primary human neutrophils,where LPS induced a rapid cell membrane reorganization of TREM-1,which confirmed that TREM-1 is regulated differently in primary human neutrophils and monocytes.In addition,we show that the ectodomain of TREM-1 is able to homooligomerize in a concentration-dependent manner,which suggests that the clustering of TREM-1 on the membrane promotes its oligomerization.We further show that the adapter protein DAP12 stabilizes TREM-1 surface expression and multimerization.TREM-1 multimerization at the cell surface is also mediated by its endogenous ligand,a conclusion supported by the ability of the TREM-1 inhibitor LR12 to limit TREM-1 multimerization.These results provide evidence for ligand-induced,receptor-mediated dimerization of TREM-1.Collectively,our findings uncover the mechanisms necessary for TREM-1 activation in monocytes and neutrophils.展开更多
In Klebsiella pneumoniae (Kp) NifA central domain, when theconservative amino acid residue Thr-290 in C3 region was replaced by Val, the function of NifA for activating the transcription of nif genes was lost. Thus th...In Klebsiella pneumoniae (Kp) NifA central domain, when theconservative amino acid residue Thr-290 in C3 region was replaced by Val, the function of NifA for activating the transcription of nif genes was lost. Thus the conservative Thr-290 residue seems critical for the activation function of NifA central domain. This point mutant of NifA central domain is used to examine the putative multimerization function of NifA central domain by merodiploid experiment. The results showed that the NifA central domain bore the multimerization determinants of NifA protein. A series of truncated mutants of NifA were constructed to determine the structural elements at the central domain critical for multimerization. It demonstrates that amino acid residues 252-453 are involved in the multimerization function of NifA central domain.展开更多
N-acetylatedα-synuclein(αSyn)has long been established as an intrinsically disordered protein associated with a dysfunctional role in Parkinson’s disease.In recent years,a physiologically relevant,higher order conf...N-acetylatedα-synuclein(αSyn)has long been established as an intrinsically disordered protein associated with a dysfunctional role in Parkinson’s disease.In recent years,a physiologically relevant,higher order conformation has been identified as a helical tetramer that is tailored by buried hydrophobic interactions and is distinctively aggregation resistant.The canonical mechanism by which the tetramer assembles remains elusive.As novel biochemical approaches,computational methods,pioneering purification platforms,and powerful imaging techniques continue to develop,puzzling information that once sparked debate as to the veracity of the tetramer has now shed light upon this new counterpart inαSyn neurobiology.Nuclear magnetic resonance and computational studies on multimericαSyn structure have revealed that the protein folding propensity is controlled by small energy barriers that enable large scale reconfiguration.Alternatively,familial mutations ablate tetramerization and reconfigure polymorphic fibrillization.In this review,we will discuss the dynamic landscape ofαSyn quaternary structure with a focus on the tetrameric conformation.展开更多
Targeted protein degradation (TPD) revolutionizes drug discovery by taking advantages of event-driven mechanism of action (MOA). Among current proximity-inducing platforms for TPD, molecular glue degraders and proteol...Targeted protein degradation (TPD) revolutionizes drug discovery by taking advantages of event-driven mechanism of action (MOA). Among current proximity-inducing platforms for TPD, molecular glue degraders and proteolysis-targeting chimeras (PROTACs) are representative strategies that facilitate interactions between an E3 ligase and a specific protein target. This leads to ubiquitination and subsequent degradation of the target by the ubiquitin–proteasome system (UPS). Despite offering unprecedented opportunities for more effective and targeted therapies, current UPS-hijacking TPD still faces key challenges. For instance, although over 600 E3 ligases have been identified in human cells, only a handful, such as cereblon (CRBN) and von Hippel-Lindau (VHL), are accessible for developing degraders1. In addition, there are ongoing questions about how to further expand the chemically tractable target space beyond monomeric proteins with cytosolic domains.展开更多
Self-association system of(R)-1,3-butanediol in dilute carbon tetrachloride(CCl4)solution is studied as a model of molecular association mixture.Analysis methods including FSMWEFA(fixed-size moving window evolving fac...Self-association system of(R)-1,3-butanediol in dilute carbon tetrachloride(CCl4)solution is studied as a model of molecular association mixture.Analysis methods including FSMWEFA(fixed-size moving window evolving factor analysis)combined with PCA(principal component analysis),SIMPLISMA (simple-to-use interactive self-modeling mixture analysis),and ITTFA(iterative target transformation factor analysis)are adopted to resolve infrared spectra of(R)-1,3-butanediol solution.Association number and equilibrium constant are computed.(R)-1,3-butanediol in dilute inert solution is determined as a monomer-trimer equilibrium system.Theoretical investigation of trimer structures is carried out with DFT(density functional theory),and structural factors are analyzed.展开更多
基金supported by the Major Scientific and Technological Project of the Henan Province,China(221100110600)the Beijing Life Science Academy,China(2024500CA0010)+1 种基金the Major Program of National Natural Science Foundation of China(32192452)the Chinese Postdoctoral Science Foundation(2023M743209)。
文摘Porcine epidemic diarrhea virus(PEDV),an enteric coronavirus,is widely spread worldwide and causes huge economic losses.The effective measure to control the viral infection is to develop ideal vaccines.Here,the collagenase equivalent domain(COE)of PEDV was displayed on the surface of nanoparticles(NPs)in order to develop a newer,safer and more effective subunit vaccine against PEDV.The monomeric COE was displayed on the mi3 protein,which self-assembles into nanoparticles composed of 60 subunits,using the SpyTag/SpyCatcher system.The size,zeta potential,microstructure of the COE-mi3 virus-like particles(VLPs)were investigated.The COE-mi3 VLPs that possessed good security,stability and better retention can be more efficiently taken up by antigen-presenting cells(APCs)and help promote dendritic cells(DCs)maturation.Moreover,COE-mi3 VLPs could prominently improve specifc antibody levels including neutralizing antibodies(NAbs),and serum IgG,mucosal IgA.Moreover,COE-mi3 VLPs elicited more activation of CD4^(+)and CD8^(+)T cells and production of IFN-γand IL-4 cytokines.In particular,COE-mi3 VLPs is an effectual antigen-delivery platform to enhance germinal center(GC)B cell responses.This structure-based self-assembly of NP gives great potential to be developed as a new subunit vaccines attractive platform,and may also provide new ideas for the development of other enteric coronavirus vaccines.
文摘The triggering receptor expressed on myeloid cells-1(TREM-1)is a receptor expressed on innate immune cells.By promoting the amplification of inflammatory signals that are initially triggered by Toll-like receptors(TLRs),TREM-1 has been characterized as a major player in the pathophysiology of acute and chronic inflammatory diseases,such as septic shock,myocardial infarction,atherosclerosis,and inflammatory bowel diseases.However,the molecular events leading to the activation of TREM-1 in innate immune cells remain unknown.Here,we show that TREM-1 is activated by multimerization and that the levels of intracellular Ca 2+release,reactive oxygen species,and cytokine production correlate with the degree of TREM-1 aggregation.TREM-1 activation on primary human monocytes by LPS required a two-step process consisting of upregulation followed by clustering of TREM-1 at the cell surface,in contrast to primary human neutrophils,where LPS induced a rapid cell membrane reorganization of TREM-1,which confirmed that TREM-1 is regulated differently in primary human neutrophils and monocytes.In addition,we show that the ectodomain of TREM-1 is able to homooligomerize in a concentration-dependent manner,which suggests that the clustering of TREM-1 on the membrane promotes its oligomerization.We further show that the adapter protein DAP12 stabilizes TREM-1 surface expression and multimerization.TREM-1 multimerization at the cell surface is also mediated by its endogenous ligand,a conclusion supported by the ability of the TREM-1 inhibitor LR12 to limit TREM-1 multimerization.These results provide evidence for ligand-induced,receptor-mediated dimerization of TREM-1.Collectively,our findings uncover the mechanisms necessary for TREM-1 activation in monocytes and neutrophils.
基金the Chinese Academy of Sciences and National High-Tech "863" Project of China
文摘In Klebsiella pneumoniae (Kp) NifA central domain, when theconservative amino acid residue Thr-290 in C3 region was replaced by Val, the function of NifA for activating the transcription of nif genes was lost. Thus the conservative Thr-290 residue seems critical for the activation function of NifA central domain. This point mutant of NifA central domain is used to examine the putative multimerization function of NifA central domain by merodiploid experiment. The results showed that the NifA central domain bore the multimerization determinants of NifA protein. A series of truncated mutants of NifA were constructed to determine the structural elements at the central domain critical for multimerization. It demonstrates that amino acid residues 252-453 are involved in the multimerization function of NifA central domain.
基金supported in part by Award No.18-7(to HRL)from the Commonwealth of Virginia’s Alzheimer’s and Related Diseases Research Award Fund,administered by the Virginia Center on Aging
文摘N-acetylatedα-synuclein(αSyn)has long been established as an intrinsically disordered protein associated with a dysfunctional role in Parkinson’s disease.In recent years,a physiologically relevant,higher order conformation has been identified as a helical tetramer that is tailored by buried hydrophobic interactions and is distinctively aggregation resistant.The canonical mechanism by which the tetramer assembles remains elusive.As novel biochemical approaches,computational methods,pioneering purification platforms,and powerful imaging techniques continue to develop,puzzling information that once sparked debate as to the veracity of the tetramer has now shed light upon this new counterpart inαSyn neurobiology.Nuclear magnetic resonance and computational studies on multimericαSyn structure have revealed that the protein folding propensity is controlled by small energy barriers that enable large scale reconfiguration.Alternatively,familial mutations ablate tetramerization and reconfigure polymorphic fibrillization.In this review,we will discuss the dynamic landscape ofαSyn quaternary structure with a focus on the tetrameric conformation.
文摘Targeted protein degradation (TPD) revolutionizes drug discovery by taking advantages of event-driven mechanism of action (MOA). Among current proximity-inducing platforms for TPD, molecular glue degraders and proteolysis-targeting chimeras (PROTACs) are representative strategies that facilitate interactions between an E3 ligase and a specific protein target. This leads to ubiquitination and subsequent degradation of the target by the ubiquitin–proteasome system (UPS). Despite offering unprecedented opportunities for more effective and targeted therapies, current UPS-hijacking TPD still faces key challenges. For instance, although over 600 E3 ligases have been identified in human cells, only a handful, such as cereblon (CRBN) and von Hippel-Lindau (VHL), are accessible for developing degraders1. In addition, there are ongoing questions about how to further expand the chemically tractable target space beyond monomeric proteins with cytosolic domains.
基金the National Natural Science Foundation of Chinathe YellowRiver Water Conservancy Commission(Grant Nos.50239080 and 40271019)
文摘Self-association system of(R)-1,3-butanediol in dilute carbon tetrachloride(CCl4)solution is studied as a model of molecular association mixture.Analysis methods including FSMWEFA(fixed-size moving window evolving factor analysis)combined with PCA(principal component analysis),SIMPLISMA (simple-to-use interactive self-modeling mixture analysis),and ITTFA(iterative target transformation factor analysis)are adopted to resolve infrared spectra of(R)-1,3-butanediol solution.Association number and equilibrium constant are computed.(R)-1,3-butanediol in dilute inert solution is determined as a monomer-trimer equilibrium system.Theoretical investigation of trimer structures is carried out with DFT(density functional theory),and structural factors are analyzed.
