Peptide-based assemblies have gained increasing attention in different areas of nanotechnology,drug delivery and molecular biology.Among these,non-natural β-peptide scaffolds are particularly promising,as their progr...Peptide-based assemblies have gained increasing attention in different areas of nanotechnology,drug delivery and molecular biology.Among these,non-natural β-peptide scaffolds are particularly promising,as their programmable and diverse secondary structures,high metabolic stability and strong self-association propensity can be easily exploited to create variable constructs.We have recently demonstrated that heterochiral,acyclic β^(3)-peptides assembled into striped lamellar nanostructures that induced antibacterial activity.The process of this assembly formation could be exploited in diverse areas,however identifying oligomerisation stages,and more importantly,controlling the spontaneous process at different levels is still lacking.In this study,a set of analogues heterochiral hexameric β^(3)-peptide sequences was investigated to understand how systematic,small variations of the sequences,such as single point mutation or N-terminal chemical modification,can influence the resulting assemblies and allow the control of formed morphologies.TEM and cryo-EM combined with molecular dynamics simulation enabled the identification and differentiation of morphological stages throughout the entire multi-step process.Depending on the position of the sequence modifications,the self-assembled structures formed small oligomers,individual protofibrils,extended,flat lamellae,bundles and macroscopic clusters.These results outline how the self-assembly process of short heterochiral β-peptides can be qualitatively fine-tuned by sequence modifications,which contribute to understanding the general peptide assembly processes for their fibrillar morphologies.展开更多
美洲鳄梨变种防御素(Persea americana var. drymifolia defensin,PaDef)是从墨西哥鳄梨果实中提取的一种具有广谱抗菌作用的防御素,其结构-活性构效关系及其抗菌机制尚未明确。该文利用定点突变的方法对重组PaDef(recombination PaDef,...美洲鳄梨变种防御素(Persea americana var. drymifolia defensin,PaDef)是从墨西哥鳄梨果实中提取的一种具有广谱抗菌作用的防御素,其结构-活性构效关系及其抗菌机制尚未明确。该文利用定点突变的方法对重组PaDef(recombination PaDef,rPaDef)进行定向分子改良。最终获得改良肽rPaDefQ33H和rPaDefK43M,其抗菌活性上调2~3倍,同时保持良好的稳定性和较低的溶血性和细胞毒性。用扫描电子显微镜和荧光显微探究rPaDef及改良肽的抗菌机制,表明rPaDef及改良肽能够在细菌表面产生孔隙,破坏受试菌的细胞完整性,最终导致细菌死亡。因此rPaDef及改良肽可以作为新型抗生素替代物,在食品贮藏保鲜、绿色饲料添加剂以及临床医药领域等方面有较大应用前景。展开更多
基金funded by the National Research,Development and Inno-vation Office,Hungary(TKP2021-EGA-31,2020-1.1.2-PIACI-KFI-2020-00021,KKP_22 Project no.144180 and FK_23 Project no.146081).Support from Hungarian Research Network(Eötvös Loránd Research Network)grant no.SA-87/2021 and KEP-5/2021 are also acknowledged.Project no.RRF-2.3.1-21-2022-00015+1 种基金supported by the European Union,Recovery and Resilience Facility.The János Bolyai Research Fellowship(A.W.)of the Hungarian Academy of Sciences is greatly acknowledged.The authors acknowledge CF CryoEM of CIISB,Instruct-CZ Centre,supported by Ministry of Education,Youth and Sports,Czech Republic(MEYS CR)(no.LM2023042)European Regional Development Fund-Project"UP CIISB"(n0.CZ.02.1.01/0.0/0.0/18_046/0015974).
文摘Peptide-based assemblies have gained increasing attention in different areas of nanotechnology,drug delivery and molecular biology.Among these,non-natural β-peptide scaffolds are particularly promising,as their programmable and diverse secondary structures,high metabolic stability and strong self-association propensity can be easily exploited to create variable constructs.We have recently demonstrated that heterochiral,acyclic β^(3)-peptides assembled into striped lamellar nanostructures that induced antibacterial activity.The process of this assembly formation could be exploited in diverse areas,however identifying oligomerisation stages,and more importantly,controlling the spontaneous process at different levels is still lacking.In this study,a set of analogues heterochiral hexameric β^(3)-peptide sequences was investigated to understand how systematic,small variations of the sequences,such as single point mutation or N-terminal chemical modification,can influence the resulting assemblies and allow the control of formed morphologies.TEM and cryo-EM combined with molecular dynamics simulation enabled the identification and differentiation of morphological stages throughout the entire multi-step process.Depending on the position of the sequence modifications,the self-assembled structures formed small oligomers,individual protofibrils,extended,flat lamellae,bundles and macroscopic clusters.These results outline how the self-assembly process of short heterochiral β-peptides can be qualitatively fine-tuned by sequence modifications,which contribute to understanding the general peptide assembly processes for their fibrillar morphologies.
文摘美洲鳄梨变种防御素(Persea americana var. drymifolia defensin,PaDef)是从墨西哥鳄梨果实中提取的一种具有广谱抗菌作用的防御素,其结构-活性构效关系及其抗菌机制尚未明确。该文利用定点突变的方法对重组PaDef(recombination PaDef,rPaDef)进行定向分子改良。最终获得改良肽rPaDefQ33H和rPaDefK43M,其抗菌活性上调2~3倍,同时保持良好的稳定性和较低的溶血性和细胞毒性。用扫描电子显微镜和荧光显微探究rPaDef及改良肽的抗菌机制,表明rPaDef及改良肽能够在细菌表面产生孔隙,破坏受试菌的细胞完整性,最终导致细菌死亡。因此rPaDef及改良肽可以作为新型抗生素替代物,在食品贮藏保鲜、绿色饲料添加剂以及临床医药领域等方面有较大应用前景。
