棕榈酸修饰的α-螺旋两亲性多肽的共组装

设计合成了3条棕榈酸修饰的两亲性多肽C₁₅H₃₁CO-(AEELAKK)₃-NH₂(PA1), C₁₅H₃₁CO-(AEALAKK)₃-NH₂(PA2) 和C₁₅H₃₁CO-(AEELAKA)₃-NH₂(PA3), 研究了其在水溶液中的自组装行为以及带净正电荷的PA2 和带净负电荷的PA3 等比例混合后的共组装行为, 并推测了其机理. 圆二色谱分析结果表明, 其二级结构均为α-螺旋结构, PA2和PA3等比例混合后α-螺旋含量升高. 利用透射电镜观察了PA1, PA2, PA3以及PA2+PA3(体积比1: 1)自组装体的形貌, 结果表明, PA2和PA3等比例混合后共组装形成了长的纳米纤维. 芘荧光探针研究了3种两亲性多肽以及PA2+PA3 的临界胶束浓度.

Coassembly of Palmitic Acid Modified α-Helical Peptide Amphiphiles

Three peptide amphiphiles(PAs) composed of a palmitic acid and three heptad repeat peptide sequences, C15H31 CO-(AEELAKK)3-NH2(PA1), C15H31 CO-(AEALAKK)3-NH2(PA2) and C15H31CO-(AEELAKA)3-NH2(PA3), were designed and synthesized. The self-assembly behavior, mechanisms of PA1, PA2, PA3 and the coassembly behavior of PA2 and PA3 mixture were investigated. The circular dichroism(CD) spectra suggested that the secondary structures of PAs were mainly α-helical structures. The α-helical structure contents of the \{positively charged PA2 and negatively charged PA3 mixture increased. The morphologies of PA1, PA2, PA3 and PA2+PA3(volume ratio 1: 1) were investigated by transmission electron microscope(TEM). The TEM results indicated that the mixture of PA2 and PA3 formed nanofibers. The critical micelle concentration values of peptides self-assembly and coassembly were calculated by pyrene probe fluorescence.