棕榈酸修饰的α-螺旋两亲性多肽的共组装

摘要

Three peptide amphiphiles (PAs) composed of a palmitic acid and three heptad repeat peptide sequences, C15 H31CO-( AEELAKK)3-NH2 ( PA1), C15 H31CO-( AEALAKK)3-NH2 ( PA2 ) and C15 H31 CO-(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 dichro-ism(CD) spectra suggested that the secondary structures of PAs were mainly α-helical structures. The α-heli-cal 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.%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C15H31 CO-(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.