沼水蛙抗菌肽brevinin-2GHb结构研究

Study on structure of brevinin-2GHb,an antimicrobial peptide from Hylarana guentheri

采用圆二色谱和液体核磁共振方法测定brevinin-2GHb在不同溶液中的二级结构,讨论其结构与功能之间的关系,推测其抗菌机制.经圆二色谱测定,该抗菌肽在水和Tris-HCl缓冲液中主要呈无规卷曲结构,而在Tris-HCl-SDS溶液中以α-螺旋结构为主.在TFE和SDS溶液中,brevinin-2GHb的α-螺旋含量随着TFE和SDS浓度的增大而增加.核磁共振研究结果表明,brevinin-2GHb在60%(体积分数)的TFE溶液中,Ile3-Arg20形成两亲性的α-螺旋.

In order to investigate structure-activity relationship,and deduce the antimicrobial mechanism of brevinin-2GHb,the secondary structures of brevinin-2GHb in different solutions were detected by circular dichroism（ CD） spectroscopy and nuclear magnetic resonance（ NMR） method. According to the results of CD spectra,the secondary structure of brevinin-2GHb was mainly random coil in H2 O and Tris-HCl buffer,while it adopted maily helical structure in Tris-HCl-SDS solution. The helical content of brevinin-2GHb increased with the increasing concentration of TFE or SDS. The result of liquid NMR method showed that residues between Ile3 and Arg20 of brevinin-2GHb folded into an amphipathic α-helix in 60%（ V / V） TFE solution.