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 H2O 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