抗菌肽CGA-N46及其衍生肽结构与抗菌活性研究

Structure and antimicrobial activity of peptide CGA- N46 and its derived peptides

为研究多肽CGA-N46及其衍生肽CGA-N16和CGA-N12的结构与抗菌活性,寻找出高效的抗真菌药物.利用生物信息学软件预测CGA-N46及其衍生肽CGA-N16、CGA-N12的空间结构;采用圆二色谱(CD)技术测定在不同环境下二级结构变化;采用MTT法测定其抗菌活性.结果表明:CGA-N46,CGA-N16和CGA-N12生物信息学分析为带正电荷、亲水性α-螺旋肽;它们在PBS、30 m M SDS溶液中的二级结构相似,呈α-螺旋构型,但在脂质体溶液中二级结构发生了变化,α-螺旋结构比例减少,其他结构的比例增加了.MTT实验结果表明:CGA-N46,CGA-N16和CGA-N12均表现出较强的抗真菌活性,但对细菌的增长没有抑制作用.CGA-N46及其衍生肽CGA-N16和CGA-N12结构发生了变化,其抗菌特性也发生了变化,本研究结果对其作用机制研究奠定了基础.

To study the structure and antimicrobial activity of CGA-N46 and its derived peptides CGA-N16, CGA-N12 and to find high effective antifungal compounds,the bioinformatics software was used to predict the spatial structure of CGA-N46 and its derived peptides CGA-N16 and CGA-N12,circular dichroism （CD） was used to study the secondary structures under different environmental conditions,and the antimicrobial activi-ty was measured with MTT assay.The results showed that CGA-N46,CGA-N16 and CGA-N12 were predic-ted to be positively charged,hydrophilic,alpha helical peptides;the secondary structure of the peptides in aque-ous solution and 30 mM SDS solution were alpha helix,but changed in liposome solution,the proportion of alpha helix reduced,and other structures′proportion increased.The MTT experimental results showed that CGA -N46,CGA-N16 and CGA -N12 present strong antifungal activity,but have no inhibitory effect on bacteria growth.With the secondary structure changing,the antimicrobial activity of CGA-N46 and its derived peptides CGA-N16,CGA-N12 changed.These results laid a foundation for the research of its mechanism of action.