Peptaibols类抗菌肽-Trichokonin Ⅵ在不同溶剂中构象变化的圆二色谱研究  

Study on Conformation Transitions of Trichokonin Ⅵ,a Peptaibol-Like Antimicrobial Peptide,in Different Solvents by Circular Dichroism Spectroscopy

作　　者：董小卫[1,1] 宋晓妍[2,3] 石梅[2] 张玉忠[2] 

机构地区：[1]山东师范大学生命科学学院,山东济南250114 [2]山东大学微生物技术国家重点实验室,山东济南250100 [3]济南大学医学与生命科学学院,山东济南250022

出　　处：《光谱学与光谱分析》2010年第2期458-461,共4页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(30870047);国家(863计划)项目(2007AA091504);教育部博士点基金项目(20060422053);山东省自然科学基金项目(Z2008B09)资助

摘　　要：TrichoderⅥ是拟康氏木霉SMF2(Trichoderma pseudokoningiiSMF2)产生的一种含有20个氨基酸的peptaibol类抗菌肽。采用圆二色谱法研究了不同极性溶剂体系和膜拟态环境对TrichokoninⅥ的二级结构的影响,TrichokoninⅥ在不同有机溶剂体系中具有典型的螺旋结构特征,而在水溶液体系中螺旋明显减少,不超过30%的三氟乙醇可以随浓度增加而诱导螺旋结构的增加。TrichokoninⅥ在磷酸缓冲液中峰的强度随浓度增加而增强,具有浓度依赖性。SDS浓度的增加可以诱导螺旋含量的增加。与非拟态环境相比,膜拟态环境可以明显增加TrichokoninⅥ的螺旋含量,表明TrichokoninⅥ可以和脂膜相互作用。Triehokonin Ⅵ, a peptaJboblike antimicrobial peptides isolated from the cultured substrates of trichoderma koningii SMF2, has 20 amino acid residues. The conformational flexibility of trichokonin Ⅵ in organic solvents with different polarities, aqueous solvents and membrane mimic solvents was studied by circular dichroism spectroscopy. Trichokonin Ⅵ takes on a typical a-helical structure in different orgarnc solvents, but helicity decreases in aqueous solvent. The helical content increases with in- creasing the concentration of TFE up to 30%. In phosphate buffered saline, the CD spectrum of trichokonin Ⅵ is concentration dependent, and the intensity of the peaks increases with increasing the concentration of trichokonin Ⅵ. SDS induces a significant transition towards a helix formation, and the CD spectra in membrane mimic solvents increase heticity compared with those recorded without membrane mimic solvents, suggesting the interaction of the peptides with the membrane.

关 键 词：Trichokonin Ⅵ PEPTAIBOLS 圆二色谱 构象 

分 类 号：Q586[生物学—生物化学]