糖基化扫描方法分析KvAP通道电压感受器S3-S4在膜中所处位置  

Membrane Localization of KvAP Voltage Sensors S3-S4 by Glycosylation Scanning Method

作　　者：张丽艳[1] 尚德志[2] 汲坤[1] 隋璐[1] 牟均[3] 

机构地区：[1]沈阳医学院基础医学院病理生理教研室,沈阳110034 [2]沈阳医学院口腔医学院颌面外科,沈阳110034 [3]沈阳医学院国资处,沈阳110034

出　　处：《中国医科大学学报》2013年第1期10-13,共4页Journal of China Medical University

基　　金：国家自然科学基金资助项目(30971177);辽宁省教育厅重点实验室项目(LS2010162)

摘　　要：目的探讨分析KvAP通道电压感受器S3-S4在膜中所处的位置。方法采用膜拓扑结构分析和糖基化扫描方法,对KvAP通道的电压感受器S3-S4在膜中所处位置进行分析。结果 KvAP通道中,S3以Ncyt/Cexo方式插入到膜中,其C端终止于G4,S4以Ncyt/Cexo方式插入到膜中,其N端终止于G40。G4及G40均位于人工插入的G-loop中。结论 KvAP通道S3片段的C端与S4片段的N端位于膜内,电压感受器S3-S4可能为非跨膜片段,S3位于膜的中间;此结果与电压门控机制中的KvAP模型一致。Objective To assess the membrane localizations of S3-S4 segments in KvAP channel voltage sensor. Methods Membrane topological analysis and glycosylation scanning methods were used to assess the membrane positions. Results In KvAP channel, S3 inserts into membrane with an Noyt/Cexo orientation and the C-terminus ends at C,4 residue;S4 inserts into membrane with an Ncyt/Cexo orientation and the N-terminus ends at G40 residue. Both of G4 and G40 residues are localized in the artificially inserted G-loop. Conclusion The C ter- minus of S3 and the N terminus of S4 of KvAP are localized within the membrane. Voltage sensor S3-S4 may function as non-transmembrane segments and S3 is localized in the middle of the membrane; the findings of current study are consistent with the KvAP model of voltage gating mechanism.

关 键 词：KvAP 电压门控机制 膜拓扑结构 电压门控钾通道 

分 类 号：Q5[生物学—生物化学]