MECHANISM OF ION TRANSPORT THROUGH MEMBRANE CHANNELS

分子水平上的离子传输化学是 只能从非常笼统的角度来理解。 本研究的目的 提高对快速和选择性离子 通过跨膜通道转运 水平 短杆菌肽家族的通道是一个强大的系统 用于研究离子、蛋白质和脂质之间的相互作用 在运输过程中。 短杆菌肽家族代表了 已知结构的相关系列肽，其中特定的 结构的变化和极化的具体位置 取代基可以与通道选择性，稳定性， 脂质依赖性和转运特性。 优势 短杆菌肽家族包括：对单价短杆菌肽 阳离子，部分阳离子间特异性，单列 特征，其普遍接受的结构，可用性 天然和合成的类似物，和一个敏感的分析， 天然和类似物构象的等效性。 本研究 将解决化学控制的基本步骤， 运输使用动力学和平衡技术。 研究中心- 短杆菌肽通道的特定修饰将用于 (i)研究通道特性和结构-功能 关系，以及（ii）设计新的分子特征， 母体分子的功能。 结果预计 揭示了控制离子通过 生物跨膜通道，一个重要的过程 用于蜂窝间通信和用于信号传输， 神经系统

The chemistry of ion transport at the molecular level is understood only in quite general terms. The aim of this research is to enhance the understanding of rapid and selective ion transport through transmembrane channels at the molecular level. The gramicidin family of channels is a powerful system for investigating the interactions among ion, protein and lipid during the transport process. The gramicidin family represents a related series of peptides of known structure, in which specific changes in structure and the specific placement of polarizable substituents can be correlated with channel selectivity, stability, lipid dependence and transport properties. Advantages of the gramicidin family include: ideal selectivity for monovalent cations, partial intercationic specificity, single-file characteristics, its generally accepted structure, the availability of natural and synthetic analogues, and a sensitive assay for the equivalence of native and analogue conformations. This research will address the chemical control of the elementary steps of transport using both kinetic and equilibrium techniques. Site- specific modifications of the gramicidin channel will be used to (i) investigate channel properties and structure-function relationships, and (ii) design new molecular features that extend the function of the parent molecule. The results are expected to reveal general principles that govern ion transport through biological transmembrane channels, a process that is important for intercellular communication and for signal transmission in the nervous system.