TRANSPORT MECHANISM OF SARCOPLASMIC RETICULUM ATPASE

本文提出的研究的总体目标是确定 肌浆网摄取Ca 2+的机制。 的 这些研究的主要焦点是， Ca 2+·Mg 2+·ATP酶，其是膜的组成部分， 利用ATP提供的化学能， Ca 2+穿过细胞膜。 一系列研究旨在 绘制出ATP酶的节段性运动， 与酶构象结合的化学相互作用， 控制运输机制。 在大多数情况下，EPR光谱将用于监测变化 在功能位点之间的相互作用距离中， 伴随步骤的酶的构象变化， 运输机制。 化学改性技术将 用于确定特定残基在ATP偶联中的作用 水解到运输。 反过来，各种分析技术 将用于整合酶的功能特性 与观察到的构象运动和decern效应 具体的修改。 细胞内Ca 2+调节对所有肌肉功能至关重要， 包括心肌和骨骼肌，在此用于 简化。 Ca ~（2+）. Mg ~（2+）. ATP酶在此过程中的主要作用 控制使这种酶的Ca 2+转运机制 首要的重要性。 最重要的是， 运输和能量转换，许多生物 膜，应澄清这些研究。

The overall aim of the research proposed here is to determine the mechanism of Ca2+ uptake by sarcoplasmic reticulum. The primary focus of these studies is the means by which the Ca2+.Mg2+.ATPase, which is an integral part of the membrane, uses the chemical energy provided by ATP to directly transport Ca2+ across the membrane. A series of studies are designed to map out segmental movements of the ATPase and to delineate the chemical interactions which couple with enzyme conformation to control the transport mechanism. For most part, EPR spectroscopy will be used to monitor changes in interaction distances between functional sites, and follow conformational changes in the enzyme which accompany steps in the transport mechanism. Chemical modification techniques will be used to decern the role of specific residues in coupling ATP hydrolysis to transport. In turn, a variety of analytical techniques will be used to integrate the functional properties of the enzyme with observed conformational movements and decern the effects of specific modifications. Intracellular Ca2+ regulation is vital to all muscle function, including cardiac and skeletal muscle, used here for purposes of simplication. The principal role of the Ca2+.Mg2+.ATPase in this control makes the Ca2+ transport mechanism of this enzyme of primary importance. Most importantly, basic mechanisms of ion transport and energy transduction, common to many biological membranes, should be clarified by these studies.