U.S.-Brazil Cooperative Research: Calcium Transport across Biological Membranes

该奖项将使巴尔的摩马里兰大学生物化学系和里约热内卢联邦大学之间的科学合作得以继续。调查人员是Guiseppi Inesi（美国）和Leopoldo deMeis（巴西）。该研究旨在澄清ATP依赖钙跨生物膜运输的机制。实验系统将由来源于肌浆网的膜泡组成，并通过肌肉组织的均质和差速离心获得。转染细胞培养物中表达的CA2+ - atp酶也将被使用。化学衍生化实验将通过在细胞培养中表达突变cDNA来补充。由转染细胞制备的微粒体表现出非常活跃的转运活性，构成了一个非常有利的系统，用于研究特定的突变。合作者有一个长期的富有成效的合作记录。这项研究的生物学意义与肌肉纤维收缩激活和松弛的控制有关。它的化学意义与酶动力学和催化作用、催化和运输活性的耦合、电解质的通道和跨膜通量以及蛋白质的结构有关。

This award will allow continuation of a scientific collabo- ration between the Biochemistry Departments of the University of Maryland at Baltimore and the Federal University of Rio de Janeiro. The investigators are Guiseppi Inesi (U.S.) and Leopoldo deMeis (Brazil). The research is aimed at a clarification of the mechanism of ATP dependent calcium transport across biological membranes. The experimental system will consist of membrane vesicles derived from sarcoplasmic reticulum, and obtained by homogenization and differential centrifugation of muscle tissue. CA2+ -ATPase expressed in transfected cell cultures will be also used. The chemical derivatization experiments will be complemented by expression of mutated cDNA in cell cultures. Microsomes prepared from transfected cells display a very active transport activity, and constitute a highly favorable system for studies of specific mutations. The collaborators have a long standing record of productive collaboration. The biological significance of this research is related to control of contractile activation and relaxation in muscle fibers. Its chemical significance is related to enzyme kinetics and catalysis, coupling of catalytic and transport activities, channels and transmembrane fluxes of electrolytes, and structure of proteins.