ENERGETICS OF AN ANION-TRANSLOCATING ATPASE

本研究的总体目标是：首先，阐明 离子泵的分子机制，其基因是天然成分 细菌耐药质粒，第二，这种运输的作用 细菌对抗生素和有毒化合物的耐药性。这个 临床耐药质粒R773携带砷耐药(Ars) 操纵子，产生对砷酸盐、亚砷酸盐和亚硫酸盐的抵抗力。 操纵子编码一个氧阴离子转运ATPase，它的功能是 三磷酸腺苷偶联挤压泵，用于有毒的氧离子。 在此协作项目分析中，将扩展以确定 这种新型阴离子泵的能量学，其具体目的是 确定了能量耦合的机理。的实验室 V.P.Skulachev教授开创了测量 线粒体、亚线粒体的膜电位和离子通量 颗粒、细菌和细菌膜泡。Skulachev教授 是唯一有资格进行这些合作研究的机构。 而质粒介导的抗生素和重金属耐药性是 由于依赖能量的外排系统可能在自然界中广泛分布， 阴离子泵似乎相当罕见。砷的外排系统 为传播性细菌的研究提供良好的模型体系 抗生素耐药性。编码ars系统的质粒还提供了一种 研究哺乳动物细胞多药耐药性的细菌模型。 ARS-ATPase在结构和功能上与 P-糖蛋白，一种在体内产生多重耐药性的蛋白质 肿瘤细胞。

The overall goals of this research are first, elucidation of the molecular mechanisms of an ion pump whose genes are natural components of a bacterial resistance plasmid, and second, the role of this transport system in bacterial resistance to antibiotics and toxic compounds. The clinical resistance plasmid R773 carries the arsenical resistance (ars) operon, which produces resistance to arsenate, arsenite, and antimonite. The operon encodes an oxyanion-translocating ATPase which functions as an ATP-coupled extrusion pump for the toxic oxyanions. In this collaborative project analysis will be extended to determine the energetics of this novel anion pump, with the specific aim of determination of the mechanism of energy coupling. The laboratory of Professor V.P. Skulachev pioneered the methodology for the measurement of membrane potentials and ion fluxes in mitochondria, submitochondrial particles, bacteria and bacterial membrane vesicles. Professor Skulachev is uniquely qualified to perform these collaborative studies. While plasmid-mediated antibiotic and heavy metal resistances which are due to energy-dependent efflux systems may be wide spread in nature, anion pumps appear to be rather rare. The arsenical efflux system provide a good model system for the study of transmissible bacterial antibiotic resistances. The plasmid encoded ars system also provides a bacterial model for the study of multidrug resistance in mammalian cells. The Ars ATPase exhibits structural and functional similarity to the P-glycoprotein, the protein which produces multiple drug resistance in tumor cells.