BIOCHEMISTRY OF BACTERIAL CELL MEMBRANES

这个项目的总体目标是研究通量(包括在和 外)穿过细菌表层的小分子。按原样 众所周知，病原微生物的多重耐药性正在成为一种 严重威胁人类健康。我们自己和其他方面的最新研究 实验室表明，在许多情况下，这种耐药性是协同作用的。 细胞表面层起渗透屏障作用的两个因素的影响 药物流入(革兰氏阴性菌外膜或 分枝杆菌的含有分枝杆菌酸的细胞壁)和活性的、多药外排 打气筒。事实上，对于更先进的抗菌剂来说， 细菌的酶灭活，如氟喹诺酮类，这一机制 防止药物进入目标已成为一种主要机制 抵抗的力量。在这项研究中，我们计划继续我们对两者的描述 在这些抵抗机制中。因此，我们将把《慢性子》人物定性为 生物体，如铜绿假单胞菌，这些蛋白质有助于 这些细菌通过减缓内流而产生的普遍的内在耐药性 在它们的外膜上覆盖着抗菌剂。我们会研究 分枝杆菌的细胞壁极大地减缓了 大多数药物通过产生一层有组织的霉菌酸和其他物质进入 脂类。另一方面，我们将研究多药外排的机制。 泵，特别是那些显示出令人难以置信的广泛范围的泵 特异性，如大肠杆菌的AcrAB，它几乎能挤出任何 亲油性或两亲性化合物，包括染料、消毒剂、洗涤剂、 溶剂和几乎所有的抗生素(氨基糖苷类除外)。这些泵 当细菌处于压力下时，似乎会变得更强烈， 监管的路径将被界定。最后，作为ABC的原型 转运蛋白，包括P-糖蛋白和CFTR，麦芽糖转运蛋白 一种高度嗜热的狂犬病杆菌的复合体将被提纯，因为 来自超嗜热菌的蛋白质往往会产生衍射性很好的晶体，并且 非常需要获得这一重要类别的结晶学数据 传送者。

The overall goal of this project is to study the flux (both in and out) of small molecules across the surface layers of bacteria. As is well-known, multiple resistance in pathogenic microorganisms is becoming a serious threat to human health. Recent studies in our own and other laboratories suggest that in many cases such resistance is the synergistic effect of two factors, the cell surface layer acting as permeability barrier for the influx of drugs (outer membrane of Gram-negative bacteria or mycolate-containing cell wall of mycobacteria) and active, multidrug efflux pumps. In fact, for more advanced antimicrobial agents that resist the enzymatic inactivation of bacteria, such as fluoroquinolones, this mechanism that prevents the access of drugs to the target has become a primary mechanism of resistance. In this study, we plan to continue our characterization of both of these resistance mechanisms. Thus we will characterize the "slow" porins of organism such as Pseudomonas aeruginosa, the proteins that contribute to the generalized intrinsic resistance of these bacteria by slowing down the influx of antimicrobial agents across their outer membrane. We will study the mechanism in which the cell wall of mycobacteria drastically slows down the entry of most agents by producing an organized layer of mycolic acid and other lipids. At the other end, we will investigate the mechanism of multidrug efflux pumps, especially those pumps that show an incredibly wide range of specificity, such as AcrAB of Escherichia coli that extrudes almost any lipophilic or amphiphilic compounds, including dyes, disinfectants, detergents, solvents, and practically all antibiotic (except aminoglycosides). These pumps appear to become expressed more strongly when the bacteria are under stress, and the pathway of regulation will be defined. Finally, as a prototype of ABC transporter, which includes P-glycoprotein and CFTR, the maltose transporter complex of a hyperthermophile Pyrococcus furiosus will be purified, because proteins from hyperthermophiles tend to produce well-diffracting crystals, and there is great need to obtain crystallographic data on this important class of transporters.