BIOCHEMICAL CHARACTERIZATION OF P-GLYCOPROTEIN

癌症化疗中的一个主要问题仍然是肿瘤的发展。 细胞对多种化疗药物的耐药性。过度表达 多药耐药基因(Mdr1)导致P- 肿瘤细胞质膜上的糖蛋白(P-gp)。这种蛋白质 作为药物外排泵发挥作用，导致肿瘤细胞对许多 细胞毒性药物。这项赠款提案的长期目标是：(1) 进一步了解结构决定因素和生化 P-gp的特性，以及(2)通过以下方法揭示其分子机制 P-gp可以识别多种亲脂剂，包括 包括细胞毒药物和多药耐药调节剂。这样做的具体目的是 建议(1)合成特异的光亲和探针，(2) 研究药物与P-gp的相互作用模式，(3)鉴别药物 P-gp的结合域，以及(4)纯化P-gp和 确定药物结合位点的特定氨基酸序列(S)。 这些研究将增加我们对生物化学和 P-gp的分子性质，可以为Rational提供一个框架 设计和合成有效的MDR调节剂。

A major problem in cancer chemotherapy remains the development of tumor cell resistance to multiple chemotherapeutic agents. Overexpression of the multidrug resistance gene (MDR1) leads to the appearance of P- glycoprotein (P-gp) in the plasma membrane of tumor cells. This protein functions as a drug efflux pump resulting in tumor cell resistance to many cytotoxic drugs. The long-term objectives of this grant proposal are (1) to further understand the structural determinants and biochemical characteristics of P-gp, and (2) to unravel the molecular mechanism by which P-gp can recognize a wide variety of lipophilic agents including both cytotoxic drugs and MDR modulators. The specific aims of this proposal are to (1) synthesize specific photoaffinity probes, (2) investigate the modes of drug interaction with P-gp, (3) identify drug binding domains of P-gp, and (4) purify drug binding fragments of P-gp and identify the specific amino acid sequences of the drug binding site(s). These studies will increase our knowledge of the biochemistry and molecular nature of P-gp and could provide a framework for the rational design and synthesis of effective MDR modulators.