BIOCHEMICAL CHARACTERIZATION OF P-GLYCOPROTEIN

癌症化疗的一个主要问题仍然是肿瘤的发展 细胞对多种化疗剂的抗性。 过表达 多药耐药基因（MDR 1）导致P- 糖蛋白（P-gp）在肿瘤细胞的质膜。 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 本计划的长远目标是（1） 为了进一步了解结构决定因素和生物化学 P-gp的特性，以及（2）通过 该P-gp可以识别多种亲脂性试剂， 细胞毒性药物和MDR调节剂。 具体目标是 提出了（1）合成特异性光亲和探针，（2） 研究药物与P-gp的相互作用方式;（3）鉴定药物 P-gp的结合结构域，和（4）纯化P-gp的药物结合片段， 鉴定药物结合位点的特定氨基酸序列。 这些研究将增加我们的生物化学知识， P-gp的分子性质，并可以提供一个合理的框架， 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.