BIOCHEMICAL CHARACTERIZATION OF P-GLYCOPROTEIN

癌症化疗的一个主要问题仍然是肿瘤的发展 细胞对多种化疗药物产生耐药性。 过度表达 多重耐药基因（MDR1）导致P-的出现 肿瘤细胞质膜中的糖蛋白（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药物产生耐药性 细胞毒性药物。 本拨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的特征，以及（2）通过以下方式揭示分子机制： 其中 P-gp 可以识别多种亲脂性试剂，包括 细胞毒性药物和 MDR 调节剂。 本次活动的具体目标 建议是（1）合成特定的光亲和探针，（2） 研究药物与P-gp相互作用的模式，(3)鉴定药物 P-gp 的结合域，以及 (4) 纯化 P-gp 的药物结合片段和 识别药物结合位点的特定氨基酸序列。 这些研究将增加我们对生物化学和 P-gp 的分子性质，可以为合理的研究提供框架 有效的MDR调节剂的设计和合成。

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.