MDR1 MULTIDRUG TRANSPORTER--MECHANISM AND INHIBITION

MDR1多药转运蛋白——机制和抑制

• 批准号: 6377068
• 负责人: DAVID M CLARKE
• 金额: $ 12.63万
• 依托单位: UNIVERSITY OF TORONTO
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-07-01 至 2004-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6377068
• 关键词: P glycoprotein; adenosine triphosphate; adenosinetriphosphatase; antimetabolites; binding sites; biological transport; cell line; conformation; crosslink; disulfiram; drug metabolism; enzyme activity; enzyme substrate; gene expression; glycoprotein biosynthesis; hydrolysis; inhibitor /antagonist; multidrug resistance; protease inhibitor; proteasome; protein structure function; western blottings

The long-term objectives of the application are to understand the structure, mechanism and biosynthesis of the human multidrug resistance P-glycoprotein (P-gp). This knowledge will then be used to develop strategies to shut off the transporter during cancer chemotherapy or treatment of AIDS. P-gp interferes in the treatment of cancer and AIDS by preventing anticancer drugs or HIV-1 protease inhibitors from reaching their targets. Efforts to develop effective inhibitory drugs that specifically bind to P-gp have been hampered by the lack of structural information about the drug-binding domain and the conformational changes that take place during transport. These issues will be addressed by testing the hypothesis that transmembrane segments 5, 6, 11 and 12 of P-gp form the drug-binding domain and that they undergo conformational changes during drug transport. These hypotheses will be tested using a Cys-less mutant of P-gp together with cysteine-scanning mutagenesis, thiol-reactive substrates and disulfide crosslinking. A new approach will also be developed to inhibit P-gp function by inhibiting folding and exit of P-gp from the endoplasmic reticulum. Preliminary evidence suggests that some compounds can block the conversion of a biosynthetic intermediate of P-gp into mature enzyme.

该应用的长期目标是了解人类多药耐药P-糖蛋白（P-gp）的结构、机制和生物合成。 然后，这些知识将用于制定在癌症化疗或艾滋病治疗期间关闭转运蛋白的策略。 P-gp 通过阻止抗癌药物或 HIV-1 蛋白酶抑制剂达到其目标来干扰癌症和艾滋病的治疗。由于缺乏有关药物结合域的结构信息以及运输过程中发生的构象变化，开发特异性结合 P-gp 的有效抑制药物的努力受到阻碍。 这些问题将通过测试以下假设来解决：P-gp 的跨膜片段 5、6、11 和 12 形成药物结合结构域，并且它们在药物转运过程中经历构象变化。 这些假设将使用 P-gp 的无 Cys 突变体以及半胱氨酸扫描诱变、硫醇反应底物和二硫键交联进行测试。还将开发一种新方法，通过抑制 P-gp 折叠和从内质网退出来抑制 P-gp 功能。初步证据表明，某些化合物可以阻止 P-gp 生物合成中间体转化为成熟酶。