STRUCTURE AND FUNCTION OF IMMUNOPHILIN

亲免素的结构和功能

• 批准号: 2003840
• 负责人: Hengming Ke
• 金额: $ 17.82万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-01-01 至 1998-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2003840
• 关键词: X ray crystallography; cis trans isomerization; computer program /software; computer simulation; crystallization; cyclosporines; drug receptors; enzyme complex; enzyme mechanism; enzyme structure; enzyme substrate; enzyme substrate complex; immunosuppressive; isozymes; peptidylprolyl isomerase; physical model; proline; structural biology

Cytoplasmic signal transduction during T cell activation is mediated by a complex of calcineurin and cyclophilin (CyP). CyP is a binding protein for the immunosuppressive drug cyclosporine A (CsA) and also an enzyme catalyzing the cis yields trans isomerization of peptidyl-prolyl bonds. Calcineurin, a seine/threonine phosphatase has been recently identified as a receptor of the CyP-CsA complex in vitro. This proposal is aimed at structural studies of mammalian CyPs and their complexes with substrates and CsA by X-ray protein crystallography, including: (I) determination of three-dimensional structures of human CyP A complexed with CsA and the CsA derivatives of dimethyl-Bmt1-CsA and MeAla6-CsA (II) determination of three-dimensional structures of human CyP A complexed with three proline substrates of Ser-Pro, His-Pro, and Ala-Ala-Pro-Phe, (III) structural comparison between CyP-CsA and CyP-substrate, (IV) determination of the three-dimensional structure of human CyP B, and (V) determination of the three-dimensional structure of murine CyP C. These studies will present a structural basis for cytoplasmic signal transduction in T cell activation, provide insight into the mechanism of peptidyl-prolyl isomerization and its relationship to immunosuppression, and serve as a guideline for the design of new immunosuppressive drugs. Routine methods will be used for crystallization (dialysis or vapor diffusion), preliminary characterization of crystals (precession and still photos), and heavy atom derivative preparation. Diffraction data will be collected on either a Hamlin multiwire detector or a phosphate image plate in our laboratory. Crystal structures will be determined by the molecular replacement or multiple isomorphous replacement method. Models will be built in an ESV10 graphic system and refined by the PROLSQ or XPLOR program.

T细胞活化过程中的胞浆信号转导途径 钙调神经磷酸酶和亲环素的复合体(CYP)。CYP是一种结合蛋白 对于免疫抑制药物环孢素A(CsA)和一种酶 在顺式催化下，肽基-脯氨酸键发生反式异构化。 钙调神经磷酸酶是最近发现的一种色氨酸/苏氨酸磷酸酶。 作为CYP-CsA复合体的体外受体。这项提议旨在 哺乳动物细胞色素P450及其配合物的结构研究 X-射线蛋白质结晶学测定底物和CsA，包括：(I) 人CYP A复合体的三维结构测定 CsA和二甲基-Bmt1-CsA和MeAla6-CsA的CsA衍生物(II) 人CYP A复合体的三维结构测定 用Ser-Pro、His-Pro和Ala-Ala-Pro-Phe的三种脯氨酸底物， (三)CYP-CSA和CYP-底物的结构比较，(四) 人细胞色素B的三维结构测定和(V) 测定小鼠细胞色素C的三维结构。 这些研究将为细胞质信号提供结构基础 T细胞活化中的转导，为深入了解 肽-脯氨基异构化及其与免疫抑制的关系 为新型免疫抑制药物的设计提供了指导。 将使用常规方法进行结晶(透析或蒸气 扩散)，晶体的初步表征(进动和 静态照片)，以及重原子衍生品的制备。绕射数据 将在哈姆林多丝探测器或磷酸盐上收集 我们实验室的图像板。晶体结构将由以下因素决定 分子置换或多重同构置换方法。 模型将在ESV10图形系统中建立并由PROLSQ进行改进 或XploR程序。