STRUCTURE AND FUNCTION OF IMMUNOPHILIN

亲免素的结构和功能

• 批准号: 2068057
• 负责人: Hengming Ke
• 金额: $ 16.48万
• 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/2068057
• 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细胞活化过程中的细胞质信号转导是由