THE MECHANISM OF THE GROUP TRANSFER PROCESS

团体转移流程的机制

• 批准号: 3268019
• 负责人: WILLIAM J RAY
• 金额: $ 19.23万
• 依托单位: PURDUE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1977
• 资助国家: 美国
• 起止时间: 1977-12-01 至 1987-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3268019
• 关键词: X ray crystallography; blood chemistry; crystallization; enzyme model; enzyme structure; enzyme substrate complex; glucose phosphate; ligands; nuclear magnetic resonance spectroscopy; phosphoglucomutase; zinc

A continuation of research on the catalytic mechanism of the phosphoglucomutase reaction is proposed which includes X-ray diffraction studies on the crystalline enzyme. Judging from the quality of the data thus far collected, this should produce electron density maps with a resolution of 2.7 Angstroms and, together with the amino acid sequence of the enzyme, a model accurate to near atomic resolution. The structure of the active site region of the enzyme and various analog complexes of enzyme-metal-ion-substrate/intermediate/product will be examined to identify the important contact residues. An investigation of the role of co-solutes in the crystal growth process also will be continued in an attempt to improve crystal quality and thus the attainable resolution for active site studies. NMR studies of the relationship between the activating metal ion and the phosphat group that is transferred will be continued in an attempt to determine at what point in the cycle the initial metal-phosphate coordination is eliminated. Kinetic studies are planned to determine whether or not the two dephosphoenzyme-glucose-bisphosphate complexes thought to be involved sequentially in the catalytic cycle are interconverted more rapidly than they are formed or react. Preliminary structural studies on the related phospho-enzyme, gluclose bisphosphate synthase, will be initiated to assess possible similarities to the structure of phosphoglucomutase. Attempts to purify to homogeneity the protein that acts as the zinc buffer in serum will be continued by using muscle phosphoglucomutase to measure zinc-buffering capacity.

继续研究有关催化机制的研究 提出了包括X射线衍射的磷酸葡萄糖酶反应 晶体酶的研究。 从数据质量来看 到目前为止收集的，这应该产生用A的电子密度图 分辨率为2.7埃斯特罗姆，并与氨基酸序列一起 酶，一种模型，准确到近原子分辨率。 结构 酶的活性位点区域和各种模拟复合物的 将检查酶 - 金属离子 - 基底/中间/产品 确定重要的接触残留物。 调查的作用 在晶体生长过程中的共同点也将继续 尝试提高水晶质量，从而实现可实现的解决方案 主动地点研究。 NMR研究 激活金属离子和转移的磷酸组将是 继续试图确定周期中的何时初始 消除了金属磷酸盐的配位。 动力学研究计划 确定两个dephosphoenzyme----葡萄糖 - 双磷酸酯是否是否 被认为在催化循环中依次涉及的复合物是 互连比形成或反应更快。 初步的 相关磷酸酶，双磷酸的结构研究 合成酶将开始评估与 磷酸葡萄糖酶的结构。 试图净到同质性 用作血清中锌缓冲液的蛋白质将继续使用 肌肉磷酸葡萄糖酶测量缓冲能力。