...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Biochemistry >X-ray and NMR characterization of covalent complexes of trypsin, borate, and alcohols.
【24h】

X-ray and NMR characterization of covalent complexes of trypsin, borate, and alcohols.

机译：胰蛋白酶，硼酸盐和醇的共价配合物的X射线和NMR表征。

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

An understanding of the physiological and toxicological properties of borate and the utilization of boronic acids in drug development require a basic understanding of borate-enzyme chemistry. We report here the extension of our recent NMR studies indicating the formation of a ternary borate-alcohol-trypsin complex. Crystallographic and solution state NMR studies of porcine trypsin were performed in the presence of borate and either of three alcohols designed to bind to the S1 affinity subsite: 4-aminobutanol, guanidine-3-propanol, and 4-hydroxymethylbenzamidine. Quaternary complexes of trypsin, borate, S1-binding alcohol, and ethylene glycol (a cryoprotectant), as well as a ternary trypsin, borate, and ethylene glycol complex have been observed in the crystalline state. Borate forms ester bonds to Ser195, ethylene glycol (two bonds), and the S1-binding alcohol (if present). Spectra from (1)H and (11)B NMR studies confirm that these complexes also exist in solution and also provide evidence for the formation of ternary trypsin, borate, and S1-subsite alcohol complexes which are not observed in the crystals using our experimental protocols. Analysis of eight crystal structures indicates that formation of an active site borate complex is in all cases accompanied by a significant (approximately 4%) increase in the b-axis dimension of the unit cell. Presumably, our inability to observe the ternary complexes in the crystalline state arises from the lower stability of these complexes and consequent inability to overcome the constraints imposed by the lattice contacts. A mechanism for the coupling of the lattice contacts with the active site that involves a conformational rearrangement of Gln192 is suggested. The structures presented here represent the first crystallographic demonstration of covalent binding of an enzyme by borate.
机译：对硼酸盐的生理学和毒理学性质以及在药物开发中利用硼酸的理解需要对硼酸盐-酶化学有基本的了解。我们在这里报告了我们最近的NMR研究的扩展，表明了三元硼酸盐-醇-胰蛋白酶复合物的形成。猪胰蛋白酶的晶体学和溶液状态NMR研究是在硼酸盐和设计用来结合S1亲和性亚位点的三种醇中的一种进行的：4-氨基丁醇，胍基-3-丙醇和4-羟甲基苯甲m。已经观察到处于结晶状态的胰蛋白酶，硼酸盐，与S1结合的醇和乙二醇的四元复合物（防冻剂），以及胰蛋白酶，硼酸盐和乙二醇的三元复合物。硼酸酯与Ser195，乙二醇（两个键）和与S1结合的醇（如果存在）形成酯键。 （1）H和（11）B NMR研究的光谱证实，这些络合物也存在于溶液中，也提供了形成三重胰蛋白酶，硼酸盐和S1-亚位醇络合物的证据，而使用我们的实验在晶体中未观察到协议。对八种晶体结构的分析表明，在所有情况下，形成活性位点硼酸盐复合物都伴随着晶胞b轴尺寸的显着增加（约4％）。据推测，我们无法观察到结晶态的三元复合物是由于这些复合物的稳定性较低，因此无法克服晶格接触所施加的约束。提出了一种将晶格接触与活性位点偶联的机制，该机制涉及Gln192的构象重排。此处介绍的结构代表了硼酸盐与酶共价结合的第一个晶体学证明。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号