...
首页> 外文期刊>Biochemistry >Catalysis of Electron Transfer by Selenocysteine
【24h】

Catalysis of Electron Transfer by Selenocysteine

机译:硒代半胱氨酸催化电子转移

获取原文
获取原文并翻译 | 示例
           

摘要

Selenium is an essential element that is involved in biological redox processes.The electrode potentials of the selenocysteine half-reactions RSe~(centre dot)+ e~ -> RSe-,(RSeSeR)~(centre dot-)+ e~--> 2 RSe~-,and RSeSeR + 2 e~--> 2 RSe~-[E deg '(pH 7)] are +0.43,+0.18,and-0.38 V,respectively,at pH 7.The spectra of RSe~(centre dot)and(RSeSeR)~(centre dot-)are characterized by absorption maxima at 460 nm(epsilon- 560 M~(-1)cm~(-1))and 455 nm(epsilon = 7100 M~(-1)cm~(-1)),respectively.The bond dissociation energy of RSe-H has been calculated,and the value of 310 kJ/mol is in agreement with literature values.In comparison with the sulfur analogue cysteine,the more facile accessibility of the radical oxidation state is striking and may have biological implications,such as in mediation of one-electron-and two-electron-transfer processes,as illustrated by catalysis by selenocysteine of the electron transfer between dithiothreitol and benzyl viologen.
机译:硒是生物氧化还原过程中必不可少的元素。硒代半胱氨酸半反应RSe〜(中心点)+ e〜-> RSe-,(RSeSeR)〜(中心点-)+ e〜-的电极电势> 2 RSe〜-和RSeSeR + 2 e〜-> 2 RSe〜-[E deg'(pH 7)]在pH 7时分别为+ 0.43,+ 0.18和-0.38V。 〜(中心点)和(RSeSeR)〜(中心点-)的特征在于在460 nm(ε-560 M〜(-1)cm〜(-1))和455 nm(ε= 7100 M〜(分别计算了-1)cm〜(-1))。计算了RSe-H的键解离能,其310 kJ / mol的值与文献值相符。与硫类似物半胱氨酸相比,自由基氧化态的简便可及性是惊人的,并且可能具有生物学意义,例如介导单电子和二电子转移过程,如硒代半胱氨酸催化二硫苏糖醇与苄基紫精之间的电子转移。

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