Ligand binding to heme proteins: relevance of low-temperature data.
Ligand binding to heme proteins: relevance of low-temperature data.
复制标题
配体与血红素蛋白的结合：低温数据的相关性。
DOI：
10.1021/bi00359a011
复制
发表时间：
1986
期刊：
影响因子：
2.9
通讯作者：
Shyamsunder,E
中科院分区：
文献类型：
--
作者：
Ansari,A;DiIorio,EE;Dlott,DD;Frauenfelder,H;Iben,IE;Langer,P;Roder,H;Sauke,TB;Shyamsunder,E
伊利诺伊大学厄巴纳-香槟分校物理系，厄巴纳，伊利诺伊州 61801 收稿日期：1985 年 7 月 9 日；修订稿于 1986 年 2 月 10 日收到 摘要：一氧化碳与成人血红蛋白 ß 链的结合已通过闪光光解作用进行了研究，时间范围为 100 ps 至数秒，温度范围为 40 至 300 K。低于约 180 K，结合直接从口袋发生（过程 I），并且随时间呈非指数关系。高于约 180 K，一些一氧化碳分子从口袋中逃逸到蛋白质基质中。高于约 240 K，可以测量到逃逸到溶剂中。过程 I 可以在高达 300 K 的温度下观察到。低温数据顺利外推到 300 K，证明在 180 K 以下获得的结果提供了功能相关的信息。实验再次表明，即使在生理温度下，结合过程也受到血红素铁的最终结合步骤的调节，并且高温下的测量不足以完全理解结合过程。
Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 Received July 9, 1985; Revised Manuscript Received February 10, 1986 abstract: Binding of carbon monoxideto the ß chain of adult human hemoglobin has been studied by flash photolysis over the time range from about 100 ps to seconds and the temperature range from 40 to 300 K. Below about 180 K, binding occurs directly from the pocket (process I) and is nonexponential in time. Above about 180 K, some carbon monoxide molecules escape from the pocket into the proteinmatrix. Above about 240 K, escape into thesolvent becomes measurable. Process I can be observed up to 300 K. The low-temperature data extrapolate smoothly to 300 K, proving that the results obtained below 180 K provide functionally relevant information. The experiments show again that the binding process even at physiological temperatures is regulated by the final binding step at the heme iron and that measurements at high temperatures are not sufficient to fully understand the association process.