Amino Acid Influence on Copper Binding to Peptides: Cysteine Versus Arginine
Amino Acid Influence on Copper Binding to Peptides: Cysteine Versus Arginine
复制标题
DOI：
10.1016/j.jasms.2009.12.020
复制
发表时间：
2010-04-01
影响因子：
3.2
通讯作者：
Russell, David H.
中科院分区：
文献类型：
--
作者：
Wu, Zhaoxiang;Fernandez-Lima, Francisco A.;Russell, David H.
利用基质辅助激光解吸电离(MALDI)、飞行时间质谱仪(TOF-MS)和理论计算[密度泛函理论(DFT)]研究了半胱氨酸侧链对铜离子与多肽结合的影响，以及铜离子与半胱氨酸(-SH/SO3H)和精氨酸的竞争性相互作用。对[M+Cu](+)和[M+2CuH](+)离子的理论和实验(裂解反应)研究结果表明，半胱氨酸侧链(-SH)和半胱氨酸(-SO3H)是重要的铜离子配体。例如，我们证明了铜离子与-SH或SO3H基团竞争配位；然而，我们也提供了证据，证明SH/SO3H基团的质子是可移动的，并可以转移到精氨酸胍基团。对于[M+2CuH](+)离子，-SH/SO3H基的去质子化在能量上比羧基更有利，生成的硫酸盐/磺酸盐基团对[M+2CuH](+)离子的配位结构和碎裂模式起着重要的作用。(J am Soc质谱仪2010，21,522-533)(C)2010年美国质谱学学会
Matrix assisted laser desorption/ionization (MALDI) time-of-flight (TOF) mass spectrometry (MS) and theoretical calculations [density functional theory (DFT)] were utilized to investigate the influence of cysteine side chain on Cu+ binding to peptides and how Cu+ ions competitively interact with cysteine (-SH/SO3H) versus arginine. Results from theoretical and experimental (fragmentation reactions) studies on [M + Cu](+) and [M + 2Cu - H](+) ions suggest that cysteine side chains (-SH) and cysteic acid (-SO3H) are important Cu+ ligands. For example, we show that Cu+ ions are competitively coordinated to the -SH or SO3H groups; however, we also present evidence that the proton of the SH/SO3H group is mobile and can be transferred to the arginine guanidine group. For [M + 2Cu - H](+) ions, deprotonation of the -SH/SO3H group is energetically more favorable than that of the carboxyl group, and the resulting thiolate/sulfonate group plays an important role in the coordination structure of [M + 2Cu - H](+) ions, as well as the fragmentation patterns. (J Am Soc Mass Spectrom 2010,21, 522-533) (C) 2010 American Society for Mass Spectrometry