Kinetics of protein modification reactions.
Kinetics of protein modification reactions.
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蛋白质修饰反应的动力学。
DOI：
10.1042/bj2170341
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发表时间：
1984
期刊：
影响因子：
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通讯作者：
E. T. Rakitzis
中科院分区：
文献类型：
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作者：
E. T. Rakitzis
或部分共价，所研究的蛋白质的键（Cohen，1970），因此也是更通用的术语“共价修饰”（Brocklehurst，1982）。迄今为止，蛋白质修饰研究的目的是：（a）确定所研究蛋白质分子的反应基团的种类和数量，（b）开发位点特异性蛋白质修饰剂，以及（c）阐明酶蛋白催化功能。如果不对蛋白质修饰过程的化学反应进行彻底的动力学分析，这些目标都无法完全实现。在本文中，将回顾迄今为止在蛋白质修饰反应研究中开发的动力学方法。重点将主要放在蛋白质修饰的实际或假设案例的形式描述上，但也会考虑分子动力学方面（温度对化学修饰速率的影响）。酶蛋白的修饰常常伴随着酶催化活性的丧失（不可逆的酶抑制），在这种情况下，最好同时研究酶蛋白的修饰和失活。如果蛋白质分子以氨基酸残基的直接衍生化以外的方式进行修饰，则可能导致酶活性丧失。从动力学的角度来看，蛋白质三级和四级结构的丢失、酶结合辅助因子的修饰、配体结合和蛋白质的构象异构很重要，因为这些因素可能决定修饰残基浓度与反应时间的关系图的形状。蛋白质修饰导致的酶活性丧失可能是完全的或部分的。在后一种情况下，失活可能是酶的V表达减少，或K表达增加，或两者兼而有之。正是由于诸如此类的考虑，蛋白质化学修饰的动力学不能完全脱离蛋白质的热变性、光失活和辐射介导的酶失活以及高离子强度介导的蛋白质解折叠等过程的动力学。
or partially covalent, bond of the protein under study (Cohen, 1970), hence also the more general term 'covalent modification' (Brocklehurst, 1982). Protein modification studies have so far aimed at: (a) the determination of the kind and number of reactive groups of the protein molecule under study, (b) the development of site-specific protein modifying agents, and (c) the elucidation of enzyme protein catalytic function. None of these objectives may be fully realized without a thorough kinetic analysis of the chemical reactions of the protein modification process. In this article a review of the kinetic approaches so far developed in the study of protein modification reactions will be presented. Emphasis will mainly be placed on formalistic descriptions of actual or hypothetical cases of protein modification, but aspects of molecular kinetics (influence of temperature on the rate of chemical modification) will also be considered. Modification of enzyme protein is frequently accompanied by loss of enzyme catalytic activity (irreversible enzyme inhibition), and in such cases enzyme protein modification and inactivation are best studied simultaneously. Loss of enzyme activity may result if the protein molecule is modified in ways other than a straightforward derivatization of amino acid residues. Loss of protein tertiary and quaternary structure, modification of enzyme-bound cofactors, ligand binding and conformational isomerism of the protein are important from the kinetics point of view, in that these factors may determine the shape of the plot of concentration of modified residues versus reaction time. Enzyme activity loss, consequent to protein modification, may be complete or partial. In the latter case, inactivation may be the expression of a diminished V, or an increased K., of the enzyme, or both. It is because of considerations such as these that the kinetics of chemical modification of proteins cannot be considered entirely apart from the kinetics of such processes as heat denaturation of proteins, photoinactivation and radiationmediated inactivation of enzymes, and high-ionicstrength-mediated protein unfolding.