On the significance of the retention of ligand by protein.
On the significance of the retention of ligand by protein.
复制标题
关于蛋白质保留配体的意义。
DOI：
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发表时间：
1975
影响因子：
11.1
通讯作者：
M. Schwartz
中科院分区：
文献类型：
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作者：
T. Silhavy;S. Szmelcman;W. Boos;M. Schwartz
当结合蛋白质及其配体的溶液在大量无配体的介质上透析时，配体从含有蛋白质的隔室中退出的速度可能非常慢，比在没有蛋白质的情况下观察到的速度慢得多。这就是我们所说的蛋白质对配体的滞留。一个简单的计算表明，当蛋白质浓度超过总配体浓度时，配体的退出遵循准一级动力学，半衰期与(1+(P)/Kd)成正比，其中(P)是结合部位的浓度，Kd是配体与蛋白质之间平衡的离解常数。以大肠杆菌的麦芽糖结合蛋白为例，对这一关系进行了实验验证；讨论了生化技术中保留效应的含义，以及它在生物现象中的可能意义，如细菌的趋化和运输，激素的作用机制，或神经冲动的传递。
When a solution of binding protein and its ligand is dialyzed against a large volume of ligand-free medium the rate of exit of the ligand from the protein-containing compartment can be extremely slow, much slower than the rate observed in the absence of protein. This is what we call retention of ligand by protein. A simple calculation demonstrates that when the protein concentration is in large excess over the total ligand concentration, the exit of ligand follows quasi-first-order kinetics, the half-life being proportional to (1 + (P)/Kd), where (P) is the concentration of binding sites, and Kd the dissociation constant characteristic of the equilibrium between the ligand and the protein. Experimental verification of this relation is provided in the case of the periplasmic maltose-binding protein of Escherichia coli; The implications of the retention effect in biochemical techniques are discussed, as well as its possible significance in biological phenomena, such as bacterial chemotaxis and transport, mechanism of hormone action, or transmission of the nerve impulse.