The total quasi-steady-state approximation is valid for reversible enzyme kinetics
The total quasi-steady-state approximation is valid for reversible enzyme kinetics
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DOI：
10.1016/j.jtbi.2003.09.006
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发表时间：
2004-02-07
影响因子：
2
通讯作者：
Edelman, ER
中科院分区：
文献类型：
--
作者：
Tzafriri, AR;Edelman, ER
酶动力学的不可逆Michaelis-Menten方案的Briggs-Haldane近似几乎在每一本生物化学教科书中都被引用，并且被广泛认为是准稳态近似的经典例子。虽然具有类似的重要性，但可逆Michaelis-Menten方案没有得到很好的表征。这是一个严重的限制，因为即使是完成的酶反应也可能是可逆的。本文推导了可逆Michaelis-Menten的全准稳态近似（tQSSA），并描述了其有效域。tQSSA允许推导出一致有效的低酶浓度极限的近似，ET远小于S-T + K-M，并且在某些更严格的条件下也适用于高酶浓度，例如S-T远小于E-T + K-M。利用这些简单的解析近似，提出了一种序贯实验理论方法来明确地估计可逆Michaelis-Menten方案的所有动力学参数。(C) 2003 Elsevier Ltd.版权所有。
The Briggs-Haldane approximation of the irreversible Michaelis-Menten scheme of enzyme kinetics is cited in virtually every biochemistry textbook and is widely considered the classic example of a quasi-steady-state approximation. Though of similar importance, the reversible Michaelis-Menten scheme is not as well characterized. This is a serious limitation since even enzymatic reactions that go to completion may be reversible. The current work derives a total quasi- steady-state approximation (tQSSA) for the reversible Michaelis-Menten and delineates its validity domain. The tQSSA allows the derivation of uniformly valid approximations for the limit of low enzyme concentrations, ET much less than S-T + K-M, and under certain more restrictive conditions also for high enzyme concentrations such that S-T much less than E-T + K-M. Using these simple analytical approximations, a sequential experimentaltheoretical method is suggested for unambiguously estimating all the kinetic parameters of the reversible Michaelis-Menten scheme. (C) 2003 Elsevier Ltd. All rights reserved.