Sen A K
Department of Mathematical Sciences, Purdue University School of Science, Indianapolis, IN 46205.
Biochem J. 1990 Jul 1;269(1):141-7. doi: 10.1042/bj2690141.
In this paper the method of signal-flow graphs is used for calculating the Control Coefficients of metabolic pathways in terms of enzyme elasticities. The method is applied to an unbranched pathway (a) without feedback or feedforward regulation and (b) with feedback inhibition of the first enzyme by the last variable metabolite. It is shown that, by using a signal-flow graph, the control structure of a metabolic pathway can be represented in a graphical manner directly from the configuration of the pathway, without the necessity of writing the governing equations in a matrix form. From a signal-flow graph the various Control Coefficients can be evaluated in an easy and straightforward fashion without recourse to matrix inversion or other algebraic techniques. A signal-flow graph also provides a visual framework for analysing the cause-effect relationships of the individual enzymes.
本文采用信号流图法，根据酶弹性来计算代谢途径的控制系数。该方法应用于（a）无反馈或前馈调节的无分支途径以及（b）最后一个可变代谢物对第一个酶具有反馈抑制作用的无分支途径。结果表明，通过使用信号流图，可以直接从途径的结构以图形方式表示代谢途径的控制结构，而无需将控制方程写成矩阵形式。从信号流图中，可以以简单直接的方式评估各种控制系数，而无需进行矩阵求逆或其他代数技术。信号流图还为分析各个酶的因果关系提供了一个可视化框架。
