Sakamoto N, Naka T
Biosystems. 1986;19(4):317-26. doi: 10.1016/0303-2647(86)90009-2.
A transfer-function representation of reaction velocity is devised to describe analytically and approximately an input-output response of allosteric enzyme around a steady state. The transfer function is derived on assuming an exponential change in reaction velocity for the indicial response to substrate influx rate. The validity of the representation with variation in the kinetic parameters and flow rates is examined for the response of Koshland-Nemethy-Filmer (KNF) and Monod-Wyman-Changeux (MWC) dimeric models by comparing with the exact response obtained from the computer simulation, that is, by numerical integration of the rate equation. The representation has a wider valid region with a decrease in influx rate than with an increase. For the KNF model the representation is valid for negative cooperativity, but invalid for positive cooperativity. For the MWC model the validity decreases with stronger cooperativity. With the transfer functions valid for the Michaelis-Menten and allosteric reactions, we may derive the transfer-function representation for many metabolic pathways.
设计了反应速度的传递函数表示法，以解析并近似描述变构酶在稳态附近的输入-输出响应。该传递函数是在假设反应速度对底物流入速率的阶跃响应呈指数变化的情况下推导出来的。通过与计算机模拟得到的精确响应（即通过速率方程的数值积分）进行比较，研究了该表示法在动力学参数和流速变化时对科什兰德-内梅蒂-菲尔默（KNF）和莫诺-怀曼-尚热（MWC）二聚体模型响应的有效性。该表示法在流入速率降低时的有效区域比在流入速率增加时更宽。对于KNF模型，该表示法对负协同性有效，但对正协同性无效。对于MWC模型，有效性随协同性增强而降低。利用对米氏反应和变构反应有效的传递函数，我们可以推导出许多代谢途径的传递函数表示法。
