Baláz S, Wiese M, Seydel J K
Slovak Polytechnic, Department of Biochemical Technology, Bratislava, Czech.
Sci Total Environ. 1991 Dec;109-110:357-75. doi: 10.1016/0048-9697(91)90190-p.
A simple kinetic description of the fate of low-molecular-weight compounds in biosystems was derived using the mass action law. Michaelis-Menten kinetics of enzymatic reactions was considered with respect to its two boundary cases, namely first- and zero-order kinetics. Absorption, membrane accumulation, non-covalent protein binding, biotransformation, and excretion have been included in the model, with only the last two steps being considered as time-dependent on the pertinent time scale of hours and days. This time hierarchy allowed for simplification of the resulting expression. In accordance with the results of uptake experiments and contrary to previous approaches, transport of organic molecules into the cell was not considered as the rate-limiting step. The decisive compound properties were found to be hydrophobicity and the intrinsic rate parameters of biotransformation and excretion. The model was applied to the elucidation of the dependence of the observed biotransformation rate parameters on hydrophobicity. The resulting equations are consistent with literature data.
利用质量作用定律推导了生物系统中低分子量化合物命运的简单动力学描述。考虑了酶促反应的米氏动力学及其两个边界情况，即一级和零级动力学。该模型包括吸收、膜积累、非共价蛋白质结合、生物转化和排泄，其中只有最后两步在数小时和数天的相关时间尺度上被视为时间依赖性的。这种时间层次结构使得所得表达式得以简化。与摄取实验结果一致且与先前的方法相反，有机分子进入细胞的转运未被视为限速步骤。发现决定性的化合物性质是疏水性以及生物转化和排泄的固有速率参数。该模型用于阐明观察到的生物转化速率参数对疏水性的依赖性。所得方程与文献数据一致。
