Vrzheshch P V
Biofizika. 2013 Nov-Dec;58(6):953-60.
With the use of a graph theory new relations for steady-state enzyme kinetics are derived and strictly proved for the arbitrary mechanism of an enzyme-catalysed reaction containing a reversible segment. Using these relations, a general principle for rapid equilibrium assumption is formulated and proved: the reversible bound segment can be considered as an equilibrium segment only when the values of the base trees that are not proper to this segment can be neglected (within a prescribed accuracy) in relation to the values of the base trees that belong to this segment. In contrast with the foreign base trees the base trees that are proper to the segment have the following properties: the tree that is directed to the base within this segment does not contain the edges leaving this segment; and the tree that is directed to the base outside the segment contains only one edge leaving this segment. Equilibrium variations are assessed for steady-state intermediates concentrations of the equilibrium segment, numerical expressions are obtained for the accuracy of determination of the intermediates concentrations as well as for the accuracy of determination of the rate of enzyme-catalysed reaction in case of using rapid equilibrium assumption.
利用图论，推导并严格证明了含可逆片段的酶催化反应任意机制的稳态酶动力学新关系。利用这些关系，阐述并证明了快速平衡假设的一般原理：只有当不属于该片段的基树的值相对于属于该片段的基树的值可以忽略不计（在规定精度内）时，可逆结合片段才可视为平衡片段。与外部基树不同，属于该片段的基树具有以下特性：指向该片段内碱基的树不包含离开该片段的边；指向该片段外碱基的树仅包含一条离开该片段的边。评估了平衡片段稳态中间体浓度的平衡变化，得到了在使用快速平衡假设时中间体浓度测定精度以及酶催化反应速率测定精度的数值表达式。
