A microscopic model of enzyme kinetics
| Autor: | Y. Nemerson, R. Gentry, Liqiang Ye |
|---|---|
| Rok vydání: | 1995 |
| Předmět: |
Kinetics
Biophysics Perfect fluid 030204 cardiovascular system & hematology Residence time (fluid dynamics) Binding Competitive Models Biological Biophysical Phenomena Substrate Specificity Diffusion 03 medical and health sciences 0302 clinical medicine Vacancy defect Animals Humans Molecule Computer Simulation Enzyme kinetics Enzyme Inhibitors 030304 developmental biology 0303 health sciences Ideal (set theory) Chemistry Substrate (chemistry) Enzymes Enzyme Activation Chemical physics Physical chemistry Research Article |
| Zdroj: | Biophysical Journal. 69:356-361 |
| ISSN: | 0006-3495 |
| DOI: | 10.1016/s0006-3495(95)79907-6 |
| Popis: | Many in vivo enzymatic processes, such as those of the tissue factor pathway of blood coagulation, occur in environments with facilitated substrate delivery or enzymes bound to cellular or lipid surfaces, which are quite different from the ideal fluid environment for which the Michaelis-Menten equation was derived. To describe the kinetics of such reactions, we propose a microscopic model that focuses on the kinetics of a single-enzyme molecule. This model provides the foundation for macroscopic models of the system kinetics of reactions occurring in both ideal and nonideal environments. For ideal reaction systems, the corresponding macroscopic models thus derived are consistent with the Michaelis-Menten equation. It is shown that the apparent Km is in fact a function of the mechanism of substrate delivery and should be interpreted as the substrate level at which the enzyme vacancy time equals the residence time of ES-complexes; it is suggested that our microscopic model parameters characterize more accurately an enzyme and its catalytic efficiency than does the classical Km. This model can also be incorporated into computer simulations of more complex reactions as an alternative to explicit analytical formulation of a macroscopic model. |
| Databáze: | OpenAIRE |
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