Equilibrium constants of the equilibrium between the enzyme [C3 convertase]-substrate complex and free enzyme and substrate

Range Table - link
Organism Human Homo sapiens
Reference Vogel CW, Müller-Eberhard HJ. The cobra venom factor-dependent C3 convertase of human complement. A kinetic and thermodynamic analysis of a protease acting on its natural high molecular weight substrate. J Biol Chem. 1982 Jul 25 257(14):8292-9 p.8296 table IIIPubMed ID6919543
Method Abstract: "Enzymes of the complement system exhibit, unlike most other proteases, a high substrate specificity, hydrolyzing only a single peptide bond in their protein substrates. This property allowed the performance of a detailed analysis of the enzymatic activity of a protease acting on its natural high molecular weight substrate."
Comments P.8296 left column 3rd paragraph: "Since the encounter of C3 and enzyme proceeds under rapid equilibrium conditions, the Michaelis constant, Km, is identical with the substrate constant, Ks, which is the reciprocal of the equilibrium constant K for the equilibrium between the enzyme-substrate complex and free enzyme and substrate. Therefore, it was possible to calculate the equilibrium constants K for the four temperatures studied (Table III). The standard enthalpy, ΔH˚, of the formation of the enzyme-substrate complex was calculated from the slope of the linear van't Hoff plot and a value of 5300 cal/mol was obtained. The standard Gibbs energies, ΔG˚, for formation of the complex are listed in Table IV, and the standard entropy, ΔS˚, was found to be 39.71 cal/mol/K."
Entered by Uri M
ID 114396