Kinetics of intra- and intermolecular zymogen activation with formation of an enzyme-zymogen complex.
A mathematical description was made of an autocatalytic zymogen activation mechanism involving both intra- and intermolecular routes. The reversible formation of an active intermediary enzyme-zymogen complex was included in the intermolecular activation route, thus allowing a Michaelis-Menten constant to be defined for the activation of the zymogen towards the active enzyme. Time-concentration equations describing the evolution of the species involved in the system were obtained. In addition, we have derived the corresponding kinetic equations for particular cases of the general model studied. Experimental design and kinetic data analysis procedures to evaluate the kinetic parameters, based on the derived kinetic equations, are suggested. The validity of the results obtained were checked by using simulated progress curves of the species involved. The model is generally good enough to be applied to the experimental kinetic study of the activation of different zymogens of physiological interest. The system is illustrated by following the transformation kinetics of pepsinogen into pepsin.
Fuentes
Matilde Esther
ME
Grupo de Modelización en Bioquímica, Departamento de Química-Física, Escuela Politécnica Superior de Albacete, Universidad de Castilla-La Mancha, Albacete, Spain.
Varón
Ramón
R
García-Moreno
Manuela
M
Valero
Edelmira
E
D000818:Animals; D004792:Enzyme Precursors / Q000378:metabolism*; D007700:Kinetics; D020116:Pepsinogen A / Q000378:metabolism*; D015203:Reproducibility of Results; D013552:Swine
D004792:Enzyme Precursors; D020116:Pepsinogen A