title: Self-sustained pH oscillations in immobilized proteolytic enzyme systems.
abstract: This work represents our first step toward fulfilling the need to discover a model system for experimental investigations of temporal oscillations, pattern formations, and other non-linearity related dynamic behavior in immobilized-enzyme-membrane systems. In this paper, the regions in the parameter space where self-sustained pH oscillations can be induced were determined via extensive numerical simulation for five enzyme-membrane systems involving four proteolytic enzymes: alpha-chymotrypsin, trypsin, bromelain, and ficin. From this study, we concluded that, even with current enzyme-immobilization techniques, the possibility of experimentally observing self-sustained pH oscillations in a flat membrane immobilized with alpha-chymotrypsin and using N-acetyl-L-tryptophan ethyl ester as a substrate is high. Under suitable conditions and with extra efforts, self-sustained oscillations may also occur in membrane systems immobilized with ficin, trypsin and bromelain.
authors.affiliation: Department of Chemical Engineering, West Virginia University, Morgantown 26506-6102, USA.
authors.forename: T
authors.initials: T
authors.lastname: Ohmori
authors.forename: R Y
authors.initials: RY
authors.lastname: Yang
mesh_terms: D001120:Arginine / Q000031:analogs & derivatives; D003198:Computer Simulation; D004058:Diffusion; D010450:Endopeptidases / Q000737:chemistry*; D004800:Enzymes, Immobilized; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008956:Models, Chemical
chemical_list: D004800:Enzymes, Immobilized; D001120:Arginine; C009727:benzoylarginine ethyl ester; D010450:Endopeptidases