Effect of dynamic channelling on the transient-state kinetics of coupled enzyme reactions

Evidence is presented to show that the presence of a channelled reaction br anch in a coupled two-enzyme reaction leads to a slower overall relaxation of the system towards steady state following perturbations of the reaction conditions. A predominant part of the total reaction flux change resulting from perturbations may be governed by transients that are more rapid in the presence than in the absence of a channel, but only under specific conditi ons that are not likely to be of biological relevance. (C) 1999 Academic Pr ess.