Regulation | Metabolite channeling in energy metabolism

Abstract

Metabolite channeling is a general mechanism to increase efficiency of sequential reactions in a metabolic pathway. It describes the transfer of intermediates between sequential enzymes without equilibration of these metabolites with the surrounding bulk solution, forming so-called metabolons or microcompartments. It is structurally based on colocalization or complex formation of the participating enzymes and on specific diffusion limitations. In energy metabolism, metabolite channeling can maintain locally high and constant levels of “high energy phosphates” such as ATP or GTP, thus increasing the efficiency of the corresponding reactions. This involves enzymes like creatine kinase, nucleoside diphosphate kinase, or glycolytic enzymes.