Purification and Properties of Purified Hexokinase from the African Trypanosomes and Trypanosoma equiperdum

SYNOPSIS. Hexokinase was in both soluble and particulate fractions of extracts of Trypanosoma brucei, T. gambiense, T. rhodesiense and T. equiperdum. These enzymes have been purified some 350‐fold from crude extracts by sonication, (NH4)2SO4 fractionation, and DEAE Sephadex column chromatography. Purified hexokinases had: A) temperature optimum 45‐50 C; B) pH optimum 6.5‐7.0; C) Mg++ and ATP requirements; D) inhibition by ADP, p‐hydroxymercuribenzoate, glucose‐6‐phosphate, and competitive inhibition by mannose, glucosamine, N‐acetyl‐D‐glucosamine and xylose; E) ability to phosphorylate glucose, fructose, mannose, 2‐deoxy‐D‐glucose and glucosamine; F) a glucose requirement for stabilization. T. equiperdum hexokinase was inhibited 33% by ADP as compared to 17‐20% with brucei group hexokinase, and showed 22% activity when ITP was substituted for ATP in contrast to 35‐40% with brucei group hexokinase.