Expression, Purification and Preliminary Crystallographic Studies of Human Hexokinase I

Abstract

Human hexokinase type I, one of the four isozymes consisting of a single polypeptide chain of about l 00 kDa, has been cloned in the pET expression plasmid in a truncated form lacking a segment of 11 apolar amino acids at the N-terminus. The protein has been overexpressed in E.coii and purified to homogeneity. Truncated hexokinase I has been crystallized in the presence of glucose 6-phosphate and of the ATP analogue AMP-PNP. The crystals belong to the monoclinic space group P21, with unit cell constants: a= 84.2 A, b = 177.7 A, c = 88.2 A, 13 = 90.8° and diffract to 3.0 A resolution.