Purification and Properties of Pig-Heart Hexokinase.

Hexokinase has been purified from pig heart to a specific activity of 80 units/mg. The enzyme has an s20 of 5.11 ± 0.15S and a molecular weight of 97000. Dodecyl-sulphate-polyacrylamide electrophoresis and maleylation of the enzyme each suggest that it contains a single polypeptide chain. Amino-acid analysis reveals similarities between the compositions of heart and brain hexokinases. Steady-state kinetic investigations at sub-optimal substrate concentrations are consistent with a mechanism in which at least one of the substrates is in equilibrium with its enzyme · substrate complex. [ABSTRACT FROM AUTHOR]