Difference in hydrophobicity between mitochondria-bindable and non-bindable forms of hexokinase purified from rat brain.

Hexokinase able to bind to mitochondria was purified to homogeneity from rat brain by two successive DEAE-cellulose chromatographic steps. The enzyme lost only the binding ability with almost undetectable change in molecular weight on mild chymotrypsin digestion. The bindable hexokinase was adsorbed to a Phenyl-Sepharose column and eluted with a Lubrol PX gradient, whereas non-bindable hexokinase and yeast hexokinase were not adsorbed under the similar conditions. These results suggest that mitochondria-bindable hexokinase has a hydrophobic region on its surface, which is responsible for the specific interaction with mitochondria.