[Hexokinase isoenzyme II has a segment responsible for specific interaction of the enzyme with mitochondrial membranes].

It was found that the ability of rat skeletal muscle hexokinase isozyme II binding to mitochondrial membranes is realized in full in the presence of Mg2+, glucose and putrescine as adsorption reagent. The hexokinase-membrane complexes obtained through the use of these reagents displayed similar stability as could be judged from their dissociation under identical conditions: either in the presence of KCl used in high concentrations or under the effect of a specific solubilization reagent--glucose-6-phosphate used in physiological concentrations. Within the composition of enzyme-membrane complexes hexokinase had the same kinetic properties which differed, however, from those of the nonbound to mitochondria enzyme. The data obtained are discussed in relation to the hexokinase isozyme II domain responsible for the specific binding of the enzyme to mitochondrial membranes and termed as the "adsorption domain". The availability of this domain is postulated in terms of the concept on the adsorption mechanism of hexokinase isozyme II activity control in skeletal muscles.