COMMENTS ON KINETICS AND MECHANISM OF YEAST HEXOKINASE ACTION - IS BINDING SEQUENCE OF SUBSTRATES TO ENZYME ORDERED OR RANDOM

The mechanism of action of yeast hexokinase was reinvestigated in light of a recent report in which it was suggested that substrates add to the enzyme in an ordered manner with the binding of glucose required to precede the binding of ATP. Initial velocity experiments were undertaken with AMP which is a competitive inhibitor for ATP, and with the product inhibitor glucose‐6‐phosphate. The results of these studies serve to exclude the ordered mechanism for yeast hexokinase from consideration. A discussion is presented in an attempt to show that yeast hexokinase may react in a random fashion with its substrates before forming a ternary complex of enzyme‐ATP‐glucose. Copyright © 1969, Wiley Blackwell. All rights reserved