Hexokinase isozymic profiles from the liver of 68 vertebrate species are presented. The comparison of the diverse patterns observed, as well as the kinetic and physicochemical properties of the isozymes, reveals that the hexokinases from mammals are very similar to those from turtles and amphibians. The hexokinases from birds, lizards and snakes on the other hand are similar within themselves and different from the enzymes from mammals and amphibians. Liver pyruvate kinases show about the same behavior. The hexokinase system from vertebrate muscle however is very uniform in all the species studied consisting mainly of hexokinase B.
Amphibians Animals