Subunit structure of human glucose 6-phosphate dehydrogenase and its genetic implication

Abstract

Electrophoretic patterns of the subunits from the normal (B) and from the common A type variant of human glucose 6-phosphate dehydrogenase, following dissociation in the presence of 8m urea, were examined. A single protein band was found in both enzymes, indicating that the B and the A enzyme each consists of different subunits and do not have common subunits in their molecules. Since the A enzyme is a structural variant resulting from a single amino acid substitution, it can be concluded that the human G6PD consists of several identical subunits and that only one structural gene is involved in producing the enzyme. The findings of only a tyrosine residue as amino-terminal as well as a glycine residue as carboxy-terminal are in agreement with this conclusion.