Mediterranean glucose 6-phosphate dehydrogenase (G6PD) deficiency--near normal decay of the mutant enzyme protein in circulating erythrocytes.
Complete removal of leucocytes and platelets from erythrocytes and the development of a sensitized procedure for the assay of G6PD activity allowed the biochemical mechanisms of the Mediterranean variety of G6PD deficiency to be re-evaluated. Activity in the young erythrocytes from 9 G6PD-deficient subjects averaged 0.1% of the levels observed in the corresponding erythrocyte fraction from normal individuals: moreover, the decline of activity during aging of the G6PD-deficient erythrocytes was comparable with that observed for the normal enzyme. Mutant G6PD purified from granulocytes of a G6PD-deficient subject and entrapped within the corresponding erythrocytes was remarkably stable. Exposure of native erythrocytes to an oxidative stress (divicine plus ascorbate) resulted in a decrease of G6PD activity that was significantly more rapid and extensive in control than in G6PD-deficient cells. These results seem to exclude enhanced intracellular breakdown of the mutant protein within the circulating erythrocytes.
D001205:Ascorbic Acid / Q000494:pharmacology; D004905:Erythrocyte Aging; D004912:Erythrocytes / Q000201:enzymology*; D005954:Glucosephosphate Dehydrogenase / Q000097:blood / Q000378:metabolism; D005955:Glucosephosphate Dehydrogenase Deficiency / Q000235:genetics*; D006461:Hemolysis; D006801:Humans; D008297:Male; D008521:Mediterranean Islands; D009154:Mutation; D011744:Pyrimidinones / Q000494:pharmacology
D011744:Pyrimidinones; C026511:divicine; D005954:Glucosephosphate Dehydrogenase; D001205:Ascorbic Acid