Constant rate of evolution in the antigenicity of glucose 6-phosphate dehydrogenase revealed by the enzyme inhibition method.
Rabbit and chicken antisera against pure and impure rat glucose 6-phosphate dehydrogenase (G6PD) samples were prepared, and their inhibition potencies (RIP) were measured against G6PDs from 26 vertebrate and invertebrate species. The results demonstrated that the -logRIP values of antisera against G6PDs from various test species neatly correlate with paleontologically estimated divergence times between rat and the test species. This suggests that the antigenicity of G6PD has evolved at a constant rate. The correlation coefficients were evidently greater with chicken antisera than with rabbit antisera, but did not markedly differ between chicken antisera elicited to pure and impure rat G6PD samples. Based on the data obtained with chicken antisera, it is estimated that lineages which separated 250-300 million years ago differ in their G6PDs by one unit of the -logRIP.
D000818:Animals; D000941:Antigens; D005075:Biological Evolution; D002645:Chickens; D005954:Glucosephosphate Dehydrogenase / Q000037:antagonists & inhibitors / Q000276:immunology*; D007106:Immune Sera; D007448:Invertebrates; D011817:Rabbits; D051381:Rats; D011919:Rats, Inbred Strains; D013045:Species Specificity; D014714:Vertebrates
D000941:Antigens; D007106:Immune Sera; D005954:Glucosephosphate Dehydrogenase