Biochemical and genetic characterization of the Lowell variant. A new phenotype of 6-phosphogluconate dehydrogenase.

A new electrophoretic variant of 6-phosphogluconate dehydrogenase (6PGD) has been detected in the Caucasian population in North Carolina, and family studies have shown this variant to be transmissible. This variant has been given the trivial name "Lowell" and the allele controlling its synthesis in conjunction with 6PGDA has been named 6PGDL. The banding pattern produced by the Lowell variant after electrophoresis is not affected by either NADP or 2-mercaptoethanol. Inhibition studies with urea and iodoacetate have shown that this variant is inhibited to approximately the same degree as the Richmond and Friendship variants. Thermostability studies have shown that the isozyme bands encoded by 6PGDA, 6PGDElcho, 6PGDC, and 6PGDL have a relative thermal stability in the order 6PGDA greater than 6PGDElcho greater than 6PGDC greater than 6PGDL.