A variant of rabbit phosphoglucose isomerase

Abstract

An autosomally inherited variant of the rabbit enzyme phosphoglucose isomerase that differs both electrophoretically and kinetically from the usual (wild-type) rabbit enzyme has been investigated. Animals homozygous for this character have an isomerase with considerably decreased activity (in the erythrocytes), an increased Km for fructose 6-phosphate, an increased Ki for 6-phosphogluconate and a decreased stability towards heat and urea. The variant enzyme has been demonstrated in erythrocytes, leucocytes and tissues from the affected rabbits. The kinetic evidence suggests that the mutation present in the variant enzyme affects a histidine residue.