Purification and characterization of human phosphoglucose isomerase

Abstract

1. 1. The glycolytic enzyme phosphoglucose isomerase ( d-glucose-6-phosphate ketol isomerase, EC 5.3.1.9) has been purified from human muscle. This preparation was homogeneous by several criteria. 2. 2. The molecular weight of the enzyme obtained by the sedimentation-equilibrium method was 134 000. Following dissociation in guanidine hydrochloride the molecular weight was 61 000, indicating a dimeric structure for the enzyme. The isoelectric point of the enzyme was determined by electrofocusing and found to be pH 8.9. 3. 3. The amino acid composition of the enzyme was determined.