Human erythrocyte phosphoglucomutase: comparison of the kinetic properties of PGM1 and PGM2 isoenzymes.
Kinetic properties of PGM1 and PGM2 phosphoglucomutase "primary" isoenzymes from human erythrocytes were studied. The two enzyme forms share a "ping-pong" kinetic mechanism and show similar Km for substrate (glucose 1-P) and cofactor (glucose 1,6-P2). Micromolar concentrations of fructose 1,6-P2 and glycerate 2,3-P2 inhibit both PGM1 and PGM2 isoenzymes to a similar extent. The sole PGM2 form is affected by ribose monophosphates (ribose 1-P and ribose 5-P) that act as mutase inhibitors vs. glucose 1,6-P2 and as apparent activators vs. glucose 1-P. The interaction between PGM2 isoenzyme and ribose monophosphates is discussed in the light of the ability of this form to also display phosphoribomutase activity.
D019794:2,3-Diphosphoglycerate; D004163:Diphosphoglyceric Acids / Q000378:metabolism; D004912:Erythrocytes / Q000201:enzymology*; D005635:Fructosediphosphates / Q000378:metabolism; D019298:Glucose-6-Phosphate; D005958:Glucosephosphates / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007527:Isoenzymes / Q000097:blood*; D007700:Kinetics; D008274:Magnesium / Q000378:metabolism; D010733:Phosphoglucomutase / Q000097:blood*
D004163:Diphosphoglyceric Acids; D005635:Fructosediphosphates; D005958:Glucosephosphates; D007527:Isoenzymes; D019794:2,3-Diphosphoglycerate; D019298:Glucose-6-Phosphate; D010733:Phosphoglucomutase; D008274:Magnesium; C029063:fructose-1,6-diphosphate