Isozymes of phosphoglyceromutase from the developing endosperm of Ricinus communis: isolation and kinetic properties.
The isozymes of phosphoglyceromutase from the developing endosperm of Ricinus communis have been partially purified. The purified cytosolic and plastid isozymes have specific activities of 622.8 and 83.8 mumol min-1 mg protein-1, respectively. They both have relative molecular masses of approximately 64,000. The cytosolic enzyme has lower Km values for both 2-phosphoglycerate and 3-phosphoglycerate than the plastid enzyme. The Km values for 3-phosphoglycerate are 330 +/- 25 and 430 +/- 48 microM for the cytosolic and plastid isozymes, respectively. The corresponding Km values for 2-phosphoglycerate are 60 +/- 10 and 112 +/- 22 microM. The two isozymes also have different pH optima and heat labilities. Neither isozyme requires 2,3-bisphosphoglycerate or a divalent cation and neither is regulated by metabolites.
D003600:Cytosol / Q000201:enzymology; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D007527:Isoenzymes / Q000302:isolation & purification*; D007700:Kinetics; D008970:Molecular Weight; D010736:Phosphoglycerate Mutase / Q000302:isolation & purification*; D010770:Phosphotransferases / Q000302:isolation & purification*; D010947:Plants, Toxic; D012278:Ricinus / Q000201:enzymology* / Q000254:growth & development
D007527:Isoenzymes; D010770:Phosphotransferases; D010736:Phosphoglycerate Mutase