The isocitrate dehydrogenases of Acinetobacter lwoffi. Separation and properties of two nicotinamide-adenine dinucleotide phosphate-linked isoenzymes.
Two isoenzymes of NADP-linked isocitrate dehydrogenase have been identified in Acinetobacter lwoffi and have been termed isoenzyme-I and isoenzyme-II. The isoenzymes may be separated by ion-exchange chromatography on DEAE-cellulose, by gel filtration on Sephadex G-200, or by zonal ultracentrifugation in a sucrose gradient. Low concentrations of glyoxylate or pyruvate effect considerable stimulation of the activity of isoenzyme-II. The isoenzymes also differ in pH-dependence of activity, kinetic parameters, stability to heat or urea and molecular size. Whereas isoenzyme-I resembles the NADP-linked isocitrate dehydrogenases from other organisms in having a molecular weight under 100000, isoenzyme-II is a much larger enzyme (molecular weight around 300000) resembling the NAD-linked isocitrate dehydrogenases of higher organisms.
D000421:Alcaligenes / Q000201:enzymology*; D002499:Centrifugation, Density Gradient; D002848:Chromatography, DEAE-Cellulose; D002850:Chromatography, Gel; D006038:Glyoxylates; D007521:Isocitrate Dehydrogenase / Q000302:isolation & purification*; D007527:Isoenzymes / Q000302:isolation & purification; D007700:Kinetics; D008970:Molecular Weight; D009249:NADP; D011773:Pyruvates; D013696:Temperature; D014508:Urea
D006038:Glyoxylates; D007527:Isoenzymes; D011773:Pyruvates; D009249:NADP; D014508:Urea; D007521:Isocitrate Dehydrogenase