Chorismate mutase isoenzymes from Sorghum bicolor: purification and properties

Arch Biochem Biophys. 1985 Dec;243(2):374-84. doi: 10.1016/0003-9861(85)90514-4.


Two forms of chorismate mutase (EC, designated as CM-1 and CM-2, have been detected in etiolated seedlings of Sorghum bicolor after DEAE-cellulose chromatography. CM-1 and CM-2 contained 44 and 56%, respectively, of the total activity measured after DEAE-cellulose chromatography. CM-1 was activated by tryptophan and inhibited by phenylalanine and tyrosine. In contrast, CM-2 was insensitive to all three aromatic amino acids. CM-1 and CM-2 were purified 1389- and 1018-fold, respectively, by anion exchange, hydrophobic, and dye matrix chromatography. The molecular weights estimated by gel filtration on Sephacryl S-200 were 56,000 for CM-1 and 48,000 for CM-2. Subunit molecular weights of the two forms were estimated by sodium dodecyl sulfate-gel electrophoresis at 36,000 and 51,000 for CM-1 and CM-2, respectively. Tryptophan was required for the stability of CM-1 at all stages of purification. Both isoenzymes were stable at 0 or -20 degrees C and had broad pH optima (6-10 for CM-1 and 7.5-9.5 for CM-2).

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Chorismate Mutase / isolation & purification*
  • Chromatography, Affinity
  • Chromatography, DEAE-Cellulose
  • Chromatography, Gel
  • Electrophoresis, Polyacrylamide Gel
  • Hydrogen-Ion Concentration
  • Isoelectric Focusing
  • Isoelectric Point
  • Isoenzymes / isolation & purification
  • Isomerases / isolation & purification*
  • Molecular Weight
  • Poaceae / enzymology*


  • Isoenzymes
  • Isomerases
  • Chorismate Mutase