Purification and properties of crystalline 3-methylaspartase from two facultative anaerobes, Citrobacter sp. strain YG-0504 and Morganella morganii strain YG-0601

Biosci Biotechnol Biochem. 1995 Jan;59(1):93-9. doi: 10.1271/bbb.59.93.


3-Methylaspartase (3-methylaspartate ammonia-lyase, EC from two facultative anaerobes from soil, Citrobacter sp. strain YG-0504 and Morganella morganii strain YG-0601, were purified and crystallized from their crude extracts. Both of the Citrobacter and Morganella enzymes appeared to be a dimer of subunits of M(r) 40,000 and 44,000, respectively. The enzymes had similar enzymological properties: optimum pH for the deamination reaction of (2S,3S)-3-methylaspartic acid, substrate specificity, inhibitor, divalent and monovalent cation requirement, and N-terminal amino acid sequence homology. However, some differences were detected in pH and temperature stability, optimum pH for the amination reaction of mesaconic acid, optimum temperature, specific activity, and stability during electrophoresis. Both enzymes had similar enzymological properties to the known 3-methylaspartase from an obligate anaerobic bacterium, Clostridium tetanomorphum H1, except kinetic constants and substrate specificities.

Publication types

  • Comparative Study

MeSH terms

  • Amino Acid Sequence
  • Ammonia-Lyases / chemistry
  • Ammonia-Lyases / isolation & purification*
  • Ammonia-Lyases / metabolism
  • Ammonium Chloride / chemistry
  • Aspartic Acid / chemistry
  • Aspartic Acid / metabolism
  • Cations, Divalent / chemistry
  • Cations, Monovalent / chemistry
  • Chemical Fractionation
  • Chromatography, Affinity
  • Chromatography, High Pressure Liquid
  • Citrobacter / enzymology*
  • Crystallization
  • Deamination
  • Electrophoresis, Polyacrylamide Gel
  • Enterobacteriaceae / enzymology*
  • Enzyme Stability
  • Fumarates / chemistry
  • Fumarates / metabolism
  • Hydrogen-Ion Concentration
  • Kinetics
  • Molecular Sequence Data
  • Molecular Weight
  • Sequence Homology, Amino Acid
  • Substrate Specificity


  • Cations, Divalent
  • Cations, Monovalent
  • Fumarates
  • Ammonium Chloride
  • Aspartic Acid
  • Ammonia-Lyases
  • methylaspartate ammonia-lyase