Purification and characterization of an anaerobically induced alanine aminotransferase from barley roots

• Author(s) / Creator(s)

  • Good, A. G.
  • Muench, D. G.

• Alanine aminotransferase (AlaAT, EC 2.6.1.2) is an enzyme that is induced under anaerobic conditions in cereal roots. In barley (Hordeum vulgare L.) roots, there are a number of isoforms of AlaAT. We have identified the anaerobically induced isoform and have purified it to homogeneity. The isolation procedure involved a two-step ammonium sulfate precipitation, gel filtration, ion-exchange chromatography, and chromatofocusing. The enzyme was purified approximately 350-fold to a specific activity of 2231 units/milligram protein. The apparent molecular masses of the native and sodium dodecyl sulfate-denatured AlaAT proteins are 97 and 50 kilodaltons, respectively, indicating that the native enzyme is probably a homodimer. AlaAT has a number of interesting characteristics when compared with other plant aminotransferases. AlaAT does not require the presence of pyridoxyl-5-phosphate to retain its activity, and it appears to be very specific in the reactions that it will catalyze.

• Date created

  1992

• Subjects / Keywords

  • Lactate-dehydrogenase
  • Aspartate-aminotransferase
  • Expressions
  • Proteins
  • Pathways
  • Tissue
  • Maize
  • Induction
  • Glyoxylate aminotransferase
  • Serine

• Type of Item

  Article (Published)

• DOI

  https://doi.org/10.7939/R30J24

• License

  © 1992 American Society of Plant Biologists. This version of this article is open access and can be downloaded and shared. The original author(s) and source must be cited.