4-methyleneglutamine synthetase: a new amide synthetase present in germinating peanuts

Biochem Biophys Res Commun. 1983 Mar 16;111(2):484-9. doi: 10.1016/0006-291x(83)90332-7.

Abstract

Enzymatic activity which catalyzes the synthesis of 4-methyleneglutamine from 4-methyleneglutamic acid + ammonia was detected in and partially purified from cotyledons of peanut seeds germinated 5 to 7 days. This activity was separated from glutamine and asparagine synthetases by ammonium sulfate precipitation and DEAE-cellulose chromatography. The enzyme is distinct from these other amide synthetases in its substrate specificity, lack of amide/hydroxylamine exchange, and use of ammonium ion as amide donor together with formation of AMP from ATP. The activity is quite labile in solution, but is retained as a precipitate in ammonium sulfate or when frozen in 12.5% glycerol at -77 degrees C. This activity might be responsible for catalyzing the rapid synthesis of 4-methyleneglutamine which occurs in germinating peanuts.

Publication types

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

MeSH terms

  • Adenosine Triphosphate / metabolism
  • Amide Synthases*
  • Arachis
  • Chromatography, DEAE-Cellulose
  • Glutamates / biosynthesis
  • Kinetics
  • Ligases / analysis*
  • Ligases / metabolism
  • Plants / enzymology*
  • Substrate Specificity

Substances

  • Glutamates
  • 4-methyleneglutamic acid
  • Adenosine Triphosphate
  • Ligases
  • Amide Synthases
  • 4-methyleneglutamine synthetase