Substrate specificity of the short chain fatty acyl-coenzyme a synthetase of Pinus radiata

Suzanne G. Orchard, J. W. Anderson

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3 Citations (Scopus)


The short chain fatty acid-CoA synthetase of the female gametophytic tissue of Pinus radiata exhibited highest affinity for propionate and butyrate (Km(app.) = 0.073 mM for both substrates) when examined by 32PPi-ATP exchange. Relative to the activity at 1 mM propionate, partially purified enzyme supported exchange with acetate (100%), acrylate (114%), crotonate (107%) and thioglycollate (70%), but with varying degrees of affinity as reflected by their different Km(app) values (2.56, 1.41,0.45 and 1.26 mM, respectively). All other unhalogenated C2, C3 and Q carboxylic acids examined did not support PPi-ATP exchange. Partially purified enzyme supported low rates of exchange in the presence of 2-chloroacetate, 2-bromoacetate, 3-chloropropionate, 3-bromopropionate, 2-chlorobutyrate and 2-bromobutyrate; the apparent Km values were 2.74, 1.03, 0.15, 0.17, 0.85 and 0.23 mM, respectively. In the presence of propionate and one of the unhalogenated or halogenated substrates, the PPi-ATP exchange was consistent with competition for a common substrate binding site. All other halogenated derivatives of acetate and propionate did not support PPi-ATP exchange. The enzyme displayed an absolute requirement for Mg2+ (optimum concentration 1.5 mM).

Original languageEnglish
Pages (from-to)1465-1472
Number of pages8
Issue number6
Publication statusPublished - 1 Jan 1996
Externally publishedYes


  • Acetate
  • Acetate-related compounds
  • Butyrate
  • Chlorinated carboxylic acids
  • Dicarboxylic acids
  • Fatty acyl-CoA synthetase
  • Fluoroacetate
  • Halogenated carboxylic acids
  • Pinaceae
  • Pinus radiata
  • Propionate
  • Propionate-related compounds

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