Protein biotinylation in higher plants: Characterization of biotin holocarboxylase synthetase activity from pea (Pisum sativum) leaves

Abstract

Biotin holocarboxylase synthetase was partially purified from pea leaves by a sequence of ammonium sulphate fractionation and DEAF 52-cellulose chromatography. Enzyme activity was assayed using apo-(biotin carboxyl carrier protein) from an Escherichia coli bir A mutant affected in biotin holocarboxylase synthetase activity. Conditions for optimal catalytic activity and biochemical parameters of the plant enzyme were determined. This is the first direct evidence of the existence of biotin holocarboxylase synthetase activity in plants.