The Biosynthesis of Phenylacetic Acids in the Blue-Green Alga Anacystis nidulans: Evidence for the Involvement of a Thylakoid-Bound L-Amino Acid Oxidase

Phenylacetic acid and p-hydroxyphenylacetic acid are formed upon incubation of photosynthetic membranes from the prokaryotic alga Anacystis nidulans with L-phenylalanine and L-tyrosine, respectively. The corresponding phenylpyruvic acids act as intermediates as shown by trapping them as the stable oximino acids. The first step in this reaction sequence appears to be catalyzed by a thylakoid-bound L-amino acid oxidase. Already existing evidence concerning phenylacetic acid formation at thylakoid membranes of higher plants via an L-amino acid oxidase and the results obtained with A. nidulans give another example of aromatic amino acids between chloroplasts and