Messenger RNA coding for phenylalanine ammonia-lyase. Characterization and partial purification from cell suspension cultures of Petroselinum hortense

Abstract

The mRNA coding for phenylalanine ammonia-lyase was partially purified from irradiated cell suspension cultures of parsley (Petroselinum hortense). The product of cell-free translation of the mRNA in a reticulocyte lysate was isolated by immunoprecipitation and compared with the native enzyme subunit. Evidence for the identity, or at least a great similarity, of both was provided by tryptic-peptide and gel-electrophoretic analyses. Under partially denaturing conditions, phenylalanine ammonia-lyase mRNA sedimented as a 20--21-S molecule in a sucrose gradient and had an apparent molecular weight of about 1.05 x 10(6) on a polyacrylamide gel. Approximately two-thirds of the polynucleotide sequence of the mRNA were estimated to be required as coding sequence for the enzyme. We suggest that phenylalanine ammonia-lyase mRNA is unlikely to code for more than of three coordinately induced enzymes.