title: Purification and properties of phenylalanine ammonia-lyase from leaf mustard.
abstract: Phenylalanine ammonia-lyase (PAL, EC 4.3.1.5), the first enzyme in phenylpropanoid biosynthesis, catalyzes the elimination of ammonium ion from L-phenylalanine. In the present study, PAL was purified through ammonium sulfate fractionation, DEAE-cellulose chromatography, Sephadex G-200 chromatography, and Q-Sepharose chromatography from the cytosolic fraction of leaf mustard (Brassica juncea var. integrifolia). It consists of 4 subunits, each having an estimated molecular weight of about 40,000 on SDS-polyacrylamide gel electrophoresis (SDS-PAGE). The optimal pH and temperature of the purified enzyme are 9.0 and 45 degrees C, respectively. Its activity is inhibited by Zn2+ ion, and it is strongly activated by caffeic acid. The purified PAL seems to have some characteristics different from those obtained with other PALs.
authors.affiliation: Division of Life Sciences, College of Natural Sciences, Kangwon National University, Choonchun, Korea.
authors.forename: H W
authors.initials: HW
authors.lastname: Lim
authors.forename: S S
authors.initials: SS
authors.lastname: Park
authors.forename: C J
authors.initials: CJ
authors.lastname: Lim
mesh_terms: D000596:Amino Acids / Q000494:pharmacology; D002934:Cinnamates / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D007526:Isoelectric Point; D007700:Kinetics; D008670:Metals / Q000494:pharmacology; D008970:Molecular Weight; D009149:Mustard Plant / Q000201:enzymology*; D010636:Phenols / Q000494:pharmacology; D010649:Phenylalanine / Q000378:metabolism; D010650:Phenylalanine Ammonia-Lyase / Q000737:chemistry*; D010940:Plant Proteins / Q000737:chemistry / Q000302:isolation & purification; D010946:Plants, Medicinal; D013438:Sulfhydryl Compounds / Q000494:pharmacology; D013696:Temperature
chemical_list: D000596:Amino Acids; D002934:Cinnamates; D008670:Metals; D010636:Phenols; D010940:Plant Proteins; D013438:Sulfhydryl Compounds; C029010:cinnamic acid; D010649:Phenylalanine; D010650:Phenylalanine Ammonia-Lyase