title: Purification and partial characterization of a peroxidase from plant cell cultures of Cassia didymobotrya and biotransformation studies.
abstract: An acidic peroxidase (EC 1.11.1.7) produced by cell suspension cultures of Cassia didymobotrya (wild senna) was purified from culture medium collected on the 29th day. The enzyme was shown to be a glycoprotein with a pI of 3.5, a molecular mass of approx. 43 kDa by SDS/PAGE and 50 kDa by gel filtration. The N-terminal sequence was very similar to those of other plant peroxidases. The peroxidase was characterized by a high specificity towards coniferyl alcohol and other natural phenolics such as guaiacol and ferulic and caffeic acids. These findings suggest that the enzyme is involved in lignification processes of the cell wall. Moreover, the enzyme was able to catalyse the oxidation of 4,3',4'-trihydroxychalcone and 4, 3',4'-trihydroxy-3-methoxychalcone to the corresponding 3, 3'-biflavanones, as mixtures of racemic and meso forms.
authors.affiliation: C.N.R. Centro Chimica dei Recettori e delle Molecole Biologicamente Attive, Istituto di Chimica e Chimica Clinica, Facoltà di Medicina e Chirurgia, Università Cattolica S. Cuore, L.go F. Vito 1, 00168 Roma, Italy. a.vitali@uniserv.ccr.rm.cnr.it
authors.forename: A
authors.initials: A
authors.lastname: Vitali
authors.forename: B
authors.initials: B
authors.lastname: Botta
authors.forename: G
authors.initials: G
authors.lastname: Delle Monache
authors.forename: S
authors.initials: S
authors.lastname: Zappitelli
authors.forename: P
authors.initials: P
authors.lastname: Ricciardi
authors.forename: S
authors.initials: S
authors.lastname: Melino
authors.forename: R
authors.initials: R
authors.lastname: Petruzzelli
authors.forename: B
authors.initials: B
authors.lastname: Giardina
mesh_terms: D000595:Amino Acid Sequence; D001711:Biotransformation; D002241:Carbohydrates / Q000032:analysis; D002366:Cassia / Q000201:enzymology*; D002473:Cell Wall / Q000378:metabolism; D002478:Cells, Cultured; D002599:Chalcone / Q000378:metabolism; D004795:Enzyme Stability; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D007526:Isoelectric Point; D007527:Isoenzymes / Q000378:metabolism; D007700:Kinetics; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010446:Peptide Fragments / Q000737:chemistry; D009195:Peroxidase / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D010946:Plants, Medicinal; D017385:Sequence Homology; D013053:Spectrophotometry; D013379:Substrate Specificity
chemical_list: D002241:Carbohydrates; D007527:Isoenzymes; D010446:Peptide Fragments; D002599:Chalcone; D009195:Peroxidase