title: Purification and characterization of alpha-3',4'-anhydrovinblastine synthase (peroxidase-like) from Catharanthus roseus (L.) G. Don.
abstract: An H2O2-dependent enzyme capable of coupling catharanthine and vindoline into alpha-3',4'-anhydrovinblastine (AVLB) was purified to apparent homogeneity from Catharanthus roseus leaves. The enzyme shows a specific AVLB synthase activity of 1.8 nkat/mg, and a molecular weight of 45.40 kDa (SDS-PAGE). In addition to AVLB synthase activity, the purified enzyme shows peroxidase activity, and the VIS spectrum of the protein presents maxima at 404, 501 and 633 nm, indicating that it is a high spin ferric heme protein, belonging to the plant peroxidase superfamily. Kinetic studies revealed that both catharanthine and vindoline were substrates of the enzyme, AVLB being the major coupling product.
authors.affiliation: Department of Botany and Institute for Molecular and Cell Biology, University of Porto, Portugal.
authors.forename: M
authors.initials: M
authors.lastname: Sottomayor
authors.forename: M
authors.initials: M
authors.lastname: López-Serrano
authors.forename: F
authors.initials: F
authors.lastname: DiCosmo
authors.forename: A
authors.initials: A
authors.lastname: Ros Barceló
mesh_terms: D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D006735:Horseradish Peroxidase / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D007700:Kinetics; D008970:Molecular Weight; D018515:Plant Leaves; D010946:Plants, Medicinal / Q000201:enzymology*; D014747:Vinblastine / Q000031:analogs & derivatives / Q000378:metabolism; D014748:Vinca Alkaloids / Q000378:metabolism
chemical_list: D014748:Vinca Alkaloids; C009667:vindoline; D014747:Vinblastine; D006735:Horseradish Peroxidase; C017836:catharanthine