title: A novel peroxidase purified from Marsdenia megalantha latex inhibits phytopathogenic fungi mediated by cell membrane permeabilization.
abstract: An antifungal class III peroxidase was purified from Marsdenia megalantha latex (named Mo-POX) using DEAE-cellulose and gel filtration chromatography on a Superose 12 HR 10/30 column. Mm-POX has an apparent molecular mass of 67.0kDa and a pI of 5.2, shares identity with other peroxidases, and follows Michaelis-Menten kinetics. It has a high affinity for guaiacol and hydrogen peroxide. The pH and temperature optima for Mm-POX were 5.0-7.0 and 60°C, respectively. The catalytic activity of Mm-POX was decreased in the presence of classic peroxidase inhibitors including azide, dithiothreitol, ethylenediamine tetraacetic acid, and sodium metabisulfite and high concentrations of Na+, Mn+, and salicylic acid. In contrast, Ca+and Mg+, even at low concentrations, enhanced the Mm-POX enzymatic activity. This protein inhibited the germination of the conidia of the phytopathogenic fungi Fusarium oxysporum and Fusarium solani by acting through a membrane permeabilization mechanism. Mm-POX also induced oxidative stress in F. solani. Mm-POX is the first enzyme to be isolated from the M. megalantha species and it has potential use in the control of plant disease caused by important phytopathogenic fungi. This adds biotechnological value to this enzyme.
authors.affiliation: Department of Biochemistry and Molecular Biology, Federal University of Ceara, 60440-900 Fortaleza, CE, Brazil; University of International Integration of the Afro-Brazilian Lusophony, 62790-000 Redençao, CE, Brazil.
authors.forename: Henrique P
authors.initials: HP
authors.lastname: Oliveira
authors.affiliation: Department of Biochemistry and Molecular Biology, Federal University of Ceara, 60440-900 Fortaleza, CE, Brazil.
authors.forename: Rodolpho G G
authors.initials: RGG
authors.lastname: Silva
authors.affiliation: Department of Biochemistry and Molecular Biology, Federal University of Ceara, 60440-900 Fortaleza, CE, Brazil.
authors.forename: Jose T A
authors.initials: JTA
authors.lastname: Oliveira
authors.affiliation: Department of Biochemistry and Molecular Biology, Federal University of Ceara, 60440-900 Fortaleza, CE, Brazil.
authors.forename: Daniele O B
authors.initials: DOB
authors.lastname: Sousa
authors.affiliation: Department of Biochemistry and Molecular Biology, Federal University of Ceara, 60440-900 Fortaleza, CE, Brazil.
authors.forename: Mirella L
authors.initials: ML
authors.lastname: Pereira
authors.affiliation: Department of Biochemistry and Molecular Biology, Federal University of Ceara, 60440-900 Fortaleza, CE, Brazil.
authors.forename: Pedro F N
authors.initials: PFN
authors.lastname: Souza
authors.affiliation: Department of Biology, Federal University of Ceara, 60440-900 Fortaleza, CE, Brazil.
authors.forename: Arlete A
authors.initials: AA
authors.lastname: Soares
authors.affiliation: Center of Bioscience and Biotechnology, State University of North Fluminense Darcy Ribeiro, 28013-602 Campos dos Goytacazes, RJ, Brazil.
authors.forename: Valdirene M
authors.initials: VM
authors.lastname: Gomes
authors.affiliation: School of Pharmacy, University of Fortaleza, 60811-905 Fortaleza, CE, Brazil.
authors.forename: Ana C O
authors.initials: ACO
authors.lastname: Monteiro-Moreira
authors.affiliation: School of Pharmacy, University of Fortaleza, 60811-905 Fortaleza, CE, Brazil.
authors.forename: Frederico B M B
authors.initials: FBMB
authors.lastname: Moreno
authors.affiliation: Department of Biochemistry and Molecular Biology, Federal University of Ceara, 60440-900 Fortaleza, CE, Brazil. Electronic address: imvasco@ufc.br.
authors.forename: Ilka M
authors.initials: IM
authors.lastname: Vasconcelos
mesh_terms: D000595:Amino Acid Sequence; D000935:Antifungal Agents / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology; D002463:Cell Membrane Permeability / Q000187:drug effects*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004795:Enzyme Stability; D005670:Fusarium / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D007840:Latex / Q000737:chemistry*; D031101:Marsdenia / Q000737:chemistry*; D008670:Metals / Q000494:pharmacology; D050296:Microbial Viability / Q000187:drug effects; D008970:Molecular Weight; D009195:Peroxidase / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D010944:Plants / Q000382:microbiology*; D017382:Reactive Oxygen Species / Q000378:metabolism; D020156:Salicylic Acid / Q000494:pharmacology; D013172:Spores, Fungal / Q000187:drug effects / Q000254:growth & development; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D000935:Antifungal Agents; D004791:Enzyme Inhibitors; D007840:Latex; D008670:Metals; D017382:Reactive Oxygen Species; D009195:Peroxidase; D020156:Salicylic Acid
keywords: Antifungal protein; Fusarium; Latex; Marsdenia megalantha; Peroxidase; Protein defense