title: Fungicidal properties, sterol binding, and proteolytic resistance of the synthetic peptide D4E1.
abstract: The fungicidal properties of the synthetic peptide D4E1 were studied with nongerminated and germinating conidia of Aspergillus flavus, Aspergillus fumigatus, Aspergillus niger, Fusarium moniliforme, and Fusarium oxysporum. The minimal lethal concentrations (MLC) needed to kill 100% of germinating conidia of A. fumigatus, A. flavus, and A. niger were 12.5, 12.5, and 25 microM, respectively. The MLC value for nongerminated and germinating conidia of both Fusarium spp. was 3.0 microM. Except for A. fumigatus, D4E1 was inactive against the nongerminated conidia of the Aspergillus spp. Physicochemical studies showed D4E1 complexed with ergosterol, a sterol present in conidial walls. Cholesterol, present in nongerminated conidia of F. moniliforme, had a greater affinity for D4E1 than did ergosterol. D4E1 was more resistant to fungal and plant protease degradation than the natural peptide, cecropin A. These in vitro results suggest D4E1 is a candidate for transgenic expression in plants to enhance host resistance to fungal infection.
authors.affiliation: Southern Regional Research Center, United States Department of Agriculture, New Orleans, LA 70124, USA. adelucca@nola.srrc.usda.gov
authors.forename: A J
authors.initials: AJ
authors.lastname: De Lucca
authors.forename: J M
authors.initials: JM
authors.lastname: Bland
authors.forename: C
authors.initials: C
authors.lastname: Grimm
authors.forename: T J
authors.initials: TJ
authors.lastname: Jacks
authors.forename: J W
authors.initials: JW
authors.lastname: Cary
authors.forename: J M
authors.initials: JM
authors.lastname: Jaynes
authors.forename: T E
authors.initials: TE
authors.lastname: Cleveland
authors.forename: T J
authors.initials: TJ
authors.lastname: Walsh
mesh_terms: D000935:Antifungal Agents / Q000378:metabolism* / Q000494:pharmacology*; D023181:Antimicrobial Cationic Peptides; D001230:Aspergillus / Q000187:drug effects* / Q000378:metabolism; D001673:Biodegradation, Environmental; D002784:Cholesterol / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D004875:Ergosterol / Q000378:metabolism; D005670:Fusarium / Q000187:drug effects* / Q000378:metabolism; D008826:Microbial Sensitivity Tests; D010447:Peptide Hydrolases / Q000378:metabolism; D010455:Peptides / Q000187:drug effects / Q000378:metabolism* / Q000494:pharmacology*; D013261:Sterols / Q000378:metabolism*; D013997:Time Factors
chemical_list: D000935:Antifungal Agents; D023181:Antimicrobial Cationic Peptides; D010455:Peptides; D013261:Sterols; C031161:cecropin A; D002784:Cholesterol; D010447:Peptide Hydrolases; D004875:Ergosterol