title: Characterization of the novel antifungal chitosanase PgChP and the encoding gene from Penicillium chrysogenum.
abstract: The protein PgChP is a new chitosanase produced by Penicillium chrysogenum AS51D that showed antifungal activity against toxigenic molds. Two isoforms were found by SDS-PAGE in the purified extract of PgChP. After enzymatic deglycosylation, only the smaller isoform was observed by SDS-PAGE. Identical amino acid sequences were obtained from the two isoforms. Analysis of the molecular mass by electrospray ionization-mass spectrometry revealed six major peaks from 30 to 31 kDa that are related to different levels of glycosylation. The pgchp gene has 1,146 bp including four introns and an open reading frame encoding a protein of 304 amino acids. The translated open reading frame has a predicted mass of 32 kDa, with the first 21 amino acids comprising a signal peptide. Two N glycosylation consensus sequences are present in the protein sequence. The deduced sequence showed high identity with fungal chitosanases. A high level of catalytic activity on chitosan was observed. PgChP is the first chitosanase described from P. chrysogenum. Given that enzymes produced by this mold species are granted generally recognized as safe status, PgChP could be used as a food preservative against toxigenic molds and to obtain chitosan oligomers for food additives and nutraceuticals.
authors.affiliation: Universidad de Extremadura, Cáceres, Spain.
authors.forename: Andrea
authors.initials: A
authors.lastname: Rodríguez-Martín
authors.forename: Raquel
authors.initials: R
authors.lastname: Acosta
authors.forename: Susan
authors.initials: S
authors.lastname: Liddell
authors.forename: Félix
authors.initials: F
authors.lastname: Núñez
authors.forename: María José
authors.initials: MJ
authors.lastname: Benito
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Asensio
mesh_terms: D000595:Amino Acid Sequence; D000935:Antifungal Agents / Q000302:isolation & purification / Q000494:pharmacology*; D048271:Chitosan / Q000378:metabolism; D003001:Cloning, Molecular; D005520:Food Preservatives / Q000302:isolation & purification / Q000494:pharmacology*; D005658:Fungi / Q000187:drug effects*; D005800:Genes, Fungal; D006026:Glycoside Hydrolases / Q000235:genetics / Q000302:isolation & purification / Q000494:pharmacology*; D006031:Glycosylation; D008969:Molecular Sequence Data; D010408:Penicillium chrysogenum / Q000201:enzymology*; D016415:Sequence Alignment; D013379:Substrate Specificity
chemical_list: D000935:Antifungal Agents; D005520:Food Preservatives; D048271:Chitosan; D006026:Glycoside Hydrolases; C019868:chitosanase