Expression and Characterization of a Novel Antifungal Exo-ß-1,3-glucanase from Chaetomium cupreum.
Appl Biochem Biotechnol
; 182(1): 261-275, 2017 May.
Article
em En
| MEDLINE
| ID: mdl-27854040
ABSTRACT
A novel ß-1,3-glucanase gene, designated Ccglu17A, was cloned from the biological control fungus Chaetomium cupreum Ame. Its 1626-bp open reading frame encoded 541 amino acids. The corresponding amino acid sequence showed highest identity (67 %) with a glycoside hydrolase family 17 ß-1,3-glucanase from Chaetomium globosum. The recombinant protein Ccglu17A was successfully expressed in Pichia pastoris, and the enzyme was purified to homogeneity with 10.1-fold purification and 47.8 % recovery yield. The protein's molecular mass was approximately 65 kDa, and its maximum activity appeared at pH 5.0 and temperature 45 °C. Heavy metal ions Fe2+, Mn2+, Cu2+, Co2+, Ag+, and Hg2+ had inhibitory effects on Ccglu17A, but Ba2+ promoted the enzyme's activity. Ccglu17A exhibited high substrate specificity, almost exclusively catalyzing ß-1,3-glycosidic bond cleavage in various polysaccharoses to liberate glucose. The enzyme had a Km of 2.84 mg/mL and Vmax of 10.7 µmol glucose/min/mg protein for laminarin degradation under optimal conditions. Ccglu17A was an exoglucanase with transglycosylation activity based on its hydrolytic properties. It showed potential antifungal activity with a degradative effect on cell walls and inhibitory action against the germination of pathogenic fungus. In conclusion, Ccglu17A is the first functional exo-1,3-ß-glucanase to be identified from C. cupreum and has potential applicability in industry and agriculture.
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01-internacional
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MEDLINE
Assunto principal:
Proteínas Fúngicas
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Chaetomium
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Glucana 1,3-beta-Glucosidase
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Glucanos
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Antifúngicos
Idioma:
En
Revista:
Appl Biochem Biotechnol
Ano de publicação:
2017
Tipo de documento:
Article