Purification and characterization of 40-kDa sterigmatocystinO-methyltransferase involved in aflatoxin biosynthesis

Autor:	Biing-Hui Liu, Fun S. Chu, Deepak Bhatnagar
Rok vydání:	1999
Předmět:	chemistry.chemical_classification Aflatoxin Aspergillus Methyltransferase biology Toxicology biology.organism_classification O-methyltransferase chemistry.chemical_compound Enzyme Biochemistry chemistry Affinity chromatography biology.protein Gene Sterigmatocystin
Zdroj:	Natural Toxins. 7:63-69
ISSN:	1522-7189 1056-9014
Popis:	Sterigmatocystin-O-methyltransferase (ST-OMTase), an enzyme catalyzing O-methylation of sterigmatocystin with S-adenosylmethionine (SAM), was purified to electrophoretic homogeneity by immunoaffinity chromatography. A novel spectrofluorometric method was established to quantitatively determine the enzymatic activity of ST-OMTase. The purified protein, with a molecular weight of 40 kDa by SDS-PAGE, was sensitive to thiol reagents and low concentrations of heavy metal ions. Using a nutritional shift assay, the expression patterns for ST-OMTase and the transcripts of its corresponding gene, omtA, correlated well with that for aflatoxin B1 formation. Neither methyltransferase activity nor omtA, mRNA was detected in the fungal cultures of nonaflatoxigenic isolates, including A. flavus, A. sojae, A. nidulans and A. versicolor under optimal growing conditions for aflatoxin B1 production. Copyright ­© 1999 John Wiley & Sons, Ltd.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::1a088709cf2fe55186254e8644df389d https://doi.org/10.1002/(sici)1522-7189(199903/04)7:2<63::aid-nt41>3.0.co Zobrazit plný text záznamu Plný text