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Purification and characterization of ββ‐N‐acetylhexosaminidase from the phytopathogenic fungus Bipolaris sorokiniana
Author(s) -
Geimba M. P.,
Riffel A.,
Brandelli A.
Publication year - 1998
Publication title -
journal of applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.889
H-Index - 156
eISSN - 1365-2672
pISSN - 1364-5072
DOI - 10.1111/j.1365-2672.1998.00580.x
Subject(s) - bipolaris , fungus , microbiology and biotechnology , biology , filamentous fungus , botany , fungi imperfecti , phytotoxin , biochemistry , enzyme , toxin
N‐acetylhexosaminidase (HEX) from the phytopathogenic fungus Bipolaris sorokiniana was isolated and characterized. The production of HEX by B. sorokiniana was not altered by growing on different carbon sources. Enzyme purification was carried out by sequential liquid chromatography on Sephacryl S‐200 HR, and p‐aminobenzyl‐2‐acetamido‐2‐deoxy‐β‐ d ‐thioglucopyranoside agarose. The purification was about 70‐fold, with a yield of 41%, determined with p‐nitrophenyl‐N‐acetylglucosaminide as substrate. The enzyme had pH and temperature optima of 4·5 and 55 °C, respectively. The molecular weight of non‐denatured enzyme was estimated as 120 000 Da by gel filtration chromatography, and about 55 000 Da by SDS‐PAGE. The fungal HEX had glycosylated residues as evidenced by binding to Concanavalin‐A. Bipolaris sorokiniana enzyme was also active with p‐nitrophenyl‐chitobioside and p‐nitrophenyl‐N‐acetylgalactosaminide as substrates.