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A chitosanase from Paecilomyces lilacinus with binding affinity for specific chito‐oligosaccharides
Author(s) -
Chen YiYun,
Cheng ChihYu,
Haung TeLin,
Li YawKuen
Publication year - 2005
Publication title -
biotechnology and applied biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.468
H-Index - 70
eISSN - 1470-8744
pISSN - 0885-4513
DOI - 10.1042/ba20040041
Subject(s) - chitosanase , paecilomyces , biochemistry , chemistry , affinity chromatography , hydrolysis , enzyme , biology , chromatography , botany
A purple‐spore, rhizosphere‐inhabiting nematophagous fungus, further identified as Paecilomyces lilacinus , was found to grow on chitosanase‐detecting plate. An induced endochitosanase having a molecular mass of 23 kDa was purified from the culture medium by a single cation‐exchange column‐chromatography step. Its optimum pH, optimum temperature and pI were found to be 6.0, 50 °C and 8.3 respectively. The N‐terminal amino acid sequence of the purified enzyme was partially determined. On the basis of the partial sequence XQLPANLXXIYD and the BLAST results, the purified chitosanase was classified as a new member of the family 75 glycohydrolases. Complete hydrolysis of 95% deacetylated chitosan by the isolated chitosanase released chitotriose, chitotetraose and chitopentaose as the major hydrolytic products. Two oligosaccharides, which were further determined to be GlcN–GlcN–GlcNAc and GlcNAc–GlcN–GlcN–GlcNAc by chemical methylation followed by liquid chromatography–tandem MS analysis, were obtained after the denaturation of the purified chito‐sanase. This is the first documented finding that chitosanase can be produced in a Paecilomyces strain and that it has binding affinity for specific N‐acetylated oligosaccharides.