A chitosanase from Paecilomyces lilacinus with binding affinity for specific chito-oligosaccharides.
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 degrees 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 chitosanase. 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.
Center of Interdisciplinary Molecular Science and Department of Applied Chemistry, National Chiao Tung University, 1001 Ta-Hseh Rd, Hsin-Chu, Taiwan, Republic of China.
Yi-Yun
YY
Chen
Chih-Yu
CY
Cheng
Te-Lin
TL
Haung
Yaw-Kuen
YK
Li
D000595:Amino Acid Sequence; D002686:Chitin / Q000378:metabolism*; D048271:Chitosan / Q000378:metabolism; D004795:Enzyme Stability; D006026:Glycoside Hydrolases / Q000302:isolation & purification* / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000378:metabolism*; D010143:Paecilomyces / Q000201:enzymology*; D021241:Spectrometry, Mass, Electrospray Ionization
D009844:Oligosaccharides; D002686:Chitin; D048271:Chitosan; D006026:Glycoside Hydrolases; C019868:chitosanase