Purification and characterization of a xylanase from the thermophilic ascomycete Thelavia terrestris 255B.
Thielavia terrestris 255B, a thermophilic ascomycete, produced two major forms of xylanase with pIs of 4.6 (xylanase I) and 6.1 (xylanase II). The latter enzyme could be purified to greater than 99% homogeneity using anion-exchange chromatography and gel filtration. Xylanase II had a mol wt of 25.7 kDa (SDS-PAGE) and a pH and a temperature optimum of 3.6-4.0 and 60-65 degrees C, respectively. The ratio of the enzyme's activity against xylan and carboxymethylcellulose was 500-1000 to 1, indicating a possible application of this enzyme in biobleaching processes. The amino acid sequence of this protein is being determined, and initial data suggest that the enzyme belongs to a group of low-mol wt xylanases that have been isolated from both bacteria and fungi.
Gilbert
M
M
Department of Biology, University of Ottowa, Canada.
Breuil
C
C
Yaguchi
M
M
Saddler
J N
JN
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D001203:Ascomycota / Q000201:enzymology*; D004795:Enzyme Stability; D006026:Glycoside Hydrolases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D007527:Isoenzymes / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D008969:Molecular Sequence Data; D013379:Substrate Specificity; D043325:Xylan Endo-1,3-beta-Xylosidase
D000596:Amino Acids; D007527:Isoenzymes; D006026:Glycoside Hydrolases; D043325:Xylan Endo-1,3-beta-Xylosidase