Protein Expression and Purification, Vol.94, 40-45, 2014
Cellulose-inducible xylanase Xyl10A from Acremonium cellulolyticus: Purification, cloning and homologous expression
Cellulose-inducible endo-beta-1,4-xylanase (Xyl10A) from the mesophilic fungus Acremonium cellulolyticus was purified, characterized, and expressed by a homologous expression system. A. cellulolydcus CF2612 produces a high level of xylanase upon induction by Solka-Floc cellulose. To identify this xylanase, the major fraction showing xylanase activity was purified from the CF-2612 culture supernatant, and its gene was identified from the genome sequence. Amino acid sequence homology of Xyl10A revealed that the purified xylanase, designated Xyl10A, exhibited significant homology to family 10 of the glycoside hydrolases (GH10), possessing a cellulose-binding module 1 in the C-terminal region. The xyl10A gene was cloned and expressed in A. cellulolyticus under the control of a glucoamylase promoter. Two recombinant Xyl10As (Xyl10A-I, 53 kDa, and Xyl10A-II, 51 kDa) were purified that have slightly different molecular weights based on SDS-PAGE. The Xyl10As had the same physicochemical and enzymatic properties as wtXyllOA: high thermostability (T-m 80.5 degrees C), optimum pH 5.0 and specific activity 232-251 U/mg for birchwood xylan. The molecular weights of N-deglycosylated Xyl10As were consistent with that of wild-type Xyl10A(wtXyll OA, 51 kDa). CI 2013 Elsevier Inc. All rights reserved.