title: Promotion of efficient Saccharification of crystalline cellulose by Aspergillus fumigatus Swo1.
abstract: Swollenin is a protein from Trichoderma reesei that has a unique activity for disrupting cellulosic materials, and it has sequence similarity to expansins, plant cell wall proteins that have a loosening effect that leads to cell wall enlargement. In this study we cloned a gene encoding a swollenin-like protein, Swo1, from the filamentous fungus Aspergillus fumigatus, and designated the gene Afswo1. AfSwo1 has a bimodular structure composed of a carbohydrate-binding module family 1 (CBM1) domain and a plant expansin-like domain. AfSwo1 was produced using Aspergillus oryzae for heterologous expression and was easily isolated by cellulose-affinity chromatography. AfSwo1 exhibited weak endoglucanase activity toward carboxymethyl cellulose (CMC) and bound not only to crystalline cellulose Avicel but also to chitin, while showing no detectable affinity to xylan. Treatment by AfSwo1 caused disruption of Avicel into smaller particles without any detectable reducing sugar. Furthermore, simultaneous incubation of AfSwo1 with a cellulase mixture facilitated saccharification of Avicel. Our results provide a novel approach for efficient bioconversion of crystalline cellulose into glucose by use of the cellulose-disrupting protein AfSwo1.
authors.affiliation: Department of Biotechnology, The University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan.
authors.forename: Xin-ai
authors.initials: XA
authors.lastname: Chen
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Ishida
authors.forename: Nemuri
authors.initials: N
authors.lastname: Todaka
authors.forename: Risa
authors.initials: R
authors.lastname: Nakamura
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Maruyama
authors.forename: Haruo
authors.initials: H
authors.lastname: Takahashi
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Kitamoto
mesh_terms: D001232:Aspergillus fumigatus / Q000201:enzymology* / Q000235:genetics; D001236:Aspergillus oryzae / Q000235:genetics; D050260:Carbohydrate Metabolism; D002266:Carboxymethylcellulose Sodium / Q000378:metabolism; D002482:Cellulose / Q000378:metabolism*; D002686:Chitin / Q000378:metabolism; D003001:Cloning, Molecular; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D004795:Enzyme Stability; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism*; D015870:Gene Expression; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000302:isolation & purification / Q000378:metabolism; D017422:Sequence Analysis, DNA; D013379:Substrate Specificity; D013696:Temperature; D014990:Xylans / Q000378:metabolism
chemical_list: D004271:DNA, Fungal; D005656:Fungal Proteins; D011994:Recombinant Proteins; D014990:Xylans; D002686:Chitin; D002482:Cellulose; D002266:Carboxymethylcellulose Sodium