title: Purification and characterization of two 1,4-beta-xylan endohydrolases from the rumen fungus Neocallimastix frontalis.
abstract: Two beta-endoxylanases produced by Neocallimastix frontalis have been purified by ammonium sulfate precipitation, gel filtration, and ion-exchange chromatography. Xylanase I is a nonglycosylated protein with an apparent molecular mass of 45 kDa. Xylanase II is a glycoprotein with an apparent molecular mass of 70 kDa. The pH optima of these enzymes were 5.5 and 6, respectively, and the temperature optimum was 55 degrees C for each enzyme. The endo mode of action of the enzymes was revealed by thin-layer chromatography of xylan hydrolysates. Antibodies raised against each purified protein exhibited no cross-reaction, confirming the biochemical specificities of the enzymes. Both enzymes exhibited carboxymethyl cellulase activity, and xylanase I was absorbed on crystalline cellulose, indicating that these enzymes might belong to the F family of beta-1,4-glycanases.
authors.affiliation: Laboratoire de Biologie Cellulaire Fongique, CGMC, UMR Centre National de la Recherche Scientifique 106, Université Lyon I, Villeurbanne, France.
authors.forename: B
authors.initials: B
authors.lastname: Gomez de Segura
authors.forename: M
authors.initials: M
authors.lastname: Fevre
mesh_terms: D000818:Animals; D002482:Cellulose / Q000378:metabolism; D008411:Chytridiomycota / Q000201:enzymology*; D043364:Endo-1,4-beta Xylanases; D006026:Glycoside Hydrolases / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D006031:Glycosylation; D006863:Hydrogen-Ion Concentration; D007120:Immunochemistry; D008970:Molecular Weight; D012417:Rumen / Q000382:microbiology*; D012756:Sheep; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D002482:Cellulose; D006026:Glycoside Hydrolases; D043364:Endo-1,4-beta Xylanases