title: [Purification and properties of an endocellulase from the thermophilic fungus Chaetomium thermophile].
abstract: An endocellulase from culture supernatant of a thermophilic fungus Chaetomium thermophile was purifided to homogeneity, by using ammonium sulfate fraction, DEAE-Sepharose Fast-flow chromatography, Phenyl-Sepharose Fast Flow chromatography and Sephacryl S-100 chromatography. The enzyme was a glycoprotein with an apparent molecular weight of 67,800 and 69,800, as determinded by 12.5% SDS-PAGE and gel filtration respectively. The endocellulase was optimally active at pH 4.0-4.5 and 60 degrees C. It was thermostable at 60 degrees C and retained 30% activity after 60 min at 70 degrees C. The half life time of the enzyme at 80 degrees C was 25 min. Different metal ions showed different effects on the endocellulase activity. Na+ enhanced the enzyme activity, whereas Fe2+, Ag+, Cu2+, Ba2+ and Zn2+ cause obvious inhibition. But it didn't work on crystalline cellulose.
authors.affiliation: Department of Environmental Biology, Shandong Agricultural University, Taian 271018, China.
authors.forename: Mei
authors.initials: M
authors.lastname: Lu
authors.forename: Duochuan
authors.initials: D
authors.lastname: Li
authors.forename: Chengsheng
authors.initials: C
authors.lastname: Zhang
mesh_terms: D002118:Calcium / Q000494:pharmacology; D002480:Cellulase / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D002597:Chaetomium / Q000201:enzymology*; D003300:Copper / Q000494:pharmacology; D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D008970:Molecular Weight; D013696:Temperature
chemical_list: D003300:Copper; D002480:Cellulase; D002118:Calcium