Open AccessPurification and characterization of an extracellular β‐xylosidase from the rumen anaerobic fungus Neocallimastix frontalis
Author(s) -
Hebraud Michel,
Fevre Michel
Publication year - 1990
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1990.tb03853.x
Subject(s) - isoelectric point , chemistry , size exclusion chromatography , hydrolysis , ammonium , chromatography , ammonium sulfate precipitation , isoelectric focusing , xylanase , enzyme , ion chromatography , molecular mass , rumen , biochemistry , enzyme assay , cellulase , fermentation , organic chemistry
The purification of β‐xylosidase (gb‐ d ‐xyloside xylohydrolase, EC 3.2.1.37) from Neocallimastix frontalis was performed by ammonium sulphate precipitation, ion exchange chromatography, gel filtration and preparative isoelectric focusing. The enzyme has a molecular mass of 180 000 Da, an isoelectric point at pH 4.35 and catalysed the hydrolysis of p‐nitrophenyl‐β‐d‐xylopyranoside optimally at pH 6.5 and 35°C with K m of 0.33 mg ml −1 . The enzymatic activity was strongly increased by the presence of Ca 2+ , Mn 2+ , Zn 2+ , Co 2+ or Mg 2+ and completely inhibited by Hg 2+ and p ‐chloromercuribenzoate. The purified protein also had a low level of xylanase activity.