alpha-L-arabinofuranosidase production by Aspergillus nidulans.
The effects of some physico-chemical parameters on production of extracellular alpha-L-arabinofuranosidase by Aspergillus nidulans were examined. Highest levels of alpha-L-arabinofuranosidase were generated with cultures grown on 1% (w/v) purified beet pulp arabinan at 30 degrees C and at an initial pH of 7.0. The enzyme was shown to be very sensitive to the action of proteases. Zymogram overlay of a protein profile obtained by SDS-PAGE revealed the occurrence of a band (M(r) 36,000) exhibiting alpha-L-arabinofuranosidase activity. The isoelectric pH of the enzyme lay near 4.3. Temperature and pH optima for the activity of crude alpha-L-arabinofuranosidase preparations were 55 degrees C and 5.5, respectively. Enzyme activity was greatly reduced by thiol reagents such as Hg2+ and p-hydroxymercuribenzoate and showed a Km value of 2.7 mM on p-nitrophenyl alpha-L-arabinofuranoside as substrate.
Fernández-Espinar
M T
MT
Unidad de Bioingeniería, Instituto de Agroquímica y Tecnología de Alimentos, CSIC, Valencia, Spain.
Peña
J L
JL
Piñaga
F
F
Vallés
S
S
D001233:Aspergillus nidulans / Q000201:enzymology*; D001426:Bacterial Proteins / Q000096:biosynthesis; D002412:Cations / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D005285:Fermentation; D006026:Glycoside Hydrolases / Q000096:biosynthesis* / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007526:Isoelectric Point; D007700:Kinetics; D008970:Molecular Weight; D009005:Monosaccharides / Q000378:metabolism; D017672:Nitrogen Compounds / Q000378:metabolism; D011134:Polysaccharides / Q000378:metabolism; D013696:Temperature
D001426:Bacterial Proteins; D002412:Cations; D009005:Monosaccharides; D017672:Nitrogen Compounds; D011134:Polysaccharides; D006026:Glycoside Hydrolases; C019713:alpha-N-arabinofuranosidase