Physicochemical properties of a novel alpha-L-arabinofuranosidase from Rhizomucor pusillus HHT-1.
The zygomycete fungus Rhizomucor pusillus HHT-1, cultured on L(+)arabinose as a sole carbon source, produced extracellular alpha-L-arabinofuranosidase. The enzyme was purified by (NH4)2SO4 fractionation, gel filtration, and ion exchange chromatography. The molecular mass of this monomeric enzyme was 88 kDa. The native enzyme had a pI of 4.2 and displayed a pH optimum and stability of 4.0 and 7.0-10.0, respectively. The temperature optimum was 65 degrees C, and it was stable up to 70 degrees C. The Km and Vmax for p-nitrophenyl alpha-L-arabinofuranoside were 0.59 mM and 387 micromol x min(-1) x mg(-1) protein, respectively. Activity was not stimulated by metal cofactors. The N-terminal amino acid sequence did not show any similarity to other arabinofuranosidases. Higher hydrolytic activity was recorded with pnitrophenyl alpha-L-arabinofuranoside, arabinotriose, and sugar beet arabinan; lower hydrolytic activity was recorded with oat-spelt xylan and arabinogalactan, indicating specificity for the low molecular mass L(+)-arabinose containing oligosaccharides with furanoside configuration.
Shofiqur Rahman
A K
AK
Department of Bioprocessing, Faculty of Agriculture, Gifu University, Yanagido, Japan.
Kawamura
S
S
Hatsu
M
M
Hoq
M M
MM
Takamizawa
K
K
D000595:Amino Acid Sequence; D006026:Glycoside Hydrolases / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D020103:Rhizomucor / Q000201:enzymology* / Q000254:growth & development; D017422:Sequence Analysis, DNA; D013696:Temperature
D006026:Glycoside Hydrolases; C019713:alpha-N-arabinofuranosidase