Purification and properties of alpha-galactosidases from Vicia faba seeds.
Two forms of alpha-galactosidase, I and II, exist in Vicia faba seeds and these have been purified 3660- and 337-fold respectively. They behaved as homogeneous preparations when examined by ultracentrifugation, disc electrophoresis and gel filtration. The apparent molecular weights of enzymes I and II, as determined by gel filtration, were 209000 and 38000 respectively. The carbohydrate contents of enzymes I and II were 25% and 2.8% respectively, and the enzymes differed in their aromatic amino acid compositions. Enzyme I was split into six inactive subunits in the presence of 6m-urea. alpha-Galactosidases I and II showed different pH optima and K(m) and V(max.) values with p-nitrophenyl alpha-d-galactoside and raffinose as substrates, and also differed in their thermal stabilities.
D000596:Amino Acids / Q000032:analysis; D002241:Carbohydrates / Q000032:analysis; D002850:Chromatography, Gel; D004589:Electrophoresis, Disc; D005696:Galactosidases / Q000032:analysis / Q000302:isolation & purification*; D006863:Hydrogen-Ion Concentration; D008970:Molecular Weight; D009844:Oligosaccharides; D012639:Seeds / Q000201:enzymology*; D014461:Ultracentrifugation; D014508:Urea
D000596:Amino Acids; D002241:Carbohydrates; D009844:Oligosaccharides; D014508:Urea; D005696:Galactosidases