Purification and physical properties of sweet-almond alpha-galactosidase.

1. alpha-Galactosidase from sweet almonds was purified about 2000-fold through eight steps. 2. The enzyme preparation was free from other related enzymes known to occur in sweet almonds, and behaved as a homogeneous protein on filtration through Sephadex G-75. 3. A molecular weight of about 33000 was determined from the gel-filtration data. 4. The ultraviolet-absorption spectrum and thermal inactivation of the enzyme are described. 5. The purified enzyme hydrolysed p-nitrophenyl alpha-d-galactoside at a much faster rate than melibiose. 6. The pH optimum was at 5.5-5.7. 7. Besides hydrolysis, it also catalysed transfer of galactosyl residues, chain elongation of melibiose and the synthesis of oligosaccharides from galactose.