Patent ID: 7993896

Claim:
An isolated Streptomyces griseoplanus α-galactosidase for removing immunodominant α-galactose monosaccharides from blood group B or AB reactive cells in blood products, wherein the α-galactosidase has the following characteristics: (i) active in red blood cell conversion at neutral pH, and (ii) isolated and purified from a non-recombinant strain of Streptomyces griseoplanus, wherein said α-galactosidase enzyme is isolatable by a method comprising the steps of: (1) fermentation culturing of an α-galactosidase producing Streptomyces griseoplanus strain; (2) disrupting the cultured Streptomyces griseoplanus strain of step (1); (3) isolating an α-galactosidase-containing supernatant fraction from the disrupted Streptomyces griseoplanus strain of step (2) by centrifugation; (4) treating the α-galactosidase-containing supernatant fraction of step (3) with ammonium sulfate to yield a 20 to 60 percent ammonium sulfate fraction enriched in the α-galactosidase; (5) purifying the α-galactosidase from the 20 to 60 percent ammonium sulfate fraction of step (4) by anion exchange chromatography followed by cation exchange chromatography to yield an ion exchange purified α-galactosidase; and (6) fractionating the ion exchange purified α-galactosidase of step (5) by size-exclusion chromatography to yield a purified α-galactosidase which elutes with a molecular weight in the range of 40-80 kD.