enzymatic conversion of red blood cells of blood groups, by using an ab acetylgalactosaminidases-galactosidases and with substrate specificity and unique kinetic properties.

摘要

An α-galactosidase to remove type B antigen reactive cells of the blood group B or AB blood products, wherein said α-galactosidase has the following characteristics: (i) has no detectable activity with a P1 antigen, (ii) is cleave α1,3 linkages activated to-D-galactose in a type B to pH 6-8 branched antigen, and (iii) can be isolated by a method comprising the steps of: (1) providing a fermentation culture of a strain Streptomyces griseoplanus # 2357 of which produces, α-galactosidase deposited as ATCC deposit No. PTA-4077; (2) destabilize Streptomyces griseoplanus strain cultivated in step (1) by French press method; (3) isolating a supernatant fraction containing the α-galactosidase strain Streptomyces griseoplanus destabilized, step (2) by centrifugation xg 10 000; (4) fractionating the supernatant fraction containing the α-galactosidase from step (3) with ammonium sulphate to produce a fraction of 20 to 60 percent enriched in α-galactosidase ammonium sulfate; (5) dissolving the precipitate of α-galactosidase fraction 20 to 60 percent ammonium step (4) in 20 mM Tris (pH 7.5) and clarified by centrifugation sulfate, (6) fractionating sequentially by chromatography Q sepharose (20 mM Tris buffer, pH 7.5 with a NaCl gradient 0-1.5 M), S-sepharose (buffer 20 mM NaOAc, pH 5.3 with a gradient of 0-1.0 M NaCl) and filtration chromatography S12 gel (20 mM NaOAc buffer, pH 5.3, with 0.5 M NaCl and 20 mM NaPO 4, pH 6.5, 0-5 M NaCl) to produce a purified α-galactosidase, which elutes with a molecular weight of 40-80 kilodalton.