Rapid procedures for determination of endo-N-acetyl-alpha-D-galactosaminidase in Clostridium perfringens, and of the substrate specificity of exo-beta-D-galactosidases.

Culture fluid of Clostridium perfringens hydrolyzed the synthetic, chromogenic substrates beta-Gal-(1 leads to 3)-alpha-GalNAc-1 leads to OPh and beta-Gal-(1 leads to 3)-alpha-GalNAc-1 leads to OC6H4-NO2-o or -p to beta-Gal-(1 leads to 3)-GalNAc and the aglycon. Such assays facilitated the characterization and purification of this endo-N-acetyl-alpha-D-galactosaminidase activity. This activity was purified 1200-fold by fractionation with ammonium sulfate and chromatography on columns of Sephadex-G200, DEAE-Sephadex, and hydroxylapatite. The final preparation showed activity over a broad range of pH, with an optimum at 9.0, but less-pure material had two pH optima, 4.0 and 9.0. Another assay method, which employed the synthetic, chromogenic substrates beta-Gal-(1 leads to 3)-beta-GlcNAc-1 leads to OC6H4NO2-p, beta-Gal-(1 leads to 4)-beta GlcNAc-1 leads to OC6H4NO2-p, and beta-Gal-(1 leads to 6)-beta-GlcNAc-1 leads to OC6H4NO2-p, was developed for the rapid identification of the linkage specificity of exo-beta-D-galactosidases from any source via a coupled reaction with N-acetyl-beta-D-hexosaminidase.