A sialidase from horse liver was co-purified with b-galactosidase and carboxypeptidase A

Abstract

The solubilized sialidase was purified using anion-exchange chromatography on Fractogel EMD TMAE-650 (M) followed by affinity chromatography on p-aminophenyl thio-?-D-galactopyranoside-agarose and chromatofocusing on PBE 94 with a factor and yield of about 18 and 0.2 %, respectively. The enzyme was found to be associated with ?- galactosidase and carboxypeptidase A. The purified enzyme liberated sialic acid residues from sialooligosaccaharides (a-2,3- was preferred than a-2,6-sialyllactose), sialoglycoprotein and ganglioside such as GM3 and GD1a, however, the GM2 and GD1b are not suitable substrates for the sialidase as were also shown for BSM and guinea pig serum. The Neu2en5Ac is a strong competitive inhibitor with Ki of 47.5 µM.