Purification and characterization of novel salt‐active acharan sulfate lyase from Bacteroides stercoris HJ‐15

Salt‐active acharan sulfate lyase (no EC number) has been purified from Bacteroides stercoris HJ‐15, which was isolated from human intestinal bacteria with GAG degrading enzymes. The enzyme was purified to apparent homogeneity by a combination of QAE‐cellulose, diethylaminoethyl (DEAE)‐cellulose, CM‐Sephadex C‐50, HA ultrogel and phosphocellulose column chromatography with the final specific activity of 81.33 µmol·min−1·mg−1. The purified salt‐active acharan sulfate lyase was activated to 5.3‐fold by salts (KCl and NaCl). The molecular weight of salt‐active acharan sulfate lyase was 94 kDa by SDS/PAGE and gel filtration. The salt‐active acharan sulfate lyase showed optimal activity at pH 7.2 and 40 °C. Salt‐active acharan sulfate lyase activity was potently inhibited by Cu2+, Ni2+ and Zn2+. This enzyme was inhibited by some agents, butanediol and p‐chloromercuric sulfonic acid, which modify arginine and cysteine residues. The purified Bacteroidal salt‐active acharan sulfate lyase acted to the greatest extent on acharan sulfate, to a lesser extent on heparan sulfate and heparin. The biochemical properties of the purified salt‐active acharan sulfate lyase are different from those of the previously purified heparin lyases. However, these findings suggest that the purified salt‐active acharan sulfate lyase may belong to heparin lyase II.