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 micro mol x min-1 x 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 degrees 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.