Partial Purification and Characterization of an Endo-α-N-acetylgalactosaminidase from the Culture Medium of Diplococcus pneumoniae1

Abstract

The culture medium of Diplococcus pneumoniae contains enzymic activity that cleaves Galbeta1 leads to 3GalNAc from desialized human erythrocyte membrane glycoprotein. The enzyme was purified 180-fold by ammonium sulfate fractionation, gel filtration through a Sephadex G-200 column, and DEAE A-25 Sephadex chromatography. The purified enzyme liberates Galbeta1 leads to 3GalNAc from glycopeptides and glycoproteins with Galbeta1 leads to 3GalNAcalpha1 leads to Ser and Thr moieties. The optimum pH of this enzyme is 6.0. Using glycopeptides obtained by trypsin digestion of human erythrocyte membrane glycoprotein as a substrate, a Km of 0.20 mM (on the basis of the amount of Galbeta1 leads to 3GalNAc residues) was obtained. So far, the enzyme appears to have a strict specificity for Galbeta1 leads to 3GalNAcalpha1 leads to Ser and Thr structures, because no oligosaccharides larger than trisaccharides were liberated from porcine submaxillary mucin.

Identification of a Pneumococcal Glycosidase That Modifies O-Linked Glycans

“…S. pneumoniae is known to express O-glycosidase activity (4,15,41), as it was previously detected in culture supernatants (15); however, the majority of other pneumococcal glycosidases are predicted to be surface associated in a sortase-dependent manner (40). To narrow the number of O-glycosidase candidate genes, we investigated whether the S. pneumoniae protein is surface associated and if sortase A (SrtA) is required for surface localization.…”

Direct demonstration of increased expression of Thomsen-Friedenreich (TF) antigen in colonic adenocarcinoma and ulcerative colitis mucin and its concealment in normal mucin.

“…Abbreviations used in this paper: AFGP, Antarctic fish antifreeze glycopeptides; Gal, D-galactose; GaINAc, N-acetyl-D-galactosamine; ulcerative colitis and carcinomatous colonic mucin, using highpH anion-exchange chromatography (HPAEC) coupled with pulsed amperometric detection (PAD) after specific enzymatic release with endo-a-N-acetylgalactosaminidase (O-glycanase), which hydrolyzes glycosidic bonds formed by N-acetylgalactosamine and the hydroxyl group of either serine or threonine only when in the sequence Gal/3 -3GalNAc-a-O-Ser/Thr (24,25 …”

Identification and Molecular Cloning of a Novel Glycoside Hydrolase Family of Core 1 Type O-Glycan-specific Endo-α-N-acetylgalactosaminidase from Bifidobacterium longum

“…This enzyme also serves as a powerful tool for elucidating the presence of O-glycans in glycoproteins (7), the role of O-glycan in the biological events (8), and analysis of the O-glycan binding site (9), because the enzyme selectively cleaves and removes the disaccharide from the targets without damaging them. To date, endo-␣-GalNAcases have been purified from Clostridium perfringens (10), Streptococcus pneumoniae (11)(12)(13)(14)(15), Alcaligenes sp. (16), and Bacillus sp.…”