The synthetic glycosides, p-nitrophenyl- and o-nitrophenyl-2-acetamido-2-deoxy-3-O-beta-D-galacto... more The synthetic glycosides, p-nitrophenyl- and o-nitrophenyl-2-acetamido-2-deoxy-3-O-beta-D-galactopyranosyl-alpha- D-galactopyranosides, were found to be effective chromogenic substrates for an endo-alpha-N-acetyl-D-galactosaminidase. We did not experience any problems when these substrates were used for the screening of column fractions during the purification of the endoenzyme from Diplococcus pneumoniae culture filtrates. However, it should be pointed out that a combination of exo-beta-galactosidase, capable of cleaving beta 1-->3 linkages, and an exo-alpha-N-acetyl galactosaminidase would also liberate nitrophenol from the above substrates. The enzyme had no action on several other synthetic glycosides tested indicating the strict specificity of this enzyme for the disaccharide Gal beta-->GalNAc linked via an alpha-linkage to the aglycone. The enzyme was inactive when the aglycone was methanol but shows activity against the glycosides of phenol, nitrophenols, serine, and threonine. The use of p-nitrophenyl-2-acetamido-2-deoxy-3-O-beta -D-galactopyranosyl-beta-D-galactopyranoside, which is a competitive inhibitor of the endoenzyme, as an affinity ligand for the purification of the enzyme is described.
The preceding paper (Williams, D., and Schachter, H. (1980) J. Biol. Chem. 255, 0000-0000) descri... more The preceding paper (Williams, D., and Schachter, H. (1980) J. Biol. Chem. 255, 0000-0000) described a novel N-acetylglucosaminyltransferase in canine submaxillary gland microsomes which catalyzed the incorporation of GlcNAc into mucin acceptors. We show in the present report that the enzyme catalyzes th following reaction: UDP-GlcNAc + Gal beta 1-3GalNAc-X leads to Gal beta 1-3(GlcNAc beta 1-6) GalNAc-X + UDP, where X can be porcine submaxillary mucin polypeptide (Km = 5.2 mM), antifreeze glycoprotein polypeptide (Km = 23 mM), alpha-O-p-nitrophenyl (Km = 0.52 mM), beta-O-p-nitrophenyl (Km = 0.92 mM), alpha-O-o-nitrophenyl (Km = 0.86 mM), alpha-O-benzyl (Km = 0.77 mM), alpha-O-methyl (Km = 4.2 mM), or -H (Km = 1.2 mM). Ineffective acceptors (< 5% of the activity with Gal beta 1-3GalNAc-alpha-p-nitrophenyl) are asialo-ovine submaxillary mucin, asialo-alpha 1 acid glycoprotein, Gal beta 1-3GlcNAc-beta-p-nitrophenyl, Gal beta 1-3GlcNAc-alpha-methyl, Gal beta1-3GlcNAc, Gal beta 1-3-N-acetylgalactosaminitol, and D-fucose beta 1-3GalNAc-alpha-benzyl, indicating that both the Gal and GalNAc residues are essential for acceptor activity. The beta 1 leads to 6-linkage of GlcNAc to GalNAc in the acceptor Gal beta 1-3GalNAc-alpha-O-benzyl was established by methylation analysis and high resolution 1H nuclear magnetic resonance spectroscopy of a large scale preparation of product. Preliminary evidence has been obtained indicating that sialic acid linked alpha 2-6 to GalNAc or L-fucose linked alpha 1-2 to Gal inhibit the action of the beta 6-N-acetylglucosaminyltransferase on Gal beta 1-3GalNAc-porcine submaxillary mucin polypeptide.
ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance t... more ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
The key intermediates (IVa) and (IVb) are synthesized from the protected mannosides (I) as outlin... more The key intermediates (IVa) and (IVb) are synthesized from the protected mannosides (I) as outlined in the reaction scheme.
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Sialyltransferase, /3-1,4 galactosyltransferase and some glycosidases levels are modified in biol... more Sialyltransferase, /3-1,4 galactosyltransferase and some glycosidases levels are modified in biological fluids from tumor bearing patients. We are attempting to determine whether a possible raise in the serum level of glycosyltransferases or glycosidases could be correlated with the presence of serum antigenic markers. The study includes sera obtained from cancer patients characterized by elevated level in at least one antigenic marker : CEA, CA 125 or CA 19.9 and several sera from tumor bearing patients negative for these markers. In each enzymatic assay, the mean of healthy donor level + 2 STE was chosen as cut off value. For sialyltransferase, no positive correlation has been found (with asialofetuine as acceptor). In sera positive for different markers (metastasis) the level of/3-1, 4 galactosyltransferase was extremely high. A positive correlation was found for this enzyme level and for the CA 125 level (in women and men). For N-acetyl-/3-D-glucosaminidase, a positive correlation has been found with the presence of elevated CA 19.9 levels. Several sera were positive for sialylor galactosyltransferase and negative for the three antigenic markers. Our result suggest that enzymatic assays in conjunction with the more widely used antigenic markers could have a predictive value. We thank GALEPHAR for financial support.
... 3. SWAMINATHAN, KHUSHI L. MATTA, LARRY A. DONOSO, AND OM P. BAHL$ ... The assay was based on ... more ... 3. SWAMINATHAN, KHUSHI L. MATTA, LARRY A. DONOSO, AND OM P. BAHL$ ... The assay was based on the determination of the reducing sugar from the hydrolysate of 2-Oan-mannopyranosyl-n-man-nose by the method of Somogyi and Nelson as described by Spiro (19). ...
ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance t... more ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance t... more ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
The synthetic glycosides, p-nitrophenyl- and o-nitrophenyl-2-acetamido-2-deoxy-3-O-beta-D-galacto... more The synthetic glycosides, p-nitrophenyl- and o-nitrophenyl-2-acetamido-2-deoxy-3-O-beta-D-galactopyranosyl-alpha- D-galactopyranosides, were found to be effective chromogenic substrates for an endo-alpha-N-acetyl-D-galactosaminidase. We did not experience any problems when these substrates were used for the screening of column fractions during the purification of the endoenzyme from Diplococcus pneumoniae culture filtrates. However, it should be pointed out that a combination of exo-beta-galactosidase, capable of cleaving beta 1-->3 linkages, and an exo-alpha-N-acetyl galactosaminidase would also liberate nitrophenol from the above substrates. The enzyme had no action on several other synthetic glycosides tested indicating the strict specificity of this enzyme for the disaccharide Gal beta-->GalNAc linked via an alpha-linkage to the aglycone. The enzyme was inactive when the aglycone was methanol but shows activity against the glycosides of phenol, nitrophenols, serine, and threonine. The use of p-nitrophenyl-2-acetamido-2-deoxy-3-O-beta -D-galactopyranosyl-beta-D-galactopyranoside, which is a competitive inhibitor of the endoenzyme, as an affinity ligand for the purification of the enzyme is described.
The preceding paper (Williams, D., and Schachter, H. (1980) J. Biol. Chem. 255, 0000-0000) descri... more The preceding paper (Williams, D., and Schachter, H. (1980) J. Biol. Chem. 255, 0000-0000) described a novel N-acetylglucosaminyltransferase in canine submaxillary gland microsomes which catalyzed the incorporation of GlcNAc into mucin acceptors. We show in the present report that the enzyme catalyzes th following reaction: UDP-GlcNAc + Gal beta 1-3GalNAc-X leads to Gal beta 1-3(GlcNAc beta 1-6) GalNAc-X + UDP, where X can be porcine submaxillary mucin polypeptide (Km = 5.2 mM), antifreeze glycoprotein polypeptide (Km = 23 mM), alpha-O-p-nitrophenyl (Km = 0.52 mM), beta-O-p-nitrophenyl (Km = 0.92 mM), alpha-O-o-nitrophenyl (Km = 0.86 mM), alpha-O-benzyl (Km = 0.77 mM), alpha-O-methyl (Km = 4.2 mM), or -H (Km = 1.2 mM). Ineffective acceptors (< 5% of the activity with Gal beta 1-3GalNAc-alpha-p-nitrophenyl) are asialo-ovine submaxillary mucin, asialo-alpha 1 acid glycoprotein, Gal beta 1-3GlcNAc-beta-p-nitrophenyl, Gal beta 1-3GlcNAc-alpha-methyl, Gal beta1-3GlcNAc, Gal beta 1-3-N-acetylgalactosaminitol, and D-fucose beta 1-3GalNAc-alpha-benzyl, indicating that both the Gal and GalNAc residues are essential for acceptor activity. The beta 1 leads to 6-linkage of GlcNAc to GalNAc in the acceptor Gal beta 1-3GalNAc-alpha-O-benzyl was established by methylation analysis and high resolution 1H nuclear magnetic resonance spectroscopy of a large scale preparation of product. Preliminary evidence has been obtained indicating that sialic acid linked alpha 2-6 to GalNAc or L-fucose linked alpha 1-2 to Gal inhibit the action of the beta 6-N-acetylglucosaminyltransferase on Gal beta 1-3GalNAc-porcine submaxillary mucin polypeptide.
ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance t... more ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
The key intermediates (IVa) and (IVb) are synthesized from the protected mannosides (I) as outlin... more The key intermediates (IVa) and (IVb) are synthesized from the protected mannosides (I) as outlined in the reaction scheme.
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Sialyltransferase, /3-1,4 galactosyltransferase and some glycosidases levels are modified in biol... more Sialyltransferase, /3-1,4 galactosyltransferase and some glycosidases levels are modified in biological fluids from tumor bearing patients. We are attempting to determine whether a possible raise in the serum level of glycosyltransferases or glycosidases could be correlated with the presence of serum antigenic markers. The study includes sera obtained from cancer patients characterized by elevated level in at least one antigenic marker : CEA, CA 125 or CA 19.9 and several sera from tumor bearing patients negative for these markers. In each enzymatic assay, the mean of healthy donor level + 2 STE was chosen as cut off value. For sialyltransferase, no positive correlation has been found (with asialofetuine as acceptor). In sera positive for different markers (metastasis) the level of/3-1, 4 galactosyltransferase was extremely high. A positive correlation was found for this enzyme level and for the CA 125 level (in women and men). For N-acetyl-/3-D-glucosaminidase, a positive correlation has been found with the presence of elevated CA 19.9 levels. Several sera were positive for sialylor galactosyltransferase and negative for the three antigenic markers. Our result suggest that enzymatic assays in conjunction with the more widely used antigenic markers could have a predictive value. We thank GALEPHAR for financial support.
... 3. SWAMINATHAN, KHUSHI L. MATTA, LARRY A. DONOSO, AND OM P. BAHL$ ... The assay was based on ... more ... 3. SWAMINATHAN, KHUSHI L. MATTA, LARRY A. DONOSO, AND OM P. BAHL$ ... The assay was based on the determination of the reducing sugar from the hydrolysate of 2-Oan-mannopyranosyl-n-man-nose by the method of Somogyi and Nelson as described by Spiro (19). ...
ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance t... more ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance t... more ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
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