Purification and characterization of fetal bovine serum beta-N-acetyl-D-galactosaminyltransferase and beta-D-glucuronyltransferase involved in chondroitin sulfate biosynthesis.

Abstract

beta-N-Acetylgalactosaminyltransferase II and beta-glucuronyltransferase II, involved in chondroitin sulfate biosynthesis, transfer an N-acetylgalactosamine (GalNAc) and glucuronic acid (GlcA) residue, respectively, through beta-linkages to an acceptor chondroitin oligosaccharide derived from the repeating disaccharide region of chondroitin sulfate. They were copurified from fetal bovine serum approximately 2500-fold and 850-fold, respectively, by sequential chromatographies on Red A-agarose, phenyl-Sepharose, S-Sepharose and wheat germ agglutinin-agarose. Identical and inseparable chromatographic profiles of both glycosyltransferase activities obtained through the above chromatographic steps and gel filtration suggest that the purified enzyme activities are tightly coupled, which could imply a single enzyme with dual transferase activities; beta-N-acetylgalactosaminyltransferase and beta-glucuronyltransferase, reminiscent of the heparan sulfate polymerase reaction. However, when a polymerization reaction was performed in vitro with the purified serum enzyme preparation under the polymerization conditions recently developed for the chondroitin-synthesizing system, derived from human melanoma cells, each monosaccharide transfer took place, but no polymerization occurred. These results may suggest that the purified serum enzyme preparation contains both beta-N-acetylgalactosaminyltransferase II and beta-glucuronyltransferase II activities on a single polypeptide or on the respective polypeptides forming an enzyme complex, but is different from that obtained from melanoma cells in that it transfers a single GalNAc or GlcA residue but does not polymerize chondroitin.

• Authors: K Tsuchida, T Lind, H Kitagawa, U Lindahl, K Sugahara, K Lidholt
• Journal: European journal of biochemistry (Eur J Biochem) Vol. 264 Issue 2 Pg. 461-7 (Sep 1999) ISSN: 0014-2956 [Print] England
• PMID: 10491092 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Multienzyme Complexes
• Chondroitin
• Chondroitin Sulfates
• N-Acetylgalactosaminyltransferases
• Glucuronosyltransferase

Topics

• Animals
• Cattle
• Chondroitin (metabolism)
• Chondroitin Sulfates (biosynthesis)
• Chromatography, Gel
• Chromatography, Ion Exchange
• Enzyme Stability
• Fetal Blood (enzymology)
• Glucuronosyltransferase (blood)
• Multienzyme Complexes (chemistry)
• N-Acetylgalactosaminyltransferases (blood)