Determination of iduronic acid and glucuronic acid in sulfated chondroitin/dermatan hybrid chains by 1H-nuclear magnetic resonance spectroscopy

Abstract

The relative proportion of L: -iduronic acid (IdoA) and D: -glucuronic acid (GlcA) is of great importance for the structure-function relationship of chondroitin sulfate (CS)/dermatan sulfate (DS). However, determination of the isotypes of uronic acid residues in CS/DS is still a challenge, due to the instability of free uronic acid released by chemical degradation and its conversion to unsaturated uronic acid by digestion with bacterial eliminase. (1)H-Nuclear magnetic resonance (NMR) spectroscopy is a promising tool with which to address this issue, but the traditional method based on the assignment of the ring proton signals of IdoA and GlcA residues still has drawbacks such as the serious overlap of signals in the (1)H-NMR spectrum of CS/DS polysaccharides. We found that the proton signals of the N-acetyl group of N-acetyl-D: -galactosamines in CS and DS could be clearly distinguished and accurately integrated in the one-dimensional (1D) (1)H-NMR spectrum. Based on this finding, here we report a novel, sensitive, and nondestructive 1D (1)H-NMR-based method to determine the proportion of IdoA and GlcA residues in CS/DS hybrid chains.

Cloning and Characterization of a Novel Chondroitin Sulfate/Dermatan Sulfate 4-O-Endosulfatase from a Marine Bacterium

“…The activity of this sulfatase toward polysaccharides was lower than that for disaccharides and was higher for CS-A (820 milliunits/mg) than for CS-E (390 milliunits/mg) or DS (610 milliunits/mg). CS-E from squid cartilage contains more than 60% disulfated E unit GlcUA␤1-3GalNAc(4S,6S) (36), which might explain the lower activity of the sulfatase against this material, as found for disaccharides. In contrast, DS from porcine skin contains more than 90% monosulfated iA unit IdoUA␣1-3GalNAc(4S) (36) and should represent an optimum substrate; however, the lower enzyme activity toward the iA unit than toward the A unit suggests that the attachment of a uronic acid residue to the 4-O-sulfated galactosamine affects the enzyme activity and that GlcUA in CS is a more suitable substrate than IdoUA.…”

Specific interaction of the envelope glycoproteins E1 and E2 with liver heparan sulfate involved in the tissue tropismatic infection by hepatitis C virus

“…These results may reflect the difference in their total negative charge as represented by the number of sulfate groups per disaccharide unit. CS-D and CS-E contain 1.2 and 1.6 sulfate groups per disaccharide [41], respectively. To further characterize the binding of the recombinant E1 and E2 proteins to highly sulfated CS, the inhibitory effect of CS-E and CS-D on the binding of the E1 and E2 proteins to immobilized heparin was examined.…”

Identification of human hyaluronidase-4 as a novel chondroitin sulfate hydrolase that preferentially cleaves the galactosaminidic linkage in the trisulfated tetrasaccharide sequence

“…1E and 1F), suggesting weak activity toward CS-C. Although both CS-A and CS-C contain the "A" disaccharide unit [GlcUAβ1-3GalNAc(4-O-sulfate)] (76 and 13%, respectively) and "C" disaccharide unit [GlcUAβ1-3GalNAc(6-O-sulfate)] (24 and 79%, respectively), (Li et al 2008). Therefore, FITC-labeled CS-D, which is rich in D units (23%), was examined.…”