High impact information on L-Iduronic acid

• Glucuronyl C5-epimerase catalyzes the conversion of d-glucuronic acid to l-iduronic acid units in heparan sulfate biosynthesis [1].
• Targeted disruption of a murine glucuronyl C5-epimerase gene results in heparan sulfate lacking L-iduronic acid and in neonatal lethality [2].
• All identified protein-binding HS epitopes contain l-iduronic acid (IdoA) [2].
• Further characterization of the epitope recognized by JM-403, based on enzyme-linked immunosorbent assay inhibition tests with chemically/enzymatically modified polysaccharides, indicated that one or more N-sulfated glucosamine units are invariable present, whereas L-iduronic acid and O-sulfate residues appear to inhibit JM-403 reactivity [3].
• L-Iduronic acid-rich skin decorin and GAG chains had a greater accelerating effect than proteoglycan and GAG chains from cartilage that had lower L-iduronic acid content [4].

Biological context of L-Iduronic acid

• The larger oligosaccharides obtained after chondroitinase-AC digestion of sulfated products yielded L-iduronic acid upon acid hydrolysis and were susceptible to chondroitinase-ABC digestion [5].
• The results suggest that the 2-sulfamino group is essential for maintaining a molecular conformation consistent with the ability for the L-iduronic acid residues to complex with calcium ions [6].
• We report in this work the total synthesis of a close analogue of the pentasaccharide active site of heparin, in which the L-iduronic acid residue has been deoxygenated at position three [7].

Anatomical context of L-Iduronic acid

• The formation of L-iduronic acid during biosynthesis of dermatan sulphate has been studied in culture human fibroblasts and in microsomes from the same cells [8].
• The latter ones, obtained in 10% yield, have been used as a substrate for the direct measurement of the enzyme L-iduronic acid 2-sulfate sulfatase present in human plasma and fibroblast homogenates [9].

Associations of L-Iduronic acid with other chemical compounds

• The procedures used to follow the kinetics of glycosaminoglycan hydrolysis can also be sued to obtain quantitative analyses of L-iduronic acid, D-glucuronic acid and hexosamine in these polymers [10].
• The results of these studies indicate that both 2-O-sulphate and the negative charge of the carboxy group [L-iduronic acid (IdoA) residues] are required for specific interactions of heparin-derived oligosaccharides with bFGF and for modulation of bFGF mitogenic activity [11].

Gene context of L-Iduronic acid

• On the other hand, when [35S]glycosaminoglycans formed from DSDS after incubation with [35S]PAPS and C6ST-1 were digested with chondroitinase ACII, a major part of the radioactivity was recovered in fractions larger than hexasaccharides, indicating that C6ST-1 transferred sulphate to the GalNAc residues located in the L-iduronic acid-rich region [12].
• The epitope of 473HD, but not of CS-56 or MO-225, was eliminated from DSD-1-PG by digestion with chondroitinase B, suggesting the close association of L-iduronic acid with the 473HD epitope [13].
• By contrast, an unusually large coupling between H-2 and H-3 of the sulfated L-iduronic acid residue suggests a greater departure from the 1C4 conformation of this residue. when present in the binding sequence to AT-III than in the regular sequences [14].
• A substrate for direct measurement of L-iduronic acid 2-sulfate sulfatase [9].
• The pentasaccharide containing L-iduronic acid as the sole hexuronic acid showed higher affinity for FGF-2 than the other pentasaccharides, where one hexuronic acid unit at least is D-glucuronic acid [15].

Analytical, diagnostic and therapeutic context of L-Iduronic acid

• Hydrolysis and N-acetylation followed by paper chromatography showed that the L-iduronic acid-containing products were devoid of 3H [8].
• Following reduction, depolymerization, and lyophilization, D-glucuronic acid is converted to D-Glc and L-iduronic acid to 1,6-anhydro-idose [16].
• A high-performance liquid chromatography (HPLC) method with pulsed amperometric detection (PAD) was used for the determination of the acid hydrolysis products of L-iduronic acid containing oligosaccharides isolated from biological sources [17].

References