Structural studies on sulfated oligosaccharides derived from the carbohydrate‐protein linkage region of chondroitin sulfate proteoglycans of whale cartilage

Abstract

From the carbohydrate-protein linkage region of whale cartilage proteoglycans, which bear predominantly chondroitin 4-sulfate, one nonsulfated, two monosulfated and one disulfated hexasaccharide alditols were isolated after exhaustive digestions with Actinase E and chondroitinase ABC, and subsequent 8-elimination. Their structures were analyzed by chondroitinase ACII digestion in conjunction with HPLC and by 500-MHz 'H-NMR spectroscopy. The nonsulfated compound (A) had the following conventional structure :

Development of a mouse monoclonal antibody against the chondroitin sulfate-protein linkage region derived from shark cartilage

“…1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 22 It has also been reported that xylosyltransferase, galactosyltransferases, and GlcAT-I are distributed in ER/cis-Golgi, cis-/medial-Golgi, and medial-/trans-Golgi, respectively [46]. These results suggest that nascent PGs are transported from cis-to trans-Golgi compartments during maturation, and that the sulfation of the linkage region takes place before the transfer of the first N-acetylhexosamine residue to the tetrasaccharide core and could be a signal for the differential assembly of CS and HS chains as proposed previously [7,21,26]. …”

“…Namely, the 4-O-sulfation of a Gal-3 residue and 6-O-sulfation of both Gal-2 and Gal-3 residues have been found in CS/DS, but not HS/Hep. Interestingly, syndecan-1, a hybrid-type PG bearing both HS and CS chains, carries a 4-O-sulfate on the Gal-3 of only the CS chains [9], supporting the notion that 4-O-sulfation is a modification specific to CS chains [7]. In contrast, phosphorylation occurs on the Xyl of both CS/DS and HS/Hep [9].…”

“…The 4-O-sulfated Gal-3 structure has been shown in CS from various mammalian tissues and cells including rat chondrosarcoma [7] and human plasma [42]. The kinase that phosphorylates the Xyl residue has recently been identified as FAM20B [43].…”

“…We have carried out a series of structural studies of the GAG-protein linkage region, based on the working hypothesis that there may be differences in the region's structure among GAG chains and such differences may contribute to the determination of the type and/or character of the GAG species to be synthesized [6,7]. These structural studies have revealed unique modifications, such as 4-O-sulfated Gal, 6-O-sulfated Gal, and -O-phosphorylated Xyl.…”

One of the major sulphated proteins secreted by rat hepatocytes contains low-sulphated chondroitin sulphate

“…In fact, it has recently been shown that the so-called stellate cells, or lipocytes, produce 6-fold more glycosaminoglycans per cell in culture than do hepatocytes (Arenson et al, 1988 (Pertoft & Smedsr0d, 1987 Chondroitinase ABC degrades chondroitin sulphate chains to disaccharides but leaves the innermost six sugar residues (XylGal-Gal-GluA-GalNAc-GluA) intact. Of these, the GalNAc and possibly one ofthe Gal residues may be sulphated (Sugahara et al, 1988). Therefore hydrolysis of a 35SO42--labelled chondroitin sulphate chain by chondroitinase ABC will yield both radioactive disaccharides and a radioactive hexasaccharide (Hascall et al, 1972).…”