Linkage region

Fig. 2.—Schematic Representation of the Heparin Proteoglycan. [The polysaccharide chains, bound to the polypeptide matrix through a linkage region," are cleaved by tissue endoglycosidases (arrows) after the transformations illustrated in Scheme 1.]...

Fig. 5. —Tentative Model for a Heparin Chain Containing the Linkage Region. [1 and 2 are sites of cleavage with 2-pyridone, affording fragments A and B A may be further cleaved by a more drastic treatment. The active site for antithrombin is proposed - 8 to be within fragment A. ...

Fic. 6.—Proposed Distribution of Disaccharide Units Along an Average Heparin Chain.151 [For simplicity, possible linkage regions and antithrombin-binding sequences are not considered. For notations, see legend and footnote to Scheme 1. Arrows indicate possible insertion of units G-Ana.]... 

Lipidated peptides embodying the characteristic linkage region found in the parent lipoproteins and bearing additional functional groups, which could be traced in biological systems or which allowed for their use in biophysical experiments, were used successfully in model studies. However, such model studies only provide a limited amount of information. In order to approximate the situation in a biological system more precisely, experiments with differently lipidated proteins are required. 

Application to a Linkage Region Fragment from Connective Tissue Proteogfycans... 

These conformations were subjected to a combined MD/EM refinement using the NOESY derived constraints as pseudoenergy functions. Families of conformations for the whole molecule were then constructed from the structures derived for each linkage. This procedure was demonstrated on a fragment from the carbohydrate-protein linkage region of connective tissue proteoglycans. 

We will illustrate our methodology using 0-3-D-galactopyranosyl -(1->4) 0-3 D-xylopyranosyl-(1->0)-L-serine (GXS), a fragment from the carbohydrate-protein linkage region of xylose/serine linked proteoglycans. 

Synthesis of an O-Linked Glycopeptidomimetic (Glycopeptoid) Corresponding to the Linkage Region of Proteoglycans... 

In dermatan sulfate from shark skin, there is about a 40% excess of sulfate groups over 2-acetamido-2-deoxy-D-galactose residues.300 The small proportions of D-glucu-ronic acid (d-GUA) present in dermatan sulfate occur in regions of the carbohydrate chains both near to, and far from, the carbohydrate-peptide linkage region. The isolation of the tetrasaccharide... 

Evidence for the structure of the main repeating-chain of chondroitin sulfate, as well as the sequence at the linkage region to protein, has come... 

---