Carbohydrates peptides

Soybean concentrate production involves the removal of soluble carbohydrates, peptides, phytates, ash, and substances contributing undesirable flavors from defatted flakes after solvent extraction of the oil. Typical concentrate production processes include moist heat treatment to insolubilize proteins, followed by aqueous extraction of soluble constituents aqueous alcohol extraction and dilute aqueous acid extraction at pH 4.5. 

D-Xylosy]-L-serine as a Carbohydrate-peptide Linking Moiety...434... 

In this Section, the nature of the linkages between the protein chain and the carbohydrate moieties in glycoproteins will be considered, and some indication of their occurrence will be given. It will become clear that, in a number of examples, a given polypeptide chain is glycosidically substituted at more than one point. Sometimes, the amino acid residue at two such points is of a different type, so that more than one type of carbohydrate-peptide bond occurs in the same protein, It is likely that more examples of this kind of structure will be found as more features of the constitution of glycoproteins involved in membranes and connective tissue are determined. 

The Amino Acid and Sugar Residues that are Generally Engaged in Carbohydrate-peptide Linkages in Glycoproteins... 

III. Polypeptide Chains Carrying More Than One Type of Carbohydrate-peptide Linkage... 

The possibility of categorizing glycoproteins according to the nature of the carbohydrate-peptide bond contained has been suggested.38 To some extent, this method is possible, but, as was pointed out, it does not result in a rigid classification, for examples are known in which more than one type of carbohydrate moiety is attached to a given polypeptide chain. 

Collagen and basement membrane may contain several types of carbohydrate-peptide linkage. They clearly contain linkages in which 5-hydroxy-L-lysine is involved, as already discussed (see p. 436). From the preparations studied were also isolated glycopep-tides in which an asparagine-2-acetamido-2-deoxy-D-glucose linking moiety was present.1Bl-200... 

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... 

---