Fetuin glycopeptide

Figure 33 An early glycan photoaffinity probe. This moiecuie was used to map gaiactose-binding sites on the asialoglycoprotein receptor. The probe was prepared from a desialylated fetuin glycopeptide galactose residues were modified with aryl azides (shown in red) and the peptide was labeled by radioiodination (shown in blue).

D-Galactose tends to be the next innermost sugar in nonreducing, terminal positions. Thus, about 70-80% of the D-galactose residues of sialic acid-free fetuin,248,319 or of a glycopeptide isolated from it,248 were released by the action of /3-D-galactosidase. Similar results were... 

The NMR spectroscopic study of two glycopeptides from calf fetuin found different chemical shifts for identical trisaccharides linked to different amino acids of the peptide [176]. One trisaccharide, 0 -D-NeuiVAc-(2-3)- 3-D-Gal-(l-3)-a-D-GaUVAc, is found attached to either Glu-Ala-Pro-Ser-Ala or two trisaccharides are linked to Gly-Pro-Ser-Ala-Thr-Pro-Ala. However, the two identical sugar parts showed different chemical shifts, this was interpreted that the sugar chains either have different conformations or are interacting with the peptide or with the second oligosaccharide chain in different ways. 

Fetuin Papain, trypsin, chymotrypsin, pepsin, subtilisin Glycopeptides Spiro (1962)... 

Oligosaccharides from glycopeptides by hydarazinolyses Derivatization 2-pyridylamine dimethylamine/borane D FI Aex = 320 nm Aem = 380 nm C Fused silica (60 cm x 50 pm i.d.) polyimine coated E 100 mmol 1 phosphate, pH 2.5 200 mmol I borate V 20 kV Glycopeptides obtained by trypsine digestion of human transferrin, serum fetuin, human immunoglobulin, bovine, spleen ribonuclease, yeast invertase... 

FIGURE 4 HPLC chromatograms of the peptides produced from bovine fetuin by trypsin and Asp-N as measured by the electrospray mass spectrometer (A) Total ion current (TIC) (B) reconstructed ion chromatogram (RIC) for ion 204. Glycopeptides containing residues Asn 81, Asn 138, Asn 158, Ser 253, and Thr 262/Ser 264 were observed in the LC/MS analysis. Reprinted, with permission, from Carr et al. (1993). 

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