Triantennary glycopeptide

The flexibility of the sugar linkages in glycoproteins results in multiple conformations that can be detected by time-resolved fluorescence experiments. Figure B9.1.1 shows an example of a triantennary glycopeptide labeled with a... 

Fig. B9.1.1. Distance distribution of a triantennary glycopeptide reflecting the multiple conformations (adapted from Wu et al. ).

Compound 48 is a triantennary glycopeptide containing a terminal Fuc group a-(l— 3)-linked to GlcNAc-7. This compound was derived from asialo aracid glycoprotein67-8 (peptide moiety Asn-Lys) and from asialo ceruloplasmin84 (peptide moiety Asn). The 500-MHz, H-n.m.r. spectrum of the glycopeptide obtained from the latter source is shown in Fig. 35 its spectral parameters are listed in Table XVI. 

Figure B9.1.1 shows an example of a triantennary glycopeptide labeled with a...

Scheme 13.18 JV-linked glycopeptide with a triantennary structure.

Scheme 47 Glycopeptide Assembly with Triantennary Building Block 1491...

Compound 9 is a triantennary, asialo glycopeptide that can be isolated from various desialylated glycoproteins.1-4 The 500-MHz, H-n.m.r. spectrum of 9, derived from a,-acid glycoprotein,66-69 is given in Fig. 9, and the n.m.r. parameters are compiled in Table V. The spectral features of this glycopeptide bear a high similarity to those of compound 8 (see Table V). 

Compound 34 is a triantennary, sialo glycopeptide terminated with NeuAc a-(2- 6)-linked to Gal in all three branches it could be obtained by exhaustive, in vitro sialylation of compound 9 with /3-D-ga-lactoside a-(2— 6)-sialyltransferase.13,78 The Gln-Asn analog of compound 34, in admixture with compound 53 and a glycopeptide analog of 41, has been isolated from human-plasma ceruloplasmin (see compound 53). The 500-MHz, -n.m.r. spectrum of 34 is given in Fig. 26, and its pertinent spectral parameters are listed in Table X. 

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