Influence of glycosylation on the conformational preferences of folded oligopeptides

Synthesis, characterization, and conformational analysis by FT-IR absorption, 1H NMR and X-ray diffraction techniques are described for a series of side-chain O-glycosylated Thr peptides of different main-chain length rich in the helicogenic Aib residue. The results obtained, compared with those of related peptides containing side-chain protected Thr and Ser residues and host Aib homo-oligomers, also reported in this work, provided new information on the preferred conformation of the naturally occurring antifreeze glycopeptides.