Application of high-field proton magnetic resonance spectroscopy in the structural determination of membrane-derived Sindbis virus glycopeptides

Abstract
Sindbis virus membrane glycopeptides were purified in chemical quantities and their oligosaccharide structures analyzed by 1H NMR spectroscopy at 360 MHz. Interpretable spectra could be obtained with .apprx. 100 .mu.g of oligosaccharide. Spectral analysis of the sialyl glycopeptides S1, S2 and S3 at high and low temperatures confirms their structures to be NANA.alpha.(2,3)Gal.beta.(1,4)-GlcNAc.beta.(1,2)Man.alpha.(1,6)-[NANA.alpha.(2,3)Gal.beta.(1,4)-GlcNAc.beta.(1,2)Man.alpha.(1,3)]-Man.beta.(1,4)GlcNAc.beta.(1,4)-[Fuc.alpha.-(1,6)]-GlcNAc.beta.1-Asn. These are heterogeneous with respect to sialic acid (NANA). Spectra of 2 endo-.beta.-N-acetylglucosaminidase products of the S4 glycopeptides are reported. The interpretation of these spectra is consistent with Man5GlcNAc and Man7GlcNAc oligosaccharide structures. Their chemical shifts are essentially identical with those reported for ovalbumin glycopeptides of the same composition, with exception to the perturbations arising from their oligosaccharide nature.