CONFORMATIONAL ANALYSIS OF N-GLYCOSYLATION SITE Asn-X-Thr/Ser IN GLYCOPROTEINS
A. Ya. AVANOV, G. M. LIPKIND*
Institute of Biochemistry, Academy of Sciences of the Armenian SSR, Yerevan; *N. D. Zelinsky Institute of Organic Chemistry, Academy of Sciences of the USSR, Moscow
Abstract: Theoretical conformational analysis of oligopeptides CH3CO-Asn-X-Thr-NHCH3 (X=Gly, Ala, Pro), modelling N-glycosylation site, and their glycosylatcd derivatives CH3CO-(GlcNAcβl-4GlcNAcβl)Asn-X-Thr-NHCH3 has been carried out. Active conformations of the site are found, corresponding to structural prerequisites of N-glycosylation: Asn residue's position in p-turn and hydrogen bond formation between side chains of Asn and Thr/Ser residues. In this case the L conformation of the central residue X is most probable. Since Pro residue does not possess this conformation, sequences with X=Pro are not glycosylated. It is shown that glycosylation of the above-mentioned sites is accompanied by reorientation of the Asn residue's side chains.
Russian Journal of Bioorganic Chemistry 1990, 16 (3):309-317