Download MendeleyContrasting the conformational effects of alpha-O-GalNAc and alpha-O-Man glycan protein modifications and their impact on the mucin-like region of alpha-dystroglycan.
Borgert, A., Foley, B.L., Live, D.(2021) Glycobiology 31: 649-661
- PubMed: 33295623
- DOI: https://doi.org/10.1093/glycob/cwaa112
- Primary Citation of Related Structures:
2MK7 - PubMed Abstract:
We have carried out a comparative study of the conformational impact of modifications to threonine residues of either α-O-Man or α-O-GalNAc in the context of a sequence from the mucin-like region of α-dystroglycan. Both such modifications can coexist in this domain of the glycoprotein. Solution NMR experiments and molecular dynamics calculations were employed. Comparing the results for an unmodified peptide Ac- PPTTTTKKP-NH2 sequence from α-dystroglycan, and glycoconjugates with either modification on the Ts, we find that the impact of the α-O-Man modification on the peptide scaffold is quite limited, while that of the α-O-GalNAc is more profound. The results for the α-O-GalNAc glycoconjugate are consistent with what has been seen earlier in other systems. Further examination of the NMR-based structure and the MD results suggest a more extensive network of hydrogen bond interactions within the α-O-GalNAc-threonine residue than has been previously appreciated, which influences the properties of the protein backbone. The conformational effects are relevant to the mechanical properties of α-dystroglycan.
Organizational Affiliation:
Department of Medical Research, Gundersen Health System, 1900 South Ave., La Crosse, WI 54601, USA.
