Conformational study on glycosylated asparagine-oligopeptides by NMR spectroscopy and molecular dynamics calculations
โ Scribed by Stefania Mazzini; Leonardo Scaglioni; Professor Rosanna Mondelli; Raniero Rocchi; Laura Biondi; Marina Gobbo
- Book ID
- 105360459
- Publisher
- John Wiley and Sons
- Year
- 2005
- Tongue
- English
- Weight
- 312 KB
- Volume
- 11
- Category
- Article
- ISSN
- 1075-2617
- DOI
- 10.1002/psc.644
No coin nor oath required. For personal study only.
โฆ Synopsis
The conformational properties of the homo oligomers of increasing chain length Boc-(Asn)(n)-NHMe (n = 2, 4, 5), (GlcNAc-beta-Asn)(n)-NHMe (n = 2, 4, 5, 8) and Boc-GlcNAc(Ac)(3)-beta-Asn-NHMe (n = 2, 4, 5) were studied by using NOE experiments and molecular dynamic calculations (MD). Sequential NOEs and medium range NOEs, including (i,i+2) interactions, were detected by ROESY experiments and quantified. The calculated inter-proton distances are longer than those characteristic of beta-turn secondary structures. Owing to the large conformational motions expected for linear peptides, MD simulations were performed without NMR constraints, with explicit water and by applying different treatments of the electrostatic interactions. In agreement with the NOE results, the simulations showed, for all peptides, the presence of both folded and unfolded structures. The existence of significant populations of beta-turn structures can be excluded for all the examined compounds, but two families of structures were more often recognized. The first one with sinusoidal or S-shaped forms, and another family of large turns together with some more extended conformations. Only the glycosylated pentapeptide shows in vacuo a large amount of structures with helical shaped form. The results achieved in water and in DMSO are compared and discussed, together with the effect of the glycosylation.
๐ SIMILAR VOLUMES
The conformation of diribosylribitol phosphate was studied by means of NMR spectroscopy and molecular dynamics (MD). Starting from 3 J( 1 H, 1 H), 3 J( 31 P, 1 H) and 3 J( 31 P, 13 C) couplings, measured from 1 H NMR, 13 C NMR and COSY spectra, the conformations of the ribose residues and the phosph