Position effect of cross-strand side-chain interactions on beta-hairpin formation
Protein Science, (2000)Аннотация
Previous conformational analysis of 10-residue linear peptides enabled us to identify some cross-strand side-chain
interactions that stabilize b-hairpin conformations. The stabilizing influence of these interactions appeared to be greatly
reduced when the interaction was located at the N- and C-termini of these 10-residue peptides. To investigate the effect
of the position relative to the turn of favorable interactions on b-hairpin formation, we have designed two 15-residue
b-hairpin forming peptides with the same residue composition and differing only in the location of two residues within
the strand region. The conformational properties of these two peptides in aqueous solution were studied by 1H and 13C
NMR. Differences in the conformational behavior of the two designed 15-residue peptides suggest that the influence of
stabilizing factors for b-hairpin formation, in particular, cross-strand side-chain interactions, depends on their proximity
to the turn. Residues adjacent to the turn are most efficient in that concern. This result agrees with the proposal that the
turn region acts as the driving force in b-hairpin folding.
Keywords: b-hairpin; b-turn; NMR; peptide design; protein folding; side-chain interactions