Showing papers by "Sam Griffiths-Jones published in 1999"
TL;DR: Temperature and pH-induced unfolding studies indicate that the folding-unfolding equilibrium approximates to a two-state model, and a pocket of "high density" water bridging between the Asn side-chain and peptide main-chain that suggests solvent-mediated interactions may play an important role in modulating phi,psi propensities in the NG turn region.
154 citations
TL;DR: Differences in hairpin stability have been analyzed in terms of an electrostatic interaction between charged groups on the terminal residues and the hydrophobic component of the Lys1 side chain.
Abstract: Analysis of the contribution of ion pairing interactions to the stability of a β-hairpin in aqueous solution has been studied quantitatively by NMR. A thermodynamic cycle has been constructed involving a combination of a single mutation (Lys→Gly) and a “pH switch” (CO2-→CO2H) to remove stepwise the contributions to stability from the interaction between the C-terminal carboxylate group of Ile16 and the side chains of Lys1 and Lys2. Turning these interactions “on” and “off” is shown to affect the chemical shifts of all residues, including those in the turn, such as to suggest that folding of the hairpin approximates to a two-state process. Two independent NMR methods have been used to analyze the thermodynamics of folding and are found to be in good agreement. Differences in hairpin stability have been analyzed in terms of an electrostatic interaction between charged groups on the terminal residues and the hydrophobic component of the Lys1 side chain: we estimate the primary electrostatic interaction to c...
81 citations