Conformation of a model peptide of the tandem repeat decapeptide in musseladhesive protein by NMR and MD simulations

The conformation of a model peptide (Ala-Lys-Pro Ser-Tyr-Hyp-Hyp-Thr-Tyr-Ly s) of the tandem repeat decapeptide sequence of Mytilus edulis foot protein -1 (mefp-1) has been studied by H-1 and C-13 2D-NMR in three diverse media- DMSO-d(6), water (pH 3.5) and 40% hexafluoroacetone (HFA), Various NMR para meters that were used to deduce the secondary structure were chemical shift (H-1 and C-13), temperature coefficients of NH chemical shifts, 3J(NH alph a) coupling constants and the pattern of intra and inter-residue NOEs. Mole cular dynamics simulations making integral use of the NMR data shows that t he conformation of the peptide is conserved in all the three media. The str ucture in the three solvents is best defined as a left-handed polyproline I I helix (PPII). (C) 2001 Elsevier Science Ltd. All rights reserved.