NMR EVIDENCE FOR THE NUCLEATION OF A BETA-HAIRPIN PEPTIDE CONFORMATION IN WATER BY AN ASN-GLY TYPE I' BETA-TURN SEQUENCE

The contribution of the beta-turn sequence to the folding and stabilit y of a peptide beta-hairpin in water has been analysed from studies of a truncated peptide lacking one beta-strand and hence the majority of the interstrand hydrophobic interactions; NMR analysis shows that the Asn-Gly type I' beta-turn conformation is significantly populated, su ggesting that the intrinsic conformation preference of the turn sequen ce may play an important role in nucleating hairpin folding.