BIOACTIVE AND MODEL PEPTIDES CHARACTERIZED BY THE HELICOGENIC (ALPHA-ME)PHE RESIDUE

We have synthesized and fully characterized the hypersweet super-aspar tame analogue pCN-C6H4-NHCO-L-Asp-L-(alphaMe)Phe-OMe 1; the [D-(alphaM e)Phe]3-analogue of the formyl-methionyl tripeptide chemoattractant HC O-L-Met-L-Leu-D-(alphaMe)Phe-OMe 2, the first D-chemotactic peptide be ing found more active than its L-diastereomer; and the model pentapept ide BrBz-D-(alphaMe)Phe-(Aib)2-D-(alphaMe)Phe-Aib-OtBu 3. The preferre d conformation of the three peptides, as determined by X-ray diffracti on analyses, is discussed in terms of the proposed receptor models for sweet perception [peptide 1] and neutrophil chemotaxis [peptide 4, an d as a promising candidate for molecular recognition studies [peptide 3].