Synthesis and binding properties of endomorphin-2 analogs containing alpha-hydroxymethyl amino acids

Novel endomorphin-2 analogs containing the unusual amphiphilic amino acid (R)- and (S)-alpha-hydroxymethyltyrosine in position 1 and (R)- and (S)-alpha-hydroxymethylphenylalanine in the positions 3 and 4 were synthesized via the solid-phase method. The binding characteristics of the synthetic analogs may suggest that alpha-hydroxymethyl substitution of amino acid residues influences the conformation of a peptide much more than simply increasing the local amphiphilic character of the peptide.