Inhibition of beta-amyloid toxicity by short peptides containing N-methyl amino acids.

Single N-methyl amino acid-containing peptides related to the central hydrophobic region beta16-20 (Lys-Leu-Val-Phe-Phe) of the beta-amyloid protein are able to reduce the cytotoxicity of natural beta1-42 in PC12 cell cultures. N-methyl phenylalanine analogs yield statistically significant increments in cell viability (Student's t-test < 0.01%) and are nontoxic in the same assay. These promising results indicate that these peptide molecules could be a starting point for the development of potential therapeutic compounds for the treatment of Alzheimer's disease.