Stabilization of alpha-helical structures in short peptides via end capping.
The alpha-helix-stabilizing effect of different amino acid residues at the helical termini of short peptides in aqueous solution has been determined. Several dodecapeptides containing alanine, asparagine, aspartate, glutamine, glutamate, and serine at the amino terminus and arginine, lysine, and alanine at the carboxyl terminus were synthesized, and the alpha-helical content of each peptide was measured by using circular dichroism spectroscopy. The trend in alpha-helix-inducing ability of these amino acids was found to be as follows: aspartate > asparagine > serine > glutamate > glutamine > alanine at the amino terminus and arginine > lysine > alanine at the carboxyl terminus. Our results agree with the Presta and Rose hypothesis [Presta, L. G. & Rose, G. D. (1988) Science 240, 1632-1641] on the role of end capping in helix stabilization.
Forood
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Department of Chemistry, University of California, Davis 95616.
Feliciano
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Nambiar
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D000595:Amino Acid Sequence; D000596:Amino Acids / Q000737:chemistry; D002942:Circular Dichroism; D003080:Cold Temperature; D005459:Fluorides; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000737:chemistry* / Q000187:drug effects; D011188:Potassium / Q000494:pharmacology; D017680:Potassium Compounds; D017433:Protein Structure, Secondary; D013056:Spectrophotometry, Ultraviolet; D014270:Trifluoroethanol / Q000494:pharmacology
D000596:Amino Acids; D009842:Oligopeptides; D017680:Potassium Compounds; D014270:Trifluoroethanol; C033320:potassium fluoride; D005459:Fluorides; D011188:Potassium