Amphipathic control of the 310‐/α‐helix equilibrium in synthetic peptides |
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Authors: | L G J Hammarstrm TJ Gauthier RP Hammer ML McLaughlin |
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Institution: | L. G. J. Hammarström,T.J. Gauthier,R.P. Hammer,M.L. McLaughlin |
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Abstract: | Abstract: A series of short, amphipathic peptides incorporating 80% Cα,Cα‐disubstituted glycines has been prepared to investigate amphipathicity as a helix‐stabilizing effect. The peptides were designed to adopt 310‐ or α‐helices based on amphipathic design of the primary sequence. Characterization by circular dichroism spectroscopy in various media (1 : 1 acetonitrile/water; 9 : 1 acetonitrile/water; 9 : 1 acetonitrile/TFE; 25 mm SDS micelles in water) indicates that the peptides selectively adopt their designed conformation in micellar environments. We speculate that steric effects from ith and ith + 3 residues interactions may destabilize the 310‐helix in peptides containing amino acids with large side‐chains, as with 1‐aminocyclohexane‐1‐carboxylic acid (Ac6c). This problem may be overcome by alternating large and small amino acids in the ith and ith + 3 residues, which are staggered in the 310‐helix. |
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Keywords: | 310‐helix α ‐helix amphipathic peptides Cα Cα ‐disubstituted glycines CD spectroscopy helix equilibrium |
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