Chain-length dependence for secondary structure formation of homo-oligopeptides from epsilon-tert.-butyloxycarbonyl-L-lysine with a lipophilic C-terminal group.

C Toniolo, G M Bonora, I F Lüscher, C H Schneider

Index: Int. J. Pept. Protein Res. 23(1) , 47-54, (1984)

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Abstract

A solid-state and solution analysis of the homo-oligopeptides from epsilon-tert.-butyloxycarbonyl-L-lysine with p-oxymethylbenzylcholestan-3 beta-yl succinate as C-terminal group, using infrared absorption and circular dichroism, is described. The occurrence of intermolecular beta-structure is seen in the solid state and in solvents of low polarity, e.g. methylene chloride, for peptides of intermediate size (from pentamer to decamer). Conversely, the eicosapeptide exhibits a high percentage of alpha-helical structure both in the solid state and in 2,2,2-trifluoroethanol. The influence of the C-terminal group on the conformational preferences of the epsilon-blocked homo-oligolysines in the solid state and in organic solvents appears negligible.