[Modeling of alpha-superhelical proteins. Selection of sequence, synthesis, and properties].

An analysis of the alpha-tropomyosin primary structure suggests a periodic sequence able to form an alpha-superhelical conformation. A repeating unit (the heptapeptide monomer) was obtained by sequential synthesis in solution using pentafluorophenyl esters of the N-protected amino acids. The polyheptapeptide (Glu-Lys-Lys-Leu-Glu-Glu-Ala)n with an average molecular weight 6500 has been synthesized by polymerization of the heptamer. It is shown that the polymer product forms a stable alpha-superhelix at acidic pH in water solution.