Theoretical Study of a Nonpeptidic Polydisulfide α-Helix.
A carbon-sulfur molecule has been designed as a mimic of peptides. Density functional theory calculations showed that the oxidation of 10 moles of methanedithiol led to a polydisulfide oligomer, HS(CH2SS)9CH2SH. The polydisulfide can adopt an α-helix type of secondary structure, where the chain is coiled. Unlike proteins, the S-S bonds in the polydisulfide function as secondary rather than tertiary structural elements. The helix contains 8 non-hydrogen atoms per turn, 2.7 Å methylenes per turn, a pitch distance of 8.6 Å, and a radius of 1.00 Å. The methylene sites could carry R group residues similar to amino acids.
Department of Chemistry and Graduate Center, Brooklyn College of CUNY, Brooklyn, New York, USA.
Benjamin
B
Rudshteyn
Alvaro
A
Castillo
Alexander
A
Greer
carbon-sulfur polymers; disulfides; peptide mimics; secondary structure; α-helices