Vicinal disulfide turns.
The formation of a disulfide bond between adjacent cysteine residues is accompanied by the formation of a tight turn of the protein backbone. In nearly 90% of the structures analyzed a type VIII turn was found. The peptide bond between the two cysteines is in a distorted trans conformation, the omega torsion angle ranges from 159 to -133 degrees, with an average value of 171 degrees. The constrained nature of the vicinal disulfide turn and the pronounced difference observed between the oxidized and reduced states, suggests that vicinal disulfides may be employed as a 'redox-activated' conformational switch.
Carugo
Oliviero
O
International Centre for Genetic Engineering and Biotechnology, Padriciano 99, 34012 Trieste, Italy.
Cemazar
Masa
M
Zahariev
Sotir
S
Hudáky
Ilona
I
Gáspári
Zoltán
Z
Perczel
András
A
Pongor
Sándor
S
D003545:Cysteine / Q000737:chemistry*; D004220:Disulfides / Q000737:chemistry*; D015202:Protein Engineering; D017510:Protein Folding; D017433:Protein Structure, Secondary
D004220:Disulfides; D003545:Cysteine