Abstract
Disulphide bridges involving juxtaposed half-cystines are observed in a number of protein three-dimensional structures analyzed from the Protein Data Bank. These disulphide bridges comprise a ring of 8-atoms corresponding to Cα1-C-N-Cα2-Cβ2-Sγ2-Sγ1-Cβ1-Cα1 in the two half-cystines. The presence of such disulphide bridges introduces a bend or kink in the protein polypeptide chain.
Keywords: Protein Data Bank (PDB), Disulphide Bridges, neurotoxin, Cys83, oxidoreductases