Juxtaposed half-cystines as disulphide bridged partners in protein tertiary structure

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-S γ2-Sγ1-Cβ1-C β1 in the two half-cystines. The presence of such disulphide bridges introduces a 'bend' or 'kink' in the protein polypeptide chain. © 2006 Bentham Science Publishers Ltd.