[High-sulfur protein subunits in keratins]

Abstract

The quaternary structure of keratins contains a definite amount (to 40%) of protein-subunits with higher content of sulphur composing cystine, cysteine and other derivatives of these amino acids. These proteins are characterized by low molecular weight (to 30 kDa), significant heterogeneity and disordered, most probably, globular ternary structure in a free state. Being a constituent of the amorphous part of keratin (the so-called "matrix") and forming numerous intra- and intermolecular disulphide links, they stabilize the quaternary structure and promote resistance of keratins in solution and action of proteolytic enzymes.