Keratin Keratin Keratin () is one of a family of fibrous structural proteins. It is the key structural material making up hair, horns, claws, hooves, and the outer layer of human skin. Keratin is also the protein that protects epithelial cells from damage or stress. Keratin is extremely insoluble in water and organic solvents. Keratin monomers assemble into bundles to form intermediate filaments, which are tough and form strong unmineralized epidermal appendages found in reptiles, birds, amphibians, and mammals. The only other biological matter known to approximate the toughness of keratinized tissue is chitin. Keratin derives from Greek ' from '
Vitelline membrane outer layer protein I (VMO-I) has considerable activity to synthesize N-acetylchito-oligosaccharide from N-acetylglucosamine hexasaccharides but no hydrolysis activity. VMO-I is composed of 163 aa The structure consists of three beta-sheets forming Greek key motifs, which are related by an internal pseudo three-fold symmetry. Furthermore, the structure of VOMI has strong similarity to the structure of the delta-endotoxin, as well as a carbohydrate-binding site in the top region of the common fold. VMO-I revealed a unique structure of the P-prism fold, a new type of multi-sheet assembly. Vitelline membrane outer layer protein I (VMO-I) In molecular biology, this entry refers to a protein domain called, the