Keratin 19 Keratin 19 Keratin, type I cytoskeletal 19 also known as cytokeratin-19 (CK-19) or keratin-19 (K19) is a 40 kDa protein that in humans is encoded by the "KRT19" gene. Keratin 19 is a type I keratin. Keratin 19 is a member of the keratin family. The keratins are intermediate filament proteins responsible for the structural integrity of epithelial cells and are subdivided into cytokeratins and hair keratins. Keratin 19 is a type I keratin. The type I cytokeratins consist of acidic proteins which are arranged in pairs of heterotypic keratin chains. Unlike its related family members, this smallest known acidic
Lectin their particular high specificity for foreign glycoconjugates (e.g. those of fungi, invertebrates, and animals) and used in biomedicine for blood cell testing and in biochemistry for fractionation. Although they were first discovered more than 100 years ago in plants, now lectins are known to be present throughout nature. It is generally believed that the earliest description of a lectin was given by Peter Hermann Stillmark in his doctoral thesis presented in 1888 to the University of Dorpat. Stillmark isolated ricin, an extremely toxic hemagglutinin, from seeds of the castor plant ("Ricinus communis"). The first lectin to be purified on a