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Related to Keratins: actin, hard keratin



fibrous proteins whose fibers are a component of the horny layer of the epidermis and of hair, wool, feathers, scales, nails, horns, beaks, and hooves.

Keratins are insoluble in water and organic solvents and resistant to the action of proteolytic enzymes. It has been established by X-ray structural analysis that the polypeptide chains of keratins may be either twisted or elongated. The structure of nonelongate fibers (α-structure) is characteristic of the keratins of mammals; reptiles and birds have the elongate form (β-structure) as well (for example, in feathers). The insolubility of keratins is caused by the presence of transverse disulfide bonds between the polypeptide chains. The principal structural elements of α-keratins are cylindrical microfibrillae (diameter 75Å), which consist of spiraled protofibrillae twisted in pairs. The keratins of mammals are distinguished chiefly by their amino-acid composition, by the manner in which the microfibrillae are packaged, and by the amount of matrix (the high-sulfur protein in which they are embedded).


Finean, Dzh. Biologicheskie ul’trastruktury. Moscow, 1970. (Translated from English.)
Freizer, R. “Keratiny.” In the collection Molekuly i kletki, issue 5. Moscow, 1970. (Translated from English.)


References in periodicals archive ?
Meanwhile, European researchers identified KLHL24 mutations in families from Finland, Germany, Israel, Italy, Switzerland, and Qatar and confirmed that these mutations affect the equilibrium between intermediate keratin filaments and keratin breakdown that is necessary for skin integrity (Am J Hum Genet.
The keratin degrading bacterial strains were isolated by enrichment culture technique.
Cashmere has a very good textile performance, which is closely related to the keratin component and structure.
It is associated with mutations in five keratin genes viz.
As we age, our bodies produce less keratin and collagen, two key structural proteins that are essential to the health of the tissues that comprise hair, skin, and nails.
We also discovered transcriptional changes in a striking number of keratins (KRT) and their associated proteins (KRTAP) as well as matrix-metalloproteinases (MMPs) and other structural proteins (Table 2).
The researchers also put synthetic versions of these keratin fragments to the test against an array of nasty pathogens.
12) Domains and sub-domains are determined by the amino acid sequence of the keratin and serve various functions in the assembly of keratin filaments and in the binding of keratins and keratin filaments to cell adhesion complexes or to signalling molecules.
Human hairs used as substrate for keratin extraction were collected from local hair salon in Maha Sarakham Province, Thailand.
The improvement in PASI scores in the tonsillectomy group was strongly correlated with a reduction in circulating, cross-reactive, skin-homing CLA+ CD8+ T cells responsive to 16 homologous M protein and skin keratin peptides.
Keratins were then visualized using an enhanced chemiluminescence system according to the manufacturer's instructions (Pierce, Rockford, IL, USA).
Yeh and Miller have shown in their communication that AE3 is more sensitive than AE1/AE3 in detecting certain type II keratins, such as keratin 8, which is commonly expressed by fibroblastic-type reticulum cells, a phenomenon similar to our findings between AE1/AE3 and pancytokeratin or CAM5.