keratin


Also found in: Dictionary, Thesaurus, Medical, Acronyms, Wikipedia.

keratin

(kĕr`ətĭn), any one of a class of fibrous proteinprotein,
any of the group of highly complex organic compounds found in all living cells and comprising the most abundant class of all biological molecules. Protein comprises approximately 50% of cellular dry weight.
..... Click the link for more information.
 molecules that serve as structural units for various living tissues. The keratins are the major protein components of hair, wool, nails, horn, hoofs, and the quills of feathers. These proteins generally contain large quantities of the sulfur-containing amino acidsamino acid
, any one of a class of simple organic compounds containing carbon, hydrogen, oxygen, nitrogen, and in certain cases sulfur. These compounds are the building blocks of proteins.
..... Click the link for more information.
, particulary cysteinecysteine
, organic compound, one of the 20 amino acids commonly found in animal proteins. Only the l-stereoisomer participates in the biosynthesis of mammalian protein.
..... Click the link for more information.
. The helical keratin molecules twist around each other to form elongated strands called intermediate filaments. The formation of a covalent chemical bondchemical bond,
mechanism whereby atoms combine to form molecules. There is a chemical bond between two atoms or groups of atoms when the forces acting between them are strong enough to lead to the formation of an aggregate with sufficient stability to be regarded as an
..... Click the link for more information.
 called a disulfide bridge between the sulfer atoms on two cysteins on separate polypeptide chains of keratin allows for the cross-linkage of these chains and results in a fairly rigid aggregate. This phenomenon is seen to be consistent with the physiological role of the keratins, which provide a tough, fibrous matrix for the tissues in which they are found. Human hair is approximately 14% cystine (cysteins cross-linked by disulfide bridges).

keratin

[′ker·əd·ən]
(biochemistry)
Any of various albuminoids characteristic of epidermal derivatives, such as nails and feathers, which are insoluble in protein solvents, have a high sulfur content, and generally contain cystine and arginine as the predominating amino acids.

keratin

A proteinaceous material used as a retarder for plaster.

keratin

, ceratin
a fibrous protein that occurs in the outer layer of the skin and in hair, nails, feathers, hooves, etc.
References in periodicals archive ?
EBS affects more than 400,000 individuals worldwide and is usually linked to heterozygous missense mutations in genes encoding keratins 5 and 14, Dr.
Out of 12 proteolytic bacterial strains, only 4 showed zone formation on keratin agar plate.
A novel H1 mutation in keratin 6a in an infant with pachyonychia congenita.
Use the TRESemme Keratin Smooth Shampoo, as it cleanses the hair and scalp and smoothens out strands with keratin.
Ageing processes influence keratin and KAP expression in human hair follicles.
Given a BI-RADS 4a classification, subsequent ultrasound-guided biopsy was performed and showed squamous epithelium with abundant basket weave keratin and giant cells (Figure 3), suggesting an epidermal inclusion cyst.
Modulation of keratin 1, 10 and involucrin expression as part of the complex response of the human keratinocyte cell line HaCaT to ultraviolet radiation," Interdisciplinary Toxicology, vol.
Ghaloom said street peddlers promote smuggled Keratin products and sell them to beauty salons, which makes these salons a source of danger to clients' health.
A cocktail of 224 pollutants found in city air destroys keratin proteins that protect the skin from moisture loss.
Dateline s representation that its Keratin Complex Smoothing Therapy hair straightening product was comprised of at least 35% natural keratin was false or misleading, with the court finding that it contained less than 3% natural keratin.
A clear keratin solution was obtained after 2-3 days of dialysis.