Keratin
What is Keratin?
Keratin is the fibrous structural protein of hair, nails, horn, hoofs, wool, feathers, and the epithelial cells in the outermost layer of skin. Keratin proteins can be subdivided into two groups: Alpha- Keratins, and Beta-Keratins, depending on their secondary structure which is influenced by hydrogen bonding.
Alpha- Keratins
Alpha Keratins are found in hair, skin, and the wool of mammals. They are primarily fibrous and helical in structure.
Beta- Keratins
Beta- Keratins are found in birds and reptiles and are made up of parallel sheets of polypeptide chains.
An Example of Keratin in action
Because of Keratins strengthening properties, people sometimes use Keratin Treatments to help with damaged/broken hair. These are the results of doing so.
More about Keratin
Composition of Keratin
In Keratin, the amino acid composition varies depending on the tissue it occurs in, and it's function. Cysteine residues which become linked covalently through disulfide bonds form Cystines which are highly responsible for Keratin's stability. The length of the fibres depend on how much water they contain. 16% water ( complete hydration ) increases their length by approximately 10 to 12 percent.
Importance of Keratin
Some Keratin proteins have been found to regulate key cellular activities such as cell growth and protein synthesis.
Properties of Keratin
Physical Properties- Water soluble, Hard Structure
Chemical Properties- Relatively Non- Reactive with Oxygen, Flammable if heat is applied, Reactive with acids.