Keratin is a fibrous protein found in vertebrates, primarily in hair, nails, skin, and horns. It is known for its strength, elasticity, insolubility, toughness, and flexibility. There are two main types of keratin:
- α-keratin (alpha-keratin): This type of keratin is found in mammals and is responsible for the structure of hair, skin, nails, and horns. It is rich in hydrophobic amino acids, which contribute to its strength and resilience.
- β-keratin (beta-keratin): This type of keratin is found in reptiles and birds and is responsible for the scales, feathers, and claws of these animals. It has a different structure than α-keratin and is generally more rigid.
Within α-keratin, there are two subtypes:
- Type I: There are 28 types of Type I keratins.
- Type II: There are 26 types of Type II keratins.
The specific type of keratin present in different tissues depends on the species and the function of the tissue.
In addition to the two main types of keratin, there are also various keratin treatments available, such as Brazilian keratin treatment, which is designed for thick, curly hair.
