Keratins are a group of fibrous proteins that are the major structural components of human hair, nails, and the outer layer of the skin. They are also found in the beaks, feathers, scales, and horns of various animals. Keratins are characterized by their tough, insoluble nature and their ability to provide strength and protection to the structures they form.
The human genome encodes more than 50 different keratins, which are classified into two types: type I and type II. These keratins differ in their amino acid composition and sequence. Type I keratins are acidic, while type II keratins are basic. They form heterodimers and associate with each other to create keratin intermediate filaments, which are the building blocks of the various keratinized tissues.
Keratins are crucial for maintaining the structural integrity of hair, nails, and the epidermis. They provide resistance against physical damage, contribute to the barrier function of the skin, and help retain moisture. Additionally, keratins are involved in the regulation of cell growth, differentiation, and wound healing processes.
A disruption in the production or assembly of keratins can lead to various genetic disorders known as keratinopathies. These diseases can cause abnormalities in the skin, hair, and nails, such as hyperkeratosis (excessive keratin production), fragile skin, or hair loss.
Overall, keratins play a vital role in maintaining the structural and functional properties of various tissues, ensuring their proper functioning and protection.
