keratiinit

Keratiini is a fibrous structural protein that is a key component of hair, nails, and the outer layer of skin in humans and other animals. It is also found in feathers, horns, claws, and hooves. Keratiini is known for its toughness and its ability to form protective layers. This protein is rich in sulfur-containing amino acids, particularly cysteine, which form disulfide bonds. These strong covalent bonds help to cross-link the protein chains, contributing significantly to the strength and resilience of keratinized structures.

There are two main types of keratiini: alpha-keratiini and beta-keratiini. Alpha-keratiini is found in mammals, while beta-keratiini is more common in reptiles and birds. The structure of keratiini is often described as a coiled coil, where alpha-helices wrap around each other. This arrangement provides both flexibility and strength.

In the cosmetic industry, keratiini is widely used in hair care products such as shampoos, conditioners, and treatments. It is believed to help strengthen hair, improve its texture, and reduce frizz. Keratiini treatments for hair, often called "keratiini straightening" or "Brazilian blowouts," aim to smooth the hair cuticle and make hair more manageable. However, the effectiveness and long-term impact of these treatments can vary. The protein itself is relatively insoluble in water, making it a durable material.