β-keratin or beta-keratin (not to be confused with β-carotene) is rich in stacked β pleated sheets, in contrast to alpha-keratin, a fibrous protein rich in alpha helices. β-keratin is found in reptiles. It adds much more rigidity to reptilian skin than alpha-keratin does to mammalian skin. β-keratin is impregnated into the stratum corneum of the reptilian skin, providing waterproofing and the prevention of desiccation. In birds, beaks, claws and feathers also contain &#… (More on Beta-keratin)