Natural fiber Keratin is a structural protein located at the hard surfaces in many vertebrates. Keratin has two forms, α-keratin and β-keratin and are used by different classes of animals. The naming convention for proteins follows that for keratin, alpha keratin is helical and beta keratin is sheet like. Alpha keratin is found in mammalian hair, skin, nails, horn and quills, while beta keratin can be found in avian and reptilian species in scales, feathers, and beaks. The two different structures of keratin have dissimilar mechanical properties, as seen in their dissimilar applications. The relative alignment of the keratin fibrils has a
Nestin (protein) of actively growing pluripotent adult stem cells. Green fluorescent protein (GFP), whose expression is driven by the nestin regulatory element in transgenic mice, serves to mark hair follicle stem cells. These cells can differentiate into neurons, glia, keratinocytes, smooth muscle cells and melanocytes in vitro. Thus, hair follicle stem cells provide an effective, accessible, autologous source of stem cells for treatment of peripheral nerve injury. Nestin has recently received attention as a marker for detecting newly formed endothelial cells. Nestin is an angiogenesis marker of proliferating endothelial cells in colorectal cancer tissue. Nestin (protein) has been shown to interact with