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
HHV capsid portal protein HHV capsid portal protein HHV Capsid Portal Protein, or HSV-1 U-6 protein, is the protein which forms a cylindrical portal in the capsid of Herpes simplex virus (HSV-1). The protein is commonly referred to as the "HSV-1 U-6" protein because it is the transcription product of Herpes gene U-6. The Herpes viral DNA enters and exits the capsid via the capsid portal. The capsid portal is formed by twelve copies of portal protein arranged as a ring; the proteins contain a leucine zipper sequence of amino acids which allow them to adhere to each other. Each icosahedral capsid contains a