Trichobilharzia regenti which are capable of keratin and collagen degradation. Experiments with laboratory prepared recombinant form of the cysteine peptidase cathepsin B2 of "T. regenti" (TrCB2) confirmed its ability to cleave skin proteins (collagen, keratin and elastin). After penetration the skin, cercariae transform to schistosomula and start a migration through the host’s body. They avoid penetration into blood capillaries and rather prefer entering peripheral nerves in host’s limbs. Schistosomula are found in peripheral nerves of ducks and mice as soon as 1.5 and 1 day post infection (DPI), respectively. In both types of hosts, schistosomula exhibit a high affinity to the central
Alpha-keratin of most biological importance of alpha-keratin is its structural stability. When exposed to mechanical stress, α-keratin structures can retain their shape and therefore can protect what they surround. Under high tension, alpha-keratin can even change into beta-keratin, a stronger keratin formation that has a secondary structure of beta-pleated sheets. Alpha-keratin tissues also show signs of viscoelasticity, allowing them to both be able to stretch and absorb impact to a degree, though they are not impervious to fracture. Alpha-keratin strength is also affected by water content in the intermediate filament matrix; higher water content decreases the strength and stiffness of the