| Popis: |
(English): Trichobilharzia regenti is a neurotropic parasite of birds from the family Schistosomatidae. Cercariae, the invasive stages of these trematodes actively penetrate the host skin employing excretory- secretory products (ESPs), which contain proteolytic enzymes able to disrupt host tissues and thus reach the successful transmission. The most abundant secreted enzyme responsible for cercarial penetration of the human schistosome S. mansoni is a cercarial elastase. This serine peptidase is well known for the degradation of skin proteins such as elastin, keratin, collagen or laminin. However, the active expression of the orthologue of this enzyme has never been found in the genus Trichobilharzia. For this reason, it was firmly believed, that cercaria of T. regenti uses mainly cysteine peptidases for the invasion of the host, particularly cathepsins, which were repeatedly identified in this life stage. To strengthen this hypothesis, we incubated T. regenti cercariae in the apparatus with the excised duck skin stimulating the release of their glands' content. The collected ESPs were further analysed by shotgun mass-spectrometry and for the first time, the protein form of cercarial elastase was identified. Unfortunately, we failed to produce its active recombinant protein in yeast and bacterial... |
