Characterization of a 14 kDa oocyst wall protein of Eimeria tenella and E. acervulina

We have extracted a protein of 14 kDa from purified oocyst walls of several Eimeria species. Polyclonal antibodies were raised in rats against the 14 kDa proteins of E. acervulina and E. tenella. On immunoblots these antisera reacted in a highly specific manner with the homologous 14 kDa antigens, but not with heterologous antigens. In addition, specific binding of the two antisera to oocyst wall fragments of E. acervulina and E. tenella was demonstrated by immunofluorescence. Partial amino-terminal sequences comprising 20 amino acid residues were obtained from the 14 kDa oocyst wall proteins of E. acervulina and E. tenella. They are characterized by an abundance of amino acids containing hydroxyl groups in their side chains (serine, tyrosine, threonine). Binding of the oocyst wall protein of E. tenella by peanut agglutinin indicates the presence of O-linked carbohydrate

In Silico Identification of Specialized Secretory-Organelle Proteins in Apicomplexan Parasites and In Vivo Validation in Toxoplasma gondii

Apicomplexan parasites, including the human pathogens Toxoplasma gondii and Plasmodium falciparum, employ specialized secretory organelles (micronemes, rhoptries, dense granules) to invade and survive within host cells. Because molecules secreted from these organelles function at the host/parasite interface, their identification is important for understanding invasion mechanisms, and central to the development of therapeutic strategies. Using a computational approach based on predicted functional domains, we have identified more than 600 candidate secretory organelle proteins in twelve apicomplexan parasites. Expression in transgenic T. gondii of eight proteins identified in silico confirms that all enter into the secretory pathway, and seven target to apical organelles associated with invasion. An in silico approach intended to identify possible host interacting proteins yields a dataset enriched in secretory/transmembrane proteins, including most of the antigens known to be engaged by apicomplexan parasites during infection. These domain pattern and projected interactome approaches significantly expand the repertoire of proteins that may be involved in host parasite interactions

Characterization of a 14 kDa oocyst wall protein of Eimeria tenella and E. acervulina

We have extracted a protein of 14 kDa from purified oocyst walls of several Eimeria species. Polyclonal antibodies were raised in rats against the 14 kDa proteins of E. acervulina and E. tenella. On immunoblots these antisera reacted in a highly specific manner with the homologous 14 kDa antigens, but not with heterologous antigens. In addition, specific binding of the two antisera to oocyst wall fragments of E. acervulina and E. tenella was demonstrated by immunofluorescence. Partial amino-terminal sequences comprising 20 amino acid residues were obtained from the 14 kDa oocyst wall proteins of E. acervulina and E. tenella. They are characterized by an abundance of amino acids containing hydroxyl groups in their side chains (serine, tyrosine, threonine). Binding of the oocyst wall protein of E. tenella by peanut agglutinin indicates the presence of O-linked carbohydrates

Effect of Fluid Viscoelasticity on Turbulence and Large-Scale Vortices behind Wall-Mounted Plates

Direct numerical simulations of turbulent viscoelastic fluid flows in a channel with wall-mounted plates were performed to investigate the influence of viscoelasticity on turbulent structures and the mean flow around the plate. The constitutive equation follows the Giesekus model, valid for polymer or surfactant solutions, which are generally capable of reducing the turbulent frictional drag in a smooth channel. We found that turbulent eddies just behind the plates in viscoelastic fluid decreased in number and in magnitude, but their size increased. Three pairs of organized longitudinal vortices were observed downstream of the plates in both Newtonian and viscoelastic fluids: two vortex pairs were behind the plates and the other one with the longest length was in a plate-free area. In the viscoelastic fluid, the latter vortex pair in the plate-free area was maintained and reached the downstream rib, but its swirling strength was weakened and the local skin-friction drag near the vortex was much weaker than those in the Newtonian flow. The mean flow and small spanwise eddies were influenced by the additional fluid force due to the viscoelasticity and, moreover, the spanwise component of the fluid elastic force may also play a role in the suppression of fluid vortical motions behind the plates