Molecular and functional characterization of a Schistosoma bovis annexin: Fibrinolytic and anticoagulant activity

31 páginas, 7 figuras. -- The definitive version is available at http://www.elsevier.comAnnexins belong to an evolutionarily conserved multigene family of proteins expressed throughout the animal and plant kingdoms. Although they are soluble cytosolic proteins that lack signal sequences, they have also been detected in extracellular fluids and have been associated with cell surface membranes, where they could be involved in anti-haemostatic and anti-inflammatory functions. Schistosome annexins have been identified on the parasite’s tegument surface and excretory/secretory products, but their functions are still unknown. Here we report the cloning, sequencing, in silico analysis, and functional characterization of a Schistosoma bovis annexin. The predicted protein has typical annexin secondary and tertiary structures. Bioassays with the recombinant protein revealed that the protein is biologically active in vitro, showing fibrinolytic and anticoagulant properties. Finally, the expression of the native protein on the tegument surface of S. bovis schistosomula and adult worms is demonstrated, revealing the possibility of exposure to the host’s immune system and thus offering a potential vaccine target for the control of schistosomiasis in ruminants.This research was funded by project AGL2007-60413/GAN, granted by the 562 Spanish Ministry of Science and Innovation. E. De la Torre-Escudero is holder of a 563 Ministry of Science and Innovation predoctoral grant and R. Manzano-Román is funded 564 by the JAEDoc program (CSIC-FSE).Peer reviewe