Model representing the association of secreted AP65 with membranes. AP65 is secreted to the extracellular environment and re-associates on the parasite surface. This figure shows a protein site on the parasite (labeled R) to which AP65 binds. It is probable that AP65 can re-associate as a monomer or a dimer. In the case of the AP65-dimer one amino-terminus is available to interact with the protein site on the parasite (R) and the second one with an equivalent host cell site (labeled R') forming a bridge that promotes adherence.