Tick salivary platelet aggregation inhibitor that plays an important part in the anti-hemostatic strategy of ticks (PubMed:11932256). Inhibits platelet aggregation induced by ADP (IC(50)=130 nM), collagen, the thrombin receptor-activating peptide, and epinephrine, although platelets are activated and their shape changed (PubMed:11932256). Binding to platelets is similar for resting and activated platelets (Kd=50-70 nM) (PubMed:15147758). Acts by specifically binding to platelet membrane glycoprotein IIb-IIIa (ITGA2B/ITGB3) in a divalent metal ion dependent manner (Probable) (PubMed:15147758). In contrast to many disintegrins which only interacts with the beta-3 subunit, this protein interacts with the two subunits (alpha-IIb and beta-3) (Probable). Also causes disaggregation of aggregated platelets without influencing the activated spherical shape associated with aggregated platelets and causes a decrease in the number of pseudopodia on the activated platelet surface (PubMed:12593588). Does not show any inhibitory activity for the different serine proteases tested (PubMed:11932256). Before secretion, is localized to dense core granule type 'a' and to granule type 'b', but not to granules 'c' or 'd'. Expressed in salivary glands.