Avathrin: a novel thrombin inhibitor derived from a multicopy precursor in the salivary glands of the ixodid tick,Amblyomma variegatum

Tick saliva is a rich source of antihemostatic compounds. We amplified a cDNA from the salivary glands of the tropical bont tick (Amblyomma variegatum) using primers based on the variegin sequence, which we previously identified as a novel thrombin inhibitor from the same tick species. The transcript encodes a precursor protein comprising a signal peptide and 5 repeats of variegin-like sequences that could be processed into multiple short...