Identification of anticoagulant activities in the salivary glands of the soft tick,Ornithodoros savignyi

Salivary gland extracts of the sand tampan, Ornithodoros savignyi, prolonged the activated partial thromboplastin time (APTT) and prothrombin time (PT) significantly in a concentration-dependent manner. There was also a pronounced inhibition of human activated factor Xa (fXa) by salivary gland extracts. The salivary gland extracts inhibited chromogenic assays specific for both fXa and thrombin. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) of the salivary gland proteins followed by elution of specific areas or bands from a polyvinylidene difluoride (PVDF)-membrane, showed that various anticoagulant factors are present when screened by means of the APTT assay. The most active component was associated with a band of M_r of 14 kDa. Partial purification of this component was achieved using isoelectric focusing (IEF) and size-exclusion highperformance liquid chromatography (HPLC).