Abstract:

Objective To study the bioactive components in ticks which inhibit platelet aggregation， and to understand the molecular mechanism of tick-host interaction. Methods Sephadex G-50 gel filtration and high performance liquid chromatography （HPLC） were used to purify the platelet aggregation inhibitor from Ixodes sinensis. Its molecular weight and purity were checked by matrix-assisted laser desorption ionization time-of-flight （MALDI-TOF） mass spectrometry. Platelet-rich plasma （PRP） of rabbit was used to examine the function of platelet aggregation inhibitor. Results A purified platelet aggregation inhibitor was identified from I.sinensis with a molecular weight of 8 065. It inhibited platelet aggregation induced by ADP with strong potency. The inhibition of platelet aggregation reached over 90% under a concentration of 10 μg/ml. Conclusion An inhibitor of platelet aggregation from I.sinensis was identified， which may play an important role for ticks to successfully get blood meal from their hosts.

Key words: Ixodes sinensis, Platelet aggregation inhibitor, Serine protease, Activity, Blood meal