Apyrase with anti-platelet aggregation activity from the nymph of the camel tick Hyalomma dromedarii
- 36 Downloads
Apyrase is one of the essential platelet aggregation inhibitors in hematophagous arthropods due to its ability to hydrolyze ATP and ADP molecules. Here, an apyrase (TNapyrase) with antiplatelet aggregation activity was purified and characterized from the nymphs of the camel tick Hyalomma dromedarii through anion exchange and gel filtration columns. The homogeneity of TNapyrase was confirmed by native-PAGE, SDS-PAGE as well as with isoelectric focusing. Purified TNapyrase had a molecular mass of 25 kDa and a monomer structure. TNapyrase hydrolyzed various nucleotides in the order of ATP > PPi > ADP > UDP > 6GP. The Km value was 1.25 mM ATP and its optimum activity reached at pH 8.4. The influence of various ions on TNapyrase activity showed that FeCl2, FeCl3 and ZnCl2 are activators of TNapyrase. EDTA inhibited TNapyrase activity competitively with a single binding site on the molecule and Ki value of 2 mM. Finally, TNapyrase caused 70% inhibition of ADP-stimulated platelets aggregation and is a possible target for antibodies in future tick vaccine studies.
KeywordsCamel tick nymph Hyalomma dromedarii Apyrase Purification Antiplatelet aggregation
Platelet poor plasma
Platelet rich plasma
Tick nymph apyrase
The National Research Centre, Egypt is greatly appreciated for funding this study.
- Darwish DA, Masoud HM, Ibrahim MA (2015) Apyrase from embryo of the camel tick Hyalomma dromedarii. RJPBCS 6(1):1687–1695Google Scholar
- Dutta S, Gogoi D, Mukherjee AK (2015) Anticoagulant mechanism and platelet deaggregation property of a non-cytotoxic, acidic phospholipase A2 purified from Indian cobra (Naja naja) venom: inhibition of anticoagulant activity by low molecular weight heparin. Biochimie 110:93–106PubMedCrossRefGoogle Scholar
- Hansford KM, Carter D, Gillingham EL, Hernandez-Triana LM, Chamberlain J, Cull B, McGinley L, Phipps LP, Medlock JM (2019) Hyalomma rufipes on an untraveled horse: Is this the first evidence of Hyalomma nymphs successfully moulting in the United Kingdom? Ticks Tick-Borne Dis 10:704–708PubMedCrossRefGoogle Scholar
- Smith I (1969) Acrylamide gel disc electrophoresis. In: Smith I (ed) Electrophoretic techniques. Academic Press, New York, pp 365–515Google Scholar