Apyrase with anti-platelet aggregation activity from the nymph of the camel tick Hyalomma dromedarii.

Autor: Masoud HMM; Molecular Biology Department, National Research Centre, 33 El Bohouth St. (former El Tahrir St.), Dokki, P.O. 12622, Giza, Egypt. hssnmasoud@yahoo.com., Helmy MS; Molecular Biology Department, National Research Centre, 33 El Bohouth St. (former El Tahrir St.), Dokki, P.O. 12622, Giza, Egypt., Darwish DA; Molecular Biology Department, National Research Centre, 33 El Bohouth St. (former El Tahrir St.), Dokki, P.O. 12622, Giza, Egypt., Abdel-Monsef MM; Molecular Biology Department, National Research Centre, 33 El Bohouth St. (former El Tahrir St.), Dokki, P.O. 12622, Giza, Egypt., Ibrahim MA; Molecular Biology Department, National Research Centre, 33 El Bohouth St. (former El Tahrir St.), Dokki, P.O. 12622, Giza, Egypt.
Jazyk: angličtina
Zdroj: Experimental & applied acarology [Exp Appl Acarol] 2020 Mar; Vol. 80 (3), pp. 349-361. Date of Electronic Publication: 2020 Jan 11.
DOI: 10.1007/s10493-020-00471-9
Abstrakt: 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 K m 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 FeCl 2 , FeCl 3 and ZnCl 2 are activators of TNapyrase. EDTA inhibited TNapyrase activity competitively with a single binding site on the molecule and K i 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.
Databáze: MEDLINE
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