Saliva of the soft tick, Ornithodoros moubata, contains anti-platelet and apyrase activities.
1. Pilocarpine-induced saliva of the soft tick Ornithodoros moubata inhibits platelet aggregation induced by ADP or collagen, even when diluted 2000 times into platelet rich plasma. 2. Saliva contains apyrase (ATP-diphosphohydrolase) activity, which has an optimal pH of 7.0 for ADP and of 8.0 for ATP hydrolysis, respectively. Both Ca2+ and Mg2+ activate the reactions. 3. The mean specific activities for ATP and ADP hydrolysis at pH 7.5 were 0.97 and 0.74 mumoles orthophosphate/min/mg protein. 4. These results, which demonstrate for the first time such activities in the saliva of soft ticks, support the hypothesis that the saliva of blood sucking arthropods serves an anti-hemostatic role during feeding and that large amounts of salivary apyrase activity have evolved independently in hematophagous arthropods.
Ribeiro
J M
JM
Harvard School of Public Health, Department of Tropical Public Health, Boston, MA 02115.
Endris
T M
TM
Endris
R
R
D000244:Adenosine Diphosphate / Q000378:metabolism; D000249:Adenosine Monophosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D001081:Apyrase / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D002413:Cations, Divalent; D006801:Humans; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007700:Kinetics; D008274:Magnesium / Q000378:metabolism; D010975:Platelet Aggregation Inhibitors; D012463:Saliva / Q000378:metabolism*; D013045:Species Specificity; D013987:Ticks / Q000502:physiology*
D002413:Cations, Divalent; D010975:Platelet Aggregation Inhibitors; D000249:Adenosine Monophosphate; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D001081:Apyrase; D008274:Magnesium; D002118:Calcium