Ayadualin, a novel RGD peptide with dual antihemostatic activities from the sand fly Lutzomyia ayacuchensis, a vector of Andean-type cutaneous leishmaniasis

作者：Kato Hirotomo^*; Gomez Eduardo A; Fujita Megumi; Ishimaru Yuka; Uezato Hiroshi; Mimori Tatsuyuki; Iwata Hiroyuki; Hashiguchi Yoshihisa

来源：Biochimie, 2015, 112: 49-56.

DOI：10.1016/j.biochi.2015.02.011

• RDG peptide
• Sand fly
• Saliva
• Anticoagulant
• Antiplatelet

Sequence analysis of the Lutzomyia (Lu.) ayacuchensis salivary gland cDNA library identified a short peptide containing an RGD (Arg-Gly-Asp) sequence flanked by two cysteine residues in the C-terminal end as the most abundant transcript. In the present study, a recombinant protein of the RGD-containing peptide, designated ayadualin, was expressed in Escherichia colt and its activity was characterized. Ayadualin inhibited both collagen and ADP-induced platelet aggregations by interfering with the binding of integrin alpha(IIb)beta(3) to fibrinogen. The RGD sequence and cysteine residues located on both sides of the RGD sequence were essential for the inhibitory action. Moreover, ayadualin efficiently inhibited the intrinsic blood coagulation pathway irrespective of the RGD sequence. Measuring the enzymatic activity of coagulation factors using chromogenic substrates revealed that ayadualin efficiently inhibited factor XIIa (FXIIa) activity in a dose-dependent manner. In addition, pre-incubation of ayadualin with FXII inhibited FXIIa activity, while activated FXIIa was not affected by ayadualin, indicating that ayadualin inhibits the activation of FXII, but not enzymatic activity of FXIIa. These results indicated that ayadualin plays an important role in the blood feeding of Lu. ayacuchensis by inhibiting host hemostasis via dual mechanisms.

• 出版日期2015-5