Characterization of the binding of a glycosylated serine protease from Euphorbia cf. lactea latex to human fibrinogen

Abstract

In this study, the binding of a glycosylated serine protease (EuP-82) with human fibrinogen was investigated by isothermal titration calorimetry (ITC). ITC analysis indicated that the binding of EuP-82 to fibrinogen in the conditions with or without the activator (Ca ) was an exothermic reaction (dominant negative enthalpy), which tended to be driven by hydrogen bonding and van der Waals interactions. In contrast, the binding of fibrinogen-EuP-82 in the condition with the inhibitor (Zn ) was an unfavorable endothermic reaction. EuP-82 could not inhibit the platelet activity in citrated whole blood via the ADP-receptor pathways (mainly, P2Y1 and P2Y12), but it could enhance the platelet aggregation. The ITC together with whole blood platelet aggregation suggested that EuP-82 provided multiple fibrinogen-binding sites that were not related to the arginine-glycine-aspartate (RGD) and the dodecapeptide sequences of fibrinogen. In addition, EuP-82 had neither thrombin-like activity nor anticoagulant activity. The SR-FTIR spectra revealed that EuP-82 was a glycoprotein. Deglycosylation of EuP-82 did not affect its proteolytic activity. Moreover, EuP-82 did not exhibit any toxicity to the living cells (NIH-3T3). This study supports that EuP-82 may be useful for wound-healing material through stabilizing the clot via the platelet induction for the first process.

Fabrication of silver chloride nanoparticles using a plant serine protease in combination with photoactivation and investigation of their biological activities

“…This work was supported by the Suranaree University of Technology Research Fund for promoting academic accomplishment to be published in international journals [grant no. IRD1-102-60- [12][13][14][15][16][17][18][19]. We would like to thank the Synchrotron Light Research Institute (public organization), Thailand for providing the facility to perform the XAS experiments at BL5.2: SUT-NANOTEC-SLRI Beamline.…”

“…EuP‐82 is a dimeric serine protease that can bind to and hydrolyze human fibrinogen . In addition, EuP‐82 can bind to some metal ions, e.g., calcium (Ca 2+ ) and zinc (Zn 2+ ), which then activate or inhibit its proteolytic activity, respectively . In this study, EuP‐82 was chosen for AgCl‐NPs fabrication since its binding of metal ions may prevent the aggregation of metal compounds.…”