Purification and characterization of Cc-Lec, C-type lactose-binding lectin: A platelet aggregation and blood-clotting inhibitor from Cerastes cerastes venom

- Cc-Lec modeled 3D structure appeared as homodimer cross-linked by one disulfide bridge.
- Cc-Lec exhibited in vivo long-lasting anticoagulation even two days post-treatment with any lethality for mice.
- Cc-Lec mediated dose dependently, the inhibition of thrombosis since it behaved as a potent inhibitor of FXa by abolishing amidolytic activity.
- Cc-Lec prohibited platelet aggregation induced by ADP, arachidonic acid and fibrinogen suggesting its interaction with their specific receptors namely P2Y1 and/or P2Y12, TPα and GPIIbIIIa respectively.

In this study, we reported for the first time the biochemical and structural characterization of Cc-Lec, a C-type lectin purified from Cerastes cerastes venom by affinity chromatography. This lectin was homogeneous by SDS-PAGE, and was shown to be a 34 271.59 Da polypeptide by Electrospray mass spectrometry MS-ES-TOF. Its identified sequence of 160 amino acids corresponding to one subunit, revealed a high identity with other related proteins. Cc-Lec modeled 3D structure appeared as homodimer cross-linked by one disulfide bridge. Cc-Lec exhibited a calcium dependent hemagglutinating activity against human group O erythrocytes. Cc-Lec inhibited platelet aggregation induced by ADP, arachidonic acid or fibrinogen suggesting its interaction with their specific receptors namely P2Y1 and/or P2Y12, GPIIb/IIIa and TPα respectively. Cc-Lec was not lethal for mice until 10 mg/kg administered by i.p. route. The lectin displayed a lasting anticoagulation on mice plasma even two days post-injection. This anticoagulation seems to be related to its interaction with coagulation factors Xa and IXa. Therefore, Cc-Lec prevented FXa amidolytic activity with Km = 4.33 10−4 μg/mL and ki = 14.4 μg/mL. It seems to interact with these targets through CRD domain which could make it a good target as a pharmacological promising molecule in thrombosis diagnosis and therapy.