title: Anti-platelet activity of a three-finger toxin (3FTx) from Indian monocled cobra (Naja kaouthia) venom.
abstract: A low molecular weight anti-platelet peptide (6.9 kDa) has been purified from Naja kaouthia venom and was named KT-6.9. MALDI-TOF/TOF mass spectrometry analysis revealed the homology of KT-6.9 peptide sequence with many three finger toxin family members. KT-6.9 inhibited human platelet aggregation process in a dose dependent manner. It has inhibited ADP, thrombin and arachidonic acid induced platelet aggregation process in dose dependent manner, but did not inhibit collagen and ristocetin induced platelet aggregation. Strong inhibition (70%) of the ADP induced platelet aggregation by KT-6.9 suggests competition with ADP for its receptors on platelet surface. Anti-platelet activity of KT-6.9 was found to be 25 times stronger than that of anti-platelet drug clopidogrel. Binding of KT-6.9 to platelet surface was confirmed by surface plasma resonance analysis using BIAcore X100. Binding was also observed by a modified sandwich ELISA method using anti-KT-6.9 antibodies. KT-6.9 is probably the first 3 FTx from Indian monocled cobra venom reported as a platelet aggregation inhibitor.
authors.affiliation: Department of Biological Sciences, Birla Institute of Technology and Science, Pilani, K.K. Birla Goa Campus, Zuarinagar, Goa 403726, India.
authors.forename: Chandrasekhar
authors.initials: C
authors.lastname: Chanda
authors.forename: Angshuman
authors.initials: A
authors.lastname: Sarkar
authors.forename: Srinivas
authors.initials: S
authors.lastname: Sistla
authors.forename: Dibakar
authors.initials: D
authors.lastname: Chakrabarty
mesh_terms: D000244:Adenosine Diphosphate / Q000494:pharmacology; D016718:Arachidonic Acid / Q000037:antagonists & inhibitors / Q000494:pharmacology; D001792:Blood Platelets / Q000187:drug effects*; D002478:Cells, Cultured; D000077144:Clopidogrel; D004546:Elapid Venoms / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D006801:Humans; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology*; D058921:Purinergic P2Y Receptor Antagonists / Q000494:pharmacology; D013917:Thrombin / Q000037:antagonists & inhibitors / Q000494:pharmacology; D013988:Ticlopidine / Q000031:analogs & derivatives / Q000494:pharmacology
chemical_list: D004546:Elapid Venoms; C587293:KT-6.9 peptide, Naja kaouthia; C521753:Naja kaouthia venom; D010975:Platelet Aggregation Inhibitors; D058921:Purinergic P2Y Receptor Antagonists; D016718:Arachidonic Acid; D000244:Adenosine Diphosphate; D000077144:Clopidogrel; D013917:Thrombin; D013988:Ticlopidine
keywords: 3FTx; ADP; Anti-platelet; FITC; G-protein coupled receptor; GPCR; Indian cobra venom; KT-6.9; MW; P2Y receptor; RP-HPLC; SPR; adenosine di-phosphate; fluorescein isothiocyanate; molecular weight; reversed phase high performance liquid chromatography; surface plasma resonance