TY - JOUR
T1 - Convulxin, a potent platelet-aggregating protein from crotalus durissus terrificus venom, specifically binds to platelets
AU - Francischetti, Ivo M.B.
AU - Saliou, Bernard
AU - Leduc, Mireille
AU - Carlini, Celia R.
AU - Hatmi, Mohamed
AU - Randon, Jacques
AU - Faili, Ahmad
AU - Cassian, Bon
N1 - Funding Information:
.~ch-flon,lrtl~rrtlen-tW.s e are very grateful to Dr J. d’Alayer (Labordtoire de Microsequences, lnstitut Pasteur. Paris) for performing the amino acid sequences.T his work was supported in part by funds from the European Community (contract no. CII-CT94-0073).
PY - 1997/8
Y1 - 1997/8
N2 - Convulxin, a very potent aggregating protein from rattlesnake venom, was purified by a new procedure and its heterodimeric structure α3β3 was confirmed. The polypeptide N-terminal sequences of convulxin subunits were determined by Edman degradation. They are very similar and appear homologous to botrocetin from Bothrops jararaca venom and to rattlesnake lectin from Crotalus atrox venom, both being classified among the C-type lectin family. The binding of 125I-labelled convulxin to blood platelets has also been analysed under equilibrium conditions. These studies indicated that convulxin binds to platelets with a high affinity (K(d) = 30 pM) on a small number of binding sites (1000 binding sites per cell). The high-affinity binding of convulxin appears specific to platelets, since it is not observed on other cell types such as neutrophils and erythrocytes. Also, the high-affinity binding of convulxin to membranes platelet is not inhibited by α-thrombin, fibrinogen, collagen, laminin binding inhibitor, RGDS peptide, adenosine diphosphate, platelet-activating factor-acether, serotonin or epinephrine. This, together with the recent observation that platelet activation by convulxin is partially mediated by phospholipase C and involves other mechanisms as well, indicates that convulxin may interact with a specific platelet acceptor (receptor) protein which has yet to be characterized.
AB - Convulxin, a very potent aggregating protein from rattlesnake venom, was purified by a new procedure and its heterodimeric structure α3β3 was confirmed. The polypeptide N-terminal sequences of convulxin subunits were determined by Edman degradation. They are very similar and appear homologous to botrocetin from Bothrops jararaca venom and to rattlesnake lectin from Crotalus atrox venom, both being classified among the C-type lectin family. The binding of 125I-labelled convulxin to blood platelets has also been analysed under equilibrium conditions. These studies indicated that convulxin binds to platelets with a high affinity (K(d) = 30 pM) on a small number of binding sites (1000 binding sites per cell). The high-affinity binding of convulxin appears specific to platelets, since it is not observed on other cell types such as neutrophils and erythrocytes. Also, the high-affinity binding of convulxin to membranes platelet is not inhibited by α-thrombin, fibrinogen, collagen, laminin binding inhibitor, RGDS peptide, adenosine diphosphate, platelet-activating factor-acether, serotonin or epinephrine. This, together with the recent observation that platelet activation by convulxin is partially mediated by phospholipase C and involves other mechanisms as well, indicates that convulxin may interact with a specific platelet acceptor (receptor) protein which has yet to be characterized.
UR - http://www.scopus.com/inward/record.url?scp=0030801096&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0030801096&partnerID=8YFLogxK
U2 - 10.1016/S0041-0101(97)00021-4
DO - 10.1016/S0041-0101(97)00021-4
M3 - Article
C2 - 9278971
AN - SCOPUS:0030801096
SN - 0041-0101
VL - 35
SP - 1217
EP - 1228
JO - Toxicon
JF - Toxicon
IS - 8
ER -