A new monoclonal antibody, mAb 204-11, that influences the binding of platelet GPVI to fibrous collagen.
The newly identified platelet collagen receptor glycoprotein VI binds to fibrous collagen, inducing platelet activation. Several antibodies against GPVI have been reported, including a patient's auto-antibodies, that activates platelets through their ability to crosslink this glycoprotein. We have developed a monoclonal antibody (mAb) against GPVI using the recombinant extracellular domain of GPVI as an antigen. This antibody, mAb 204-11, induced platelet aggregation and tyrosine phosphorylation of proteins similar to those induced by GPVI-reactive proteins, collagen and convulxin. Its interaction with GPVI was analyzed by measuring the effect of the antibody on GPVI binding to collagen using a dimeric form of recombinant GPVI, GPVI-Fc2. MAb 204-11 inhibited the binding of GPVI-Fc2 to fibrous collagen particles, but enhanced the GPVI binding to immobilized collagen, suggesting that the antibody binds to a region near the collagen binding site of GPVI. MAb 204-11 also inhibited the GPVI binding to convulxin at a low concentration, but not completely. Since mAb 204-11 reacts specifically with GPVI and is applicable for immunoblotting and immunoprecipitation, this antibody would be useful for studies on GPVI.
Moroi
Masaaki
M
Department of Protein Biochemistry, Institute of Life Science, Kurume University, 2432-3 Aikawa-machi, Kurume, Fukuoka-ken, 839-0861, Japan. mmoroi@mbox.lsi.kurume-u.ac.jp
Mizuguchi
Jun
J
Kawashima
Sachiko
S
Nagamatsu
Michiko
M
Miura
Yoshiki
Y
Nakagaki
Tomohiro
T
Ito
Katsuaki
K
Jung
Stephanie M
SM
D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology*; D000937:Antigen-Antibody Reactions; D001665:Binding Sites; D003094:Collagen / Q000737:chemistry / Q000378:metabolism*; D000939:Epitopes; D007141:Immunoglobulin Fc Fragments / Q000494:pharmacology; D051379:Mice; D008807:Mice, Inbred BALB C; D010980:Platelet Membrane Glycoproteins / Q000276:immunology / Q000378:metabolism*; D011485:Protein Binding / Q000187:drug effects; D011994:Recombinant Proteins
D000911:Antibodies, Monoclonal; D000939:Epitopes; D007141:Immunoglobulin Fc Fragments; D010980:Platelet Membrane Glycoproteins; D011994:Recombinant Proteins; C098341:platelet membrane glycoprotein VI; D003094:Collagen