Photoaffinity labeling of integrin alpha IIb beta 3 (glycoprotein IIb-IIIa) on intact platelets with 8-azido-[gamma-32P]ATP.
The fibrinogen receptor GPIIb-IIIa plays a crucial role in platelet aggregation. Here we show that the adenine nucleotide, 8-azido-ATP, inhibits ADP-induced conformational change of the platelet fibrinogen receptor GPIIb-IIIa (integrin alpha IIb beta 3). Photoaffinity labeling of intact platelets with 8-azido-[gamma-32P]ATP exclusively modifies two plasma-membrane glycoproteins which are identical with both subunits of GPIIb-IIIa. The presence of adenine-nucleotide-binding sites on GPIIb-IIIa implies that the platelet fibrinogen receptor is directly regulated by extracellular adenine nucleotides.
Mayinger
P
P
Medizinische Klinik I, Klinikum Grosshadern, Ludwig-Maximilians Universität München, Germany.
Gawaz
M
M
D000244:Adenosine Diphosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000031:analogs & derivatives* / Q000494:pharmacology; D000345:Affinity Labels / Q000494:pharmacology*; D001345:Autoradiography; D001386:Azides / Q000494:pharmacology*; D001792:Blood Platelets / Q000187:drug effects*; D002478:Cells, Cultured; D004591:Electrophoresis, Polyacrylamide Gel; D005455:Fluorescent Antibody Technique; D006801:Humans; D010761:Phosphorus Radioisotopes; D010777:Photochemistry; D010980:Platelet Membrane Glycoproteins / Q000737:chemistry / Q000187:drug effects*; D011487:Protein Conformation / Q000187:drug effects
D000345:Affinity Labels; D001386:Azides; D010761:Phosphorus Radioisotopes; D010980:Platelet Membrane Glycoproteins; C017040:8-azidoadenosine 5'-triphosphate; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate