Disruption of protein-membrane binding and identification of small-molecule inhibitors of coagulation factor VIII.
Factor VIII is a critical member of the blood coagulation cascade. It binds to the membrane surfaces of activated platelets at the site of vascular injury via a highly specific interaction between factor VIII's carboxy-terminal C2 domain and their phosphatidylserine-rich lipid bilayer. We have identified small-molecule inhibitors of factor VIII's membrane binding activity that have IC50 values as low as 2.5 microM. This interaction is approximately 10(3)-fold tighter than that of free o-phospho-L-serine. These compounds also inhibit factor VIII-dependent activation of factor X, indicating that disruption of membrane lipid binding leads to inhibition of the intrinsic coagulation pathway. The tightest binding inhibitor is specific and does not prevent membrane binding by the closely related coagulation factor V. These results indicate that this and related compounds may be used as leads to develop novel antithrombotic agents.
Graduate Program in Biomolecular Structure and Design, University of Washington, Seattle, Washington 98195, USA.
P Clint
PC
Spiegel
Shari M
SM
Kaiser
Julian A
JA
Simon
Barry L
BL
Stoddard
D019774:Blood Coagulation Factor Inhibitors / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D005169:Factor VIII / Q000037:antagonists & inhibitors* / Q000737:chemistry* / Q000378:metabolism; D020128:Inhibitory Concentration 50; D008565:Membrane Proteins / Q000037:antagonists & inhibitors* / Q000737:chemistry* / Q000378:metabolism; D008970:Molecular Weight; D011485:Protein Binding / Q000502:physiology; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism
D019774:Blood Coagulation Factor Inhibitors; D008565:Membrane Proteins; D011994:Recombinant Proteins; D005169:Factor VIII