Flow as a regulator of the activation of factor X by tissue factor.
A novel enzyme reactor for phospholipid-dependent reactions was used to study the effects of flow on tissue factor-initiated coagulation. Microcapillaries were coated with a phospholipid bilayer containing tissue factor, a transmembrane protein that is an essential cofactor for a plasma procoagulant enzyme, factor VII. We show that, in contrast to static, closed systems, the steady-state catalytic activity is independent of enzyme concentration and the time to steady state becomes a function of the enzyme concentration.
Gemmell
C H
CH
Department of Medicine, Mt Sinai School of Medicine, NY 10029.
Turitto
V T
VT
Nemerson
Y
Y
D000818:Animals; D001783:Blood Flow Velocity; D002196:Capillaries / Q000502:physiology; D002417:Cattle; D005167:Factor VII / Q000378:metabolism; D015942:Factor VIIa; D005170:Factor X / Q000378:metabolism*; D015951:Factor Xa; D066298:In Vitro Techniques; D010743:Phospholipids; D012697:Serine Endopeptidases / Q000378:metabolism*; D013379:Substrate Specificity; D013925:Thromboplastin
D010743:Phospholipids; D005167:Factor VII; D005170:Factor X; D013925:Thromboplastin; D012697:Serine Endopeptidases; D015942:Factor VIIa; D015951:Factor Xa