Anticorps CD42b

GP-Ib, a surface membrane protein of platelets, participates in the formation of platelet plugs by binding to the A1 domain of vWF, which is already bound to the subendothelium.

Glycoprotein Ib (GP Ib) is a platelet surface membrane glycoprotein composed of a heterodimer, an alpha chain and a beta chain, that is linked by disulfide bonds. The Gp Ib functions as a receptor for von Willebrand factor (VWF). The complete receptor complex includes noncovalent association of the alpha and beta subunits with platelet glycoprotein IX and platelet glycoprotein V. The binding of the GP Ib-IX-V complex to VWF facilitates initial platelet adhesion to vascular subendothelium after vascular injury, and also initiates signaling events within the platelet that lead to enhanced platelet activation, thrombosis, and hemostasis. This gene encodes the alpha subunit. Mutations in this gene result in Bernard-Soulier syndromes and platelet-type von Willebrand disease. The coding region of this gene is known to contain a polymophic variable number tandem repeat (VNTR) domain that is associated with susceptibility to nonarteritic anterior ischemic optic neuropathy.

Non-arteritic anterior ischemic optic neuropathy: An ocular disease due to ischemic injury to the optic nerve. It usually affects the optic disk and leads to visual loss and optic disk swelling of a pallid nature. Visual loss is usually sudden, or over a few days at most and is usually permanent, with some recovery possibly occurring within the first weeks or months. Patients with small disks having smaller or non-existent cups have an anatomical predisposition for non-arteritic anterior ischemic optic neuropathy. As an ischemic episode evolves, the swelling compromises circulation, with a spiral of ischemia resulting in further neuronal damage.

Bernard-Soulier syndrome: A coagulation disorder characterized by a prolonged bleeding time, unusually large platelets, thrombocytopenia, and impaired prothrombin consumption.

Bernard-Soulier syndrome A2, autosomal dominant: A coagulation disorder characterized by mild to moderate bleeding tendency, thrombocytopenia, and an increased mean platelet volume. Some individuals have no symptoms. Mild bleeding tendencies manifest as epistaxis, gingival bleeding, menorrhagia, easy bruising, or prolonged bleeding after dental surgery.

Pseudo-von Willebrand disease: A bleeding disorder characterized by abnormally enhanced binding of von Willebrand factor by the platelet glycoprotein Ib (GP Ib) receptor complex. Hemostatic function is impaired due to the removal of VWF multimers from the circulation.

Glycocalicin is the product of a proteolytic cleavage/shedding, catalyzed by ADAM17, which releases most of the extracellular domain. Binding sites for vWF and thrombin are in this part of the protein.

Membrane.