Haematologia 20. (1987)
1987 / 1. szám - Niewiarowski, S.: Platelet membrane components and receptors
1* Haematohgia 20 (1), pp. 3—14 ( 1987) Platelet Membrane Components and Receptors* S. Niewiarowski Thrombosis Research Center and Department of Physiology, Temple University Health Sciences Center, Philadelphia, PA 19140, USA (Received January 7, 1986; accepted February 10, 1986) Receptor-ligand interactions on the platelet membrane control a number of phenomena unique to platelets such as shape change, aggregation, release reaction of secretion, clot retraction and activation of clotting factors. Localization of receptor on the well-defined platelet membrane glycoproteins appears to be a major target of numerous studies in the field of platelet research. The author is reviewing methodological development in this field including surface labeling of the platelets, one and two dimensional electrophoresis, development of monoclonal and polyclonal antibodies to platelet membrane glycoproteins and receptors, immunoblotting, radiolabeled ligand studies and preparative techniques. Classification of membrane glycoproteins is briefly discussed. The current knowledge of the receptors for fibrinogen and other adhesive proteins, clotting factors, ADP and prostanoids is reviewed. Keywords: platelet membranes, receptors, receptor-ligand interaction, membrane glycoproteins, platelet function Introduction Plasma membranes have an essential function in mammalian cells. Influences from the extracellular environment must be translated across them and all cytoplasmic products can only reach the outside of the cell by the same membranecontrolled mechanism. The principal components of plasma membrane are lipids, proteins and carbohydrates. Lipids constitute the structural framework of the biological membrane while biological specificity resides primarily in the proteins interacting with the lipid bilayer. It is now well established that membrane receptors are associated with specific proteins. The membrane protein can either be peripheral or integral. The former can be located on either the inner or the outer surface of the plasma membrane. The latter spans the lipid bilayers with part of the protein located outside the cell, a portion spanning the bilayer and residual part inside the cell. The outside portion of the integral protein is usually glycosylated and this is important in the process of cellular recognition. The part of the integral protein located inside the cell may interact with components of the cell * Paper presented at the Vlllth Meeting of the European-African Division of the International Society of Haematology, Warsaw, Poland, September 1985 VNU Science Press, Utrecht Akadémiai Kiadó, Budapest