Immunologic Determination of Proteins Found in Low Concentrations in Human Serum

Abstract

Abstract Of 42 well-characterized proteins of human blood plasma, 23 previously have been determined by quantitative immunochemical methods. Quantitative data on an additional 10 plasma proteins are now communicated. Antiserums against the following proteins have been prepared: α1B-glycoprotein (easily precipitable α1-glycoprotein). α1T-glycoprotein (tryptophane-poor α1-glycoprotein), α1-antichymotrypsin (α1X-glycoprotein), α2-antithrombin (antithrombin III), Zn-α2-glycoprotein, α2-neuramino-glycoprotein (C'1 esterase inhibitor), β2-glycoprotein II and III, γD-globulin. These proteins were determined in normal human serums by applying radial immunodiffusion. Highly purified and physicochemically well-defined proteins were used as standards. Coagulation factor XIII (fibrin-stabilizing factor) was determined immunochemically in normal plasma using a specific antiserum. A genetically determined deficiency of β2-glycoprotein I has been found in healthy individuals. As yet, no conclusions on the biologic function of this protein can be drawn from the results. The available data on physiologic function and pathophysiologic abnormalities of all proteins mentioned are discussed.