Odum L
Department of Clinical Chemistry, Rigshospitalet, University of Copenhagen, Denmark.
Biol Chem Hoppe Seyler. 1990 Dec;371(12):1153-8.
Inter-alpha-trypsin inhibitor (ITI) consists of 3 polypeptides cross-linked by chondroitin sulphate, which is o-glycosidically linked to the smallest of the polypeptides, designated bikunin. Pre-alpha-trypsin inhibitor (p alpha I) consists of bikunin and a fourth polypeptide, also associated by chondroitin sulphate. Crossed immunoelectrophoresis (CIE) of plasma, using immunoglobulins to ITI, revealed 3 precipitation-lines, two of which increased in size during disease. Molecular mass determination by polyacrylamide gel electrophoresis showed that the immunoprecipitates contained mixtures of proteins. Therefore CIE is unfit for quantitation of the individual proteins related to ITI. Immunoblotting suggested that the plasma concentrations of p alpha I and of bikunin was increased in uraemia, rheumatoid arthritis and after trauma. The plasma concentrations of ITI and of p alpha I were decreased in a patient with endocarditis.
α-胰蛋白酶抑制剂（ITI）由3种通过硫酸软骨素交联的多肽组成，硫酸软骨素以O-糖苷键连接到最小的多肽，即比库宁。前α-胰蛋白酶抑制剂（pαI）由比库宁和第四种多肽组成，它们也通过硫酸软骨素相连。用针对ITI的免疫球蛋白对血浆进行交叉免疫电泳（CIE），显示出3条沉淀线，其中两条在疾病期间大小增加。通过聚丙烯酰胺凝胶电泳测定分子量表明，免疫沉淀物含有蛋白质混合物。因此，CIE不适用于定量与ITI相关的单个蛋白质。免疫印迹法表明，在尿毒症、类风湿性关节炎和创伤后，pαI和比库宁的血浆浓度升高。一名心内膜炎患者的ITI和pαI血浆浓度降低。
