Ohtani H, Sakaguchi K, Saito M
J Clin Pathol. 1982 Apr;35(4):385-9. doi: 10.1136/jcp.35.4.385.
The protein contents and binding modes of immunoglobulin-amylase complexes were investigated. Amylase staining after immunoelectrophoresis permitted identification of IgA-lambda type in three cases, IgA-kappa type in two cases and IgG-kappa type in one case. The precipitin line of Fab fragment of IgA in four patient's sera after papain digestion was found to have amylase activity. Sucrose density gradient ultracentrifugation studies showed that these complexes were divided into three groups: Group I complexes were dissociated in acid pH, and at pH 7.0 the immunoglobulins, which were isolated at the acid pH, became rebound to serum amylase; Group II complexes were dissociated by acidification, but did not reform at pH 7.0; Group III complexes were unaffected by acidification. We suggest that the immunoglobulin-amylase complexes belonging to groups I and II result from an antigen-antibody reaction. Precipitin curves resulting from the addition of increasing quantities of the patient's serum containing 9 S or 11 S immunoglobulin-amylase complexes to specific antisera revealed that these complexes contained not only monoclonal IgA, but also alpha-1-antitrypsin (alpha 1 AT) and albumin. These IgA complexes could have bound non-specifically to alpha 1 AT and albumin, forming the larger macroamylase complexes.
对免疫球蛋白 - 淀粉酶复合物的蛋白质含量和结合模式进行了研究。免疫电泳后的淀粉酶染色在三例中鉴定出IgA - λ型，两例中鉴定出IgA - κ型，一例中鉴定出IgG - κ型。木瓜蛋白酶消化后，在四名患者血清中发现IgA的Fab片段的沉淀线具有淀粉酶活性。蔗糖密度梯度超速离心研究表明，这些复合物分为三组：I组复合物在酸性pH下解离，在pH 7.0时，在酸性pH下分离出的免疫球蛋白与血清淀粉酶重新结合；II组复合物经酸化后解离，但在pH 7.0时不再重新形成；III组复合物不受酸化影响。我们认为，属于I组和II组的免疫球蛋白 - 淀粉酶复合物是由抗原 - 抗体反应产生的。向特异性抗血清中添加越来越多含有9S或11S免疫球蛋白 - 淀粉酶复合物的患者血清所得到的沉淀曲线显示，这些复合物不仅含有单克隆IgA，还含有α1 - 抗胰蛋白酶（α1AT）和白蛋白。这些IgA复合物可能非特异性地与α1AT和白蛋白结合，形成更大的巨淀粉酶复合物。
