Mosmann T, Baumal R
J Immunol. 1975 Oct;115(4):955-62.
We have devised a rapid method for obtaining large amounts of J chain from IgA in the ascitic fluid of mice bearing the MOPC 315 tumor. The J chain was released by reduction from the MOPC 315 IgA adsorbed onto a DNP-lysyl-Sepharose column, and was further purified by DEAE Sephadex chromatography. The mouse J chain was characterized as to its electrophoretic mobility, amino acid composition, apparent size, presence in different immunoglobulin classes, and reactivity with an antiserum containing anti-J chain activity. Variant cell lines have been selected from the IgA-producing mouse myeloma cell line MOPC 315. The variants did not synthesize detectable quantities of alpha heavy chains but continued to synthesize and secrete light chains. J chain was synthesized by both parent and variant cell lines but only secreted by the parent cells. It is postulated that J chain synthesis is not dependent on alpha heavy chain synthesis, but that secretion of J chain by MOPC 315 cells occurs only because of its attachment to the Ig1 molecule.
我们设计了一种快速方法，可从携带MOPC 315肿瘤的小鼠腹水中的IgA中获取大量J链。通过还原从吸附在DNP-赖氨酰-琼脂糖柱上的MOPC 315 IgA中释放J链，并通过DEAE葡聚糖凝胶色谱进一步纯化。对小鼠J链的电泳迁移率、氨基酸组成、表观大小、在不同免疫球蛋白类别中的存在情况以及与含有抗J链活性的抗血清的反应性进行了表征。已从产生IgA的小鼠骨髓瘤细胞系MOPC 315中筛选出变异细胞系。这些变异体不合成可检测量的α重链，但继续合成和分泌轻链。亲本细胞系和变异细胞系均合成J链，但只有亲本细胞分泌J链。据推测，J链的合成不依赖于α重链的合成，但MOPC 315细胞分泌J链仅是因为它与Ig1分子结合。
