Lessard J L
Molecular Cytology Laboratory, Children's Hospital Research Foundation, Cincinnati, Ohio 45229.
Cell Motil Cytoskeleton. 1988;10(3):349-62. doi: 10.1002/cm.970100302.
Two IgG1, kappa monoclonal antibodies (Mab) against actin have been obtained from a fusion in which chicken gizzard actin was used as the immunogen. One Mab, designated B4, shows a preferential reactivity toward enteric smooth muscle actin but also cross-reacts with skeletal, cardiac, and aorta actins on the basis of immunoblots, ELISA assays, and indirect immunofluorescence. However, this antibody does not react with either cytoplasmic actin in any of these assay systems. A second Mab, designated C4, reacts with all six known vertebrate isoactins as well as Dictyostelium discoideum and Physarum polycephalum actins. Thus B4 Mab appears to react with an epitope that is at least partially shared among the muscle actins but not found in cytoplasmic actins, while C4 Mab binds to an antigenic determinant that has been highly conserved among the actins. The binding sites of both Mabs on skeletal actin overlap that of pancreatic DNase I. Both antibodies bind a SV8 proteolytic product comprising the amino-terminal two-thirds of the actin molecule, and their epitopes appear to overlap since C4 can compete for the binding of B4 to skeletal actin. Neither antibody is able to prevent actin polymerization.
通过以鸡胗肌动蛋白作为免疫原进行细胞融合，已获得两种针对肌动蛋白的IgG1 κ单克隆抗体（Mab）。一种Mab命名为B4，基于免疫印迹、酶联免疫吸附测定和间接免疫荧光，它对肠道平滑肌肌动蛋白表现出优先反应性，但也与骨骼肌、心肌和主动脉肌动蛋白发生交叉反应。然而，在任何这些检测系统中，该抗体均不与细胞质肌动蛋白发生反应。第二种Mab命名为C4，它与所有六种已知的脊椎动物肌动蛋白异构体以及盘基网柄菌和多头绒泡菌的肌动蛋白发生反应。因此，B4 Mab似乎与一个表位发生反应，该表位至少部分存在于肌肉肌动蛋白之间，但在细胞质肌动蛋白中未发现，而C4 Mab则与肌动蛋白中高度保守的一个抗原决定簇结合。两种Mab在骨骼肌肌动蛋白上的结合位点与胰腺DNA酶I的结合位点重叠。两种抗体均结合一种包含肌动蛋白分子氨基末端三分之二的SV8蛋白水解产物，并且它们的表位似乎重叠，因为C4可以竞争B4与骨骼肌肌动蛋白的结合。两种抗体均不能阻止肌动蛋白聚合。
