De Château M, Nilson B H, Erntell M, Myhre E, Magnusson C G, Akerström B, Björck L
Department of Medical and Physiological Chemistry, University of Lund, Sweden.
Scand J Immunol. 1993 Apr;37(4):399-405. doi: 10.1111/j.1365-3083.1993.tb03310.x.
Protein L, a cell wall molecule of certain strains of the anaerobic bacterial species Peptostreptococcus magnus, shows high affinity for human immunoglobulin (Ig) light chains. In the present study protein L was tested against a panel of human myeloma proteins of the IgG, IgM, IgA and IgE classes, and strong binding was seen with antibodies carrying kappa light chains. A high degree of specificity for Ig was demonstrated in binding experiments with human plasma proteins. Apart from human Ig, strong protein L-binding activity was also detected in the serum of 12 out of 23 tested additional mammalian species, including other primates and rodents. Subsequent analysis with purified Ig samples demonstrated the binding of protein L to Ig of important laboratory animal species such as the mouse, the rat and the rabbit. The affinity constants for the interactions between protein L and polyclonal IgG of these species were 2.6 x 10(9), 3.9 x 10(8) and 7.4 x 10(7), respectively. In non-human species, the binding of protein L was also found to be mediated through Ig light chains, and the results demonstrate the potential value of protein L as an immunochemical tool.
蛋白质L是厌氧细菌大消化链球菌某些菌株的一种细胞壁分子，对人免疫球蛋白（Ig）轻链具有高亲和力。在本研究中，用一组IgG、IgM、IgA和IgE类别的人骨髓瘤蛋白对蛋白质L进行了测试，发现它与携带κ轻链的抗体有强烈结合。在与人血浆蛋白的结合实验中证明了蛋白质L对Ig具有高度特异性。除人Ig外，在23种受试的其他哺乳动物物种（包括其他灵长类动物和啮齿动物）的12种血清中也检测到了强烈的蛋白质L结合活性。随后用纯化的Ig样品进行分析，证明蛋白质L与重要实验动物物种（如小鼠、大鼠和兔子）的Ig有结合。蛋白质L与这些物种的多克隆IgG之间相互作用的亲和常数分别为2.6×10⁹、3.9×10⁸和7.4×10⁷。在非人类物种中，还发现蛋白质L的结合也是通过Ig轻链介导的，结果证明了蛋白质L作为一种免疫化学工具的潜在价值。
