Department of Microbiology and Immunology, University of Nevada School of Medicine, Reno, NV 89557, USA.
Mol Immunol. 2013 Oct;55(3-4):337-44. doi: 10.1016/j.molimm.2013.03.010. Epub 2013 Apr 17.
Bacillus anthracis is surrounded by an anti-phagocytic capsule that is entirely composed of γ-linked D-glutamic acid (γDPGA). γDPGA is required for virulence and is produced in large quantities following spore germination. We have previously described the isolation of several γDPGA-reactive mAbs. The reagents are effective in both immunoprotection and diagnostic applications. The current work was done to further investigate the specificity of γDPGA-reactive mAbs. The specificity of each mAb was characterized using surface plasmon resonance. Our results indicate that each mAb is stereoselective for binding to D-glutamic acid oligomers, but to varying degrees. In particular, mAb F26G3 is highly selective for γDPGA; alterations in stereochemistry disrupted recognition. These differences in mAb reactivity suggest that binding of γDPGA by mAb F26G3 is more specific than non-directional ionic interactions between a negatively charged antigen and a positively charged antibody.
炭疽杆菌被一种抗吞噬的荚膜所包围,该荚膜完全由γ-连接的 D-谷氨酸(γDPGA)组成。γDPGA 是毒力所必需的,并且在孢子萌发后大量产生。我们之前已经描述了几种 γDPGA 反应性 mAb 的分离。这些试剂在免疫保护和诊断应用中都很有效。目前的工作是进一步研究 γDPGA 反应性 mAb 的特异性。使用表面等离子体共振对每种 mAb 的特异性进行了表征。我们的结果表明,每种 mAb 对 D-谷氨酸低聚物的结合都是立体选择性的,但程度不同。特别是,mAb F26G3 对 γDPGA 具有高度选择性;立体化学的改变破坏了识别。这些 mAb 反应性的差异表明,mAb F26G3 与 γDPGA 的结合比带负电荷的抗原和带正电荷的抗体之间的非定向离子相互作用更具特异性。