Takeda T, Nair G B, Suzuki K, Shimonishi Y
Department of Infectious Diseases Research, National Children's Medical Research Center, Tokyo, Japan.
Infect Immun. 1990 Sep;58(9):2755-9. doi: 10.1128/iai.58.9.2755-2759.1990.
A monoclonal antibody (MAb) against synthetic heat-stable enterotoxin of Vibrio cholerae non-O1 (NAG-ST) was produced. The MAb, namely, 2F, belonged to the immunoglobulin G1 class. Ascitic fluid drawn from pristane-primed BALB/c mice injected with a 2F-producing clone demonstrated anti-NAG-ST activity which could be detected in enzyme-linked immunosorbent assay even at a dilution of 1:128,000. Fifty-fold-diluted ascitic fluid could completely neutralize the activity of NAG-ST (synthetic and native) and Vibrio mimicus ST (identical to NAG-ST) in suckling mice. In the same assay, 2F could also neutralize Yersinia enterocolitica ST (Y-ST) but did not neutralize Escherichia coli STh and STp. A similar pattern of reactivity occurred in a competitive enzyme-linked immunosorbent assay with homologous and heterologous toxins. Competitive inhibition curves with synthetic peptides representing NAG-ST and its shorter analogs revealed that aspartic acid located at position 2 from the N terminus of NAG-ST was the essential residue of the recognized epitope. Significantly, in Y-ST, to which 2F cross-reacted, aspartic acid is in the corresponding position as that of NAG-ST, thereby confirming our conclusions that the epitope defining this MAb is aspartic acid.
制备了一种针对霍乱弧菌非O1型（NAG-ST）合成热稳定肠毒素的单克隆抗体（MAb）。该单克隆抗体，即2F，属于免疫球蛋白G1类。从注射了产生2F的克隆的经 pristane 预处理的BALB/c小鼠中抽取的腹水表现出抗NAG-ST活性，即使在1:128,000的稀释度下，在酶联免疫吸附测定中也能检测到。五十倍稀释的腹水可完全中和乳鼠中NAG-ST（合成的和天然的）以及拟态弧菌ST（与NAG-ST相同）的活性。在同一测定中，2F也可中和小肠结肠炎耶尔森菌ST（Y-ST），但不能中和大肠杆菌STh和STp。在与同源和异源毒素的竞争性酶联免疫吸附测定中出现了类似的反应模式。用代表NAG-ST及其较短类似物的合成肽进行的竞争性抑制曲线表明，位于NAG-ST N端第2位的天冬氨酸是被识别表位的必需残基。重要的是，在2F发生交叉反应的Y-ST中，天冬氨酸处于与NAG-ST相应的位置，从而证实了我们的结论，即定义该单克隆抗体的表位是天冬氨酸。
