Styrene has been reported to be pneumotoxic and hepatotoxic in humans and animals. Styrene oxide, a major reactive metabolite of styrene, has been found to form covalent binding with proteins, such as albumin and hemoglobin. Styrene oxide has two optical isomers and it was reported that the (R)-enantiomer was more toxic than the (S)-enantiomer. The purpose of this study was to develop polyclonal antibodies that can stereoselectively recognize proteins modified by styrene oxide enantiomers at cysteine residues. Immunogens were prepared by alkylation of thiolated keyhole limpet hemocyanin (KLH) with styrene oxide enantiomers. Polyclonal antibodies were raised by immunization of rabbits with the chiral immunogens. Titration tests showed all six rabbits generated high titers of antisera that recognize (R)- or (S)-coating antigens accordingly. No cross-reaction was observed toward the carrier protein (BSA). All three rabbits immunized with (R)-immunogen produced antibodies that show enantioselectivity to the corresponding antigen, while only one among the three rabbits immunized with (S)-immunogen generated antibodies with enantioselectivity of the recognition. The enantioselectivity was also observed in competitive ELISA and immunoblot analysis. Additionally, competitive ELISA tests showed that the immunorecognition required the hydroxyl group of the haptens. Immunoblot analysis demonstrated that the immunorecognition depended on the amount of protein adducts blotted and hapten loading in protein adducts. In summary, we successfully developed polyclonal antibodies to stereoselectively detect protein adducts modified by styrene oxide enantiomers.
据报道,
苯乙烯对人类和动物具有肺毒性和肝毒性。
氧化苯乙烯是
苯乙烯的一种主要活性代谢物,已被发现会与白蛋白和血红蛋白等蛋白质形成共价结合。
氧化苯乙烯有两种光学异构体,据报道,(R)-对映体比(S)-对映体毒性更大。本研究的目的是开发能够立体选择性识别半胱
氨酸残基处被
氧化苯乙烯对映体修饰的蛋白质的多克隆
抗体。免疫原是通过将
硫醇化的匙孔帽贝血青素(KLH)与
氧化苯乙烯对映体进行烷基化制备的。用手性免疫原免疫兔子可产生多克隆
抗体。滴定测试表明,所有六只兔子都产生了高滴度的抗血清,能相应地识别(R)或(S)涂层抗原。对载体蛋白(
BSA)未观察到交叉反应。用(R)-免疫原免疫的三只兔子都产生了对相应抗原具有对映选择性的
抗体,而用(S)-免疫原免疫的三只兔子中只有一只产生了具有对映选择性的
抗体。在竞争性酶联免疫吸附试验和免疫印迹分析中也观察到了对映体选择性。此外,竞争性酶联免疫吸附试验表明,免疫认知需要触价物的羟基。免疫印迹分析表明,免疫再识别能力取决于印迹的蛋白质加合物的数量和蛋白质加合物中的合蛋白负载量。总之,我们成功地开发出了立体选择性检测
氧化苯乙烯对映体修饰的蛋白质加合物的多克隆
抗体。