Frey N, Christen U, Jenö P, Yeaman S J, Shimomura Y, Kenna J G, Gandolfi A J, Ranek L, Gut J
Department of Pharmacology, Biocenter of the University, Basel, Switzerland.
Chem Res Toxicol. 1995 Jul-Aug;8(5):736-46. doi: 10.1021/tx00047a014.
Anti-CF3CO antibodies, monospecific toward trifluoroacetylated proteins (CF3CO-proteins), which are elicited in experimental animals and humans exposed to the anesthetic agent halothane, cross-react with an unknown protein of approximately 52 kDa, constitutively expressed in tissues of experimental animals and humans not previously exposed to the agent. Using anti-CF3CO antibody, the protein(s) of 52 kDa could be immunoprecipitated from solubilized rat heart homogenate. Two-dimensional gel electrophoretic analysis revealed the presence of distinct major (P1, P2) and minor (P3, P4, P5) protein components with apparent molecular masses of 52 kDa. From each of the components P1 and P2, the amino acid sequences of three peptides were determined and found to exhibit 100% identity with the corresponding amino acid sequences of the E2 subunit of the rat 2-oxoglutarate dehydrogenase complex (OGDC). Additionally to the E2 subunit of OGDC, anti-CF3CO antibody also recognized on immunoblots the purified E2 subunit of the branched chain 2-oxoacid dehydrogenase complex (BCOADC) and protein X, a constituent of the pyruvate dehydrogenase complex (PDC), in a manner sensitive to competition by N6-(trifluoroacetyl)-L-lysine (CF3CO-Lys), 6(RS)-lipoic acid, and N6-(6(RS)-lipoyl)-L-lysine (lipoyl-Lys). Furthermore, a discrete population of autoantibodies was identified in sera of patients with halothane hepatitis which could not discriminate between the lipoylated target epitope present on the E2 subunit of OGDC and epitopes on CF3CO-RSA, used as model for CF3CO-proteins. These data suggest that the autoantigenicity of these proteins in halothane hepatitis is based on the molecular mimicry of CF3CO-Lys by lipoic acid, the prosthetic group common to protein X and the E2 subunits of OGDC and BCOADC.
抗CF3CO抗体对三氟乙酰化蛋白（CF3CO-蛋白）具有单特异性，这种抗体在接触麻醉剂氟烷的实验动物和人类中产生，它能与一种约52 kDa的未知蛋白发生交叉反应，该蛋白在未接触过该试剂的实验动物和人类组织中组成性表达。使用抗CF3CO抗体，可从溶解的大鼠心脏匀浆中免疫沉淀出52 kDa的蛋白。二维凝胶电泳分析显示存在明显的主要（P1、P2）和次要（P3、P4、P5）蛋白成分，其表观分子量为52 kDa。从P1和P2每个成分中，测定了三个肽段的氨基酸序列，发现它们与大鼠2-氧代戊二酸脱氢酶复合体（OGDC）E2亚基的相应氨基酸序列具有100%的同一性。除了OGDC的E2亚基外，抗CF3CO抗体在免疫印迹上还能识别支链2-氧代酸脱氢酶复合体（BCOADC）的纯化E2亚基和丙酮酸脱氢酶复合体（PDC）的组成成分蛋白X，其识别方式对N6-（三氟乙酰基）-L-赖氨酸（CF3CO-Lys）、6（RS）-硫辛酸和N6-（6（RS）-脂酰基）-L-赖氨酸（脂酰-Lys）的竞争敏感。此外，在氟烷性肝炎患者的血清中鉴定出一群离散的自身抗体，它们无法区分OGDC E2亚基上存在的脂酰化靶表位和用作CF3CO-蛋白模型的CF3CO-RSA上的表位。这些数据表明，这些蛋白在氟烷性肝炎中的自身抗原性基于硫辛酸对CF3CO-Lys的分子模拟，硫辛酸是蛋白X以及OGDC和BCOADC的E2亚基共有的辅基。
