Thiolation of protein-bound carcinogenic aldehyde - An electrophilic acrolein-lysine adduct that covalently binds to thiols
Thiolation of protein-bound carcinogenic aldehyde - An electrophilic acrolein-lysine adduct that covalently binds to thiols
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DOI：
10.1074/jbc.m202794200
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发表时间：
2002-08-02
影响因子：
4.8
通讯作者：
Uchida, K
中科院分区：
文献类型：
--
作者：
Furuhata, A;Nakamura, M;Uchida, K
丙烯醛是一种具有代表性的致癌醛，在氧化应激的生物系统中普遍存在。赖氨酸的e-氨基形成N-epsilon-（3-甲酰基-3,4-脱氢哌酸）赖氨酸（fdp -赖氨酸）作为主要产物(Uchida， K., Kanematsu， M., Morimitsu， Y., Osawa， T., Noguchi， N., and Niki， E. (1998) J. Biol。273年化学,1605816066)。在本研究中，我们测定了fdp -赖氨酸的亲电电位，并建立了一种新的蛋白质硫基化机制，在该机制中，丙烯醛修饰的蛋白质中产生的fdp -赖氨酸与巯基反应形成硫醚加合物。将巯基酶甘油醛-3-磷酸脱氢酶与丙烯醛修饰的牛血清白蛋白在37℃磷酸钠缓冲液（pH 7.2）中孵育，观察到巯基的明显丧失，酶活性下降，并形成了分子量为200 kDa的高分子质量蛋白种。根据以下观察，丙烯醛修饰蛋白中生成的fdp -赖氨酸加合物被认为是一种巯基反应性亲电试剂。(1) n -乙酰赖氨酸与丙烯醛反应制得n -乙酰基- fdp -赖氨酸，与甘油醛-3-磷酸脱氢酶共价结合。（ii） fdp -赖氨酸衍生物与谷胱甘肽反应形成谷胱甘肽缀合物。丙烯醛修饰的牛血清白蛋白与谷胱甘肽显著反应形成谷胱甘肽化蛋白。此外，观察到谷胱甘肽丙烯醛修饰蛋白与抗fdp -赖氨酸单克隆抗体的免疫反应性下降，表明丙烯醛修饰蛋白中的fdp -赖氨酸残基可能是GSH的结合位点。这些数据表明，蛋白质结合的丙烯醛的硫代化可能参与氧化应激下的氧化还原改变，由此氧化应激产生丙烯醛及其蛋白质加合物的增加，从而通过细胞中GSH的消耗进一步增强氧化应激。
Acrolein, a representative carcinogenic aldehyde that could be ubiquitously generated in biological systems under oxidative stress, shows facile reactivity with! the e-amino group of lysine to form N-epsilon-(3-formyl-3,4-dehydropiperidino)lysine (FDP-lysine) as the major product (Uchida, K., Kanematsu, M., Morimitsu, Y., Osawa, T., Noguchi, N., and Niki, E. (1998) J. Biol. Chem. 273,1605816066). In the present study, we determined the electrophilic potential of FDP-lysine and established a novel mechanism of protein thiolation in which the FDP-lysine generated in the acrolein-modified protein reacts with sulfhydryl groups to form thioether adducts. When a sulfhydryl enzyme, glyceraldehyde-3-phosphate dehydrogenase, was incubated with acrolein-modified bovine serum albumin in sodium phosphate buffer (pH 7.2) at 37degreesC, a significant loss of sulfhydryl groups, which was accompanied by the loss of enzyme activity and the formation of high molecular mass protein species (>200 kDa), was observed. The FDP-lysine adduct generated in the acrolein-modified protein was suggested to represent a thiol-reactive electrophile based on the following observations. (i) N-alpha-acetyl-FDP-lysine, prepared from the reaction of N-alpha-acetyl lysine with acrolein, was covalently bound to glyceraldehyde-3-phosphate dehydrogenase. (ii) The FDP-lysine derivative reacted with glutathione to form a GSH conjugate. (iii) The acrolein-modified bovine serum albumin significantly reacted with GSH to form a glutathiolated protein. Furthermore, the observation that the glutathiolated acrolein-modified protein showed decreased immunoreactivity with an anti-FDP-lysine monoclonal antibody suggested that the FDP-lysine residues in the acrolein-modified protein served as the binding site of GSH. These data suggest that thiolation of the protein-bound acrolein may be involved in redox alteration under oxidative stress, whereby oxidative stress generates the increased production of acrolein and its protein adducts that further potentiate oxidative stress via the depletion of GSH in the cells.