Yan L J, Traber M G, Kobuchi H, Matsugo S, Tritschler H J, Packer L
Department of Molecular and Cell Biology, University of California, Berkeley, 94720-3200, USA.
Arch Biochem Biophys. 1996 Mar 15;327(2):330-4. doi: 10.1006/abbi.1996.0130.
We observed that protein (bovine serum albumin) carbonyl content increases upon hypochlorite oxidation, and this increase is inhibited in a concentration-dependent manner in the presence of hypochlorite scavengers. Based on this observation, we tested whether some known hypochlorite scavengers (lipoic acid, cysteine, and glutathione) and some other antioxidants (uric acid, ascorbic acid, alpha-tocopherol, and probucol) could prevent protein carbonyl formation. N-acetylcysteine, dihydrolipoic acid, cysteine, and glutathione (reduced form, GSH), which otherwise could not be tested in a previously reported 5-thio-2-nitrobenzoic acid test system, were successfully evaluated in our assay. The hypochlorite scavenging capacity of different compounds, compared by determining the IC50 (concentration which produces 50% inhibition), showed that the compounds tested have the following potency: dihydrolipoic acid > GSH, N-acetylcysteine > cysteine > S-methyl glutathione > lipoic acid, ascorbic acid > cystine, GSSG, and uric acid. No scavenging ability was observed for either alpha-tocopherol or probucol.
我们观察到，次氯酸盐氧化后蛋白质（牛血清白蛋白）的羰基含量增加，并且在次氯酸盐清除剂存在的情况下，这种增加以浓度依赖的方式受到抑制。基于这一观察结果，我们测试了一些已知的次氯酸盐清除剂（硫辛酸、半胱氨酸和谷胱甘肽）以及一些其他抗氧化剂（尿酸、抗坏血酸、α-生育酚和普罗布考）是否能防止蛋白质羰基的形成。N-乙酰半胱氨酸、二氢硫辛酸、半胱氨酸和谷胱甘肽（还原形式，GSH），否则无法在先前报道的5-硫代-2-硝基苯甲酸测试系统中进行测试，在我们的试验中得到了成功评估。通过测定IC50（产生50%抑制作用的浓度）比较不同化合物的次氯酸盐清除能力，结果表明所测试的化合物具有以下效力：二氢硫辛酸>GSH、N-乙酰半胱氨酸>半胱氨酸>S-甲基谷胱甘肽>硫辛酸、抗坏血酸>胱氨酸、GSSG和尿酸。未观察到α-生育酚或普罗布考有清除能力。
