Free radical scavenging actions of metallothionein isoforms I and II
Free radical scavenging actions of metallothionein isoforms I and II
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DOI：
10.1080/10715769800300111
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发表时间：
1998-01-01
影响因子：
3.3
通讯作者：
Ebadi, M
中科院分区：
文献类型：
--
作者：
Kumari, MVR;Hiramatsu, M;Ebadi, M
采用电子自旋共振波谱法，我们研究了肝金属硫蛋白（MT）异构体I和II（MTs-I和II）对四种类型的自由基的清除作用。发现0.15 mM MT-I和0.3 mM MT-II溶液可完全抑制1，1-二苯基-2-苦肼基自由基（1.30 x 10（15）spins/ml）。此外，两种异构体对芬顿反应中产生的羟基自由基（1.75 × 10（15）spins/ml）表现出总清除作用。同样，0.3 mM的MT-I清除了几乎90%的超氧化物用2，2，6，6-四甲基-4-哌啶酮作为活性氧的自旋捕集剂，在0.3mM的MT-II溶液中，次黄嘌呤和黄嘌呤氧化酶体系产生的活性氧的自旋数为2.22 × 10 ~（15）spins/ml，而MT-II溶液仅能除去40%的活性氧（含有单线态氧、超氧和羟基自由基）并测量所得稳定氮氧加合物2，2，6，6-四甲基-4-哌啶-1-氧基的相对信号强度，我们观察到MT-II MT-I在0.3mM浓度下可完全抑制所有活性物质，抑制率达92%，而在0.15mM μ l/ml浓度下可完全抑制所有活性物质这些研究的结果表明，尽管MT的两种同种型都能够清除自由基，但MT-I似乎是超氧化物和1，1二苯基-2-苦基肼基。
By employing electron spin resonance spectroscopy, we examined the free radicals scavenging effects of hepatic metallothionein (MT) isoforms I and II (MTs-I and II) on four types of free radicals. Solutions of 0.15 mM of MT-I and 0.3 mM of MT-II were found to scavenge the 1,1-diphenyl-2-picrylhydrazyl radicals (1.30 x 10(15) spins/ml) completely. In addition, both isoforms exhibited total scavenging action against the hydroxyl radicals (1.75 x 10(15) spins/ml) generated in a Fenton reaction. Similarly, 0.3 mM of MT-I scavenged almost 90% of the superoxide (2.22 x 10(15) spins/ml) generated by the hypoxanthine and xanthine oxidase system, while a 0.3 mM MT-II solution could only scavenge 40% of it. By using 2,2,6,6-tetramethyl-4-piperidone as a "spin-trap" for the reactive oxygen species (containing singlet oxygen, superoxide and hydroxyl radicals) generated by photosensitized oxidation of riboflavin and measuring the relative signal intensities of the resulting stable nitroxide adduct, 2,2,6,6-tetramethyl-4-piperidine-1-oxyl we observed that MT-II (0.3 mM) could scavenge 92%, while MT-I at 0.15 mM mu l/ml concentrations could completely scavenge all the reactive species (2.15 x 10(15) spins/ml) generated.The results of these studies suggest that although both isoforms of MT are able to scavenge free radicals, the MT-I appears to be a superior scavenger of superoxide and 1,1 diphenyl-2-picrylhydrazyl radicals.