Role of protein -SH groups in redox homeostasis - The erythrocyte as a model system
Role of protein -SH groups in redox homeostasis - The erythrocyte as a model system
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DOI：
10.1006/abbi.1998.0694
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发表时间：
1998-07-15
影响因子：
3.9
通讯作者：
Rossi, R
中科院分区：
文献类型：
--
作者：
Di Simplicio, P;Cacace, MG;Rossi, R
研究了大鼠、火鸡、人和小牛血红蛋白的巯基的反应性以及裂解红细胞中谷胱甘肽过氧化物酶、谷胱甘肽还原酶、葡萄糖-6-磷酸脱氢酶和谷氧还蛋白的酶活性，以评估它们在调节氧化还原稳态中的作用。 -SH反应性结果显示速率常数跨越四个数量级（k(2)，小牛，6.67 M-1 s(-1)；大鼠-SH快速反应，2.8 x 10(4) M-1 s(-1)）。葡萄糖-6-磷酸脱氢酶的酶活性范围为 0.402 U/ml（小牛）至 0.900 U/ml（大鼠），谷胱甘肽还原酶的酶活性范围为 0.162 U/ml（大鼠）至 0.381 U/ml（人），谷氧还蛋白的范围为 0.778 U/ml（大鼠）至 2.28 U/ml（火鸡），谷胱甘肽过氧化物酶从 2.07 U/ml（人）至 27.3 U/ml（大鼠）。四个物种的血液样本也用 0.5-1.5 mM 叔丁基过氧化氢 (t-BOOH) 或二酰胺处理，并在 120 分钟内测定谷胱甘肽衍生物种 [GSH、GSSG; 和谷胱甘肽-蛋白质混合二硫化物 (GS-SP)I 的水平，并与相应的蛋白质 -SH 组 (PSH) 反应性和酶库相关。在所有情况下，t-BOOH 都能迅速将 GSH 转化为 GSSG；通过谷胱甘肽过氧化物酶的作用；根据反应 GSSG + PSH --> GS-SP + GSH，GSSG 又转化为 GS-SP，或者通过谷胱甘肽还原酶还原回 GSH。由于大鼠中血红蛋白的快速反应-SH以及人类血液中酶库的效率的贡献，GSSG减少在大鼠和人类血液中更有效。由于 PSH 反应性低且酶的贡献较弱，小牛血在氧化应激后恢复正常值的能力相对较低。众所周知，二酰胺处理会与硫醇发生非酶促反应，在大鼠和火鸡中增加 GS-SP 水平，但在人和小牛血液中则不然，正如根据不同的相应 PSH 反应性所预期的那样。因此，具有相对较高 PSH 反应性和葡萄糖 6-磷酸脱氢酶活性的物种（例如大鼠）比这些参数相对较低的物种（小牛）具有更高的抗氧化能力。 (C) 1998 年学术出版社。
The reactivities of the sulfhydryl groups of rat, turkey, human, and calf hemoglobin were studied together with the enzyme activities of glutathione peroxidase, glutathione reductase, glucose-6-phosphate dehydrogenase, and glutaredoxin in lysed erythrocytes to evaluate their roles in regulating redox homeostasis. The results of -SH reactivity showed rate constants spanning four orders of magnitude (k(2), calf, 6.67 M-1 s(-1); rat -SH fast reacting, 2.8 x 10(4) M-1 s(-1)). Enzyme activities of glucose-6-phosphate dehydrogenase ranged from 0.402 U/ml (calf) to 0.900 U/ml (rat), glutathione reductase from 0.162 U/ml (rat) to 0.381 U/ml (human), glutaredoxin from 0.778 U/ml (rat) to 2.28 U/ml (turkey), and glutathione peroxidase from 2.07 U/ml (human) to 27.3 U/ml (rat). Blood samples of the four species were also treated with 0.5-1.5 mM tert-butyl hydroperoxide (t-BOOH) or diamide, and levels of glutathione-derived species [GSH, GSSG;, and glutathione-protein mixed disulfides (GS-SP)I were determined within 120 min and related to the corresponding protein -SH group (PSH) reactivities and enzyme repertoires. In all cases t-BOOH rapidly transformed GSH into GSSG; by the action of glutathione peroxidase; GSSG was in turn transformed into GS-SP, according to the reaction GSSG + PSH --> GS-SP + GSH, or reduced back to GSH by glutathione reductase. The GSSG reduction was more efficient in rat and human blood, due to the contribution of the fast-reacting -SH of hemoglobin, in the rat, and to the efficiency of the enzyme repertoire of human blood. Calf blood showed a relatively low capacity to restore normal values after oxidative stress, due to its low PSH reactivity and the weak contribution of its enzymes. Diamide treatment, which is known to react nonenzymatically with thiols, gave increased GS-SP levels in rat and turkey, but not in human and calf blood, as expected from the different corresponding PSH reactivities. Species with relatively high PSH reactivity and glucose 6-phosphate dehydrogenase activity, such as the rat, therefore had a higher antioxidant capacity than species (calf) in which these parameters were relatively low. (C) 1998 Academic Press.