beta-Carotene quenches singlet oxygen formed by isolated photosystem II reaction centers.
beta-Carotene quenches singlet oxygen formed by isolated photosystem II reaction centers.
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DOI：
10.1021/bi00252a013
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发表时间：
1994-12
期刊：
影响因子：
2.9
通讯作者：
A. Telfer;S. Dhami;S. Bishop;David Phillips;J. Barber
中科院分区：
文献类型：
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作者：
A. Telfer;S. Dhami;S. Bishop;David Phillips;J. Barber
通过测量1270 nm处的时间分辨发光发射，我们检测到豌豆光系统II在光照下的反应中心形成单线态氧，这与早期的工作(Macpherson，A.N.，Telfer，A.，Barber，J.，&Truscott，T.G.(1993)Biochim)一致。生物群落。法规1143,301-309)。在这篇文章中，我们表明，如果每个分离的复合体结合的β-胡萝卜素分子的数量从两个减少到一个，单线态氧的产量就会显着增加。因此，我们得出结论，β-胡萝卜素可以作为光系统II反应中心中单线态氧的有效猝灭剂。这一结论得到了以下发现的支持：随着β-胡萝卜素水平的降低，反应中心氯素的光诱导不可逆漂白速度加快。这些结果证明了单线态氧在生物环境中引起光氧化损伤的直接中介作用，并特别讨论了β-胡萝卜素在保护光系统II免受光抑制方面的作用。
By measuring time-resolved luminescence emission at 1270 nm, we have detected singlet oxygen formation by illuminated, reaction centers of photosystem II isolated from Pisum sativum, which is in agreement with earlier work (Macpherson, A. N., Telfer, A., Barber, J., & Truscott, T. G. (1993) Biochim. Biophys. Acta 1143, 301-309). In this paper we show that the yield of singlet oxygen is significantly increased if the number of beta-carotene molecules bound per isolated complex is reduced from two to one. We conclude, therefore, that beta-carotene can act as an effective quencher of singlet oxygen in the photosystem II reaction center. This conclusion is supported by the finding that the rate of light-induced irreversible bleaching of chlorins in the reaction center is increased with decreasing beta-carotene levels. The results demonstrate the direct intermediacy of singlet oxygen in causing photooxidative damage within a biological environment and are discussed, specifically, in terms of the role of beta-carotene in protecting photosystem II against photoinhibition.