An antioxidant function for DMSP and DMS in marine algae
An antioxidant function for DMSP and DMS in marine algae
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DOI：
10.1038/nature00851
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发表时间：
2002-07-18
期刊：
影响因子：
64.8
通讯作者：
Huntsman, S
中科院分区：
文献类型：
--
作者：
Sunda, W;Kieber, DJ;Huntsman, S
藻类渗透调节剂二甲基磺酸丙酸酯(DMSP)及其酶促裂解产物二甲基硫化物(DMS)对全球硫循环有重要贡献(1-3)，但其生理功能尚不确定[4]。在这里，我们报告的结果，与文献(5，6)中的结果一起，表明DMSP及其分解产物(DMS，丙烯酸酯，二甲基亚砜和甲烷磺酸)很容易清除羟基自由基和其他活性氧物种，因此可能作为一个抗氧化系统，部分受DMSP的酶裂解调节。为了支持这一假说，我们发现氧化应激源，太阳紫外线辐射(7)，二氧化碳限制(8)，铁限制，高Cu2+(参考。9)和H_2O_2显著增加细胞DMSP和/或其裂解成DMS。我们的结果表明，这种应激源与海洋浮游植物中DMSP和DMS的动态有直接联系，这可能会影响DMS的产生和释放到大气中。由于DMS在大气中氧化为硫酸提供了硫酸盐气溶胶和云凝结核的主要来源(3)，氧化应激源--包括太阳辐射和铁限制--可能涉及影响全球气候和水文循环的复杂的海洋-大气反馈循环(1，2)。
The algal osmolyte dimethylsulphoniopropionate (DMSP) and its enzymatic cleavage product dimethylsulphide (DMS) contribute significantly to the global sulphur cycle(1-3), yet their physiological functions are uncertain(4). Here we report results that, together with those in the literature(5,6), show that DMSP and its breakdown products (DMS, acrylate, dimethylsulphoxide, and methane sulphinic acid) readily scavenge hydroxyl radicals and other reactive oxygen species, and thus may serve as an antioxidant system, regulated in part by enzymatic cleavage of DMSP. In support of this hypothesis, we found that oxidative stressors, solar ultraviolet radiation(7), CO2 limitation(8), Fe limitation, high Cu2+ (ref. 9) and H2O2 substantially increased cellular DMSP and/or its lysis to DMS in marine algal cultures. Our results indicate direct links between such stressors and the dynamics of DMSP and DMS in marine phytoplankton, which probably influence the production of DMS and its release to the atmosphere. As oxidation of DMS to sulphuric acid in the atmosphere provides a major source of sulphate aerosols and cloud condensation nuclei(3), oxidative stressors-including solar radiation and Fe limitation-may be involved in complex ocean-atmosphere feedback loops that influence global climate and hydrological cycles(1,2).