Proline-rich peptide from the coral pathogen Vibrio shiloi that inhibits photosynthesis of zooxanthellae
Proline-rich peptide from the coral pathogen Vibrio shiloi that inhibits photosynthesis of zooxanthellae
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DOI：
10.1128/aem.67.4.1536-1541.2001
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发表时间：
2001-04-01
影响因子：
4.4
通讯作者：
Rosenberg, E
中科院分区：
文献类型：
--
作者：
Banin, E;Khare, SK;Rosenberg, E
珊瑚漂白细菌shiloi弧菌生物合成并分泌一种胞外肽，称为毒素P，抑制珊瑚共生藻类（虫黄藻）的光合作用。毒素P是在29℃的蛋白胨或酪胺酸培养基上生长的固定阶段产生的。甘油抑制毒素P的产生。将毒素P纯化至均匀性，得到以下12残基肽：PYPVYAPPPVVP（分子量，1,295.54）。化学合成证实了毒素P的结构。在12.5 mM NH4Cl的作用下，纯天然或人工毒素P （10 muM）在5 min内使虫黄藻的光合量子产率下降64%。抑制作用与毒素P浓度成正比。毒素P与虫黄藻紧密结合，因此随后添加NK、CI导致光合作用迅速抑制。当虫黄藻在NH、CI和毒素P的存在下孵育时，大液的pH值迅速下降（pH值为7.8 ~ 7.2），表明毒素P促进了NH进入细胞，已知NH进入细胞的吸收会破坏pH梯度，阻碍光合作用。毒素P的这种作用模式有助于解释珊瑚白化的机制。
The coral-bleaching bacterium Vibrio shiloi biosynthesizes and secretes an extracellular peptide, referred to as toxin P, which inhibits photosynthesis of coral symbiotic algae (zooxanthellae). Toxin P was produced during the stationary phase when the bacterium was grown on peptone or Casamino Acids media at 29 degreesC. Glycerol inhibited the production of toxin P. Toxin P was purified to homogeneity, yielding the following 12-residue peptide: PYPVYAPPPVVP (molecular weight, 1,295.54). The structure of toxin P was confirmed by chemical synthesis. Tn the presence of 12.5 mM NH4Cl, pure natural or synthetic toxin P (10 muM) caused a 64% decrease in the photosynthetic quantum yield of zooxanthellae within 5 min. The inhibition nas proportional to the toxin P concentration. Toxin P bound avidly to zooxanthellae, such that subsequent addition of NK,CI resulted in rapid inhibition of photosynthesis. When zooxanthellae were incubated in the presence of NH,CI and toxin P, there was a rapid decrease in the pH (pH 7.8 to 7.2) of the bulk liquid, suggesting that toxin P facilitates transport of NH, into the cell, It is known that uptake of NH, into cells can destroy the pH gradient and block photosynthesis. This mode of action of toxin P can help explain the mechanism of coral bleaching by V.shiloi.