Mechanisms to detoxify hydrogen sulfide using special amino acids in deep-sea organisms

我们通过分析牛磺酸的前体亚牛磺酸的合成途径，研究了深海热液喷口特异性动物对有毒硫化氢的适应机制。亚牛磺酸是牛磺酸的前体，可以与硫化氢结合并生成无毒的硫代牛磺酸。我们确定了亚牛磺酸的合成途径，这还没有在任何海洋无脊椎动物的报告，在深海贻贝Bathymodiolus septemdierum。我们还发现，参与亚牛磺酸合成的酶的基因在鳃中积极表达，而不管养殖水中的硫化物浓度。我们还分析了游离氨基酸，包括亚牛磺酸及其前体，以确认该途径的活性。双壳类可能是利用牛磺酸合成途径的一部分获得热液喷口区的生境。

We studied the adaptation mechanisms to toxic hydrogen sulfide in deep-sea hydrothermal vent-specific animals through the analysis of the synthetic pathway of hypotaurine, which is a precursor of taurine and can bind to hydrogen sulfide and generate non-toxic thiotaurine. We identified the hypotaurine synthesis pathway, which has not been reported in any marine invertebrates, in the deep-sea mussel Bathymodiolus septemdierum. We also revealed that the genes of the enzymes involved in the hypotaurine synthesis actively expressed in the gill regardless of the sulfide concentration in the rearing water. We also analyzed the free amino acids including hypotaurine and its precursors to confirm the activity of the pathway. Bivalves may have acquired the habitat of hydrothermal vent area by utilizing a part of the taurine synthesis pathway.