Sexton D J, Muruganandam A, McKenney D J, Mutus B
Department of Chemistry and Biochemistry, University of Windsor, Ontario, Canada.
Photochem Photobiol. 1994 Apr;59(4):463-7. doi: 10.1111/j.1751-1097.1994.tb05065.x.
Some aspects of the physiological role of NO may be mediated by stable NO-carriers such as S-nitrosoglutathione and related S-nitrosothiols. In this report we show that irradiation of S-nitrosoglutathione at either absorption band (lambda max = 340 nm or 545 nm) results in the release of nitric oxide. Photolysis of S-nitrosoglutathione at 545 nm exhibited a quantum yield of 0.056 +/- 0.002 and was best approximated by a first-order process with kobs = 4.9 x 10(-7) +/- 0.3 x 10(-7) s-1. The photolytic release of NO from S-nitrosoglutathione resulted in an enhanced cytotoxic effect of S-nitrosoglutathione on HL-60 leukemia cells. That the cytotoxic effect of S-nitrosoglutathione was diminished by the addition of oxyhemoglobin strongly suggests that NO is the cytotoxic species. The finding that NO can be readily liberated from S-nitrosoglutathione by visible radiation indicates that the photochemical properties of this compound in the visible spectrum must be considered in order to obtain meaningful data as to its physiological role and the S-nitrosoglutathione and related compounds may find use as photochemotherapeutic agents.
一氧化氮（NO）生理作用的某些方面可能由稳定的NO载体介导，如S-亚硝基谷胱甘肽及相关的S-亚硝基硫醇。在本报告中，我们表明，在任一吸收带（λmax = 340 nm或545 nm）照射S-亚硝基谷胱甘肽都会导致一氧化氮的释放。在545 nm处S-亚硝基谷胱甘肽的光解表现出量子产率为0.056±0.002，并且最适合用一级过程来近似，其中kobs = 4.9×10^(-7)±0.3×10^(-7) s^(-1)。S-亚硝基谷胱甘肽光解释放NO导致其对HL-60白血病细胞的细胞毒性作用增强。加入氧合血红蛋白后S-亚硝基谷胱甘肽的细胞毒性作用减弱，这强烈表明NO是细胞毒性物质。NO可通过可见光从S-亚硝基谷胱甘肽中轻易释放这一发现表明，为了获得关于其生理作用的有意义数据，必须考虑该化合物在可见光谱中的光化学性质，并且S-亚硝基谷胱甘肽及相关化合物可能可用作光化学治疗剂。
