Effects of Uric Acid on Nitrosation of <i>N</i>-Acetylcysteine by Diethylamine NONOate and <i>N</i>-Acetyl-<i>N</i>-nitrosotryptophan
作者:Toshinori Suzuki、Atsushi Naka、Haruka Kimura
DOI:10.1248/cpb.57.736
日期:——
N-acetylcysteine by diethylamine NONOate at neutral pH, but diminished that of N-acetyltryptophan. Uric acid also accelerated nitrosation of N-acetylcysteine by N-acetyl-N-nitrosotryptophan, having a nitroso group on the nitrogen atom of the indole ring. N-Acetyl-S-nitrosocysteine was stable even in the presence of uric acid and N-acetyltryptophan at neutral pH, while decomposition of N-acetyl-N-nitrosotryptophan
人血浆浓度的尿酸可在中性pH值下促进二乙胺NONOate对N-乙酰半胱氨酸的亚硝化作用,但可减少N-乙酰色氨酸的亚硝化作用。尿酸还通过在吲哚环的氮原子上具有亚硝基的N-乙酰基-N-亚硝基色氨酸加速了N-乙酰基半胱氨酸的亚硝化。即使在中性pH下存在尿酸和N-乙酰基色氨酸,N-乙酰基-S-亚硝基半胱氨酸也是稳定的,而尿酸和N-乙酰基半胱氨酸可促进N-乙酰基-N-亚硝基色氨酸的分解。结果表明,尿酸从二乙胺NONOate或N-乙酰基-N-亚硝基色氨酸中获得亚硝基,并将其传递至N-乙酰基半胱氨酸的巯基,从而得到N-乙酰基-S-亚硝基半胱氨酸。