Abstract
The cross-linking reaction between sulfide and S-nitrosothiol moieties has been intensively investigated and thionitrite/thionitrous acid (SNO(-)/HSNO) as well as nitrosopersulfide (SSNO(-)) were reported to be the intermediates that could serve as reservoirs for nitric oxide (NO). However, debate still exists regarding the stability and biological activity of SNO(-)/HSNO and SSNO(-). In order to investigate the chemical properties and biological activity of SNO(-) and SSNO(-), we set out to re-characterize the reaction intermediates using UV-Vis and (15)N NMR spectroscopy techniques, as well as a new (17)O NMR approach. The effects of SNO(-) and SSNO(-) on cellular NO and cGMP levels were assessed via cell culture experiments, and also the effects of SNO(-) and SSNO(-) on cell proliferation, migration, and capillary-like structure formation were evaluated with human umbilical vein endothelial cells (HUVEC). Through this work, the characteristic peaks and half-lives of SNO(-) and SSNO(-) were elucidated under various preparation conditions. The biological assays demonstrated that SSNO(-) increased the cellular NO and cGMP levels and also facilitated cell proliferation, migration and stimulated angiogenesis, while in contrast SNO(-) did not exhibit these effects.