Organic Thionitrites and Related Substances. A Review

Formation of S-Nitrosothiols from Regiospecific Reaction of Thiols with N-Nitrosotryptophan Derivatives

“…Because the formed 15 N-SNAP exhibited a sharp and intense resonance line in Me 2 SO, the NANT-dependent formation of the S-nitrosothiol via a transnitrosation reaction was unequivocally proven. Oae and Shinhama (16) suggested that S-nitrosothiols transnitrosate aromatic amines, but any evidence for such a reaction with an indole ring as the target is missing in the literature. As the 15 NO moiety of 15 N-NANT was only partly transferred to the thiol group of NAP in Me 2 SO even after a reaction period of 4 days (Fig.…”

Assessment of nitric oxide signals by triiodide chemiluminescence

“…The dynamic distribution of protein and low-molecular-weight NO compounds that subserve NO transport and signaling instantiate the variation in both FeNO and SNO reactivities (4,6,13,[16][17][18][19][20][21][22][23][24] (5,6,13,(16)(17)(18)(19)(20)(21)(22)25). Accordingly, bond dissociation energies of RSNO are reported to vary from Ϸ22 to 32 kcal⅐mol Ϫ1 (6, 26), and the dissociation constants of FeNO can vary by a factor of Ͼ10 6 (13, 23, 24), translating to intrinsic FeNO/SNO lifetimes ranging from seconds to years.…”

“…Accordingly, bond dissociation energies of RSNO are reported to vary from Ϸ22 to 32 kcal⅐mol Ϫ1 (6,26), and the dissociation constants of FeNO can vary by a factor of Ͼ10 6 (13,23,24), translating to intrinsic FeNO/SNO lifetimes ranging from seconds to years. Environmental factors that have been reported to influence SNO stability and reactivity, directly or through elicited conformational changes in proteins, include pH (low and high) (5,6,20,26), metal ions (Ca, Mg, Cu, and Fe) (6,14,20,27,28), nucleophiles (ascorbate, thiolate, and amine) (6,13), local hydrophobicity (denaturants) (29), oxidants and reductants (6,19), proteolytic enzymes (30), alkylators (31), O 2 tension (5,32), and various intramolecular interactions (H-bonding, S-, N-, O-coordination, and aromatic residue interactions) (6,16,20,22,(33)(34)(35)(36). Many of these factors also affect FeNO stability (17,23,24).…”

“…Additionally, NO can be transported in endocrine or paracrine fashion by reacting with heme iron and cysteine thiols in proteins [hemoglobin (Hb) and albumin] and peptides (glutathione and cysteinlyglycine) to form NO adducts with longer biological lifetimes (3-5); release of NO bioactivity from stable adducts is effected by allosteric and redox-based mechanisms that alter FeNO or S-nitrosothiol (SNO) reactivity (5, 6). An updated discussion of the factors influencing reactivity of S-nitrosohemoglobin, S-nitrosoalbumin, and low-molecular-weight SNO in the context of vasoregulation (5-15) can be found in supporting information (SI) Text.The dynamic distribution of protein and low-molecular-weight NO compounds that subserve NO transport and signaling instantiate the variation in both FeNO and SNO reactivities (4,6,13,[16][17][18][19][20][21][22][23][24] (5,6,13,(16)(17)(18)(19)(20)(21)(22)25). Accordingly, bond dissociation energies of RSNO are reported to vary from Ϸ22 to 32 kcal⅐mol Ϫ1 (6, 26), and the dissociation constants of FeNO can vary by a factor of Ͼ10 6 (13, 23, 24), translating to intrinsic FeNO/SNO lifetimes ranging from seconds to years.…”

S-nitrosylation of tissue-type plasminogen activator confers vasodilatory and antiplatelet properties on the enzyme.

“…First, NO displaced from S-nitrosothiol groups with Hg2+ was assayed by diazotization of sulfanilamide and subsequent coupling to the chromophore N-(1-naphthyl)ethylenediamine (18). Second, the characteristic absorption spectrum of S-nitrosothiols in the range of 320-360 nm was monitored (11,19). Third, 15N NMR was used according to the method of Bonnett et al (20): the chemical shift for RS-NO, referenced to a secondary Na'5NO2 standard assigned at 587 ppm, is relatively specific in the range of 700-800 ppm.…”