s-nitrosocysteine has been researched along with Anemia--Sickle-Cell* in 2 studies
2 other study(ies) available for s-nitrosocysteine and Anemia--Sickle-Cell
| Article | Year |
|---|---|
Responses of normal and sickle cell hemoglobin to S-nitroscysteine: implications for therapeutic applications of NO in treatment of sickle cell disease.
Factors which govern transnitrosation reactions between hemoglobin (Hb) and low molecular weight thiols may define the extent to which S-nitrosated Hb (SNO-Hb) plays a role in NO in the control of blood pressure and other NO-dependent reactions. We show that exposure to S-nitrosylated cysteine (CysNO) produces equivalent levels of SNO-Hb for Hb A(0) and sickle cell Hb (Hb S), although these proteins differ significantly in the electron affinity of their heme groups as measured by their anaerobic redox potentials. Dolphin Hb, a cooperative Hb with a redox potential like that of Hb S, produces less SNO-Hb, indicating that steric considerations outweigh effects of altered electron affinity at the active-site heme groups in control of SNO-Hb formation. Examination of oxygen binding at 5-20 mM heme concentrations revealed increases due to S-nitrosation in the apparent oxygen affinity of both Hb A(0) and Hb S, similar to increases seen at lower heme concentrations. As observed at lower heme levels, deoxygenation is not sufficient to trigger release of NO from SNO-Hb. A sharp increase in apparent oxygen affinity occurs for unmodified Hb S at concentrations above 12.5 mM, its minimum gelling concentration. This affinity increase still occurs in 30 and 60% S-nitrosated samples, but at higher heme concentration. This oxygen binding behavior is accompanied by decreased gel formation of the deoxygenated protein. S-nitrosation is thus shown to have an effect similar to that reported for other SH-group modifications of Hb S, in which R-state stabilization opposes Hb S aggregation. Topics: Anemia, Sickle Cell; Animals; Chelating Agents; Cysteine; Dolphins; Heme; Hemoglobin, Sickle; Hemoglobins; Humans; Nitric Oxide; Oxidation-Reduction; Oxygen; Protein Binding; S-Nitrosothiols; Spectrometry, Mass, Electrospray Ionization; Vasodilator Agents | 2002 |
Nitric oxide-mediated heme oxidation and selective beta-globin nitrosation of hemoglobin from normal and sickle erythrocytes.
Nitric oxide (NO) has been reported to modulate the oxygen affinity of blood from sickle cell patients (SS), but not that of normal adult blood (AA), with little or no heme oxidation. However, we had found that the NO donor compounds 2-(N, N-diethylamino)-diazenolate-2-oxide (DEANO) and S-nitrosocysteine (CysNO) caused increased oxygen affinity of red cells from both AA and SS individuals and also caused significant methemoglobin (metHb) formation. Rapid kinetic experiments in which HbA(0), AA, or SS erythrocytes were mixed with CysNO or DEANO showed biphasic time courses indicative of initial heme oxidation followed by reductive heme nitrosylation, respectively. Hemolysates treated with CysNO showed by electrospray mass spectrometry a peak corresponding to a 29 mass unit increase (consistent with NO binding) of both the beta(A) and beta(S) chains but not of the alpha chains. Therapeutic use of NO in sickle cell disease may ultimately require further optimization of these competing reactions, i.e., heme reactivity (nitrosylation or oxidation) versus direct S-nitrosation of hemoglobin on the beta-globin. Topics: Anemia, Sickle Cell; Cysteine; Diethylamines; Erythrocytes; Globins; Heme; Hemoglobin A; Hemoglobin, Sickle; Humans; Kinetics; Mass Spectrometry; Methemoglobin; Nitric Oxide; Nitrogen Oxides; Nitroso Compounds; Oxidation-Reduction; Oxygen; S-Nitrosothiols; Spectrophotometry; Thermodynamics | 2000 |