mesna has been researched along with 2-thiomalic-acid* in 2 studies
2 other study(ies) available for mesna and 2-thiomalic-acid
| Article | Year |
|---|---|
Radioprotection of DNA by thiols: relationship between the net charge on a thiol and its ability to protect DNA.
Release of free bases from calf thymus DNA upon irradiation in aerated 0.1 mol dm-3NaClO4 at pH 7 has been measured by HPLC and shown to be markedly influenced by the presence of thiols during irradiation. The ability of thiols to protect DNA was shown to depend upon the net charge (Z) at pH 7 in the order WR 1065 (Z = +2) greater than cysteamine (Z = +1) greater than 2-mercaptoethanol (Z = 0) approximately equal to dithiothreitol (Z = 0) greater than GSH (Z = -1) approximately equal to 2-mercaptoethanesulfonic acid (Z = -1) approximately equal to 2-mercaptosuccinate (Z = -2). A similar dependence of protection upon net charge was found for disulfides: cystamine (Z = +2) greater than 2-mercaptoethyl disulfide (Z = 0) greater than GSSG (Z = -2). Protection by WR 1065, but not by 2-mercaptoethanol or GSH, was found to decrease significantly with increasing ionic strength. Protection by WR 1065 and GSH was not markedly dependent upon pH between pH 6 and 8. The results are explained in terms of electrostatic interaction of the thiols with DNA, leading to high concentrations of cations near DNA, which allow them to scavenge hydroxyl radicals and repair DNA radicals effectively and to low concentrations of anionic thiols near DNA, which limit their effectiveness as protectors. Poly(dG,dC) and calf thymus DNA exhibited comparable release of G and C upon changing from 0.1 to 0.7 mol dm-3 MgSO4. Since this change causes poly(dG,dC), but not calf thymus DNA, to undergo a change from the B-form to the Z-form of DNA, both forms must have a comparable susceptibility to radiation-induced base release. Topics: Anions; Cations; Cysteamine; Dithiothreitol; DNA; DNA Damage; Glutathione; Mercaptoethanol; Mercaptoethylamines; Mesna; Radiation-Protective Agents; Sulfhydryl Compounds; Thiomalates | 1988 |
Interaction of glutathione and other low-molecular-weight thiols with DNA: evidence for counterion condensation and coion depletion near DNA.
The interaction of low-molecular-weight thiols with sonicated DNA was examined using spin filtration to concentrate the DNA. Cationic thiols (WR 1065 and cysteamine) behaved as counterions and were found to have increased concentrations in the DNA retentate relative to the filtrate. Anionic thiols (GSH, 2-mercaptoethanesulfonate, mercaptosuccinate) behaved as coions and were decreased in concentration in the DNA fraction. Concentrations of the uncharged thiol 2-mercaptoethanol were little influenced by DNA. The results demonstrate the importance of counterion condensation and coion depletion in determining the concentrations of charged species near DNA. They provide a rationale for enhanced effectiveness of WR 1065 and cysteamine as radioprotectors compared to neutral and anionic thiols and suggest that anionic thiols such as GSH should be poor radioprotectors of DNA. Topics: Anions; Cations; Cysteamine; DNA; Glutathione; Mercaptoethylamines; Mesna; Sulfhydryl Compounds; Thiomalates; Ultrasonics | 1988 |