An educational overview of the chemistry, biochemistry and therapeutic aspects of Mn porphyrins – From superoxide dismutation to H2O2-driven pathways
نویسندگان
چکیده
Most of the SOD mimics thus far developed belong to the classes of Mn-(MnPs) and Fe porphyrins(FePs), Mn(III) salens, Mn(II) cyclic polyamines and metal salts. Due to their remarkable stability we have predominantly explored Mn porphyrins, aiming initially at mimicking kinetics and thermodynamics of the catalysis of O2(-) dismutation by SOD enzymes. Several MnPs are of potency similar to SOD enzymes. The in vivo bioavailability and toxicity of MnPs have been addressed also. Numerous in vitro and in vivo studies indicate their impressive therapeutic efficacy. Increasing insight into complex cellular redox biology has been accompanied by increasing awareness of complex redox chemistry of MnPs. During O2(-) dismutation process, the most powerful Mn porphyrin-based SOD mimics reduce and oxidize O2(-) with close to identical rate constants. MnPs reduce and oxidize other reactive species also (none of them specific to MnPs), acting as reductants (antioxidant) and pro-oxidants. Distinction must be made between the type of reactions of MnPs and the favorable therapeutic effects we observe; the latter may be of either anti- or pro-oxidative nature. H2O2/MnP mediated oxidation of protein thiols and its impact on cellular transcription seems to dominate redox biology of MnPs. It has been thus far demonstrated that the ability of MnPs to catalyze O2(-) dismutation parallels all other reactivities (such as ONOO(-) reduction) and in turn their therapeutic efficacies. Assuming that all diseases have in common the perturbation of cellular redox environment, developing SOD mimics still seems to be the appropriate strategy for the design of potent redox-active therapeutics.
منابع مشابه
Corrigendum to ‘An educational overview of the chemistry, biochemistry and therapeutic aspects of Mn porphyrins – From superoxide dismutation to H2O2-driven pathways’ [Redox Biology 5C (2015) 43–65]
متن کامل
Spectroscopic study on the interaction of three water-soluble porphyrins with calf thymus DNA
Porophyrins and their metal derivatives are strong DNA binders with association constant of to . Some of these compounds have been used for the radiations sensitization therapy of cancer and are targeted to interact with cellular DNA. Binding of porphyrins to DNA changes the expectral and other physic chemical characteristic of porphyrins, The mode of binding can be extracted from inspection ...
متن کاملInfluence of Nitrogen Bases on Epoxidation of Cyclooctene with Sodium Periodate Catalysed by Manganese(III) Porphyrins
Effects of imidazoles and substituted pyridines and pure s-donors on the oxidation of cyclooctene with NaIO4 by 5,10,15,20-tetraphenylporphyrinato-manganese(III) acetate, Mn(TPP)OAc, and 5,10,15,20-Tetramesitylporphyrinato-manganese(III) acetate, Mn(TMP)OAc, catalysts in CH2Cl2-H2O solvent are studied. Coordination of the nitrogen donors to the Mn...
متن کاملSuperoxide radical and superoxide dismutases.
O2- oxidizes the [4Fe-4S] clusters of dehydratases, such as aconitase, causing-inactivation and release of Fe(II), which may then reduce H2O2 to OH- +OH.. SODs inhibit such HO. production by scavengingO2-, but Cu, ZnSODs, by virtue of a nonspecific peroxidase activity, may peroxidize spin trapping agents and thus give the appearance of catalyzing OH. production from H2O2. There is a glycosylate...
متن کاملThermodynamic of Interaction between Some Water-Soluble Porphyrins and DNA by Titration Microcalorimetry
In the present work, the interaction of three water soluble porphyrins, tetra (p-trimethyle) ammoniumphenyl porphyrin iodide (TAPP) as a cationic porphyrin, tetra sodium meso-tetrakis (p-sulphonatophenyle) porphyrin (TSPP) as an anionic porphyrin and manganese tetrakis (p-sulphonato phenyl)porphinato acetate (MnTSPP) as a metal porphyrin, with DNA have been studied by isothermaltitration microc...
متن کامل