The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.

wikigene or wiki gene protein drug chemical gene disease author authorship tracking collaborative publishing evolutionary knowledge reputation system wiki2.0 global collaboration genes proteins drugs chemicals diseases compound
Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)
 
 
 

Inhibitory effects of water-soluble cationic manganese porphyrins on peroxynitrite-induced SOS response in Salmonella typhimurium TA4107/pSK1002.

We have investigated the protective effects of water-soluble cationic Mn(III) porphyrins against peroxynitrite (ONOO-)-induced DNA damage in the cells of Salmonella typhimurium TA4107/pSK1002 and lipid peroxidation of red blood cell membranes. Mn(III) tetrakis (N-methylpyridinium-4-yl) porphine (TMPyP) and the brominated form, Mn(III) octabromo-tetrakis (N-methylpyridinium-4-yl) porphine (OBTMPyP) effectively reduced the damage and peroxidation induced by N-morpholino sydnonimine (SIN-1), which gradually generates ONOO- from O2*- and *NO produced through hydrolysis. Mn(III)OBTMPyP became 10-fold more active than the non-brominated form. In the presence of authentic ONOO-, the Mn(III) porphyrins were ineffective against damage and strongly enhanced lipid peroxidation, while the coexistence of ascorbic acid inhibited peroxidation. Using a diode array spectrophotometry, the reactions of Mn(III)TMPyP with authentic ONOO- and SIN-1 were measured. Mn(III)TMPyP is known to be catalytic for ONOO- decomposition in the presence of antioxidants. OxoMn(IV)TMPyP with SIN-1 was rapidly reduced back to Mn(III) without adding any oxidants. Further, in the SIN-1 system, the concentration of NO2- and NO3- were colorimetrically determined by Griess reaction based on the two-step diazotization. NO2- increased by addition of Mn(III) porphyrin and the ratio of NO2- to NO3- was 4-7 times higher than that (1.05) of SIN-1 alone. This result suggests that O2*- from SIN-1 acts as a reductant and *NO cogenerated is oxidized to NO2-, a primarily decomposition product of *NO. Under the pathological conditions where biological antioxidants are depleted and ONOO- and O2*- are extensively generated, the Mn(III) porphyrins will effectively cycle ONOO- decomposition using O2*-.[1]

References

 
WikiGenes - Universities