Electron transfer in di(deoxy)nucleoside phosphates in aqueous solution: rapid migration of oxidative damage (via adenine) to guanine

1993 ◽  
Vol 115 (6) ◽  
pp. 2437-2440 ◽  
Author(s):  
Luis Pedro Candeias ◽  
Steen Steenken
2014 ◽  
Vol 513-517 ◽  
pp. 65-69
Author(s):  
Xiao Jun Hu ◽  
Xin Yan Hu ◽  
Zhi Zhang

According to the principle of dynamic quenching a new ON-OFF fluorescent chemosensor for Cu2+ions was designed, this chemosensor was composed of p-tert-butylthiacalix [arene (TCA),sodium dodecyl sulfate (SDS) and perylene through the form of self-assembly in aqueous solution. Addition of Cu2+ions could result in a quenching of the fluorescence emission of perylene inside micelles, which due to intramicellar complex-fluorophore electron-transfer or energy-transfer effects induced by the complexation of TCA with the Cu2+ions.The experimental results indicated that: Under the condition of TCA/perylene was 800/1, SDS concentration was 150mmol/L and pH value above 9, according to the fluorescence quenching ,within a certain range of the concentration of Cu2+ion can be linearly determined.


1998 ◽  
Vol 94 (3) ◽  
pp. 359-363 ◽  
Author(s):  
Hari Mohan ◽  
D. K. Palit ◽  
Jai P. Mittal ◽  
L. Y. Chiang ◽  
Klaus-Dieter Asmus ◽  
...  

2012 ◽  
Vol 287 (15) ◽  
pp. 11649-11655 ◽  
Author(s):  
John A. Zuris ◽  
Syed S. Ali ◽  
Howard Yeh ◽  
Tung A. Nguyen ◽  
Rachel Nechushtai ◽  
...  

MitoNEET (mNT) is the founding member of the recently discovered CDGSH family of [2Fe-2S] proteins capable of [2Fe-2S] cluster transfer to apo-acceptor proteins. It is a target of the thiazolidinedione (TZD) class of anti-diabetes drugs whose binding modulate both electron transfer and cluster transfer properties. The [2Fe-2S] cluster in mNT is destabilized upon binding of NADPH, which leads to loss of the [2Fe-2S] cluster to the solution environment. Because mNT is capable of transferring [2Fe-2S] clusters to apo-acceptor proteins, we sought to determine whether NADPH binding also affects cluster transfer. We show that NADPH inhibits transfer of the [2Fe-2S] cluster to an apo-acceptor protein with an inhibition constant (Ki) of 200 μm, which reflects that of NADPH concentrations expected under physiological conditions. In addition, we determined that the strictly conserved cluster interacting residue Asp-84 in the CDGSH domain is necessary for the NADPH-dependent inhibition of [2Fe-2S] cluster transfer. The most critical cellular function of NADPH is in the maintenance of a pool of reducing equivalents, which is essential to counteract oxidative damage. Taken together, our findings suggest that NADPH can regulate both mNT [2Fe-2S] cluster levels in the cell as well as the ability of the protein to transfer [2Fe-2S] clusters to cytosolic or mitochondrial acceptors.


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