@article {2357, title = {Kinetics studies of the superoxide-mediated electron transfer reactions between rubredoxin-type proteins and superoxide reductases}, journal = {J Biol Inorg Chem}, volume = {11}, number = {4}, year = {2006}, note = {
0949-8257 (Print)0949-8257 (Linking)Journal ArticleResearch Support, Non-U.S. Gov{\textquoteright}t
}, month = {Jun}, pages = {433-44}, abstract = {In this work we present a kinetic study of the superoxide-mediated electron transfer reactions between rubredoxin-type proteins and members of the three different classes of superoxide reductases (SORs). SORs from the sulfate-reducing bacteria Desulfovibrio vulgaris (Dv) and D. gigas (Dg) were chosen as prototypes of classes I and II, respectively, while SOR from the syphilis spirochete Treponema pallidum (Tp) was representative of class III. Our results show evidence for different behaviors of SORs toward electron acceptance, with a trend to specificity for the electron donor and acceptor from the same organism. Comparison of the different kapp values, 176.9+/-25.0 min(-1) in the case of the Tp/Tp electron transfer, 31.8+/-3.6 min(-1) for the Dg/Dg electron transfer, and 6.9+/-1.3 min(-1) for Dv/Dv, could suggest an adaptation of the superoxide-mediated electron transfer efficiency to various environmental conditions. We also demonstrate that, in Dg, another iron-sulfur protein, a desulforedoxin, is able to transfer electrons to SOR more efficiently than rubredoxin, with a kapp value of 108.8+/-12.0 min(-1), and was then assigned as the potential physiological electron donor in this organism.
}, keywords = {Animals, Bacterial Proteins/chemistry/genetics/metabolism, Cattle, Desulfovibrio gigas/enzymology, Desulfovibrio vulgaris/enzymology, Electrochemistry, Electron Transport, Iron-Binding Proteins/chemistry/metabolism, Iron-Sulfur Proteins/chemistry/metabolism, Kinetics, Oxidoreductases Acting on Sulfur Group Donors/chemistry/metabolism, Oxidoreductases/*chemistry/genetics/metabolism, Rubredoxins/*chemistry/genetics/metabolism, Spectrophotometry, Superoxides/*chemistry/metabolism}, url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve\&db=PubMed\&dopt=Citation\&list_uids=16544159 }, author = {Auchere, F. and Pauleta, S. R. and Tavares, P and Moura, I. and Moura, J. J.} }