<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Moreno, C.</style></author><author><style face="normal" font="default" size="100%">Costa, C.</style></author><author><style face="normal" font="default" size="100%">Moura, I.</style></author><author><style face="normal" font="default" size="100%">Legall, J.</style></author><author><style face="normal" font="default" size="100%">Liu, M. Y.</style></author><author><style face="normal" font="default" size="100%">Payne, W. J.</style></author><author><style face="normal" font="default" size="100%">Van Dijk, C.</style></author><author><style face="normal" font="default" size="100%">Moura, J. J.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Electrochemical studies of the hexaheme nitrite reductase from Desulfovibrio desulfuricans ATCC 27774</style></title><secondary-title><style face="normal" font="default" size="100%">Eur J Biochem</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Cytochrome c Group/metabolism</style></keyword><keyword><style  face="normal" font="default" size="100%">Desulfovibrio/*enzymology</style></keyword><keyword><style  face="normal" font="default" size="100%">Electrochemistry</style></keyword><keyword><style  face="normal" font="default" size="100%">Electron Transport</style></keyword><keyword><style  face="normal" font="default" size="100%">Kinetics</style></keyword><keyword><style  face="normal" font="default" size="100%">Nitrite Reductases/*chemistry/metabolism</style></keyword><keyword><style  face="normal" font="default" size="100%">Paraquat/metabolism</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1993</style></year><pub-dates><date><style  face="normal" font="default" size="100%">Feb 15</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&amp;db=PubMed&amp;dopt=Citation&amp;list_uids=8383043 </style></url></web-urls></urls><number><style face="normal" font="default" size="100%">1</style></number><volume><style face="normal" font="default" size="100%">212</style></volume><pages><style face="normal" font="default" size="100%">79-86</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;The electron-transfer kinetics between three different mediators and the hexahemic enzyme nitrite reductase isolated from Desulfovibrio desulfuricans (ATCC 27774) were investigated by cyclic voltammetry and by chronoamperometry. The mediators, methyl viologen, Desulfovibrio vulgaris (Hildenborough) cytochrome c3 and D. desulfuricans (ATCC 27774) cytochrome c3 differ in structure, redox potential and charge. The reduced form of each mediator exchanged electrons with nitrite reductase. Second-order rate constants, k, were calculated on the basis of the theory for a simple catalytic mechanism and the results, obtained by cyclic voltammetry, were compared with those obtained by chronoamperometry. Values for k are in the range 10(6)-10(8) M-1 s-1 and increase in the direction D. desulfuricans cytochrome c3--&amp;gt;D. vulgaris cytochrome c3--&amp;gt;methyl viologen. An explanation is advanced on the basis of electrostatic interactions and relative orientation between the partners involved. Chronoamperometry (computer controlled) offers advantages over cyclic voltammetry in the determination of homogeneous rate constants (faster, more accurate and better reproducibility). Direct, unmediated electrochemical responses of the hexaheme nitrite reductase were also reported.&lt;/p&gt;
</style></abstract><accession-num><style face="normal" font="default" size="100%">8383043</style></accession-num><notes><style face="normal" font="default" size="100%">&lt;p&gt;0014-2956 (Print)0014-2956 (Linking)Journal ArticleResearch Support, Non-U.S. Gov'tResearch Support, U.S. Gov't, Non-P.H.S.&lt;/p&gt;
</style></notes><auth-address><style face="normal" font="default" size="100%">Departamento de Quimica, Faculdade de Ciencias e Tecnologia, Universidade Nova de Lisboa, Monte de Caparica, Portugal.</style></auth-address></record></records></xml>