<?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%">Almeida, M. G.</style></author><author><style face="normal" font="default" size="100%">Silveira, C. M.</style></author><author><style face="normal" font="default" size="100%">Guigliarelli, B.</style></author><author><style face="normal" font="default" size="100%">Bertrand, P.</style></author><author><style face="normal" font="default" size="100%">Moura, J. J.</style></author><author><style face="normal" font="default" size="100%">Moura, I.</style></author><author><style face="normal" font="default" size="100%">Leger, C.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">A needle in a haystack: the active site of the membrane-bound complex cytochrome c nitrite reductase</style></title><secondary-title><style face="normal" font="default" size="100%">FEBS Lett</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Bacterial Proteins/*chemistry/isolation &amp; purification</style></keyword><keyword><style  face="normal" font="default" size="100%">Binding Sites</style></keyword><keyword><style  face="normal" font="default" size="100%">Catalysis</style></keyword><keyword><style  face="normal" font="default" size="100%">Cytochromes a1/*chemistry/isolation &amp; purification</style></keyword><keyword><style  face="normal" font="default" size="100%">Cytochromes c1/*chemistry/isolation &amp; purification</style></keyword><keyword><style  face="normal" font="default" size="100%">Desulfovibrio desulfuricans/*enzymology</style></keyword><keyword><style  face="normal" font="default" size="100%">Heme/*chemistry</style></keyword><keyword><style  face="normal" font="default" size="100%">Nitrate Reductases/*chemistry/isolation &amp; purification</style></keyword><keyword><style  face="normal" font="default" size="100%">Potentiometry</style></keyword><keyword><style  face="normal" font="default" size="100%">Protons</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2007</style></year><pub-dates><date><style  face="normal" font="default" size="100%">Jan 23</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=17207484 </style></url></web-urls></urls><number><style face="normal" font="default" size="100%">2</style></number><volume><style face="normal" font="default" size="100%">581</style></volume><pages><style face="normal" font="default" size="100%">284-8</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Cytochrome c nitrite reductase is a multicenter enzyme that uses a five-coordinated heme to perform the six-electron reduction of nitrite to ammonium. In the sulfate reducing bacterium Desulfovibrio desulfuricans ATCC 27774, the enzyme is purified as a NrfA2NrfH complex that houses 14 hemes. The number of closely-spaced hemes in this enzyme and the magnetic interactions between them make it very difficult to study the active site by using traditional spectroscopic approaches such as EPR or UV-Vis. Here, we use both catalytic and non-catalytic protein film voltammetry to simply and unambiguously determine the reduction potential of the catalytic heme over a wide range of pH and we demonstrate that proton transfer is coupled to electron transfer at the active site.&lt;/p&gt;
</style></abstract><accession-num><style face="normal" font="default" size="100%">17207484</style></accession-num><notes><style face="normal" font="default" size="100%">&lt;p&gt;0014-5793 (Print)0014-5793 (Linking)Journal ArticleResearch Support, Non-U.S. Gov't&lt;/p&gt;
</style></notes><auth-address><style face="normal" font="default" size="100%">REQUIMTE, CQFB, Departamento de Quimica, Faculdade de Ciencias e Tecnologia, Universidade Nova de Lisboa, Quinta da Torre, 2829-516, Monte de Caparica, Portugal.</style></auth-address></record></records></xml>