BIOL 23 |
| The peroxidase from the organism Shewanella oneidensis is a diheme enzyme which, like the other peroxidases, reduces hydrogen peroxide to water by two electrons. For the catalysis to occur, most of the diheme peroxidases undergo structural changes, to open the occupied heme site to allow the substrate access. Those changes are achieved by a loop movement of the so called "L-loop", located on the peroxidatic heme, which is the low potential active site. The movement of the L-loop is triggered by the reduction of a higher potential heme that likely serves an electron transfer role. The communication between the hemes enables the dynamic behavior of the loop. We investigate the dynamic behavior of the L-loop and its role in catalysis with the electrochemical tool protein film voltammetry (PFV). The non-catalytic experiments show evidence for the L-loop movement and binding of small molecules on the open coordination upon electrochemical reduction of the high potential heme. The interaction of the hemes is further investigated with electron paramagnetic resonance and electronic absorbtion spectroscopy. |
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Frontiers in Chemical Biology
5:00 PM-7:00 PM, Sunday, August 19, 2007 BCEC -- Exhibit Hall - B2, Poster
Division of Biological Chemistry |