INOR 765 |
| The bacterial cytochrome c peroxidase from Pseudomonas aeruginosa contains a high potential heme, which accepts electrons and subsequently transfers them to a low potential heme where substrate binds. In order for catalysis the HP heme must first undergo a one-electron reduction to the ferrous state. This causes a structural rearrangement of the LP heme so H2O2 can bind. We have used protein film voltammetry to better understand the redox properties associated with the specific heme cofactors as well as the electrochemical coupling between the hemes of the Pa and E. coli enzymes. Kinetic assays have shown that the putative Ec cytochrome c peroxidase does indeed demonstrated peroxidase activity, with a Km = 8 µM. Unlike the Pa enzyme Ec CcP does not require pre-reduction of the high potential heme, nor inclusion of excess Ca2+. Electronic absorption and EPR measurements have also revealed unique features potentially associated with the third heme. |
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Bioinorganic Chemistry: Enzymes and Coenzymes
7:00 PM-10:00 PM, Tuesday, August 21, 2007 BCEC -- Exhibit Hall - B2, Poster
Sci-Mix
Division of Inorganic Chemistry |