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Molekulare und physiologische Charakterisierung des Energiestoffwechsels von Nitrosomonas europaea
| Content Provider | Semantic Scholar |
|---|---|
| Author | Gilch, Stefan |
| Copyright Year | 2010 |
| Abstract | Ammonia monooxygenase (AMO) of Nitrosomonas europaea is a metalloenzyme that catalyzes the oxidation of ammonia to hydroxylamine. This study shows that AMO resides in the cytoplasm of the bacteria in addition to its location in the membrane and is distributed about equally in both subcellular fractions. AMO in both fractions catalyzes the oxidation of ammonia and binds [ 14 C]acetylene, a mechanism-based inhibitor that specifically interacts with catalytically active AMO. Soluble AMO was purified 12-fold to electrophoretic homogeneity with a yield of 8%. AMO has a molecular mass of ~283 kDa with subunits of ~27 kDa (α-subunit, AmoA), ~42 kDa (β-subunit, AmoB), and ~24 kDa (γ-subunit, cytochrome c1) in an α3β3γ3 subunit structure. Different from β-subunit of membrane-bound AMO, AmoB of soluble AMO possesses an N-terminal signal sequence. AMO contains Cu (9.4 ± 0.6 mol [mol AMO] -1 ), Fe (3.9 ± 0.3 mol [mol AMO] -1 ), and Zn (0.5 to 2.6 mol [mol AMO] -1 ). Upon reduction the visible absorption spectrum of AMO reveals absorption bands characteristic of cytochrome c. Electron paramagnetic resonance spectroscopy of air-oxidized AMO at 50 K shows a paramagnetic signal originating from Cu 2+ and at 10 K a paramagnetic signal characteristic of heme-Fe. |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | https://epub.uni-bayreuth.de/439/1/Diss.pdf |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
