Determination of an optimal potential window for catalysis by E. coli dimethyl sulfoxide reductase and hypothesis on the role of Mo(V) in the reaction pathway.
Protein film voltammetry (PFV) of Escherichia coli dimethyl sulfoxide (DMSO) reductase (DmsABC) adsorbed at a graphite electrode reveals that the catalytic activity of this complex Mo-pterin/Fe-S enzyme is optimized within a narrow window of electrode potential. The upper and lower limits of this wi...
| Những tác giả chính: | , , , , |
|---|---|
| Định dạng: | Journal article |
| Ngôn ngữ: | English |
| Được phát hành: |
2001
|
| _version_ | 1826264366938324992 |
|---|---|
| author | Heffron, K Léger, C Rothery, R Weiner, J Armstrong, F |
| author_facet | Heffron, K Léger, C Rothery, R Weiner, J Armstrong, F |
| author_sort | Heffron, K |
| collection | OXFORD |
| description | Protein film voltammetry (PFV) of Escherichia coli dimethyl sulfoxide (DMSO) reductase (DmsABC) adsorbed at a graphite electrode reveals that the catalytic activity of this complex Mo-pterin/Fe-S enzyme is optimized within a narrow window of electrode potential. The upper and lower limits of this window are determined from the potential dependences of catalytic activity in reducing and oxidizing directions; i.e., for reduction of DMSO (or trimethylamine-N-oxide) and oxidation of trimethylphosphine (PMe(3)). At either limit, the catalytic activity drops despite the increase in driving force: as the potential is lowered below -200 mV (pH 7.0-8.9), the rate of reduction of DMSO decreases abruptly, while for PMe(3), an oxidative current is observed that vanishes as the potential is raised above +20 mV (pH 9.0). Analysis of the waveshapes reveals that both activity thresholds result from one-electron redox reactions that arise, most likely, from groups within the enzyme; if so, they represent "switches" that reflect the catalytic mechanism and may be of physiological relevance. The potential window of activity coincides approximately with the appearance of the Mo(V) EPR signal observed in potentiometric titrations, suggesting that crucial stages of catalysis are facilitated while the active site is in the intermediate Mo(V) oxidation state. |
| first_indexed | 2024-03-06T20:06:39Z |
| format | Journal article |
| id | oxford-uuid:292016da-ba3a-455d-94bb-5c322ac5f671 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T20:06:39Z |
| publishDate | 2001 |
| record_format | dspace |
| spelling | oxford-uuid:292016da-ba3a-455d-94bb-5c322ac5f6712022-03-26T12:17:10ZDetermination of an optimal potential window for catalysis by E. coli dimethyl sulfoxide reductase and hypothesis on the role of Mo(V) in the reaction pathway.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:292016da-ba3a-455d-94bb-5c322ac5f671EnglishSymplectic Elements at Oxford2001Heffron, KLéger, CRothery, RWeiner, JArmstrong, FProtein film voltammetry (PFV) of Escherichia coli dimethyl sulfoxide (DMSO) reductase (DmsABC) adsorbed at a graphite electrode reveals that the catalytic activity of this complex Mo-pterin/Fe-S enzyme is optimized within a narrow window of electrode potential. The upper and lower limits of this window are determined from the potential dependences of catalytic activity in reducing and oxidizing directions; i.e., for reduction of DMSO (or trimethylamine-N-oxide) and oxidation of trimethylphosphine (PMe(3)). At either limit, the catalytic activity drops despite the increase in driving force: as the potential is lowered below -200 mV (pH 7.0-8.9), the rate of reduction of DMSO decreases abruptly, while for PMe(3), an oxidative current is observed that vanishes as the potential is raised above +20 mV (pH 9.0). Analysis of the waveshapes reveals that both activity thresholds result from one-electron redox reactions that arise, most likely, from groups within the enzyme; if so, they represent "switches" that reflect the catalytic mechanism and may be of physiological relevance. The potential window of activity coincides approximately with the appearance of the Mo(V) EPR signal observed in potentiometric titrations, suggesting that crucial stages of catalysis are facilitated while the active site is in the intermediate Mo(V) oxidation state. |
| spellingShingle | Heffron, K Léger, C Rothery, R Weiner, J Armstrong, F Determination of an optimal potential window for catalysis by E. coli dimethyl sulfoxide reductase and hypothesis on the role of Mo(V) in the reaction pathway. |
| title | Determination of an optimal potential window for catalysis by E. coli dimethyl sulfoxide reductase and hypothesis on the role of Mo(V) in the reaction pathway. |
| title_full | Determination of an optimal potential window for catalysis by E. coli dimethyl sulfoxide reductase and hypothesis on the role of Mo(V) in the reaction pathway. |
| title_fullStr | Determination of an optimal potential window for catalysis by E. coli dimethyl sulfoxide reductase and hypothesis on the role of Mo(V) in the reaction pathway. |
| title_full_unstemmed | Determination of an optimal potential window for catalysis by E. coli dimethyl sulfoxide reductase and hypothesis on the role of Mo(V) in the reaction pathway. |
| title_short | Determination of an optimal potential window for catalysis by E. coli dimethyl sulfoxide reductase and hypothesis on the role of Mo(V) in the reaction pathway. |
| title_sort | determination of an optimal potential window for catalysis by e coli dimethyl sulfoxide reductase and hypothesis on the role of mo v in the reaction pathway |
| work_keys_str_mv | AT heffronk determinationofanoptimalpotentialwindowforcatalysisbyecolidimethylsulfoxidereductaseandhypothesisontheroleofmovinthereactionpathway AT legerc determinationofanoptimalpotentialwindowforcatalysisbyecolidimethylsulfoxidereductaseandhypothesisontheroleofmovinthereactionpathway AT rotheryr determinationofanoptimalpotentialwindowforcatalysisbyecolidimethylsulfoxidereductaseandhypothesisontheroleofmovinthereactionpathway AT weinerj determinationofanoptimalpotentialwindowforcatalysisbyecolidimethylsulfoxidereductaseandhypothesisontheroleofmovinthereactionpathway AT armstrongf determinationofanoptimalpotentialwindowforcatalysisbyecolidimethylsulfoxidereductaseandhypothesisontheroleofmovinthereactionpathway |