1993 Fiscal Year Final Research Report Summary
Studies on blue copper proteins and metal complexes as electron acceptors form a reduced enzyme
| Project/Area Number |
04640580
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
無機・錯塩・放射化学
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| Research Institution | Osaka University |
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Principal Investigator |
SUZUKI Shinnichiro Insttitute of Chemistry, College of General Education, Professor, 教養部, 教授 (70116052)
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| Project Period (FY) |
1992 – 1993
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| Keywords | blue copper protein / azurin / intermolecular electron-transfer / nitrite reductase / methylamine dehydrogenase |
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| Research Abstract |
The electron-transfer rates form Methylomonas J methylamine dehyrogenase to five blue copper proteins have been evaluated by cyclic voltammetry. The order of the electron-transfer rate constants from these copper proteins to methylamine dehydrogenase (E_<1/2>=ca.+100mV(NHE))) is as follows : azurin from Alcaligenes sp. (Az-As ; E_<1/2>=+270 mM(NHE)) > amicyanin from Methylobacterium extorquens AM1 (Am-Me ; +248 mV) > azurin-1 from Methylomonas J (Az-MJ1 ; +278 mV). Az-Az exhibited the higher activity bya factor of 7.5 as electron acceptors than Az-MJ2, but pseudoazurin from Methylomonas extorquens AM1 (pAz-Ac ; +260 mV) had hardly the activity. These findings are not due to the redox potentiols of blue copper proteins but the alignment of protein sequences. Espectially the hydrophobic phtch around hystidine imidazole guroup bound to Cu(II) in blue copper protein seems to be important to interact with methylamine dehydrogenase.
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