Methanol dehydrogenase (MDH) and c-type cytochromes from marine methanol-oxidizing bacterium, Methylophaga sp. MP, were purified and characterized. The native MDH had a molecular mass of 148 kDa and its isoelectric point was 5.5. Two c-type cytochromes, cL and cH, were found, and their isoelectric points were 3.4 and 8.0, respectively. The purified MDH had higher thermal stability than that of the other soil methylotrophic bacteria. The electron flow rate from MDH to cytochrome cL was higher than that from MDH to cytochrome CH, indicating that the physiological primary electron acceptor for MDH is cytochrome CL. The electron transfer from MDH to phenazine ethosulfate (PES, artificial electron acceptor) in the two dye (PES/DCPIP)-linked assay system was not inhibited by NaCl, whereas the electron flow from MDH to cytochrome CL in the cytochrome/ DCPIP-linked assay system was suppressed significantly by NaCl. Metal chelating agents such as EDTA showed the same effects on the MDH activity.
|Number of pages||7|
|Journal||Journal of microbiology and biotechnology|
|Publication status||Published - 2002 Jul 30|
All Science Journal Classification (ASJC) codes
- Applied Microbiology and Biotechnology