Related Experiment Videos
Copper-binding compounds from Methylosinus trichosporium OB3b
A A DiSpirito1, J A Zahn, D W Graham
1Department of Microbiology, Immunology, and Preventive Medicine, Iowa State University, Ames, Iowa 50011, USA. aland@aistate.edu
Journal of Bacteriology
|July 11, 1998
Summary
Two copper-binding compounds (CBCs) were identified in Methylosinus trichosporium OB3b. These compounds were found in higher concentrations in soluble methane monooxygenase (sMMOC) mutants, indicating a role in sMMOC regulation.
Area of Science:
- Biochemistry
- Microbiology
- Biophysical Chemistry
Background:
- Methylosinus trichosporium OB3b is a bacterium known for its methane oxidation capabilities.
- Methane monooxygenases (MMOs) are crucial enzymes in methane metabolism, existing in particulate (pMMO) and soluble (sMMO) forms.
- Copper-binding compounds (CBCs) are implicated in the regulation of MMO expression and activity.
Purpose of the Study:
- To isolate and characterize copper-binding compounds (CBCs) from Methylosinus trichosporium OB3b.
- To investigate the role of CBCs in the regulation of soluble methane monooxygenase (sMMO) in wild-type and mutant strains.
Main Methods:
- Isolation and purification of CBCs from spent culture media.
- Determination of molecular masses and amino acid sequences of CBCs.
- Spectroscopic analysis (UV-Vis absorption, low-temperature EPR) of copper-free and copper-containing CBCs.
- Quantification of CBCs in wild-type and sMMO mutant strains under varying copper conditions.
Main Results:
- Two CBCs, CBC-L1 (1,218 Da) and CBC-L2 (779 Da), were isolated and their partial amino acid sequences determined.
- Spectroscopic data revealed distinct absorption properties for copper-free and copper-bound CBCs, with EPR indicating unique copper-binding environments.
- CBC concentrations were highest in wild-type cells under copper stress and pMMO expression, but were elevated in sMMO mutants irrespective of copper levels.
Conclusions:
- CBCs are small polypeptides involved in copper binding and potentially in modulating methane monooxygenase activity.
- The differential expression patterns suggest that CBCs play a regulatory role, particularly in sMMO mutants, independent of external copper concentrations.