Particulate methane monooxygenase (pMMO) has been exfoliated and isolated from membranes of the Methylosinus trichosporium IMV 3011. It appears that the stability of pMMO in the exfoliation process is increased with increasing copper concentration in the growth medium, but extensive intracytoplasmic membrane formed under higher copper concentration may inhibit the exfoliation of active pMMO from membrane. The highest total activity of purified pMMO is obtained with an initial concentration of 6 microM Cu in the growth medium. The purified MMO contains only copper and does not utilize NADH as electron donor. Treatment of purified pMMO with EDTA resulted in little change in copper level, suggesting that the copper in the pMMO is tightly bound with pMMO.
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http://dx.doi.org/10.1016/s0006-291x(02)00647-2 | DOI Listing |
Dalton Trans
January 2025
Department of Computational Chemistry, Lund University, Chemical Centre, P. O. Box 124, SE-221 00 Lund, Sweden.
Particulate methane monooxygenase (pMMO) is the most efficient of the two groups of enzymes that can hydroxylate methane. The enzyme is membrane bound and therefore hard to study experimentally. For that reason, there is still no consensus regarding the location and nature of the active site.
View Article and Find Full Text PDFPLoS One
January 2025
Environmental Molecular Sciences Division, Pacific Northwest National Laboratory, Richland, Washington, United States of America.
Coastal wetlands, including freshwater systems near large lakes, rapidly bury carbon, but less is known about how they transport carbon either to marine and lake environments or to the atmosphere as greenhouse gases (GHGs) such as carbon dioxide and methane. This study examines how GHG production and organic matter (OM) mobility in coastal wetland soils vary with the availability of oxygen and other terminal electron acceptors. We also evaluated how OM and redox-sensitive species varied across different size fractions: particulates (0.
View Article and Find Full Text PDFEnviron Sci Technol
January 2025
Department of Atmospheric Sciences, University of Utah, Salt Lake City, Utah 84112, United States.
Methane (CH) is a greenhouse gas with a global warming potential 81.2 times higher than carbon dioxide (CO). The intentional emission of oxidants into the atmosphere has been proposed as a geoengineering solution to accelerate the oxidation of CH to CO, thereby reducing surface warming.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Departments of Molecular Biosciences and of Chemistry, Northwestern University, Evanston, IL 60208.
Methane- and ammonia-oxidizing bacteria play key roles in the global carbon and nitrogen cycles, respectively. These bacteria use homologous copper membrane monooxygenases to accomplish the defining chemical transformations of their metabolisms: the oxidations of methane to methanol by particulate methane monooxygenase (pMMO) and ammonia to hydroxylamine by ammonia monooxygenase (AMO), enzymes of prime interest for applications in mitigating climate change. However, investigations of these enzymes have been hindered by the need for disruptive detergent solubilization prior to structure determination, confounding studies of pMMO and precluding studies of AMO.
View Article and Find Full Text PDFSensors (Basel)
December 2024
Department of Environmental Engineering, Pukyong National University, Busan 48513, Republic of Korea.
Rapid industrialization and the influx of human resources have led to the establishment of industrial complexes near urban areas, exposing residents to various air pollutants. This has led to a decline in air quality, impacting neighboring residential areas adversely, which highlights the urgent need to monitor air pollution in these areas. Recent advancements in technology, such as Solar Occultation Flux (SOF) and Sky Differential Optical Absorption Spectroscopy (SkyDOAS) used as remote sensing techniques and mobile extraction Fourier Transform Infrared Spectrometry (MeFTIR) used as an in situ technique, now offer enhanced precision in estimating the pollutant emission flux and identifying primary sources.
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