The bacteriohemerythrin (McHr) from Methylococcus capsulatus (Bath) is an oxygen carrier that serves as a transporter to deliver O2 from the cytosol of the bacterial cell body to the particulate methane monooxygenase residing in the intracytoplasmic membranes for methane oxidation. Here we report X-ray protein crystal structures of the recombinant wild type (WT) McHr and its L114A, L114Y and L114F mutants. The structure of the WT reveals a possible water tunnel in the McHr that might be linked to its faster autoxidation relative to hemerythrin in marine invertebrates. With Leu114 positioned at the end of this putative water tunnel, the hydrophobic side chain of this residue seems to play a prominent role in controlling the access of the water molecule required for autoxidation. This hypothesis is examined by comparing the autoxidation rates of the WT McHr with those of the L114A, L114Y and L114F mutants. The biochemical data are correlated with structural insights derived from the analysis of the putative water tunnels in the various McHr proteins provided by the X-ray structures.
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http://dx.doi.org/10.1016/j.jinorgbio.2015.04.001 | DOI Listing |
Sci Rep
January 2025
Chengdu Engineering Corporation Limited, Chengdu, 610072, China.
The proportion of railway high-altitude buried tunnels in complex and dangerous mountainous areas in southwest China is exceptionally high. With the characteristics of suddenness, intermittency, instantaneousness, and destruction, inrushinrushing and collapse is one of the main risks in the tunnel construction process. Therefore, in the design and construction process of tunnels in Hengduan Mountain area, it is very important to identify the mechanism of sudden s inrushing and collapse risks, predict the spatial location and scale of possible inrushing and collapse, and formulate corresponding tunnel design and construction response measures.
View Article and Find Full Text PDFSensors (Basel)
January 2025
Acropolis Restoration Service, Hellenic Ministry of Culture, 10555 Athens, Greece.
This study focuses on the geotechnical evaluation of the foundation conditions of the Agrippa Monument at the Acropolis of Athens, aiming to propose interventions to improve stability and reduce associated risks. The assessment reveals highly uneven foundation conditions beneath the monument. A thorough collection of bibliographic references and geotechnical surveys was conducted, classifying geomaterials into engineering-geological units and evaluating critical parameters for geotechnical design.
View Article and Find Full Text PDFNanoscale
January 2025
4109 Newman & Wolfrom Laboratory, 100 W 18th Ave, Columbus, OH 43210, USA.
A variety of ZnCdS-based semiconductor nanoparticle heterostructures with extended exciton lifetimes were synthesized to enhance the efficacy of photocatalytic hydrogen production in water. Specifically, doped nanoparticles (NPs), as well as core/shell NPs with and without palladium and platinum co-catalysts, were solubilized into water using various methods to assess their efficacy for solar H fuel synthesis. The best results were obtained with low bandgap ZnCdS cores and ZnCdS/ZnS core/shell NPs with palladium co-catalysts.
View Article and Find Full Text PDFSci Rep
January 2025
Nanjing ShengNuo Heat Pipe Limited Company, Nanjing, 210009, China.
This study investigates the feasibility of using nano-thermal rod for deicing tunnel pavements in cold region. The heating performance of the nano-thermal rod was compared with that of carbon fiber heating wire under low voltage conditions. Experimental studies were conducted in a controlled environmental chamber to evaluate the effects of arrangement parameters (spacing, buried depth, input power) and environmental factors (ambient temperature and moisture) on heating rate and effectiveness.
View Article and Find Full Text PDFR Soc Open Sci
January 2025
State Key Laboratory of Precision Blasting, Jianghan University, Wuhan 430056, People's Republic of China.
Water stemming is an efficient method of removing blasting dust by wetting. There is still a lack of methods for rapid optimization of water stemming components with high wettability. Herein, blasting dust was collected from a tunnel in Chongqing (China) to investigate its removal performance by different water stemmings.
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