A so-called "green protein" has been purified from a moderate halophilic eubacterium, Bacillus halodenitrificans (ATCC 49067), under anaerobic conditions. The protein, which might play an important role in denitrification, dissociates mainly into two components after exposure to air: a manganese superoxide dismutase (GP-MnSOD) and a nucleoside diphosphate kinase. As a first step in elucidating the overall structure of the green protein and the role of each component, the 2.8-A resolution crystal structure of GP-MnSOD was determined. Compared with other manganese dismutases, GP-MnSOD shows two significant characteristics. The first is that the entrance to its substrate channel has an additional basic residue-Lys38. The second is that its surface is decorated with an excess of acidic over basic residues. All these structural features may be related to GP-MnSOD's high catalytic activity and its endurance against the special cytoplasm of B. halodenitrificans. The structure of GP-MnSOD provides the basis for recognizing its possible role and assembly state in the green protein.
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http://dx.doi.org/10.1016/s1047-8477(02)00531-2 | DOI Listing |
J Environ Manage
January 2025
Fujian Province Key Laboratory of Pollution Control and Resource Reuse, College of Environmental and Resource Science, Fujian Normal University, Fuzhou, 350007, Fujian Province, China. Electronic address:
Since the widespread use of antibiotics, the residues of antibiotics have frequently been detected in various water sources, making antibiotic pollution an urgent environmental issue. In this paper, one-step green synthetic reduced graphene/manganese nanoparticles (rGO/Mn NPs) composites have been utilized as a novel environmentally-friendly catalyst for tetracycline (TC) removal. The results demonstrated that rGO/Mn NPs exhibit excellent adsorption performance for TC, and can efficiently activate sodium persulfate (PDS) to oxidize and degrade TC.
View Article and Find Full Text PDFMater Today Bio
February 2025
Research Center of Nanomedicine Technology, The Second Affiliated Hospital of Guangxi Medical University, Nanning, 530000, PR China.
Nanozymes with specific catalytic activity inhibit inflammation and promote wound healing efficiently and safely. In this work, multifunctional manganese-based nanozymes (MnGA) with antioxidant properties were successfully constructed via a simple coordination reaction in which manganese chloride was used as the manganese source and gallic acid (GA) was used as the ligand solution. MnGA possesses both catalase-like (CAT-like) and superoxide dismutase-like (SOD-like) activities and a reactive nitrogen species (RNS) scavenging capacity, which enables it to efficiently inhibit the inflammatory response.
View Article and Find Full Text PDFFree Radic Biol Med
January 2025
Department of Radiation Oncology, Mays Cancer Center at UT Health San Antonio MD Anderson, Joe R. and Teresa Lozano Long School of Medicine, TX, USA. Electronic address:
Manganese superoxide dismutase (MnSOD/SOD2) is an essential mitochondrial enzyme that detoxifies superoxide radicals generated during oxidative respiration. MnSOD/SOD2 lysine 68 acetylation (K68-Ac) is an important post-translational modification (PTM) that regulates enzymatic activity, responding to nutrient status or oxidative stress, and elevated levels have been associated with human illness. To determine the in vivo role of MnSOD-K68 in the heart, we used a whole-body non-acetylation mimic mutant (MnSOD) knock-in mouse.
View Article and Find Full Text PDFMar Pollut Bull
January 2025
ICAR-National Institute of Abiotic Stress Management, Baramati, Pune-413115, India.
Contaminants are a major cause of seafood export rejections in foreign markets and have significantly impacted consumer health. This investigation addresses the issues of metal contamination and biochemical markers in Litopenaeus vannamei from East Midnapore, West Bengal, India. The analyzed metals included vanadium (V), chromium (Cr), manganese (Mn), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), molybdenum (Mo), silver (Ag), gallium (Ga), germanium (Ge), arsenic (As), selenium (Se), strontium (Sr), tin (Sn), cadmium (Cd), mercury (Hg), and lead (Pb), using Inductively Coupled Plasma Mass Spectrometry (ICP-MS).
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