Methanobactin from methanotrophs: genetics, structure, function and potential applications

2020 ◽  
Vol 367 (5) ◽  
Author(s):  
Jeremy D Semrau ◽  
Alan A DiSpirito ◽  
Parthiba Karthikeyan Obulisamy ◽  
Christina S Kang-Yun
Keyword(s):  
Hydrogen Peroxide ◽  
Superoxide Dismutase ◽  
Nitrous Oxide ◽  
Industrial Applications ◽  
Mercury Species ◽  
Copper Uptake ◽  
Bioinformatics Analyses ◽  
Methane Oxidizing Bacteria ◽  
Potential Applications ◽  
Copper Availability

ABSTRACT Aerobic methane-oxidizing bacteria of the Alphaproteobacteria have been found to express a novel ribosomally synthesized post-translationally modified polypeptide (RiPP) termed methanobactin (MB). The primary function of MB in these microbes appears to be for copper uptake, but MB has been shown to have multiple capabilities, including oxidase, superoxide dismutase and hydrogen peroxide reductase activities, the ability to detoxify mercury species, as well as acting as an antimicrobial agent. Herein, we describe the diversity of known MBs as well as the genetics underlying MB biosynthesis. We further propose based on bioinformatics analyses that some methanotrophs may produce novel forms of MB that have yet to be characterized. We also discuss recent findings documenting that MBs play an important role in controlling copper availability to the broader microbial community, and as a result can strongly affect the activity of microbes that require copper for important enzymatic transformations, e.g. conversion of nitrous oxide to dinitrogen. Finally, we describe procedures for the detection/purification of MB, as well as potential medical and industrial applications of this intriguing RiPP.

Effect of Val 73 → Trp Mutation on the Reaction of “Cambialistic” Superoxide Dismutase fromPropionibacterium shermaniiwith Hydrogen Peroxide

1997 ◽  
Vol 345 (1) ◽  
pp. 156-159 ◽  
Author(s):  
R. Gabbianelli ◽  
A. Battistoni ◽  
C. Capo ◽  
F. Polticelli ◽  
G. Rotilio ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Superoxide Dismutase

scholarly journals Cromoglycate and nedocromil enhanced the reactive oxygen species-dependent suppressions with, but not without, dexamethasone in ischaemic and histamine paw oedema of mice

1997 ◽  
Vol 6 (5-6) ◽  
pp. 369-374
Author(s):  
Y. Oyanagui
Keyword(s):  
Reactive Oxygen Species ◽  
Hydrogen Peroxide ◽  
Superoxide Dismutase ◽  
Glucocorticoid Receptor ◽  
Low Dose ◽  
Natural Antioxidant ◽  
Target Cells ◽  
Oxygen Species ◽  
Paw Oedema ◽  
Β Carotene

Anti-inflammatory actions of two anti-allergic drugs, alone or with dexamethasone (Dex) were examined in two models, because inflammation is claimed to be important for allergic events, especially for asthma. Cromoglycate and nedocromil were tested in ischaemic- and histamineinduced paw oedema models of mice. These antiallergic drugs (1–100 mg/kg, i.p.) failed to suppress these oedemata, but enhanced the suppressions by a low dose of dexamethasone (0.1 mg/kg, s.c.) at 3–8 h after Dex injection. The mode of effects by anti-allergic drugs resembled that of a natural antioxidant (α-tocopherol, β-carotene etc.), and was different from that of an immunosuppressant like FK506. The enhancing potencies of the two anti-allergic drugs were similar at 6 h after Dex in both oedemata, and were diminished by superoxide dismutase (SOD) or catalase (i.p.). Cycloheximide completely abolished suppressions. Nedocromil, but not cromoglycate, inhibits inflammatory events. Therefore, there are common unknown actions by which the two anti-allergics enhance suppression by Dex. A possible mechanism of this action was supposed to enhance the superoxide and/or hydrogen peroxide-dependent glucocorticoid receptor (GR) signalling in the target cells.

Catalase released from beneficial and plant-pathogenic pseudomonads by water and chloroform treatments

1994 ◽  
Vol 40 (8) ◽  
pp. 630-636
Author(s):  
J. I. Pounder ◽  
A. J. Anderson
Keyword(s):  
Hydrogen Peroxide ◽  
Superoxide Dismutase ◽  
Water Treatment ◽  
Pseudomonas Syringae ◽  
Small Proportion ◽  
Plant Colonization ◽  
Periplasmic Proteins ◽  
Specific Activities ◽  
Leaf Pathogen ◽  
Glucose 6 Phosphate Dehydrogenase

Survival of pseudomonads during plant colonization may involve bacterial catalases to degrade the hydrogen peroxide produced by the plant. The specific activities of catalases in lysates from two saprophytic isolates of Pseudomonas putida and Pseudomonas fluorescens and three races of Pseudomonas syringae pv. glycinea were similar. To explore the location of the bacterial catalases, cells of the pathogenic and saprophytic pseudomonads were treated with chloroform, which is reported to release periplasmic proteins. Although catalase was released by chloroform treatment, the cytoplasmic enzymes isocitrate dehydrogenase, superoxide dismutase, and glucose-6-phosphate dehydrogenase were also detected. These proteins may have come from lysis of a small proportion of the cells rather than the periplasm. Water treatment of cells also released amounts of protein similar to those derived from chloroform treatment. Similar responses were found from both pathogenic and saprophytic strains. The release of catalase and proteins from the leaf pathogen P. syringae pv. glycinea race 0 and the root-associated saprophyte P. putida decreased as the cultures aged. With P. putida and P. syringae pv. glycinea race 0, the single isozyme of catalase released by water and chloroform treatment also was detected in lysates. Additional catalase isozymes were present in lysates as the cultures aged.Key words: periplasmic proteins, survival.

scholarly journals Osmotic induction improves batch marking of larval fish otoliths with enriched stable isotopes

2014 ◽  
Vol 71 (9) ◽  
pp. 2530-2538 ◽  
Author(s):  
Emmanuel de Braux ◽  
Fletcher Warren-Myers ◽  
Tim Dempster ◽  
Per Gunnar Fjelldal ◽  
Tom Hansen ◽  
...  
Keyword(s):  
Stable Isotopes ◽  
Salmo Salar ◽  
Larval Fish ◽  
Fish Larvae ◽  
Cost Effective ◽  
Industrial Applications ◽  
Chemical Markers ◽  
Potential Applications ◽  
Recent Method ◽  
Batch Marking

Abstract Otolith marking with enriched stable isotopes via immersion is a recent method of batch marking larval fish for a range of research and industrial applications. However, current immersion times and isotope concentrations required to successfully mark an otolith limit the utility of this technique. Osmotic induction improves incorporation and reduces immersion time for some chemical markers, but its effects on isotope incorporation into otoliths are unknown. Here, we tested the effects of osmotic induction over a range of different isotope concentrations and immersion times on relative mark success and strength for 26Mg:24Mg, 86Sr:88Sr and 137Ba:138Ba on Atlantic salmon (Salmo salar) larvae. 71% and 100% mark success were achieved after 1 h of immersion for 86Sr (75 µg L−1) and 137Ba (30 µg L−1) isotopes, respectively. Compared with conventional immersion, osmotic induction improved overall mark strength for 86Sr and 137Ba isotopes by 26–116%, although this effect was only observed after 12 h of immersion and predominately for 86Sr. The results demonstrate that osmotic induction reduces immersion times and the concentrations of isotope required to achieve successful marks. Osmotically induced isotope labels via larval immersion may prove a rapid and cost-effective way of batch marking fish larvae across a range of potential applications.

scholarly journals Oxidation of glycine by Phaseolus leghaemoglobin with associated catabolic reactions at the haem

1978 ◽  
Vol 176 (2) ◽  
pp. 351-358 ◽  
Author(s):  
P Lehtovaara
Keyword(s):  
Hydrogen Peroxide ◽  
Carbon Monoxide ◽  
Superoxide Dismutase ◽  
Phaseolus Vulgaris ◽  
Initial Velocity ◽  
Root Nodules ◽  
Green Product ◽  
Oxygen Complex ◽  
Optimum Ph ◽  
Glycine Oxidase

Leghaemoglobin from the root nodules of kidney bean (Phaseolus vulgaris) reacts in alkaline glycine solutions as a glycine oxidase in a reaction that may also be regarded as a coupled oxidation. Leghaemoglobin is reduced to the ferrous form by glycinate, the oxygen complex is formed, and finally the haem is attacked to yield a green reaction product. Glycine is simultaneously oxidized to glyoxylate, and hydrogen peroxide is generated. The initial velocity of the formation of the green product is proportional to the concentrations of leghaemoglobin and glycine, and the optimum pH for the reaction is 10.2. The green product is not formed if carbon monoxide, azide of imidazole is bound to the haem, whereas oxidation of glycine to glyoxylate is not inhibited by azide and not essentially by carbon monoxide. Haem breakdown is activated by digestion of leghaemoglobin by carboxypeptidase, and partly inhibited by catalase and superoxide dismutase.

scholarly journals Evidence for production of oxidizing radicals by the particulate O-2- forming system from human neutrophils

Blood ◽  
1979 ◽  
Vol 53 (4) ◽  
pp. 666-676
Author(s):  
AI Tauber ◽  
TG Gabig ◽  
BM Babior
Keyword(s):  
Hydrogen Peroxide ◽  
Superoxide Dismutase ◽  
Ethylene Production ◽  
Human Neutrophils ◽  
Peroxy Acid ◽  
Radical Scavengers ◽  
Alkyl Peroxide ◽  
Acyl Peroxide

The particulate O-2-forming system from human neutrophils was found to oxidize methional and 2-keto-4-methylthiobutyric acid (KMB) to ethylene, indicating the formation by this system of strongly oxidizing radicals. Conforming this interpretation was the observation that ethylene production was inhibited by the radical scavengers benzoate, ethanol, and mannitol. Ethylene production was also sharply reduced by superoxide dismutase, implicatin O-2 as a precursor of oxidizing radicals. In our system catalase only partially inhibited ethylene generation from either methional or KMB, suggesting that oxidizing radicals are generated at least in part by the reacton of O-2 with compounds other than H2O2. We propose that in neutrophils oxidizing radicals are formed in a reaction between O-2 and a peroxide according to the following equation: O-2 + ROOH leads to RO . + OH- + O2, in which ROOH may be hydrogen peroxide, an alkyl peroxide, or an acyl peroxide (i.e., a peroxy acid).

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