Carbonic anhydrase activity in leaves as measured in vivo by 18O exchange between carbon dioxide and water

Planta ◽  
1995 ◽  
Vol 196 (4) ◽  
Author(s):  
Gilles Peltier ◽  
Laurent Cournac ◽  
Val�rie Despax ◽  
Bernard Dimon ◽  
Laurent Fina ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Carbonic Anhydrase ◽  
Carbonic Anhydrase Activity

Carbonic anhydrase activity in leaves as measured in vivo by18O exchange between carbon dioxide and water

Planta ◽  
1995 ◽  
Vol 196 (4) ◽  
pp. 732-739 ◽  
Author(s):  
Gilles Peltier ◽  
Laurent Cournac ◽  
Val�rie Despax ◽  
Bernard Dimon ◽  
Laurent Fina ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Carbonic Anhydrase ◽  
Carbonic Anhydrase Activity

CARBONIC ANHYDRASE IN THE PREMATURE

PEDIATRICS ◽  
1968 ◽  
Vol 42 (3) ◽  
pp. 429-436
Author(s):  
E. Poblete ◽  
D. W. Thibeault ◽  
P. A. M. Auld
Keyword(s):  
Carbon Dioxide ◽  
Carbonic Anhydrase ◽  
Premature Infants ◽  
Carbonic Anhydrase Activity ◽  
Full Term ◽  
Term Infants ◽  
Low Levels

Carbonic anhydrase activity was measured in the blood of premature and full-term infants to determine if the arterial-alveolar carbon dioxide gradient was related to low levels of carbonic anhydrase. The time at which levels in these infants approached the adult was studied as well. The study demonstrates that CO2 gradients do not correlate with blood carbonic anhydrase activity, and minimal or no activity can be associated with a small gradient. An increase in the carbonic anhydrase activity-produced by transfusion did not significantly change the CO2 gradient. Premature infants approach adult levels of activity in 6 to 7 months.

scholarly journals The Carbonic Anhydrase Inhibitor Ethoxzolamide Inhibits the Mycobacterium tuberculosis PhoPR Regulon and Esx-1 Secretion and Attenuates Virulence

2015 ◽  
Vol 59 (8) ◽  
pp. 4436-4445 ◽  
Author(s):  
Benjamin K. Johnson ◽  
Christopher J. Colvin ◽  
David B. Needle ◽  
Felix Mba Medie ◽  
Patricia A. DiGiuseppe Champion ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Carbonic Anhydrase ◽  
Regulatory System ◽  
Carbonic Anhydrase Activity ◽  
Carbonic Anhydrase Inhibitor ◽  
Fluorescent Reporter ◽  
Content Type ◽  
Pathogen Virulence ◽  
Mutant Phenotypes

ABSTRACTMycobacterium tuberculosismust sense and adapt to host environmental cues to establish and maintain an infection. The two-component regulatory system PhoPR plays a central role in sensing and responding to acidic pH within the macrophage and is required forM. tuberculosisintracellular replication and growthin vivo. Therefore, the isolation of compounds that inhibit PhoPR-dependent adaptation may identify new antivirulence therapies to treat tuberculosis. Here, we report that the carbonic anhydrase inhibitor ethoxzolamide inhibits the PhoPR regulon and reduces pathogen virulence. We show that treatment ofM. tuberculosiswith ethoxzolamide recapitulatesphoPRmutant phenotypes, including downregulation of the core PhoPR regulon, altered accumulation of virulence-associated lipids, and inhibition of Esx-1 protein secretion. Quantitative single-cell imaging of a PhoPR-dependent fluorescent reporter strain demonstrates that ethoxzolamide inhibits PhoPR-regulated genes in infected macrophages and mouse lungs. Moreover, ethoxzolamide reducesM. tuberculosisgrowth in both macrophages and infected mice. Ethoxzolamide inhibitsM. tuberculosiscarbonic anhydrase activity, supporting a previously unrecognized link between carbonic anhydrase activity and PhoPR signaling. We propose that ethoxzolamide may be pursued as a new class of antivirulence therapy that functions by modulating expression of the PhoPR regulon and Esx-1-dependent virulence.

scholarly journals Oxygen isotope exchange between water and carbon dioxide in soils is controlled by pH, nitrate availability and microbial biomass through links to carbonic anhydrase activity

2020 ◽  
Author(s):  
Sam P. Jones ◽  
Aurore Kaisermann ◽  
Jerome Ogee ◽  
Steven Wohl ◽  
Alexander W. Cheesman ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Microbial Biomass ◽  
Carbonic Anhydrase ◽  
Oxygen Isotope ◽  
Isotope Exchange ◽  
Microbial Community Composition ◽  
Soil Microbial Communities ◽  
Carbonic Anhydrase Activity ◽  
Carbonic Anhydrases ◽  
Oxygen Isotope Exchange

Abstract. The oxygen isotope composition (δ18O) of atmospheric carbon dioxide (CO2) can be used to estimate gross primary production at the ecosystem-scale and above. Understanding how and why the rate of oxygen isotope exchange between soil water and CO2 (kiso) varies can help to reduce uncertainty in the retrieval of such estimates. The expression and activity of carbonic anhydrases in soils are important drivers of variations in kiso. Here we estimate kiso and measure associated soil properties in laboratory incubation experiments using 44 soils sampled from sites across western Eurasia and northeastern Australia. Observed kiso exceeded theoretical uncatalysed rates indicating the significant influence of carbonic anhydrases on the variability observed among the soils studied. We identify soil pH as the principal source of variation, with greater kiso under alkaline conditions suggesting that shifts in microbial community composition or intra-extra cellular dissolved inorganic carbon gradients induce the expression of more or higher activity forms of carbonic anhydrases. We also show for the first time in soils that the presence of nitrate under acidic conditions reduces kiso, potentially reflecting the direct or indirect inhibition of carbonic anhydrases. This effect was confirmed by a supplementary ammonium nitrate fertilisation experiment conducted on a subset of the soils. Future changes in atmospheric nitrogen deposition or land-use may thus influence carbonic anhydrase activity. Greater microbial biomass also increased kiso under a given set of chemical conditions likely highlighting the ubiquity of carbonic anhydrase expression by soil microbial communities. These data provide the most extensive analysis of spatial variations in soil kiso to date and indicate key controls required to predict variations in kiso at the scales needed to improve efforts to constrain gross primary productivity using the δ18O of atmospheric CO2.

scholarly journals Effect of NaHS on carbonic anhydrase activity of human erythrocyte

2016 ◽  
Vol 7 (3) ◽  
pp. 23-27 ◽  
Author(s):  
Abhijit Bhakta ◽  
Maitreyi Bandyopadhyay ◽  
Sayantan Dasgupta ◽  
Santanu Sen ◽  
Arun Kumar ◽  
...  
Keyword(s):  
Carbonic Anhydrase ◽  
Normal Saline ◽  
Carbonic Anhydrase Activity ◽  
Experimental Models ◽  
Test Tube ◽  
Dependent Manner ◽  
Carbonic Anhydrases ◽  
Medical Sciences ◽  
First Time

Background: In contrast to its role as poison, hydrogen sulfide (H2S) is recently considered as a gaso-transmitter which mediates important physiologic functions in humans. Evidence is accumulating to demonstrate that inhibitors of H2S production or therapeutic H2S donor compounds exert significant effects in various experimental models. Carbonic anhydrases (CA) are a group of zinc-containing metalloenzymes that catalyse the reversible hydration of carbon dioxide. CAs activity in erythrocytes (CAI and CAII) has recently been observed to be associated with various pathological conditions especially in diabetes mellitus, hypertension and lipid disorders. Alteration of this enzyme activity has been reported by the effect of advanced glycation end products methylglyoxal and reduced glutathione.   Aims and Objectives: As H2S, being a mediator of many physiological functions and synthesized in vivo, may affect functions of many intracellular proteins like carbonic anhydrase, the objective of this study is to find out if there is any change in the carbonic anhydrase activity under the effect of H2S- donor NaHS in dose dependant manner using RBC model in vitro.Materials and Methods: Blood sample was collected from forty (40) numbers of healthy volunteers of 18-40 years of in heparin containing vials and packed cells were prepared immediately by centrifugation  The packed erythrocytes were washed three times with normal saline and  diluted (1:10) with the normal saline. One ml each of diluted packed cells was taken in eight test tubes. Serial dilutions of NaHS (1to 250 µMol/L) was added to all the test tubes except for the first test tube where only normal saline was added and   incubated at room temperature for one hour. Haemolysates was prepared from the erythrocytes with equal volume of distilled water in each tube and the CA activity was determined in the haemolysates using standardized method.Results: There is significant increase of CA activity in dose dependent manner under the effect of NaHS and also compared to the activity of hemolysate prepared without NaHS.  Conclusions:Our study for the first time demonstrated that the Carbonic Anhydrase activity of erythrocytes is significantly increases by the effect of NaHS and this study reveals some important biological role of H2S and carbonic anhydrase.Asian Journal of Medical Sciences Vol. 7(3) 2016 23-27

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