scholarly journals Comparison of pH-dependence of Carbonic Anhydrase Activity in vitro and in Living Cells

2009 ◽  
Vol 96 (3) ◽  
pp. 625a ◽  
Author(s):  
Francisco C. Villafuerte ◽  
Pawel Swietach ◽  
Shalani Patiar ◽  
Adrian L. Harris ◽  
Richard D. Vaughan-Jones
Keyword(s):  
Carbonic Anhydrase ◽  
Ph Dependence ◽  
Carbonic Anhydrase Activity ◽  
Living Cells

The Effect of Cholera Toxin on Choroid Plexus Carbonic Anhydrase Activity In Vitro

1980 ◽  
Vol 1 (4) ◽  
pp. 333-339
Author(s):  
Arthur M. Feldman ◽  
Mel H. Epstein ◽  
Fallon Maylack ◽  
Saul W. Brusilow
Keyword(s):  
Carbonic Anhydrase ◽  
Choroid Plexus ◽  
Cholera Toxin ◽  
Carbonic Anhydrase Activity

scholarly journals The Periplasmic α-Carbonic Anhydrase Activity of Helicobacter pylori Is Essential for Acid Acclimation

2005 ◽  
Vol 187 (2) ◽  
pp. 729-738 ◽  
Author(s):  
Elizabeth A. Marcus ◽  
Amiel P. Moshfegh ◽  
George Sachs ◽  
David R. Scott
Keyword(s):  
Helicobacter Pylori ◽  
Membrane Potential ◽  
Carbonic Anhydrase ◽  
Membrane Integrity ◽  
Carbonic Anhydrase Activity ◽  
Knockout Mutant ◽  
Inner Membrane ◽  
Acid Acclimation

ABSTRACT The role of the periplasmic α-carbonic anhydrase (α-CA) (HP1186) in acid acclimation of Helicobacter pylori was investigated. Urease and urea influx through UreI have been shown to be essential for gastric colonization and for acid survival in vitro. Intrabacterial urease generation of NH3 has a major role in regulation of periplasmic pH and inner membrane potential under acidic conditions, allowing adequate bioenergetics for survival and growth. Since α-CA catalyzes the conversion of CO2 to HCO3 −, the role of CO2 in periplasmic buffering was studied using an α-CA deletion mutant and the CA inhibitor acetazolamide. Western analysis confirmed that α-CA was bound to the inner membrane. Immunoblots and PCR confirmed the absence of the enzyme and the gene in the α-CA knockout. In the mutant or in the presence of acetazolamide, there was an ∼3 log10 decrease in acid survival. In acid, absence of α-CA activity decreased membrane integrity, as observed using membrane-permeant and -impermeant fluorescent DNA dyes. The increase in membrane potential and cytoplasmic buffering following urea addition to wild-type organisms in acid was absent in the α-CA knockout mutant and in the presence of acetazolamide, although UreI and urease remained fully functional. At low pH, the elevation of cytoplasmic and periplasmic pH with urea was abolished in the absence of α-CA activity. Hence, buffering of the periplasm to a pH consistent with viability depends not only on NH3 efflux from the cytoplasm but also on the conversion of CO2, produced by urease, to HCO3 − by the periplasmic α-CA.

INHIBITORS OF CARBONIC ANHYDRASE IN THE AMERICAN COCKROACH, PERIPLANETA AMERICANA (L.)

1956 ◽  
Vol 34 (1) ◽  
pp. 68-74 ◽  
Author(s):  
Ann D. Anderson ◽  
Ralph B. March
Keyword(s):  
Carbonic Anhydrase ◽  
Periplaneta Americana ◽  
Fat Body ◽  
Aqueous Media ◽  
Carbonic Anhydrase Activity ◽  
American Cockroach ◽  
Tissue Homogenates ◽  
Organic Insecticides ◽  
Cell Fragments

Carbonic anhydrase activity has been demonstrated in vitro in preparations of the head, fat body, and gut of the American cockroach, Periplaneta americana (L.), and in the adult housefly, Musca domestica L. The insect factor, which is soluble in aqueous media and can be separated from the particulate cell fragments of insect tissue homogenates is heat labile and sensitive to cyanide inactivation. It is strongly inhibited by sulphanilamide, p-aminoethylphenyl-sulphonamide, and p-chlorphenylsulphonamide. No inhibition has been found with N-substituted sulphonamides or with any of the organic insecticides examined, including DDT, lindane, dieldrin, nicotine, rotenone, pyrethrins, and para-oxon. Sensitivity of carbonic anhydrase to sulphonamides having an intact—SO2NH2 group is also characteristic of mammalian preparations. The data indicate that inhibition of insect carbonic anhydrase cannot be an important factor in the mode of action of DDT or other organic insecticides.

scholarly journals Why is there no carbonic anhydrase activity available to fish plasma?

1995 ◽  
Vol 198 (1) ◽  
pp. 31-38 ◽  
Author(s):  
J Lessard ◽  
A Val ◽  
S Aota ◽  
D Randall
Keyword(s):  
Carbonic Anhydrase ◽  
Blood Cell ◽  
Cell Volume ◽  
Red Blood Cell ◽  
Short Circuit ◽  
Hemoglobin Concentration ◽  
Carbonic Anhydrase Activity ◽  
Control Group ◽  
Acid Loading

Carbonic anhydrase (CA) is absent from the plasma of vertebrates. In vitro, CA in fish plasma will short-circuit the effect of catecholamines, which is to increase red blood cell (RBC) pH and volume, both of which enhance the affinity of hemoglobin for O2. CA was infused into trout for a period of 6 h and injected after 48 h, during which the animal was submitted to deep hypoxia (PO2=30­35 mmHg; 4.0­4.7 kPa). O2 content, lactate content, catecholamine levels, hematocrit, hemoglobin concentration and pHi were similar to those in the saline-infused control group. In contrast, cell volume was significantly higher and pHe, total CO2 content and organic phosphate levels were significantly lower than in the control group. The concentration of CA was not high enough completely to short-circuit the increase in pHi and red blood cell volume caused by catecholamines. The lower pHe in the CA-infused animals could enhance the activity of the Na+/H+ pump, which would keep the nucleotide triphosphate levels low. pH is a balance between acid loading at the muscle and acid excretion at the gills or the kidneys; we cannot distinguish between which of these resulted in a decrease of plasma pH. In conclusion, CA in plasma did not cause the expected reduction in blood oxygen content but did have a marked effect on plasma total CO2 content.

Effects of red blood cell HCO3(-)/Cl- exchange kinetics on lung CO2 transfer: theory

1981 ◽  
Vol 50 (2) ◽  
pp. 265-271 ◽  
Author(s):  
E. D. Crandall ◽  
A. Bidani
Keyword(s):  
Carbonic Anhydrase ◽  
Carbonic Anhydrase Activity ◽  
Major Influence ◽  
Gas Transfer ◽  
Red Cell ◽  
Dehydration Reactions ◽  
Lung Capillaries ◽  
Co2 Elimination

A mathematical model has been used to study the influences of the kinetics of erythrocyte HCO3(-)/Cl-- exchange on CO2 elimination in the lung. In addition to the chloride shift, the model includes 1) CO2-H2CO3 hydration-dehydration reactions in plasma and erythrocytes; 2) CO2 reactions with hemoglobin; 3) O2 binding to hemoglobin; 4)buffering of H+ intra- and extracellularly; 5) red cell volume changes; and 6) diffusion of gases between alveoli and blood. Carbonic anhydrase activity was assumed to be available to plasma as it passes through the lung capillaries. The results show that a reduction of PHCO3(-) leads to a reduction in pulmonary CO2 elimination of up to 30%, whether or not carbonic anhydrase activity is available to plasma. Characteristic slow downstream pH and PCO2 changes predicted for each case may represent an explanation for the apparent discrepancy between in vivo and in vitro slow downstream pH changes reported previously. We conclude that red cell HCO3(-)/Cl- exchange partially limits CO2 elimination from blood in the lung and may have a major influence on capillary gas transfer when its speed is abnormally slow.

scholarly journals Effects of nicotine and Vitamin E on Carbonic anhydrase activity in some rat tissues In Vivo and In Vitro

2005 ◽  
Vol 20 (1) ◽  
pp. 103-109 ◽  
Author(s):  
Mehmet Çiftçi ◽  
Metin Bülbül ◽  
Mustafa Gül ◽  
Kenan Gümüs¸tekin ◽  
S¸enol Dane ◽  
...  
Keyword(s):  
Vitamin E ◽  
Carbonic Anhydrase ◽  
Carbonic Anhydrase Activity ◽  
Rat Tissues

Carbonic anhydrase in mouse skeletal muscle and its influence on contractility

1994 ◽  
Vol 72 (5-6) ◽  
pp. 244-249 ◽  
Author(s):  
Claude H. Côté ◽  
Nicolas Jomphe ◽  
Abdul Odeimat ◽  
Pierre Frémont
Keyword(s):  
Skeletal Muscle ◽  
Carbonic Anhydrase ◽  
Specific Activity ◽  
Physiological Role ◽  
Electrophoretic Analysis ◽  
Carbonic Anhydrase Activity ◽  
Type I ◽  
Carbonic Anhydrase Iii ◽  
Metabolism Enzyme

Carbonic anhydrase III (EC 4.2.1.1) is the most abundant cytosolic protein in type I skeletal muscle fibers. Investigations of its physiological role have mostly been conducted with rat muscles, which sometimes are unsuitable for in vitro studies. The objective of the present study was to characterize the carbonic anhydrase in the mouse soleus muscle to verify if this muscle can be used as a model to further study the enzyme's function. Total carbonic anhydrase specific activity in the mouse soleus was comparable to the value for rat. However, 60% of the total carbonic anhydrase activity in the mouse was of the sulfonamide-sensitive type and, therefore, not related to carbonic anhydrase III. Electrophoretic analysis revealed the presence of a 29-kDa protein in total and cytosolic extracts of the mouse soleus. Immunoblotting with an antibody developed against rat carbonic anhydrase III showed that it was also specific for this 29-kDa peptide, which presumably is the mouse carbonic anhydrase III. Inhibition of the sulfonamide-sensitive activity had no effect on contractile and fatigue characteristics, whereas inhibition of the sulfonamide-resistant carbonic anhydrase III activity led to a significant increase in resistance to fatigue. We conclude that the mouse soleus may represent an excellent model to understand the contribution of different carbonic anhydrase isoforms to muscle physiology.Key words: muscle fatigue, carbonic anhydrase III, sulfonamide, metabolism, enzyme.

scholarly journals The Relationship of Oxidation Sensitivity of Red Blood Cells and Carbonic Anhydrase Activity in Stored Human Blood: Effect of Certain Phenolic Compounds

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Zübeyir Huyut ◽  
Mehmet Ramazan Şekeroğlu ◽  
Ragıp Balahoroğlu ◽  
Tahsin Karakoyun ◽  
Erdem Çokluk
Keyword(s):  
Lipid Peroxidation ◽  
Carbonic Anhydrase ◽  
Glutathione Peroxidase ◽  
Antioxidant Capacity ◽  
Caffeic Acid ◽  
Tannic Acid ◽  
Carbonic Anhydrase Activity ◽  
Control Group ◽  
Stored Blood

It has been reported that many modifications occur with the increase of oxidative stress during storage in erythrocytes. In order to delay these negative changes, we evaluated whether the addition of substances likely to protect antioxidant capacity in stored blood would be useful. Therefore, we investigated the effects of resveratrol, tannic acid, and caffeic acid in lipid peroxidation and antioxidant capacity of erythrocytes in stored blood. Donated blood was taken into four CPD containing blood bags. One bag was used as the control, and the others were supplemented with caffeic acid (30 μg/mL), resveratrol (30 μg/mL), and tannic acid (15 μg/mL), respectively. Erythrocyte lipid peroxidation, sensitivity to oxidation, glutathione levels and carbonic anhydrase, glutathione peroxidase, and catalase activities were measured on days 0, 7, 14, 21, and 28. In the control group, erythrocyte malondialdehyde levels and sensitivity to oxidation were increased whereas glutathione, glutathione peroxidase, and catalase levels were decreased (p<0.05). Resveratrol and caffeic acid prevented malondialdehyde accumulation and preserved glutathione, glutathione peroxidase, and catalase activities in erythrocytes. We demonstrated that resveratrol, caffeic acid, and tannic acid in stored blood could decrease the sensitivity to oxidation of erythrocytes in vitro but did not exhibit such effects on CA activity.

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