IN VIVO IMMOBILIZED CARBONIC ANHYDRASE AND ITS EFFECT ON THE ENHANCEMENT OF CO2 ABSORPTION RATE

Author(s):  
S. Fabbricino ◽  
S. Del Prete ◽  
M.E. Russo ◽  
C. Capasso ◽  
A. Marzocchella ◽  
...  
2021 ◽  
Vol 36 (1) ◽  
pp. 964-976
Author(s):  
Ilaria Dettori ◽  
Irene Fusco ◽  
Irene Bulli ◽  
Lisa Gaviano ◽  
Elisabetta Coppi ◽  
...  

Biochemistry ◽  
2009 ◽  
Vol 48 (5) ◽  
pp. 817-819 ◽  
Author(s):  
Sheridan R. MacAuley ◽  
Sabrina A. Zimmerman ◽  
Ethel E. Apolinario ◽  
Caryn Evilia ◽  
Ya-Ming Hou ◽  
...  
Keyword(s):  

Nature ◽  
1952 ◽  
Vol 170 (4325) ◽  
pp. 499-499 ◽  
Author(s):  
HENRY D. JANOWITZ ◽  
HENRY COLCHER ◽  
FRANKLIN HOLLANDER

2005 ◽  
Vol 385 (3) ◽  
pp. 715-720 ◽  
Author(s):  
Matthew D. LLOYD ◽  
Richard L. PEDERICK ◽  
Ramanathan NATESH ◽  
L. W. Lawrence WOO ◽  
Atul PUROHIT ◽  
...  

CA (carbonic anhydrase) catalyses the reversible hydration of carbon dioxide into bicarbonate, and at least 14 isoforms have been identified in vertebrates. The role of CA type II in maintaining the fluid and pH balance has made it an attractive drug target for the treatment of glaucoma and cancer. 667-Coumate is a potent inhibitor of the novel oncology target steroid sulphatase and is currently in Phase 1 clinical trials for hormone-dependent breast cancer. It also inhibits CA II in vitro. In the present study, CA II was crystallized with 667-coumate and the structure was determined by X-ray crystallography at 1.95 Å (1 Å=0.1 nm) resolution. The structure reported here is the first for an inhibitor based on a coumarin ring and shows ligation of the sulphamate group to the active-site zinc at 2.15 Å through a nitrogen anion. The first two rings of the coumarin moiety are bound within the hydrophobic binding site of CA II. Important residues contributing to binding include Val-121, Phe-131, Val-135, Leu-141, Leu-198 and Pro-202. The third seven-membered ring is more mobile and is located in the channel leading to the surface of the enzyme. Pharmacokinetic studies show enhanced stability of 667-coumate in vivo and this has been ascribed to binding of CA II in erythrocytes. This result provides a structural basis for the stabilization and long half-life of 667-coumate in blood compared with its rapid disappearance in plasma, and suggests that reversible binding of inhibitors to CA may be a general method of delivering this type of labile drug.


1965 ◽  
Vol 3 (6) ◽  
pp. 24-24

May & Baker, who have not hitherto marketed an oral diuretic, have now introduced clorexolone (Nefrolan). This drug contains the active radicals present in the thiazides but lacks the benzothiadiazine nucleus. Its pharmacological properties, uses and unwanted actions are those of the thiazides and chlorthalidone. Clorexolone does not significantly inhibit carbonic anhydrase in vivo. Whether, like other oral diuretics, it can cause diabetes mellitus1 is not yet known.


1975 ◽  
Vol 38 (4) ◽  
pp. 710-718 ◽  
Author(s):  
R. E. Forster ◽  
E. D. Crandall

A stopped-flow rapid-reaction apparatus was used to follow the time course of extracellular pH in a human red cell suspension following a sudden increase in PCO2. The extracellular pH change was slow (t1/2 similar to 3.5 s) considering the presence of carbonic anhydrase in the cells. When carbonic anhydrase was added to the extracellular fluid, the half-time was reduced to less than 20 ms. The explanation for these phenomena is that the equilibration of H+ across the red cell membrane is rate-limited by the uncatalyzed reaction CO2 plus H2O formed from H2CO3 outside the cells. A theoretical model was developed which successfully reproduced the experimental results. When the model was used to simulate CO2 exchange in vivo, it was determined that blood PCO2 and pH require long times (greater than 50 s) to approach equilibrium between cells and plasma after leaving an exchange capillary. We conclude that cell-plasma equilibrium may never be reached in vivo, and that in vitro measurements of these quantities may not represent their true values at the site of sampling.


2019 ◽  
Author(s):  
JM García-Lobo ◽  
Y Ortiz ◽  
C González-Riancho ◽  
A Seoane ◽  
B Arellano-Reynoso ◽  
...  

AbstractSome Brucella isolates are known to require an increased concentration of CO2 for growth, especially in the case of primary cultures obtained directly from infected animals. Moreover, the different Brucella species and biovars show a characteristic pattern of CO2 requirement, and this trait has been included among the routine typing tests used for species and biovar differentiation. By comparing the differences in gene content among different CO2-dependent and CO2-independent Brucella strains we have confirmed that carbonic anhydrase II (CA II), is the enzyme responsible for this phenotype in all the Brucella strains tested. Brucella species contain two carbonic anhydrases of the β family, CA I and CA II; genetic polymorphisms exist for both of them in different isolates, but only those putatively affecting the activity of CA II correlate with the CO2 requirement of the corresponding isolate. Analysis of these polymorphisms does not allow the determination of CA I functionality, while the polymorphisms in CA II consist of small deletions that cause a frameshift that changes the C-terminus of the protein, probably affecting its dimerization status, essential for the activity.CO2-independent mutants arise easily in vitro, although with a low frequency ranging from 10−6 to 10−10 depending on the strain. These mutants carry compensatory mutations that produce a full length CA II. At the same time, no change was observed in the sequence coding for CA I. A competitive index assay designed to evaluate the fitness of a CO2-dependent strain compared to its corresponding CO2-independent strain revealed that while there is no significant difference when the bacteria are grown in culture plates, growth in vivo in a mouse model of infection provides a significant advantage to the CO2-dependent strain. This could explain why some Brucella isolates are CO2-dependent in primary isolation. The polymorphism described here also allows the in silico determination of the CO2 requirement status of any Brucella strain.


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