Carbonic anhydrase activity of intact carbonic anhydrase II-deficient human erythrocytes

1988 ◽  
Vol 65 (4) ◽  
pp. 1472-1480 ◽  
Author(s):  
S. J. Dodgson ◽  
R. E. Forster ◽  
W. S. Sly ◽  
R. E. Tashian
Keyword(s):  
Carbonic Anhydrase ◽  
Normal Subjects ◽  
Relative Difference ◽  
Carbonic Anhydrase Activity ◽  
Carbonic Anhydrase Ii ◽  
Normal Cells ◽  
Reaction Velocity ◽  
Fractional Reduction ◽  
Lower Temperature ◽  
Exchange Technique

Intact erythrocytes from subjects with deficiency of blood carbonic anhydrase (CA) II and from normal subjects were assayed for enzyme activity by use of an 18O exchange technique in a solution containing 25 mM (CO2 + NaHCO3) plus 125 mM NaCl. At 25 degrees C and pH 7.4, the catalyzed reaction velocity was 0.32 +/- 0.04 M/s for the CA II-deficient and 1.60 +/- 0.12 M/s for the normal cells, a ratio of 1:5. Under the same conditions at 37 degrees C the relative difference between the CA II-deficient and normal cells was much less: the velocity for the CA II-deficient cells was 0.84 +/- 0.07 M/s and for the normal cells 1.60 +/- 0.32 M/s, a ratio of 1:1.9. Results were comparable for the hemolysates with the NaHCO3 reduced to 85 mM (the corresponding intracellular concentration): at 25 degrees C CA II-deficient cells had a velocity of 0.36 +/- 0.01 M/s compared with 1.12 +/- 0.04 M/s for the normal cells, a ratio of 1:3.1. At 37 degrees C again the relative difference between hemolysates from CA II normal and deficient cells was much less: the CA II-deficient cells had a reaction velocity of 1.17 +/- 0.22 M/s vs. 2.60 +/- 0.36 M/s for the normal cells, a ratio of 1:2.2. The greater fractional reduction of enzyme velocity of CA II-deficient cells at 25 degrees C compared with 37 degrees C appears to be explained by a greater chloride inhibition of the presumed CA I at the lower temperature.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Microsecond Simulation Analysis of Carbonic Anhydrase – II in Complex with (+)- Cathechin Revealed Molecular Interactions Responsible for Its Amelioration Effect on Fluoride Toxicity

2020 ◽  
Author(s):  
Pulala Raghuveer Yadav ◽  
Hussain Syed ◽  
Sadam DV Satyanarayana ◽  
Pavan Kumar Pindi
Keyword(s):  
Carbonic Anhydrase ◽  
Conformational Changes ◽  
Simulation Analysis ◽  
Carbonic Anhydrase Activity ◽  
Catalytic Site ◽  
Carbonic Anhydrase Ii ◽  
Fluoride Ions ◽  
Skeletal Health ◽  
Ionic Bonds ◽  
Male Wistar Rats

Fluorosis is a chronic condition caused by overexposure to fluoride, marked by impaired dental, skeletal, and non-skeletal health. In presence of excess fluoride ions, in severe cases calcification of the ligaments observed. Earlier studies have suggested that the disruption of carbonic anhydrase activity via ionic homeostasis change was associated with F toxicity. In a recent study, it was demonstrated that Tamarind fruit extract was effective in increasing the urinary F excretion in male Wistar rats via studying the mRNA expression of carbonic anhydrase II (CA II) in kidney homogenates using western blotting, immunohistochemistry and quantitative Realtime PCR based studies. We have carried out this study to understand the detailed molecular level interactions responsible for this tamarind extract based (+)-cathechin compound towards lowering the F toxicity via targeting CA-II. From our study, it was revealed that due to the ability of (+)-cathechin compound to bind tightly filling complete available space at the catalytically important site forming metal coordinated ionic bonds with His94, His96 and His119 residues helps in restricting F ions to interact with Zn ion located at the core of catalytic site responsible for its functionality. On the other hand, interaction of (+)-cathechin compound with Gln92 was observed to be critically important towards inducing conformational changes in CA-II, thus allowing (+)-cathechin compound to burry even deeply inside the catalytic site.

A micromethod for measuring carbonic anhydrase activity using 18O exchange between CO2 and H2O

1988 ◽  
Vol 65 (4) ◽  
pp. 1902-1906 ◽  
Author(s):  
N. Bitterman ◽  
L. Lin ◽  
R. E. Forster
Keyword(s):  
Enzyme Activity ◽  
Carbonic Anhydrase ◽  
High Activity ◽  
Intact Cell ◽  
Porous Membrane ◽  
Carbonic Anhydrase Activity ◽  
Published Data ◽  
Hydration Reaction ◽  
Activity Type ◽  
Reaction Velocity

We have developed a method of measuring the activity and characteristics of carbonic anhydrase (CA) using the disappearance of 18O from CO2 in 1 ml of gas contained in a glass chamber as it exchanges with H2O in 0.01 ml 0.25 M NaHCO3 solution in a thin (25 micron) porous membrane. Serial gas samples (approximately 0.02 ml) are analyzed in a mass spectrometer to obtain the rate of disappearance of the label. The enzyme activity can be measured inside intact cell or particle membranes. As little as 10(-15) mol of high-activity type CA can be detected at 25 degrees C, and the activity of 200 times this amount can be measured. The uncatalyzed hydration reaction velocity constant was 0.056 +/- 0.004 s-1, in agreement with published data.

scholarly journals Carbonic anhydrase in human platelets

1984 ◽  
Vol 217 (3) ◽  
pp. 727-730 ◽  
Author(s):  
W Siffert ◽  
G Gros
Keyword(s):  
Carbonic Anhydrase ◽  
Carbonic Anhydrase Activity ◽  
Human Platelets ◽  
Carbonic Anhydrase Ii ◽  
Affinity Column ◽  
Kinetic Properties ◽  
Km Value ◽  
Flow Apparatus ◽  
High Concentrations ◽  
Kinetics Of

The carbonic anhydrase activity of human platelets was investigated by measuring the kinetics of CO2 hydration in supernatants of platelet lysates by using a pH stopped-flow apparatus. An average carbonic anhydrase concentration of 2.1 microM was determined for pellets of human platelets. Analysis of the kinetic properties of this carbonic anhydrase yielded a Km value of 1.0 mM, a catalytic-centre activity kcat. of 130000 s-1 and an inhibition constant Ki towards ethoxzolamide of 0.3 nM. From these values, CO2 hydration inside platelets is estimated to be accelerated by a factor of 2500. When platelet lysates were subjected to affinity chromatography, only the high-activity carbonic anhydrase II could be eluted from the affinity column, whereas the carbonic anhydrase isoenzyme I, which is known to occur in high concentrations in human erythrocytes, appeared to be absent.

scholarly journals Microsecond Simulation Analysis of Carbonic Anhydrase – II in Complex with (+)- Cathechin Revealed Molecular Interactions Responsible for Its Amelioration Effect on Fluoride Toxicity

2020 ◽  
Author(s):  
Pulala Raghuveer Yadav ◽  
Hussain Syed ◽  
Sadam DV Satyanarayana ◽  
Pavan Kumar Pindi
Keyword(s):  
Carbonic Anhydrase ◽  
Conformational Changes ◽  
Simulation Analysis ◽  
Carbonic Anhydrase Activity ◽  
Catalytic Site ◽  
Carbonic Anhydrase Ii ◽  
Fluoride Ions ◽  
Skeletal Health ◽  
Ionic Bonds ◽  
Male Wistar Rats

Fluorosis is a chronic condition caused by overexposure to fluoride, marked by impaired dental, skeletal, and non-skeletal health. In presence of excess fluoride ions, in severe cases calcification of the ligaments observed. Earlier studies have suggested that the disruption of carbonic anhydrase activity via ionic homeostasis change was associated with F toxicity. In a recent study, it was demonstrated that Tamarind fruit extract was effective in increasing the urinary F excretion in male Wistar rats via studying the mRNA expression of carbonic anhydrase II (CA II) in kidney homogenates using western blotting, immunohistochemistry and quantitative Realtime PCR based studies. We have carried out this study to understand the detailed molecular level interactions responsible for this tamarind extract based (+)-cathechin compound towards lowering the F toxicity via targeting CA-II. From our study, it was revealed that due to the ability of (+)-cathechin compound to bind tightly filling complete available space at the catalytically important site forming metal coordinated ionic bonds with His94, His96 and His119 residues helps in restricting F ions to interact with Zn ion located at the core of catalytic site responsible for its functionality. On the other hand, interaction of (+)-cathechin compound with Gln92 was observed to be critically important towards inducing conformational changes in CA-II, thus allowing (+)-cathechin compound to burry even deeply inside the catalytic site.

1123: Renal Oxalate Transport Depends on Local Carbonic Anhydrase Activity in the Proximal Tubule

2004 ◽  
Vol 171 (4S) ◽  
pp. 296-296
Author(s):  
Michael Straub ◽  
Joséphine Befolo-Elo ◽  
Richard E Hautmann ◽  
Edgar Braendle
Keyword(s):  
Carbonic Anhydrase ◽  
Proximal Tubule ◽  
Carbonic Anhydrase Activity ◽  
Oxalate Transport

Inhibition Profiling of Urease and Carbonic Anhydrase II by High- Throughput Screening and Molecular Docking Studies of Structurally Diverse Organic Compounds

2020 ◽  
Vol 17 ◽  
Author(s):  
Majid Ali ◽  
Syed Majid Bukhari ◽  
Asma Zaidi ◽  
Farhan A. Khan ◽  
Umer Rashid ◽  
...  
Keyword(s):  
Molecular Docking ◽  
Carbonic Anhydrase ◽  
Metal Complexes ◽  
Organic Compounds ◽  
High Throughput ◽  
High Throughput Screening ◽  
Docking Studies ◽  
Carbonic Anhydrase Ii ◽  
Molecular Docking Studies ◽  
Ic50 Values

Background:: Structurally diverse organic compounds and available drugs were screened against urease and carbonic anhydrase II in a formulation acceptable for high-throughput screening. Objective: The study was conducted to find out potential inhibitors of urease and carbonic anhydrase II. Methods:: Quantification of the possible HITs was carried out by determining their IC50 values. Results and Discussion:: of several screened compounds including derivatives of oxadiazole, coumarins, chromane-2, 4- diones and metal complexes of cysteine-omeprazole showed promising inhibitory activities with IC50 ranging from 47 μM to 412 μM against the urease. The interactions of active compounds with active sites of enzymes were investigated through molecular docking studies which revealed that (R)-1-(4-amino-4-(5-(thiophen-2-yl)-1,3,4-oxadiazol-2-yl) butyl) guanidine possessing IC50 of 47 μM, interacts with one of the nickel metal atom of urease besides further interactions as predictable hydrogen bonds with KCX490, Asp633, His492, His407 and His409 along with Ala440 and 636. Bi-ligand metal complexes of 4-aminoantipyrine based Schiff bases showed activation of urease with AC50 ranging from 68 μM to 112 μM. Almost 21 compounds with varying functional groups including pyrimidines, oxadiazoles, imidazoles, hydrazides and tin based compounds were active carbonic anhydrase II inhibitors presenting 98 μM to 390 μM IC50 values. Several N-substituted sulfonamide derivatives were inactive against carbonic anhydrase II. Conclusion:: Among all the screened compounds, highly active inhibitor of carbonic anhydrase II was (4-(3- hydroxyphenyl)-6-phenyl-2-thioxo-1,2,3,4-tetrahydropyrimidin-5-yl)phenyl) methanone with IC50 of 98.0 μM. This particular compound showed metallic interaction with Zn ion of carbonic anhydrase II through hydroxyl group of phenyl ring.

Synthesis and Biological Potential Assessment of 2-Substituted Quinazolin-4(3H)-ones as Inhibitors of Phosphodiesterase-I and Carbonic Anhydrase-II

2015 ◽  
Vol 11 (4) ◽  
pp. 336-341 ◽  
Author(s):  
Syed Saad ◽  
Muhammad Saleem ◽  
Shahnaz Perveen ◽  
Muhammad Alam ◽  
Khalid Khan ◽  
...  
Keyword(s):  
Carbonic Anhydrase ◽  
Carbonic Anhydrase Ii ◽  
Biological Potential

Oligodendrocytes express a normal phenotype in carbonic anhydrase II-deficient mice

1989 ◽  
Vol 23 (2) ◽  
pp. 180-190 ◽  
Author(s):  
M. S. Ghandour ◽  
R. P. Skoff ◽  
P. J. Venta ◽  
R. E. Tashian
Keyword(s):  
Carbonic Anhydrase ◽  
Carbonic Anhydrase Ii ◽  
Normal Phenotype ◽  
Deficient Mice
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