Disease relevance of CA2

• Incubation of carbonic anhydrase II with acrolein results in a rapid, time-dependent loss of all but approximately 3-6% of the original catalytic activity toward CO2 hydration and HCO3- dehydration, with the inactivation rate being first-order in both acrolein and the enzyme [1].
• Our target protein was genetically engineered bovine carbonic anhydrase II (BCA) which is a monomeric globular protein, and it has been shown that the as-expressed BCA from Escherichia coli contains two conformational isomers, one with enzymatic activity (type I) and the other without (type II) [2].

High impact information on CA2

• The binding affinities between charged ligands and the members of a charge ladder of bovine carbonic anhydrase (CAII) constructed by random acetylation of the amino groups on its surface were measured by affinity capillary electrophoresis (ACE) [3].
• Our kinetic data are consistent with a formal mechanism of action for carbonic anhydrase III that is directly analogous to that of carbonic anhydrase II, in which Lys-64 of carbonic anhydrase III can act as an intramolecular H+ transfer group during CO2 hydration [4].
• The amount of residual CO2 hydratase activity is proportional to the molar excess of acrolein over carbonic anhydrase II with 5 histidyl and 3 lysyl residues being subject to alkylation under conditions where [acrolein] to [carbonic anhydrase II] ratio is greater than 100 [1].
• The Paradoxical Thermodynamic Basis for the Interaction of Ethylene Glycol, Glycine, and Sarcosine Chains with Bovine Carbonic Anhydrase II: An Unexpected Manifestation of Enthalpy/Entropy Compensation [5].
• Using microsomes from bovine kidney and lung (which had the same activity), we have measured the Km and kcat for CO2 hydration and compared these numbers with those for CA I (red blood cells and gut), CA II (red blood cells and secretory cells), and CA III (muscle) [6].

Chemical compound and disease context of CA2

• Molecular basis of ionic strength effects: interaction of enzyme and sulfate ion in CO2 hydration and HCO3- dehydration reactions catalyzed by carbonic anhydrase II [7].
• CO2 hydration and HCO3- dehydration reactions catalyzed by carbonic anhydrase II have been examined at various concentrations of sodium sulfate with a stopped-flow technique [7].

Biological context of CA2

• Previous radioautographic experiments demonstrated that binding sites labeled by [3H]5-HT and [3H]LSD in rat brain were seen in all layers of CA1, CA4 and the dentate gyrus but not in fields CA2 and CA3 of the hippocampus [8].
• This study compares the rate of denaturation with sodium dodecyl sulfate (SDS) of the individual rungs of protein charge ladders generated by acylation of the lysine epsilon-NH3+ groups of bovine carbonic anhydrase II (BCA) [9].
• Component A, caused by an inward flux of CO(2) and its subsequent hydration by CA-II, was blocked by dorzolamide in a dose-dependent manner with an 50% inhibitory concentration (IC)(50) of 2.4 micro M (95% confidence interval: 0.5 -10.85 microM) [10].
• The discrepancy between glycerol and sucrose could be largely reconciled by correcting for diffusion-unrelated effects as estimated from rate studies of considerably slower CA II catalyzed acetaldehyde hydration and p-nitrophenyl acetate hydrolysis [11].
• The kinetics of renaturation of bovine carbonic anhydrase II (CAII) were studied from 4 degrees to 36 degrees, at the relatively high [CAII] of 4 mg/mL [12].

Anatomical context of CA2

• CA-II was found in the fetal trophoblastic cells with single nuclei as well as in erythrocytes of maternal and fetal blood [13].
• The parietal cells in the abomasal epithelium were more intensely stained for CA-II, but not for CA-I and CA-III [14].
• In cattle, epithelial cells of the oesophagus showed reactions for CA-I and CA-III but not for CA-II [15].
• In the large intestine, CA-II was detected in the columnar cells in the upper part of the crypt [15].
• In parotid glands, CA-II was located in serous acinar cells, whereas CA-III, in the duct segments [14].

Associations of CA2 with chemical compounds

• An antiserum raised against taurine conjugated to bovine serum albumin by glutaraldehyde produced intense staining of hippocampal pyramidal neurons at the CA1/CA3 transition (including CA2) and of a small proportion of the granule cells [16].
• A comparison of the mechanisms of CO2 hydration by native and Co2+-substituted carbonic anhydrase II [17].
• This paper describes a systematic study of the thermodynamics of association of bovine carbonic anhydrase II (BCA) and para-substituted benzenesulfonamides with chains of oligoglycine, oligosarcosine, and oligoethylene glycol of lengths of one to five residues [5].
• Secondary interactions significantly removed from the sulfonamide binding pocket of carbonic anhydrase II influence inhibitor binding constants [18].
• Dorzolamide does not appear to accumulate in the cells, because the inhibition of CA-II did not increase after prolonged exposure to the drug [10].

Physical interactions of CA2

• The Ki values for 11 sulfonamides with CA IV were measured and in all cases showed less binding (averaging 17-fold) than to CA II [6].

Other interactions of CA2

• The polymorphic proteins were alpha-lactalbumin, beta-lactoglobulin, caseins (alpha s1, beta and chi), serum albumin, transferrin, haemoglobin, amylase I and carbonic anhydrase II [19].

Analytical, diagnostic and therapeutic context of CA2

• Pretransition and progressive softening of bovine carbonic anhydrase II as probed by single molecule atomic force microscopy [20].
• The binding of acetazolamide, p-fluorobenzensulfonamide, p-toluenesulfonamide, and sulfanilamide to nickel(II)-substituted carbonic anhydrase II has been studied by 1H NMR and electronic absorption spectroscopies [21].
• In a 3-month-old fetus of crown-rump length (CRL) 17 cm, the expression of CA-II in undifferentiated epithelial cells was observed, whereas immunostaining for CA-III remained negative [22].
• Two cytosolic carbonic anhydrase isozymes (CA-II and CA-III) were studied by immunohistochemistry in bovine parotid glands during fetal development [22].

References