Red cell carbonic anhydrase activity, 2.3 DPG concentration, and activities of three key enzymes controlling DPG metabolism (PK, PFK and DPGM) were measured in normoxic and hypoxic (incubation in 13.5% O2) chick embryos. In normoxia 2.3 DPG concentration and carbonic anhydrase activity begin to increase by the third week of incubation. Hypoxia induces a rise of 2.3 DPG concentration and carboni...

The bicarbonate permeability of the plasma membrane of intact hagfish (Myxine glutinosa) red blood cells and the intracellular carbonic anhydrase activity of these cells were determined by applying the (18)O exchange reaction using a special mass spectrometric technique. When the macromolecular carbonic anhydrase inhibitor Prontosil-Dextran was used to suppress any extracellular carbonic anhydr...

Benzolamide (CL-11,366), a potent carbonic anhydrase inhibitor, was used to examine the influence of carbonic anhydrase inhibition on the reabsorption of chloride, sodium, and bicarbonate in the rat proximal convoluted tubule. Administration of 2 mg/kg benzolamide was associated with a decrease in the tubular fluid/plasma (TF/P) chloride ratio from 1.19+/-0.10 (SEM) to 1.06+/-0.01, and an incre...

The reversible complex between the metalloenzyme bovine carbonic anhydrase B and the sulfonamide inhibitor acetazolamide can be "frozen" irreversibly by the addition of a covalent bond between the methyl group of the inhibitor and the tau-nitrogen of histidine-64. In both cases the inhibited enzyme is inactive as an esterase toward p-nitrophenyl propionate at physiological pH but retains activi...

Carbonic anhydrases catalyze the interconversion of carbon dioxide to bicarbonate. Human carbonic anhydrase isozyme III with a C-terminal hexahistidine tag was overexpressed in Eschericha coli, purified and crystallized. Diffraction data (93.4% completeness) were collected to 2.2 A resolution on an in-house R-AXIS IV++ image-plate system with Osmic mirrors and a Rigaku HU-H3R CU rotating-anode ...

The distribution and function of the enzyme carbonic anhydrase in the crab Pachygrapsus crassipes was investigated. Carbonic anhydrase was found in gill epithelial tissue but not in the haemolymph, muscle, heart, hepatopancreas or gonads of male crabs. Enzyme activity was completely inhibited in vitro by 2 x IO~M sodium acetazolamide (Diamox). Radiolabelled Diamox (2 x IO~M) in sea water was fo...

BACKGROUND Recent advances in infantile nystagmus syndrome (INS) surgery have uncovered the therapeutic importance of proprioception. In this report, we test the hypothesis that the topical carbonic anhydrase inhibitor (CAI) brinzolamide (Azopt) has beneficial effects on measures of nystagmus foveation quality in a subject with INS. METHODS Eye movement data were taken, using a high-speed dig...

CruCA4, a coral α-carbonic anhydrase (CA, EC 4.2.1.1) involved in the biomineralization process of the Mediterranean red coral, Corallium rubrum, was investigated for its activation with a panel of amino acids and amines. Most compounds showed considerable activating properties, with a rather well defined structure-activity relationship. The most effective CruCA4 activators were d-His, 4-H₂N-l-...

BACKGROUND Carbonic anhydrase (CA) of the chicken has attracted attention for a long time because it has an important role in the eggshell formation. The developmental profile of CA-II isozyme levels in chicken erythrocytes has not been determined or reported. Furthermore, the relations with CA-II in erythrocyte and egg production are not discussed. In the present study, we isolated CA-II from ...