A new isoenzyme of carbonic anhydrase has been isolated and purified from Chlamydomonas reinhardtii. This carbonic anhydrase is composed of two nonidentical subunits with apparent molecular masses of 39 and 4.5 kDa and is located in the periplasmic space. This is the second periplasmic carbonic anhydrase found in C. reinhardtii. Two genes, CAH1 and CAH2, which code for carbonic anhydrase, have ...

The purpose of this study was to examine the subcellular distribution and isoenzyme characteristics of carbonic anhydrase from the gills and respiratory air bladder of bowfin Amia calva, a primitive air-breathing fish. Separation of subcellular fractions by differential centrifugation revealed that the vast majority of carbonic anhydrase from the gills of bowfin originated from the cytoplasmic ...

In vivo experiments were conducted on spiny dogfish (Squalus acanthias) and rainbow trout (Oncorhynchus mykiss) in sea water to determine the potential role of externally oriented or gill boundary layer carbonic anhydrase in carbon dioxide excretion. This was accomplished by assessing pH changes in expired water using a stopped-flow apparatus. In dogfish, expired water was in acid-base disequil...

BACKGROUND Carbonic anhydrase IX has been linked to cancer development and progression. AIM To analyse carbonic anhydrase IX expression and anhydrase inhibition in pancreatic cancer and to correlate these findings with p53 expression and microvessel density. MATERIALS AND METHODS Seventy-seven pancreatic cancers were examined (43 males, 34 females; mean age, 64 years). The anti-carbonic anh...

The levels of carbonic anhydrase I and II isozymes in human erythrocytes were determined using the single radial immunodiffusion method in 53 patients (29 males, 24 females) under chronic hemodialysis, and zinc concentration in erythrocytes were also determined. Both carbonic anhydrase. I and II levels and zinc concentration in erythrocytes were observed to be significantly increased in chronic...

We report three experiments which show that the hydrolysis of 4-nitrophenyl acetate catalyzed by carbonic anhydrase III from bovine skeletal muscle occurs at a site on the enzyme different than the active site for CO2 hydration. This is in contrast with isozymes I and II of carbonic anhydrase for which the sites of 4-nitrophenyl acetate hydrolysis and CO2 hydration are the same. The pH profile ...

The enzyme carbonic anhydrase appears to be a central molecular component in the suite of physiological and biochemical adaptations to low salinity found in euryhaline crustaceans. It is present in high activities in the organs responsible for osmotic and ionic regulation, the gills, and more specifically, the individual gills that are specialized for active ion uptake from dilute sea water. Wi...

1. Erythrocyte carbonic anhydrase I was measured by immunoelectrophoresis in blood samples taken at intervals during the menstrual cycle of 26 normal women. Plasma progesterone concentrations were also measured in 18 of these subjects. In every case, the erythrocyte carbonic anhydrase I concentration reached a maximum at that point in the cycle when there was maximum secretion of progesterone. ...

Carbonic anhydrase isozymes, carbonic anhydrase I and II, also known as carbonate dehydratase, were isolated and purified from human erythrocytes. Rabbits were then immunized and the respective types of antisera were prepared. Using the antisera obtained, the carbonic anhydrase I and II levels in erythrocytes of healthy persons and patients with chronic glomerulonephritis, primary nephrotic syn...

Carbonic anhydrase preparations from human erythrocytes contain at least three distinct molecular forms of the enzyme (l-4), two of which-denoted here as carbonic anhydrases B and C-have been studied in detail. They differ widely in specific activity, and also in their isoelectric points (1, 4), their amino acid composition (4-6), and their chromatographic behavior (3,4). Earlier studies on the...