In the present experiments we investigated the effects of adrenalectomy and aldosterone, DOCA and hydrocortisone replacement on carbonic anhydrase activity in various organs of rats and mice. At the same time we reviewed all the experimental results hitherto obtained, and discussed the mechanism of action of aldosterone on the kidney. The characteristic feature of the action of aldosterone on r...

In zooxanthellate corals, the photosynthetic fixation of carbon dioxide and the precipitation of CaCO3 are intimately linked both spatially and temporally making it difficult to study carbon transport mechanisms involved in each pathway. When studying Tubastrea aurea, a coral devoid of zooxanthellae, we can focus on carbon transport mechanisms involved only in the calcification process. We perf...

The severity of Zn deficiency increased with increase in soil exchangeable sodium percentage (ESP) with salt sensitive variety M1-48 scoring 6 at ESP 62 as against only score 3 by salt tolerant variety Pokkali under similar soil conditions. Strikingly, zinc contents were much higher in salt tolerant variety than in salt sensitive one. Zinc application increased zinc concentration in the roots b...

Recent advances in protein design have opened avenues for the creation of artificial enzymes needed for biotechnological and pharmaceutical applications. However, designing efficient enzymes remains an unrealized ambition, as the design must incorporate a catalytic apparatus specific for the desired reaction. Here we present a de novo design approach to evolve a minimal carbonic anhydrase mimic...

To determine the role of microbes in karst processes, it is necessary to investigate the ecological distribution and characteristics of soil microorganisms in karst areas. In this paper, a preliminary study was carried out in two different karst areas of Southwest China: Nongla and the Guilin Yaji Karst Experimental Site (Guangxi). Soil samples from 10–20 cm in depth were analyzed for the numbe...

Many microalgae induce an extracellular carbonic anhydrase (eCA), associated with the cell surface, at low carbon dioxide (CO2) concentrations. This enzyme is thought to aid inorganic carbon uptake by generating CO2 at the cell surface, but alternative roles have been proposed. We developed a new approach to quantify eCA activity in which a reaction-diffusion model is fit to data on (18)O remov...

mantle coincided with the time when the greatest shell shoot was measured (Table 1, day 40). Our results support the view that, at least in mantle tissue, there is a direct correlation between shell formation and carbonic anhydrase activity. A major function of the gill is gaseous exchange, and the fact that gill carbonic anhydrase activity follows a similar pattern of change to that of new she...

The role of the cystic fibrosis transmembrane conductance regulator (CFTR) in cAMP-stimulated HCO3- secretion across the murine duodenum was investigated. Serosal-to-mucosal flux of HCO3- (Js-->m, in mu eq.cm-2.h-1) and short-circuit current (Isc; in mu eq.cm-2.h-1) were measured by the pH stat method in duodenum from CFTR knockout [CFTR(-)] and normal [CFTR(+)] mice. Under control conditions, ...

UNDER the name of carbonic anhydrase Meldrum & Roughton [1933] 2 described a new enzyme present in red blood corpuscles which catalyses both phases of the reversible reaction: H2CO3, CO2+ H20. They purified this enzyme from mammalian erythrocytes and gave a detailed account of its properties and the kinetics of the reactions which it catalyses. The greatly purified enzyme preparation obtained b...

Bundle sheath cells from leaves of a variety of C(4) species contained little or no carbonic anhydrase activity. The proportion of total leaf carbonic anhydrase in extracts of bundle sheath cells closely reflected the apparent mesophyll cell contamination of bundle sheath cell extracts as measured by the proportion of the mesophyll cell marker enzymes phosphoenolpyruvate carboxylase and pyruvat...