Carbonic anhydrase (CA) (E.C. 4.2.1.1) is a ubiquitous enzyme catalysing interconversion between CO(2) and bicarbonate. The irregular distribution of the phylogenetically distinct classes of CA in procaryotic genome suggests its complex evolutionary history in procaryotes. Genetic evidence regarding the dispensability of CA under high-CO(2) air in some model organisms indicates that CA-deficien...

A new series of aromatic and heterocyclic sulfonamides, including six new derivatives, 2-(3-cyclohexene-1-carbamido)-1,3,4-thiadiazole-5-sulfonamide (CCTS), 4-(3-cyclohexene-1-carbamido) methyl-benzenesulfonamide (CCBS), 2-(9-octadecenoylamido)-1,3,4-thiadiazole-5-sulfonamide (ODTS), 2-(4,7,10-trioxa-tetradecanoylamido)-1,3,4-thiadiazole-5-sulfonamide (TDTS), 2-(coumarine-3-carbamido)-1,3,4-thi...

Carbonated drinks elicit a sensation that is highly sought after, yet the underlying neural mechanisms are ill-defined. We hypothesize that CO(2) is converted via carbonic anhydrase into carbonic acid, which excites lingual nociceptors that project to the trigeminal nuclei. We investigated this hypothesis using three methodological approaches. Electrophysiological methods were used to record re...

Carbonic anhydrases are zinc metalloenzymes that catalyze the reversible hydration of CO(2) to form HCO(3)(-) and protons according to the following reaction: CO(2) + H(2)O <=> H(2)CO(3) <=> HCO(3)(-) + H(+). The first reaction is catalyzed by carbonic anhydrase and the second reaction occurs instantaneously. The carbonic anhydrase (CA) gene family includes ten enzymatically active members, whi...

A new series of 6, 7-dihydroxy-3-(methylphenyl) chromenones, including three new derivatives, i.e. 6,7-dihydroxy-3-(2-methylphenyl)-2H-chromen-2-one (OPC); 6,7-dihydroxy-3-(3-methylphenyl)-2H-chromen-2-one (MPC); 6,7-dihydroxy-3-(4-methylphenyl)-2H-chromen-2-one (PPC) and one previously described, namely 6,7-dihydroxy-3-phenyl-2H-chromen-2-one (DPC), were synthesized. These compounds were inves...

Background: Topical carbonic anhydrase inhibitors (CAI) are the commonly used pharmacologic agents as an ocular hypotensive in medical therapy of glaucoma. This traditional use is due to reduced aqueous production through decreased bicarbonate formation in ciliary body epithelium. Taken into account current economical burden worldwide, the well-known drugs are “rediscovered’ and repurposed. In ...

Carbonic anhydrase-azosulfonamide dissociation constants (Kd) were determined by gel filtration with high-performance liquid chromatography. By measuring the area of the elution peak at two wavelengths, Kd values were derived without having to measure a shallow trough. The procedure proved to be fast and reliable and has a general application. The dissociation constants were measured for 7-acet...

In this work, we performed a structure-based virtual screening against five carbonic anhydrase isoforms using, as a ligand library, natural components of Citrus bergamia (Bergamot) and Allium cepa var. Tropea (red onion) sources, which are some typical Calabrian products. The most relevant Bergamot and red onion components, identified as potentially new hits by means of the computational work, ...

CASE REPORT A 25-year-old woman, with metamorphopsia in her left eye of one year onset. The examination revealed a bilateral cystoid macular oedema (CME) and vascular attenuation. We describe the diagnostic tests, as well as differential diagnosis and treatment response with carbonic anhydrase inhibitors. DISCUSSION The retinitis pigmentosa sine pigment is a subtype of atypical retinitis pigm...

An improved pH-stat-technique for the determination of carbonic anhydrase is presented. As compared with common techniques the main advantages are: 1. The hydration reaction of CO2 catalyzed by carbonic anhydrase can be determined at a constant and selected pH-value, 2. the substrate concentration can be kept constant, 3. the reaction volume amounts to only 2 ml, and 4. the reaction can be meas...