Carbonic anhydrase

Scleractinian corals are of particular interest due to their ability to establish an intracellular mutualistic symbiosis with phototrophic dinoflagellates and to deposit high rates of calcium carbonate in their skeleton. Carbonic anhydrases have been shown to play a crucial role in both processes. In this study, we report the molecular cloning and characterization of a novel α-CA in the coral Stylophora pistillata. This enzyme shares homologies with the human isoform CA II and is referred to as STPCA-2. STPCA-2 is 35.2 kDa and possesses all key amino acids for catalytic activity. With a ratio between catalytic and Michaelis constants (k cat /K m ) of 8.3.10 7 M −1 s −1 is considered as highly active. Owing to its intracellular localisation in the oral endoderm and in the aboral tissue, we propose that STPCA-2 is involved in pH regulation and/or inorganic carbon delivery to symbiont and calcification.

Decreased sweat secretion is a primary side effect of topiramate in pediatric patients, but the mechanism underlying this effect remains unclear. This study aimed to better understand how topiramate decreases sweat secretion by examining its effect on the expression of carbonic anhydrase (CA) II and aquaporin-5 (AQP5), total CA activity, as well as on tissue morphology of sweat glands in mice. Both developing and mature mice were treated with a low (20 mg/kg/day) and high dose (80 mg/kg/day) of topiramate for 4 weeks. Sweat secretion was investigated by an established technique of examining mold impressions of hind paws. CA II and AQP5 expression levels were determined by immunofluorescence and immunoblotting and CA activity by a colorimetric assay. In mature mice, topiramate treatment decreased the number of pilocarpine reactive sweat glands from baseline in both the low and high dose groups by 83% and 75%, respectively. A similar decrease was seen in developing mice. Mature mice w...

Background-Inflammatory glaucoma is still a diagnostic and therapeutic dilemma and surgical intervention is always associated with a high risk of failure or reactivation of the inflammatory disease. In this study we prospectively examined the value of transscleral diode laser cyclophotocoagulation (TDLC) for the treatment of refractory inflammatory glaucoma. Methods-22 eyes of 20 consecutive patients with inflammatory, medically uncontrollable, glaucoma secondary to chronic uveitis/trabeculitis (n = 18), chemical injury (n = 2), episcleritis (n = 1), and necrotising scleritis with inflammation (n = 1) were treated by TDLC. Nine eyes (41%) had had previous failed glaucoma surgery (trabeculectomy, cyclocryocoagulation) and 15 eyes (68.2%) had had previous anterior segment surgery. All patients were followed for 1 year after the initial treatment. Results-Within 12 months of the first treatment the intraocular pressure was controlled in 77.3% of all eyes (72.2% of those with uveitic glaucoma). No serious side eVects such as activation of the inflammatory process, phthisis bulbi or persistent hypotonia were observed, except one patient with a temporary fibrin reaction. More than one treatment was necessary in 63.6% of the patients. The use of systemic carbonic anhydrase inhibitors was reduced from 68.2% before treatment to 27.3% after 1 year. Conclusion-TDLC seems to be a safe and eVective procedure for the treatment of inflammatory glaucoma and may become an alternative to trabeculectomy with antimetabolites in uveitic glaucoma. TDLC may become the surgical procedure of choice in treating secondary glaucoma caused by chemical injury and also in scleritis associated glaucoma, using reduced parameters for application.

different capacity for entering cell. It was concluded that Different isoenzymes of carbonic anhydrase (CA; EC 4.2.1.1) internal CA was necessary to 'trap' the CO 2 entering the cell have been separated using thalli of the red macroalga Porphyra leucosticta Thuret in Le Jolis. Homogenates of the and thus maintain a favorable CO 2 gradient that permits its thallus were centrifuged in order to separate soluble and diffusive entry. Changes in the O 2 evolution rate at inorganic carbon (C i ) concentration saturating for photosynthesis and on membrane proteins. The fraction containing membrane proteins was subdivided by centrifuging into two fractions: the photosynthetic conductance for C i were found when external CA was inhibited. Based on these changes and the signifi-green and nongreen membrane proteins. CA activity was detected in all the fractions. Because external CA (measured cant CA activity (ca. 9% of the total activity) found in nongreen membrane fraction, the presence of external CA on intact thallus) represented 15% of total activity, it was concluded that most of the CA (ca. 80%) was soluble and associated with plasma membrane was postulated. The presence of CA associated with chloroplast membrane was also internal. Direct evidence regarding the different function of suggested.

Biological sequestration of carbon dioxide (CO 2 ) in geological formations is one of the proposed methods to reduce the carbon dioxide released into the atmosphere. In this method, an enzyme is used to enhance the hydration and subsequent precipitation of CO 2 . In the present work, the effect of bovine carbonic anhydrase on the hydration of CO 2 , and its precipitation in the form of calcium carbonate, was studied. The enzyme enhanced the hydration reaction. The rate of hydration reaction increased with both the enzyme concentration and temperature. The precipitation of calcium carbonate was promoted in the presence of the enzyme. The concentration of the enzyme did not affect the precipitation; however, temperature impacted the precipitation of calcium carbonate. At higher temperatures, less calcium carbonate was formed. Also, in the presence of the enzyme, calcium carbonate settled more quickly. The enzyme activity was not influenced by the pH of the reaction mixture. In contrast, the formation of calcium carbonate was affected by the pH of the solution. A kinetic analysis was performed for the bovine carbonic anhydrase. Based on the experimental results, the activation energy and catalytic rate constant are estimated as 700.91 cal/mol and 0.65 s -1 , respectively.

Carbonic anhydrases (CA) play an important role in biomineralization from invertebrates to vertebrates. Previous experiments have investigated the role of CA in coral calcification, mainly by pharmacological approaches. This study reports the molecular cloning, sequencing, and immunolocalization of a CA isolated from the scleractinian coral Stylophora pistillata, named STPCA. Results show that STPCA is a secreted form of ␣-CA, which possesses a CA catalytic function, similar to the secreted human CAVI. We localized this enzyme at the calicoblastic ectoderm level, which is responsible for the precipitation of the skeleton. This localization supports the role of STPCA in the calcification process. In symbiotic scleractinian corals, calcification is stimulated by light, a phenomenon called "lightenhanced calcification" (LEC). The mechanism by which symbiont photosynthesis stimulates calcification is still enigmatic. We tested the hypothesis that coral genes are differentially expressed under light and dark conditions. By real-time PCR, we investigated the differential expression of STPCA to determine its role in the LEC phenomenon. Results show that the STPCA gene is expressed 2-fold more during the dark than the light. We suggest that in the dark, up-regulation of the STPCA gene represents a mechanism to cope with night acidosis.

The photosynthetic characteristics of four transgenic rice lines over-expressing rice NADP-malic enzyme (ME), and maize phosphoenolpyruvate carboxylase (PC), pyruvate,orthophosphate dikinase (PK), and PC+PK (CK) were investigated using outdoor-grown plants. Relative to untransformed wild-type (WT) rice, PC transgenic rice exhibited high PC activity (25-fold increase) and enhanced activity of carbonic anhydrase (more than two-fold increase), while the activity of ribulose-bisphosphate carboxylase/oxygenase (Rubisco) and its kinetic property were not significantly altered. The PC transgenic plants also showed a higher light intensity for saturation of photosynthesis, higher photosynthetic CO(2) uptake rate and carboxylation efficiency, and slightly reduced CO(2) compensation point. In addition, chlorophyll a fluorescence analysis indicates that PC transgenic plants are more tolerant to photo-oxidative stress, due to a higher capacity to quench excess light energy via photochemical and...

N-(4-Sulfamoylphenyl)-aD D-glucopyranosylamine, a promising topical antiglaucoma agent, is a potent inhibitor of the zinc enzyme carbonic anhydrase (CA, EC 4.2.1.1). The high resolution X-ray crystal structure of its adduct with the target isoform involved in glaucoma, CA II, is reported here. The sugar sulfanilamide derivative binds to the enzyme in a totally new manner as compared to other CA-inhibitor adducts investigated earlier. The sulfonamide anchor was coordinated to the active site metal ion, and the phenylene ring of the inhibitor filled the channel leading to the active site cavity. The glycosyl moiety responsible for the high water solubility of the compound was oriented towards a hydrophilic region of the active site, where no other inhibitors were observed to be bound up to now. A network of seven hydrogen bonds with four water molecules and the amino acid residues Pro201, Pro202 and Gln92 further stabilize the enzyme-inhibitor adduct. Topiramate, another sugar-based CA inhibitor, binds in a completely different manner to CA II as compared to the sulfonamide investigated here. These findings are useful for the design of potent, sugar-derived enzyme inhibitors.

Crustaceans are a remarkable group of animals because of their ability to elaborate cyclically two kinds of calcified biomineralisations: an unstretchable exoskeleton (or cuticle) and also, for many species, depending of the way of life of the considered animal, transitory calcium deposits. They are in consequence subjected to a cyclic life and notably, to a periodical balance between two sources of calcium, exogenous and/or endogenous. The storage structures, essentially composed of calcium carbonate precipitated within a proteinaceous organic matrix, are very diversified. The calcium carbonate of the cuticle of most of the species is under a crystalline state and/or an amorphous form, whereas calcium deposits are always in amorphous form. The organic matrix is responsible for the mineral polymorph and the morphology of the calcified structures. The knowledge of the features of the components of organic matrices is a necessary prerequisite to understand how these calcified mineralisations are elaborated. Nevertheless, few organic matrix proteins involved in calcification are well characterized in crustaceans to date. Another interest is that the storage structures are elaborated by calcifying/decalcifying epithelia, which mimic vertebrate epithelia. Diverse enzymatic activities have been registered at this level, such as Mg 2+ -ATPase, Na + /K + -ATPase, and carbonic anhydrase. Finally, crustaceans represent convenient models to study the hormonal control of mineralising systems because, besides the involvement of ecdysteroids, the vertebrate tripartite calcium hormonal system (calcitonin, parathyroid hormone, vitamin D) could also regulate the formation of the crustacean calcified structures.

The protein encoded by the Nce103 gene of Saccharomyces cerevisiae, a b-carbonic anhydrase (CA, EC 4.2.1.1) designated as scCA, was investigated for its activation with amines and amino acids. scCA was poorly activated by amino acids such as L-/D-His, Phe, DOPA, Trp (K A s of 82-90 lM) and more effectively activated by amines such as histamine, dopamine, serotonin, pyridyl-alkylamines, aminoethyl-piperazine/morpholine (K A s of 10.2-21.3 lM). The best activator was L-adrenaline, with an activation constant of 0.95 lM. This study may help to better understand the catalytic/activation mechanisms of the b-CAs and eventually to design modulators of CA activity for similar enzymes present in pathogenic fungi, such as Candida albicans and Cryptococcus neoformans.

DNA clones for the b-class carbonic anhydrase (CA, EC 4.2.1.1) of Helicobactor pylori (hpbCA) were obtained. A recombinant hpbCA protein lacking the N-terminal 15-amino acid residues was produced and purified, representing a catalytically efficient CA. hpbCA was strongly inhibited (K I s in the range of 24-45 nM) by many sulfonamides/sulfamates, among which acetazolamide, ethoxzolamide, topiramate, and sulpiride, all clinically used drugs. The dual inhibition of a-and/or b-class CAs of H. pylori might represent a useful alternative for the management of gastritis/gastric ulcers, as well as gastric cancer. This is also the first study showing that a bacterial b-CA can be a drug target.

There is as yet no convincing evidence that acetazolamide, a carbonic anhydrase inhibitor, is effective in obstructive sleep apnoea. A study was therefore designed to examine the effect of acetazolamide (250 mg/day) on sleep events and ventilatory control during wakefulness in nine patients with the sleep apnoea syndrome. In eight of the nine patients the apnoea index and the total duration of apnoea were reduced by acetazolamide, and the mean (SEM) apnoea index of all patients changed from 25.0 (6.7) to 18.1 (5.8) episodes an hour. Furthermore, the total time of arterial oxygen desaturation (SaO2)--more than 4% depression in SaO2 from the baseline sleeping level--divided by total sleep time was also significantly decreased and its mean (SEM) value improved from 24.1 (7.9) to 13.6 (4.8)% of total sleep time. Five of the seven patients with varying degrees of daytime hypersomnolence had their symptoms obviously improved. There was no patient whose predominant type of apnoea was conve...

Based on the body of evidence implicating ocular blood flow disturbances in the pathogenesis of glaucoma, there is great interest in the investigation of the effects of antiglaucoma drugs and systemic medications on the various ocular vascular beds. The primary aim of this article was to review the current data available on the effects of antiglaucoma drugs and systemic medications on ocular blood flow. We performed a literature search in November 2002, which consisted of a textword search in MEDLINE for the years 1968-2002. The results of this review suggest that there is a severe lack of well-designed long-term studies investigating the effects of antiglaucoma and systemic medications on ocular blood flow in glaucomatous patients. However, among the 136 articles dealing with the effect of antiglaucoma drugs on ocular blood flow, only 36 (26.5%) investigated the effects of medications on glaucoma patients. Among these 36 articles, only 3 (8.3%) were long-term studies, and only 16 (44.4%) were double-masked, randomized, prospective trials. Among the 33 articles describing the effects of systemic medications on ocular blood flow, only 11 (33.3%) investigated glaucoma patients, of which only one (9.1%) was a double-masked, randomized, prospective trial. Based on this preliminary data, we would intimate that few antiglaucoma medications have the potential to directly improve ocular blood flow. Unoprostone appears to have a reproducible antiendothelin-1 effect, betaxolol may exert a calcium-channel blocker action, apraclonidine consistently leads to anterior segment vasoconstriction, and carbonic anhydrase inhibitors seem to accelerate the retinal circulation. Longitudinal, prospective, randomized trials are needed to investigate the effects of vasoactive substances with no hypotensive effect on the progression of glaucoma.

Three benzene-1,3-disulfonamide derivatives were investigated for their interaction with 12 mammalian α-carbonic anhydrases (CAs, EC 4.2.1.1), and three bacterial/archaeal CAs belonging to the α-, β-, and γ-CA class, respectively. X-ray crystal structure of the three inhibitors in complex with the dominant human isozyme CA II revealed a particular binding mode within the cavity. The sulfonamide group in meta-position to the Zn2+-coordinated SO2NH2 moiety was oriented toward the hydrophilic side of the active site cleft, establishing hydrogen bonds with His64, Asn67, Gln92, and Thr200. The plane of the phenyl moiety of the inhibitors was rotated by 45° and tilted by 10° with respect to its most recurrent orientation in other CA II–sulfonamide complexes.

Based on the body of evidence implicating ocular blood flow disturbances in the pathogenesis of glaucoma, there is great interest in the investigation of the effects of antiglaucoma drugs and systemic medications on the various ocular vascular beds. The primary aim of this article was to review the current data available on the effects of antiglaucoma drugs and systemic medications on ocular blood flow. We performed a literature search in November 2002, which consisted of a textword search in MEDLINE for the years 1968–2002. The results of this review suggest that there is a severe lack of well-designed long-term studies investigating the effects of antiglaucoma and systemic medications on ocular blood flow in glaucomatous patients. However, among the 136 articles dealing with the effect of antiglaucoma drugs on ocular blood flow, only 36 (26.5%) investigated the effects of medications on glaucoma patients. Among these 36 articles, only 3 (8.3%) were long-term studies, and only 16 (...

Glaucoma is one of the leading causes of visual impairment and blindness. Lowering intraocular pressure (IOP) is the only proven means to slow or halt disease progression among those at higher risk of developing glaucoma and those with early to moderate or more advanced glaucoma. Recent publications have highlighted the potential for increased rates or likelihood of worsening glaucoma among those with larger IOP swings within defined time periods. The purpose of this systematic, comprehensive review and analysis of the literature was to assess the state of knowledge in the area of IOP changes over time and the potential impact of such changes on treatment. Current literature indicates that a random IOP measurement is a poor surrogate for IOP levels throughout the day and across visits. We address several key questions: 1) What is the best way to measure IOP? 2) Should multiple IOP measurements be performed in a day in the office (short-term IOP fluctuation)? 3) Is measurement at night required? 4) Should clinicians begin to assess long-term IOP fluctuation in patients under stable treatment (across days or visits)? and 5) Should therapy choices be influenced by properties of different treatment options relative to short- or long-term IOP fluctuation?

The increase in the atmospheric concentrations of one of the vital green house gasses, carbon dioxide, due to anthropogenic interventions has led to several undesirable consequences such as global warming and related changes. In the global effort to combat the predicted disaster, several CO 2 capture and storage technologies are being deliberated. One of the most promising biological carbon dioxide sequestration technologies is the enzyme catalyzed carbon dioxide sequestration into bicarbonates which was endeavored in this study with a purified C. freundii SW3 b-carbonic anhydrase (CA). An extensive screening process for biological sequestration using CA has been defined. Six bacteria with high CA activity were screened out of 102 colonies based on plate assay and presence of CA in these bacteria was further emphasized by activity staining and Western blot. The identity of selected bacteria was confirmed by 16S rDNA analysis. CA was purified to homogeneity from C. freundii SW3 by subsequent gel filtration and ion exchange chromatography which resulted in a 24 kDa polypeptide and this is in accordance with the Western blot results. The effect of host on metal ions, cations and anions which influence activity of the enzyme in sequestration studies suggests that mercury and HCO 3 ion almost completely inhibit the enzyme whereas sulfate ion and zinc enhances carbonic anhydrase activity. Calcium carbonate deposition was observed in calcium chloride solution saturated with carbon dioxide catalyzed by purified enzyme and whereas a sharp decrease in calcium carbonate formation has been noted in purified enzyme samples inhibited by EDTA and acetazolamide.

This review integrates eight aspects of cerebrospinal fluid (CSF) circulatory dynamics: formation rate, pressure, flow, volume, turnover rate, composition, recycling and reabsorption. Novel ways to modulate CSF formation emanate from recent analyses of choroid plexus transcription factors (E2F5), ion transporters (NaHCO3 cotransport), transport enzymes (isoforms of carbonic anhydrase), aquaporin 1 regulation, and plasticity of receptors for fluid-regulating neuropeptides. A greater appreciation of CSF pressure (CSFP) is being generated by fresh insights on peptidergic regulatory servomechanisms, the role of dysfunctional ependyma and circumventricular organs in causing congenital hydrocephalus, and the clinical use of algorithms to delineate CSFP waveforms for diagnostic and prognostic utility. Increasing attention focuses on CSF flow: how it impacts cerebral metabolism and hemodynamics, neural stem cell progression in the subventricular zone, and catabolite/peptide clearance from t...

A series of 2-mercapto-substituted-benzenesulfonamides has been prepared by a unique two-step procedure starting from the corresponding 2-chloro-substituted benzenesulfonamides. Compounds bearing an unsubstituted mercapto group and the corresponding S-benzoyl derivatives were investigated as inhibitors of four isoforms of the zinc enzyme carbonic anhydrase (CA, EC 4.2.1.1), i.e., the cytosolic, ubiquitous isozymes CA I and II, as well as the transmembrane, tumor associated isozymes CA IX and XII. These derivatives were medium potency hCA I inhibitors (K(I)s in the range of 1.5-5.7 microM), two derivatives were strong hCA II inhibitors (K(I)s in the range of 15-16 nM), whereas the others showed weak activity. These compounds inhibited hCA IX with inhibition constants in the range 160-1950 nM and hCA XII with inhibition constants in the range 1.2-413 nM. Some of these derivatives showed a certain degree of selectivity for inhibition of the tumor-associated over the cytosolic isoforms,...

Cyclodextrins are cylindrical oligosaccharides with a lipophilic central cavity and hydrophilic outer surface. They can form water-soluble complexes with lipophilic drugs, which 'hide' in the cavity. Cyclodextrins can be used to form aqueous eye drop solutions with lipophilic drugs, such as steroids and some carbonic anhydrase inhibitors. The cyclodextrins increase the water solubility of the drug, enhance drug absorption into the eye, improve aqueous stability and reduce local irritation. Cyclodextrins are useful excipients in eye drop formulations of various drugs, including steroids of any kind, carbonic anhydrase inhibitors, pilocarpine, cyclosporins, etc. Their use in ophthalmology has already begun and is likely to expand the selection of drugs available as eye drops. In this paper we review the properties of cyclodextrins and their application in eye drop formulations, of which their use in the formulation of dexamethasone eye drops is an example. Cyclodextrins have been used to formulate eye drops containing corticosteroids, such as dexamethasone, with levels of concentration and ocular absorption which, according to human and animal studies, are many times those seen with presently available formulations. Cyclodextrin-based dexamethasone eye drops are well tolerated in the eye and seem to provide a higher degree of bioavailability and clinical efficiency than the steroid eye drop formulations presently available. Such formulations offer the possibility of once per day application of corticosteroid eye drops after eye surgery, and more intensive topical steroid treatment in severe inflammation. While cyclodextrins have been known for more than a century, their use in ophthalmology is just starting. Cyclodextrins are useful excipients in eye drop formulations for a variety of lipophilic drugs. They will facilitate eye drop formulations for drugs that otherwise might not be available for topical use, while improving absorption and stability and decreasing local irritation.

Since 1990 eight new antiepileptic drugs (AEDs) have been developed. Among these new drugs, Topiramate (TPM) is one of the latest AEDs available for treating drug resistant partial epilepsy both in adults and in children. The mechanisms underlying TPM antiepileptic activity are still incompletely understood. However, TPM, a sulfamatesubstituted derivative of the naturally occurring monosaccharide D-fructose, has a different structure from other known AEDs. The antiepileptic activity of TPM in animal models of partial and generalized tonic-clonic seizures has been shown to be more effective as compared to other AEDs. Proposed mechanisms of action include reduction of epileptiform discharges through a voltage-dependent block of Na+ channels, enhancement of the activity of γ-aminobutyrate at some subtypes of γ-aminobutyrate receptors, and antagonism of non- N-methyl-D-aspartate (NMDA) glutamate receptors. The pharmacokinetic profile of TPM, which is characterized by its rapid and almost complete absorption after oral administration, linear pharmacokinetics, minimal protein binding and predominantly renal excretion, makes the drug a good option for the treatment. TPM was found to be effective and well tolerated in many studies conducted in adults and pediatric patients suffering from epilepsy. This review, summarising the main studies in this field, provides an overview of the current knowledge about the relevant pharmacological and clinical information on the efficacy and tolerability of TPM.

The conditions for life in the deep past were different in many important ways from conditions of life on Earth today. Simple sequence-based comparative methods of evolutionary reconstruction, applied to single genes or proteins, can therefore give an incomplete or misleading picture of ancestral life forms. One way to augment sequence-based, single-gene methods to obtain a richer and more reliable picture of the deep past, is to resurrect inferred ancestral protein sequences in living organisms, where their phenotypes can be exposed in a complex molecular-systems context, and to then link consequences of those phenotypes to biosignatures that were preserved in the independent historical repository of the geological record. Good candidates for such 'revenant gene' studies are the genes for enzymes involved in carbon-fixation or other core metabolic pathways. Resurrecting ancestral DNA using synthetic-biology methods to engineer modern host bacteria is just at the beginning of its use as a systematic method in evolutionary biology. It has great potential to refine our understanding of the historical era already probed by phylogenetic methods, and even to suggest the forces governing the assembly of living systems reaching back into the " prehistoric " past, before those sequence divergences that have left descendants into the modern era. However, good design of revenant gene studies introduces new and interesting problems in the selection of genes, biosignatures, and modern host organisms, which should be understood as part of the next step in advancement of evolutionary methods.

We present here an optimized and cost-effective approach to saturation fluorescence labeling of protein thiols for proteomic analysis. We investigated a number of conditions and reagent concentrations, including the disulfide reducing agent tris(2-carboxyethyl)phosphine (TCEP), pH, incubation time, linearity of labeling, and saturating dye/protein thiol ratio with protein standards to gauge specific and nonspecific labeling. Efficacy of labeling under these conditions was quantified using specific fluorescence estimation, defined as the ratio of fluorescence pixel intensities and Coomassie-stained pixel intensities of bands after digital imaging. Factors leading to specific versus nonspecific labeling in the presence of thiourea are also discussed. We found that reproducible saturation of available Cys residues of the proteins used as labeling standards (human carbonic anhydrase I, enolase, and a-lactalbumin) is achieved at 50-to 100-fold excess of the uncharged maleimide-functionalized BODIPY dyes over Cys. We confirmed our previous findings, and those of others, that the maleimide dyes are not affected by the presence of 2 M thiourea. Moreover, we established that 2 mM TCEP used as reductant is optimal. We also established that labeling is optimal at pH 7.5 and complete after 30 min. Low nonspecific labeling was gauged by the inclusion of non-Cys-containing proteins (horse myoglobin and bovine carbonic anhydrase) to the labeling mixture. We also showed that the dye exhibits little to no effect on the two-dimensional mobilities of labeled proteins derived from cells. (J.E. Wiktorowicz).

We have investigated, in the genomic DNA of ten Tunisian patients, the presence of a splice junction mutation at the 5" end of intron 2 in the carbonic anhydrase II gene (CAII) previously described in six CAII-deficient patients presumed to be of Arab origin. All our patients were hornozygous for this mutation and were mentally retarded, a characteristic feature of the phenotype of patients with an Arabic background. This mutation is found exclusively in patients with an Arabic background and thus may be confined to this ethnic group.

In this article, a multidimensional dynamic surface tension detector (DSTD), in a parallel configuration with a UV-visible diode array absorbance detector, is presented in a novel flow injection analysis (FIA) application to study the effects of chemical denaturants urea, guanidinium hydrochloride (GdmHCl), and guanidinium thyocyanate (GdmSCN) on the surface activity of globular proteins at the liquid-air interface. The DSTD signal is obtained by measuring the changing pressure across the liquid-air interface of 4-ll drops repeatedly forming at the end of a capillary using FIA. The sensitivity and selectivity of the DSTD signal is related to the surface-active protein concentration in aqueous solution combined with the thermodynamics and kinetics of protein interaction at a liquid-air drop interface. Rapid on-line calibration and measurement of dynamic surface tension is applied, with the surface tension converted into surface pressure results. Continuous surface tension measurement throughout the entire drop growth is achieved, providing insight into kinetic behavior of protein interactive processes at the liquid-air drop interface. Specifically, chemical denaturation of 12 commercial globular proteins-chicken egg albumin, bovine serum albumin, human serum albumin, a-lactalbumin (a-Lac), myoglobin, cytochrome c, hemoglobin, carbonic anhydrase, a-chymotrypsinogen A, b-lactoglobulin (b-LG), lysozyme, and glyceraldehyde-3-phosphate-dehydrogenase-is studied in terms of surface pressure (i.e., surface activity) after treatment with increasing concentrations of urea, GdmHCl, and GdmSCN in the 0-8, 0-6, and 0-5 M ranges, respectively. For several of these proteins, the spectroscopic absorbance changes are monitored simultaneously to provide additional information prior to drop formation. Results show that surface pressure of proteins generally increases as the denaturant concentration increases and that effectiveness is GdmSCN > GdmHCl > urea. Protein unfolding curves obtained by plotting surface pressure as a function of denaturant concentration are presented and compared with respect to unfolding curves obtained by using UV absorbance and literature data. Kinetic information relative to the protein adsorption to the air-liquid interface of two proteins, a-Lac and b-LG (chosen as representative proteins for comparison), denatured by the three denaturants is also studied and discussed.

A series of 2-(hydrazinocarbonyl)-3-substituted-phenyl-1H-indole-5-sulfonamides and 1-({[5-(aminosulfonyl)-3-phenyl-1H-indol-2-yl]carbonyl}amino)-2,4,6 trimethylpyridinium perchlorates possessing various 2-, 3-or 4-substituted phenyl groups with methyl-, halogeno-and methoxy-functionalities, as well as the perfluorophenyl moiety, have been evaluated as inhibitors of the b-carbonic anhydrases (CAs, EC 4.2.1.1) from the pathogenic fungi Cryptococcus neoformans (Can2) and Candida albicans (CaNce103). Both enzymes were potently inhibited by these sulfonamides, K I s in the range of 4.4-118 nM against Can2, and of 5.1-128 against CaNce103, respectively. Minor structural changes in the 3-substituted phenyl moiety contribute significantly to the inhibitory activity. Some of the investigated sulfonamides showed promising selectivity ratios for inhibiting Can2 over the host, human enzymes CA I and II.

The carbonic anhydrase II (CA II) deficiency syndrome is an autosomal recessive disorder that produces osteopetrosis, renal tubular acidosis, and cerebral calcification. Other features include developmental delay, short stature, cognitive defects, and a history of multiple fractures by adolescence. With one exception, all patients with osteopetrosis and renal tubular acidosis examined have proven to have CA II deficiency. All CA II-deficient patients analyzed have been found to have mutations in the CA2 gene. Previously, we used single strand conformational (SSCP) analysis to identify exons to be sequenced from CA IIdeficient patients. In this report, we amplified all seven exons by PCR from genomic DNA and directly sequenced the amplified products. Application of this method allowed identification of eleven new mutations in 21 patients referred for confirmation of the diagnosis of CA II deficiency. These mutations were scattered over the genome from exon 2 to 7. In two opportunities for prenatal diagnosis, one from cultured amniocytes and one from chorionic villus biopsy, we demonstrated the general utility of the direct sequencing method for prenatal DNA diagnosis. These studies expand our knowledge of the heterogeneity in mutations underlying the CA II deficiency syndrome.

The review summarizes current data on the existence in terrestrial higher plants of several carbonic anhydrase forms differing in their properties, molecular structure, and intracellular localization. Possible functions of these carbonic anhydrases are discussed as well as specific features of carbon-concentrating mechanisms in phototrophic tissues of plants with ë 3 and ë 4 pathways of photosynthesis.

A series of diazenylbenzenesulfonamides, azo-dye derivatives of sulfanilamide or metanilamide incorporating phenol and amine moieties, were tested for inhibition of the tumor-associated isozymes of carbonic anhydrase (CA, EC 4.2.1.1), CA IX and XII. These compounds showed moderate-low inhibitory activities against the cytosolic isoforms CA I and II (offtargets) and excellent, low nanomolar inhibitory activity against the transmembrane CA IX and XII (K(I)s in the range of 3.5-63 nM against CA IX and 5.0-69.4 nM against CA XII, respectively). The selectivity ratio for inhibiting the tumor-associated CA IX over the offtarget CA II was in the range of 15-104 for these diazenylbenzenesulfonamides, making them among the most isoform-selective inhibitors targeting tumor-associated CAs (over the ubiquitous CA II). Since CA IX/XII were recently shown to be both therapeutic and diagnostic targets for hypoxic solid tumors overexpressing these proteins, such compounds held promise for the manag...

Carbon tetrachloride (CCl 4 ) is a common hepatotoxin used in experimental models to elicit liver injury. To identify the proteins involved in CCl 4 -induced hepatotoxicity, two-dimensional gel electrophoresis was employed followed by mass spectrometry -mass spectrometry (MS/MS) to study the differentially expressed proteins during CCl 4 exposure in the Fischer 344 rat liver proteome for 5 weeks. Ten spots with notable changes between the Control and CCl 4 groups were successfully identified. Among them, four proteins with significant up-regulation, namely calcium-binding protein 1, protein disulfide isomerase, mitochondrial aldehyde dehydrogenase precursor, and, glutathione-S-transferase mu1 and six proteins with significant downregulation, namely catechol-O-methyltransferase, hemoglobin-alpha-2-chain, hemopexin precursor, methionine sulfoxide reductase A, catalase and carbonic anhydrase 3, were identified. The data indicates that CCl 4 causes hepatotoxicity by depleting oxygen radical scavengers in the hepatocytes. In this rat model, we profiled hepatic proteome alterations in response to CCl 4 intoxication. The findings should facilitate understanding of the mechanism of CCl 4 -induced liver injury.

Based on the body of evidence implicating ocular blood flow disturbances in the pathogenesis of glaucoma, there is great interest in the investigation of the effects of antiglaucoma drugs and systemic medications on the various ocular vascular beds. The primary aim of this article was to review the current data available on the effects of antiglaucoma drugs and systemic medications on ocular blood flow. We performed a literature search in November 2002, which consisted of a textword search in MEDLINE for the years 1968-2002. The results of this review suggest that there is a severe lack of well-designed long-term studies investigating the effects of antiglaucoma and systemic medications on ocular blood flow in glaucomatous patients. However, among the 136 articles dealing with the effect of antiglaucoma drugs on ocular blood flow, only 36 (26.5%) investigated the effects of medications on glaucoma patients. Among these 36 articles, only 3 (8.3%) were long-term studies, and only 16 (44.4%) were double-masked, randomized, prospective trials. Among the 33 articles describing the effects of systemic medications on ocular blood flow, only 11 (33.3%) investigated glaucoma patients, of which only one (9.1%) was a double-masked, randomized, prospective trial. Based on this preliminary data, we would intimate that few antiglaucoma medications have the potential to directly improve ocular blood flow. Unoprostone appears to have a reproducible antiendothelin-1 effect, betaxolol may exert a calcium-channel blocker action, apraclonidine consistently leads to anterior segment vasoconstriction, and carbonic anhydrase inhibitors seem to accelerate the retinal circulation. Longitudinal, prospective, randomized trials are needed to investigate the effects of vasoactive substances with no hypotensive effect on the progression of glaucoma. r