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Sample records for anhydrase ca xv

  1. The most recently discovered carbonic anhydrase, CA XV, is expressed in the thick ascending limb of Henle and in the collecting ducts of mouse kidney.

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    Sina Saari

    Full Text Available BACKGROUND: Carbonic anhydrases (CAs are key enzymes for physiological pH regulation, including the process of urine acidification. Previous studies have identified seven cytosolic or membrane-bound CA isozymes in the kidney. Recently, we showed by in situ hybridization that the mRNA for the most novel CA isozyme, CA XV, is present in the renal cortex. CA XV is a unique isozyme among mammalian CAs, because it has become a pseudogene in primates even though expressed in several other species. METHODOLOGY/PRINCIPAL FINDINGS: In the present study, we raised a polyclonal antibody against recombinant mouse CA XV that was produced in a baculovirus/insect cell expression system, and the antibody was used for immunohistochemical analysis in different mouse tissues. Positive immunoreactions were found only in the kidney, where the enzyme showed a very limited distribution pattern. Parallel immunostaining experiments with several other anti-CA sera indicated that CA XV is mainly expressed in the thick ascending limb of Henle and collecting ducts, and the reactions were most prominent in the cortex and outer medulla. CONCLUSION/SIGNIFICANCE: Although other studies have proposed a role for CA XV in cell proliferation, its tightly limited distribution may point to a specialized function in the regulation of acid-base homeostasis.

  2. Mitochondrial carbonic anhydrase CA VB: Differences in tissue distribution and pattern of evolution from those of CA VA suggest distinct physiological roles

    OpenAIRE

    Shah, Gul N.; Hewett-Emmett, David; Grubb, Jeffrey H.; Migas, Mary C.; Fleming, Robert E.; Waheed, Abdul; Sly, William S.

    2000-01-01

    A cDNA for a second mouse mitochondrial carbonic anhydrase (CA) called CA VB was identified by homology to the previously characterized murine CA V, now called CA VA. The full-length cDNA encodes a 317-aa precursor that contains a 33-aa classical mitochondrial leader sequence. Comparison of products expressed from cDNAs for murine CA VB and CA VA in COS cells revealed that both expressed active CAs that localized in mitochondria, and showed comparable activities in crude extracts and in mitoc...

  3. A DFT-Based QSARs Study of Acetazolamide/Sulfanilamide Derivatives with Carbonic Anhydrase (CA-II Isozyme Inhibitory Activity

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    Oral Oltulu

    2007-02-01

    Full Text Available This study presents Quantitative Structure Activity Relationships (QSAR studyon a pool of 18 bio-active sulfonamide compounds which includes five acetazolamidederivatives, eight sulfanilamide derivatives and five clinically used sulfonamides moleculesas drugs namely acetazolamide, methazolamide, dichlorophenamide, ethoxolamide anddorzolamide. For all the compounds, initial geometry optimizations were carried out with amolecular mechanics (MM method using the MM force fields. The lowest energyconformations of the compounds obtained by the MM method were further optimized by theDensity Functional Theory (DFT method by employing Becke’s three-parameter hybridfunctional (B3LYP and 6-31G (d basis set. Molecular descriptors, dipole moment,electronegativity, total energy at 0 K, entropy at 298 K, HOMO and LUMO energiesobtained from DFT calculations provide valuable information and have a significant role inthe assessment of carbonic anhydrase (CA-II inhibitory activity of the compounds. By usingthe multiple linear regression technique several QSAR models have been drown up with thehelp these calculated descriptors and carbonic anhydrase (CA-II inhibitory data of themolecules. Among the obtained QSAR models presented in the study, statistically the mostsignificant one is a five parameters linear equation with the squared correlation coefficient R2 values of ca. 0.94 and the squared cross-validated correlation coefficient R2CV values of ca. 0.85. The results were discussed in the light of the main factors that influence theinhibitory activity of the carbonic anhydrase (CA-II isozyme.

  4. Photoluminescence of Vanadate Garnet Ca2NaMg(2-x)V3O12:xEu3+ Phosphors Synthesized by Solution Combustion Method.

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    Kim, H; Kim, J; Lim, S; Park, K

    2016-02-01

    In this study, a series of nano-sized Ca2NaMg(2-x)V3O12:xEu3+ (0.06 combustion method. The microstructure and photoluminescence properties of the Ca2NaMg(2-x)V3O12:xEu3+ phosphors are studied in accordance with the Eu3+ content. Annealed Ca2NaMg(2-x)V3O12:xEu3+ phosphors form a single phase with the cubic garnet structure and Ia3d space group. The emission from (VO4)3- in the Ca2NaMg(2-x)V3O12:xEu3+ phosphors is almost completely quenched due to the efficient energy transfer from the (VO4)3- to the Eu3+ ions. The emission intensity increases sharply with the increased Eu3+ content, reaching a maximum value at x = 0.15, and then decreases with further Eu3+ content. Ca2NaMg1.85V3O12:0.15Eu3+ shows great potential as a red phosphor for white light-emitting diodes.

  5. Design and simulation of rate-based CO2 capture processes using carbonic anhydrase (CA) applied to biogas

    DEFF Research Database (Denmark)

    Fosbøl, Philip Loldrup; Gaspar, Jozsef; Jacobsen, Bjartur

    2017-01-01

    a potential to create negative emissions using bio-energy carbon capture and storage (BECCS). All sectors are still in the need for applying more sustainable carbon capture and storage (CCS) technologies which result in lower energy consumption while reducing the impact on the environment. Recently several....... The advantage is a noticeably lower regeneration energy compared to primary and secondary amines. As a result the cost for stripping is significantly lower. Reactivated slow tertiary amines are applied in this study with the aim of reducing energy consumption. This is achieved byusing carbonic anhydrase (CA...

  6. Mitochondrial carbonic anhydrase CA VB: differences in tissue distribution and pattern of evolution from those of CA VA suggest distinct physiological roles.

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    Shah, G N; Hewett-Emmett, D; Grubb, J H; Migas, M C; Fleming, R E; Waheed, A; Sly, W S

    2000-02-15

    A cDNA for a second mouse mitochondrial carbonic anhydrase (CA) called CA VB was identified by homology to the previously characterized murine CA V, now called CA VA. The full-length cDNA encodes a 317-aa precursor that contains a 33-aa classical mitochondrial leader sequence. Comparison of products expressed from cDNAs for murine CA VB and CA VA in COS cells revealed that both expressed active CAs that localized in mitochondria, and showed comparable activities in crude extracts and in mitochondria isolated from transfected COS cells. Northern blot analyses of total RNAs from mouse tissues and Western blot analyses of mouse tissue homogenates showed differences in tissue-specific expression between CA VB and CA VA. CA VB was readily detected in most tissues, while CA VA expression was limited to liver, skeletal muscle, and kidney. The human orthologue of murine CA VB was recently reported also. Comparison of the CA domain sequence of human CA VB with that reported here shows that the CA domains of CA VB are much more highly conserved between mouse and human (95% identity) than the CA domains of mouse and human CA VAs (78% identity). Analysis of phylogenetic relationships between these and other available human and mouse CA isozyme sequences revealed that mammalian CA VB evolved much more slowly than CA VA, accepting amino acid substitutions at least 4.5 times more slowly since each evolved from its respective human-mouse ancestral gene around 90 million years ago. Both the differences in tissue distribution and the much greater evolutionary constraints on CA VB sequences suggest that CA VB and CA VA have evolved to assume different physiological roles.

  7. Rate-based modelling and validation of a pilot absorber using MDEA enhanced with carbonic anhydrase (CA)

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    Gaspar, Jozsef; Gladis, Arne; Woodley, John

    2017-01-01

    The great paradox of the 21st century is that we must meet the increasing global demand for energy and products while simultaneously mitigating the climate change. If both these criteria are to be met, carbon capture and storage is an imperative technology for sustainable energy infrastructure...... development. Post-combustion capture is a mature capture technology, however, to make it economically attractive, design of innovative solvents and process optimization is of crucial importance. An example for promising solvent is MDEA enhanced with carbonic anhydrase (CA), due to its fast kinetics and low...... for different L/G ratios, lean CO2 loadings, gas CO2 content and packing height. We show that the developed model is suitable for CO2 capture simulation and optimization using MDEA and MDEA enhanced with CA. Furthermore, we investigate the accuracy of the General Method (GM) enhancement factor model for CO2...

  8. Alkyl sulfonic acide hydrazides: Synthesis, characterization, computational studies and anticancer, antibacterial, anticarbonic anhydrase II (hCA II) activities

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    O. Ozdemir, Ummuhan; İlbiz, Firdevs; Balaban Gunduzalp, Ayla; Ozbek, Neslihan; Karagoz Genç, Zuhal; Hamurcu, Fatma; Tekin, Suat

    2015-11-01

    Methane sulfonic acide hydrazide, CH3SO2NHNH2 (1), ethane sulfonic acide hydrazide, CH3CH2SO2NHNH2 (2), propane sulfonic acide hydrazide, CH3CH2CH2SO2NHNH2 (3) and butane sulfonic acide hydrazide, CH3CH2CH2CH2SO2NHNH2 (4) have been synthesized as homologous series and characterized by using elemental analysis, spectrophotometric methods (1H-13C NMR, FT-IR, LC-MS). In order to gain insight into the structure of the compounds, we have performed computational studies by using 6-311G(d, p) functional in which B3LYP functional were implemented. The geometry of the sulfonic acide hydrazides were optimized at the DFT method with Gaussian 09 program package. A conformational analysis of compounds were performed by using NMR theoretical calculations with DFT/B3LYP/6-311++G(2d, 2p) level of theory by applying the (GIAO) approach. The anticancer activities of these compounds on MCF-7 human breast cancer cell line investigated by comparing IC50 values. The antibacterial activities of synthesized compounds were studied against Gram positive bacteria; Staphylococcus aureus ATCC 6538, Bacillus subtilis ATCC 6633, Bacillus cereus NRRL-B-3711, Enterococcus faecalis ATCC 29212 and Gram negative bacteria; Escherichia coli ATCC 11230, Pseudomonas aeruginosa ATCC 15442, Klebsiella pneumonia ATCC 70063 by using the disc diffusion method. The inhibition activities of these compounds on carbonic anhydrase II enzyme (hCA II) have been investigated by comparing IC50 and Ki values. The biological activity screening shows that butane sulfonic acide hydrazide (4) has more activity than the others against tested breast cancer cell lines MCF-7, Gram negative/Gram positive bacteria and carbonic anhydrase II (hCA II) isoenzyme.

  9. Common genetic denominators for Ca++-based skeleton in Metazoa: role of osteoclast-stimulating factor and of carbonic anhydrase in a calcareous sponge.

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    Werner E G Müller

    Full Text Available Calcium-based matrices serve predominantly as inorganic, hard skeletal systems in Metazoa from calcareous sponges [phylum Porifera; class Calcarea] to proto- and deuterostomian multicellular animals. The calcareous sponges form their skeletal elements, the spicules, from amorphous calcium carbonate (ACC. Treatment of spicules from Sycon raphanus with sodium hypochlorite (NaOCl results in the disintegration of the ACC in those skeletal elements. Until now a distinct protein/enzyme involved in ACC metabolism could not been identified in those animals. We applied the technique of phage display combinatorial libraries to identify oligopeptides that bind to NaOCl-treated spicules: those oligopeptides allowed us to detect proteins that bind to those spicules. Two molecules have been identified, the (putative enzyme carbonic anhydrase and the (putative osteoclast-stimulating factor (OSTF, that are involved in the catabolism of ACC. The complete cDNAs were isolated and the recombinant proteins were prepared to raise antibodies. In turn, immunofluorescence staining of tissue slices and qPCR analyses have been performed. The data show that sponges, cultivated under standard condition (10 mM CaCl(2 show low levels of transcripts/proteins for carbonic anhydrase or OSTF, compared to those animals that had been cultivated under Ca(2+-depletion condition (1 mM CaCl(2. Our data identify with the carbonic anhydrase and the OSTF the first two molecules which remain conserved in cells, potentially involved in Ca-based skeletal dissolution, from sponges (sclerocytes to human (osteoclast.

  10. Extremely low-frequency electromagnetic fields affect lipid-linked carbonic anhydrase.

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    Ravera, Silvia; Pepe, Isidoro Mario; Calzia, Daniela; Morelli, Alessandro; Panfoli, Isabella

    2011-06-01

    In the last years, the effect of extremely low-frequency electromagnetic fields (ELF-EMF) on the activity of different enzymes were investigated. Only the membrane-anchored enzymes did decrease their activity, up to 50%. In this work, the effect of ELF-EMF on bovine lung membrane carbonic anhydrase (CA) were studied. Carbonic anhydrases are a family of 14 zinc-containing isozymes catalyzing the reversible reaction: CO(2)+H(2)O = HCO(3)(- )+H(+). CA differ in catalytic activity and subcellular localization. CA IV, IX, XII, XIV, and XV are membrane bound. In particular, CA IV, which is expressed in the lung, is glycosyl phosphatidyl inositol-linked to the membrane, therefore it was a candidate to inhibition by ELF-EMF. Exposure to the membranes to a field of 75 Hz frequency and different amplitudes caused CA activity to a reproducible decrease in enzymatic activity by 17% with a threshold of about 0.74 mT. The decrease in enzymatic activity was independent of the time of permanence in the field and was completely reversible. When the source of enzyme was solubilized with Triton, the field lost its effect on CA enzymatic activity, suggesting a crucial role of the membrane, as well as of the particular linkage of the enzyme to it, in determining the conditions for CA inactivation. Results are discussed in terms of the possible physiologic effects of CA inhibition in target organs.

  11. The history and rationale of using carbonic anhydrase inhibitors in the treatment of peptic ulcers. In memoriam Ioan Puşcaş (1932-2015).

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    Buzás, György M; Supuran, Claudiu T

    2016-08-01

    Carbonic anhydrase (CA, EC 4.2.1.1) inhibitors (CAIs) started to be used in the treatment of peptic ulcers in the 1970s, and for more than two decades, a group led by Ioan Puşcaş used them for this purpose, assuming that by inhibiting the gastric mucosa CA isoforms, hydrochloric acid secretion is decreased. Although acetazolamide and other sulfonamide CAIs are indeed effective in healing ulcers, the inhibition of CA isoforms in other organs than the stomach led to a number of serious side effects which made this treatment obsolete when the histamine H2 receptor antagonists and the proton pump inhibitors became available. Decades later, in 2002, it has been discovered that Helicobacter pylori, the bacterial pathogen responsible for gastric ulcers and cancers, encodes for two CAs, one belonging to the α-class and the other one to the β-class of these enzymes. These enzymes are crucial for the life cycle of the bacterium and its acclimation within the highly acidic environment of the stomach. Inhibition of the two bacterial CAs with sulfonamides such as acetazolamide, a low-nanomolar H. pylori CAI, is lethal for the pathogen, which explains why these compounds were clinically efficient as anti-ulcer drugs. Thus, the approach promoted by Ioan Puşcaş for treating this disease was a good one although the rationale behind it was wrong. In this review, we present a historical overview of the sulfonamide CAIs as anti-ulcer agents, in memoriam of the scientist who was in the first line of this research trend.

  12. Expression and characterization of a recombinant psychrophilic γ-carbonic anhydrase (NcoCA) identified in the genome of the Antarctic cyanobacteria belonging to the genus Nostoc.

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    De Luca, Viviana; Del Prete, Sonia; Vullo, Daniela; Carginale, Vincenzo; Di Fonzo, Pietro; Osman, Sameh M; AlOthman, Zeid; Supuran, Claudiu T; Capasso, Clemente

    2016-10-01

    Carbonic anhydrases (CAs, EC 4.2.1.1) catalyze the CO2 hydration/dehydration reversible reaction: CO2 + H2O ⇄ [Formula: see text] + H(+). Living organisms encode for at least six distinct genetic families of such catalyst, the α-, β-, γ-, δ-, ζ- and η-CAs. The main function of the CAs is to quickly process the CO2 derived by metabolic processes in order to regulate acid-base homeostasis, connected to the production of protons (H(+)) and bicarbonate. Few data are available in the literature on Antarctic CAs and most of the scientific information regards CAs isolated from mammals or prokaryotes (as well as other mesophilic sources). It is of great interest to study the biochemical behavior of such catalysts identified in organism living in the Antarctic sea where temperatures average -1.9 °C all year round. The enzymes isolated from Antarctic organisms represent a useful tool to study the relations among structure, stability and function of proteins in organisms adapted to living at constantly low temperatures. In the present paper, we report in detail the cloning, purification, and physico-chemical properties of NcoCA, a γ-CA isolated from the Antarctic cyanobacterium Nostoc commune. This enzyme showed a higher catalytic efficiency at lower temperatures compared to mesophilic counterparts belonging to α-, β-, γ-classes, as well as a limited stability at moderate temperatures.

  13. The Cellular Physiology of Carbonic Anhydrases

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    Breton S

    2001-07-01

    Full Text Available 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(2O = H(2CO(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, which are major players in many physiological processes, including renal and male reproductive tract acidification, bone resorption, respiration, gluconeogenesis, signal transduction, and formation of gastric acid. The newly identified CA IX (previously called MN and CA XII are related to cell proliferation and oncogenesis. Carbonic anhydrase isozymes have different kinetic properties and they are present in various tissues and in various cell compartments. CA I, II, III and VII are cytoplasmic, CA V is mitochondrial, and CA VI is present in salivary secretions. CA IV, IX, XII and XIV are membrane proteins: CA IV is a glycosyl-phosphatidylinositol-anchored protein, and CA IX, XII and XIV are transmembrane proteins. The present work will focus on the roles of CA II and CA IV in transepithelial proton secretion and bicarbonate reabsorption processes. The localization of these isoforms in selected epithelia that are involved in net acid/base transport, such as kidney proximal tubules and collecting ducts, and tubules from the male reproductive tract will be reviewed.

  14. Inhibitory Effect of Furosemide on Carbonic Anhydrase

    Institute of Scientific and Technical Information of China (English)

    CUI Jianli; ZHAO Tongjin; JIANG Yan; ZHOU Haimeng

    2006-01-01

    This study investigated the inhibitory effect of a high efficiency diuretic, furosemide, on carbonic anhydrase (CA). First, comparing the inhibitory effect of acetazolamide, a low efficiency diuretic, on CA, shows that furosemide or acetazolamide can quickly make CA inactive when its concentration is close to the enzyme concentration, different from the usual inhibitory kinetics in which the concentration of the inhibitor is far higher than the enzyme concentration. Secondly, the reaction of the enzyme indicates that the inhibitory effect of furosemide or acetazolamide on carbonic anhydrase is quickly reversible. Finally, the degree of the inhibitory effect of furosemide and of acetazolamide on CA are compared. The results show that furosemide inhibits CA less than acetazolamide.

  15. Coral Carbonic Anhydrases: Regulation by Ocean Acidification

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    Didier Zoccola

    2016-06-01

    Full Text Available Global change is a major threat to the oceans, as it implies temperature increase and acidification. Ocean acidification (OA involving decreasing pH and changes in seawater carbonate chemistry challenges the capacity of corals to form their skeletons. Despite the large number of studies that have investigated how rates of calcification respond to ocean acidification scenarios, comparatively few studies tackle how ocean acidification impacts the physiological mechanisms that drive calcification itself. The aim of our paper was to determine how the carbonic anhydrases, which play a major role in calcification, are potentially regulated by ocean acidification. For this we measured the effect of pH on enzyme activity of two carbonic anhydrase isoforms that have been previously characterized in the scleractinian coral Stylophora pistillata. In addition we looked at gene expression of these enzymes in vivo. For both isoforms, our results show (1 a change in gene expression under OA (2 an effect of OA and temperature on carbonic anhydrase activity. We suggest that temperature increase could counterbalance the effect of OA on enzyme activity. Finally we point out that caution must, thus, be taken when interpreting transcriptomic data on carbonic anhydrases in ocean acidification and temperature stress experiments, as the effect of these stressors on the physiological function of CA will depend both on gene expression and enzyme activity.

  16. Coral Carbonic Anhydrases: Regulation by Ocean Acidification.

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    Zoccola, Didier; Innocenti, Alessio; Bertucci, Anthony; Tambutté, Eric; Supuran, Claudiu T; Tambutté, Sylvie

    2016-06-03

    Global change is a major threat to the oceans, as it implies temperature increase and acidification. Ocean acidification (OA) involving decreasing pH and changes in seawater carbonate chemistry challenges the capacity of corals to form their skeletons. Despite the large number of studies that have investigated how rates of calcification respond to ocean acidification scenarios, comparatively few studies tackle how ocean acidification impacts the physiological mechanisms that drive calcification itself. The aim of our paper was to determine how the carbonic anhydrases, which play a major role in calcification, are potentially regulated by ocean acidification. For this we measured the effect of pH on enzyme activity of two carbonic anhydrase isoforms that have been previously characterized in the scleractinian coral Stylophora pistillata. In addition we looked at gene expression of these enzymes in vivo. For both isoforms, our results show (1) a change in gene expression under OA (2) an effect of OA and temperature on carbonic anhydrase activity. We suggest that temperature increase could counterbalance the effect of OA on enzyme activity. Finally we point out that caution must, thus, be taken when interpreting transcriptomic data on carbonic anhydrases in ocean acidification and temperature stress experiments, as the effect of these stressors on the physiological function of CA will depend both on gene expression and enzyme activity.

  17. Coral Carbonic Anhydrases: Regulation by Ocean Acidification

    Science.gov (United States)

    Zoccola, Didier; Innocenti, Alessio; Bertucci, Anthony; Tambutté, Eric; Supuran, Claudiu T.; Tambutté, Sylvie

    2016-01-01

    Global change is a major threat to the oceans, as it implies temperature increase and acidification. Ocean acidification (OA) involving decreasing pH and changes in seawater carbonate chemistry challenges the capacity of corals to form their skeletons. Despite the large number of studies that have investigated how rates of calcification respond to ocean acidification scenarios, comparatively few studies tackle how ocean acidification impacts the physiological mechanisms that drive calcification itself. The aim of our paper was to determine how the carbonic anhydrases, which play a major role in calcification, are potentially regulated by ocean acidification. For this we measured the effect of pH on enzyme activity of two carbonic anhydrase isoforms that have been previously characterized in the scleractinian coral Stylophora pistillata. In addition we looked at gene expression of these enzymes in vivo. For both isoforms, our results show (1) a change in gene expression under OA (2) an effect of OA and temperature on carbonic anhydrase activity. We suggest that temperature increase could counterbalance the effect of OA on enzyme activity. Finally we point out that caution must, thus, be taken when interpreting transcriptomic data on carbonic anhydrases in ocean acidification and temperature stress experiments, as the effect of these stressors on the physiological function of CA will depend both on gene expression and enzyme activity. PMID:27271641

  18. Non-Classical Inhibition of Carbonic Anhydrase

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    Lomelino, Carrie L.; Supuran, Claudiu T.; McKenna, Robert

    2016-01-01

    Specific isoforms from the carbonic anhydrase (CA) family of zinc metalloenzymes have been associated with a variety of diseases. Isoform-specific carbonic anhydrase inhibitors (CAIs) are therefore a major focus of attention for specific disease treatments. Classical CAIs, primarily sulfonamide-based compounds and their bioisosteres, are examined as antiglaucoma, antiepileptic, antiobesity, antineuropathic pain and anticancer compounds. However, many sulfonamide compounds inhibit all CA isoforms nonspecifically, diluting drug effectiveness and causing undesired side effects due to off-target inhibition. In addition, a small but significant percentage of the general population cannot be treated with sulfonamide-based compounds due to a sulfa allergy. Therefore, CAIs must be developed that are not only isoform specific, but also non-classical, i.e. not based on sulfonamides, sulfamates, or sulfamides. This review covers the classes of non-classical CAIs and the recent advances in the development of isoform-specific inhibitors based on phenols, polyamines, coumarins and their derivatives. PMID:27438828

  19. Characterization of Carbonic Anhydrase 9 in the Alimentary Canal of Aedes aegypti and Its Relationship to Homologous Mosquito Carbonic Anhydrases.

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    Dixon, Daniel P; Van Ekeris, Leslie; Linser, Paul J

    2017-02-21

    In the mosquito midgut, luminal pH regulation and cellular ion transport processes are important for the digestion of food and maintenance of cellular homeostasis. pH regulation in the mosquito gut is affected by the vectorial movement of the principal ions including bicarbonate/carbonate and protons. As in all metazoans, mosquitoes employ the product of aerobic metabolism carbon dioxide in its bicarbonate/carbonate form as one of the major buffers of cellular and extracellular pH. The conversion of metabolic carbon dioxide to bicarbonate/carbonate is accomplished by a family of enzymes encoded by the carbonic anhydrase gene family. This study characterizes Aedes aegypti carbonic anhydrases using bioinformatic, molecular, and immunohistochemical methods. Our analyses show that there are fourteen Aedes aegypti carbonic anhydrase genes, two of which are expressed as splice variants. The carbonic anhydrases were classified as either integral membrane, peripheral membrane, mitochondrial, secreted, or soluble cytoplasmic proteins. Using polymerase chain reaction and Western blotting, one of the carbonic anhydrases, Aedes aegypti carbonic anhydrase 9, was analyzed and found in each life stage, male/female pupae, male/female adults, and in the female posterior midgut. Next, carbonic anhydrase 9 was analyzed in larvae and adults using confocal microscopy and was detected in the midgut regions. According to our analyses, carbonic anhydrase 9 is a soluble cytoplasmic enzyme found in the alimentary canal of larvae and adults and is expressed throughout the life cycle of the mosquito. Based on previous physiological analyses of adults and larvae, it appears AeCA9 is one of the major carbonic anhydrases involved in producing bicarbonate/carbonate which is involved in pH regulation and ion transport processes in the alimentary canal. Detailed understanding of the molecular bases of ion homeostasis in mosquitoes will provide targets for novel mosquito control strategies into the

  20. Characterization of Carbonic Anhydrase 9 in the Alimentary Canal of Aedes aegypti and Its Relationship to Homologous Mosquito Carbonic Anhydrases

    Science.gov (United States)

    Dixon, Daniel P.; Van Ekeris, Leslie; Linser, Paul J.

    2017-01-01

    In the mosquito midgut, luminal pH regulation and cellular ion transport processes are important for the digestion of food and maintenance of cellular homeostasis. pH regulation in the mosquito gut is affected by the vectorial movement of the principal ions including bicarbonate/carbonate and protons. As in all metazoans, mosquitoes employ the product of aerobic metabolism carbon dioxide in its bicarbonate/carbonate form as one of the major buffers of cellular and extracellular pH. The conversion of metabolic carbon dioxide to bicarbonate/carbonate is accomplished by a family of enzymes encoded by the carbonic anhydrase gene family. This study characterizes Aedes aegypti carbonic anhydrases using bioinformatic, molecular, and immunohistochemical methods. Our analyses show that there are fourteen Aedes aegypti carbonic anhydrase genes, two of which are expressed as splice variants. The carbonic anhydrases were classified as either integral membrane, peripheral membrane, mitochondrial, secreted, or soluble cytoplasmic proteins. Using polymerase chain reaction and Western blotting, one of the carbonic anhydrases, Aedes aegypti carbonic anhydrase 9, was analyzed and found in each life stage, male/female pupae, male/female adults, and in the female posterior midgut. Next, carbonic anhydrase 9 was analyzed in larvae and adults using confocal microscopy and was detected in the midgut regions. According to our analyses, carbonic anhydrase 9 is a soluble cytoplasmic enzyme found in the alimentary canal of larvae and adults and is expressed throughout the life cycle of the mosquito. Based on previous physiological analyses of adults and larvae, it appears AeCA9 is one of the major carbonic anhydrases involved in producing bicarbonate/carbonate which is involved in pH regulation and ion transport processes in the alimentary canal. Detailed understanding of the molecular bases of ion homeostasis in mosquitoes will provide targets for novel mosquito control strategies into the

  1. A cytosolic carbonic anhydrase molecular switch occurs in the gills of metamorphic sea lamprey

    Science.gov (United States)

    Ferreira-Martins, D.; McCormick, Stephen; Campos, A.; Lopes-Marques, M.; Osorio, H.; Coimbra, J.; Castro, L.F.C.; Wilson, Jonthan M

    2016-01-01

    Carbonic anhydrase plays a key role in CO2 transport, acid-base and ion regulation and metabolic processes in vertebrates. While several carbonic anhydrase isoforms have been identified in numerous vertebrate species, basal lineages such as the cyclostomes have remained largely unexamined. Here we investigate the repertoire of cytoplasmic carbonic anhydrases in the sea lamprey (Petromyzon marinus), that has a complex life history marked by a dramatic metamorphosis from a benthic filter-feeding ammocoete larvae into a parasitic juvenile which migrates from freshwater to seawater. We have identified a novel carbonic anhydrase gene (ca19) beyond the single carbonic anhydrase gene (ca18) that was known previously. Phylogenetic analysis and synteny studies suggest that both carbonic anhydrase genes form one or two independent gene lineages and are most likely duplicates retained uniquely in cyclostomes. Quantitative PCR of ca19 and ca18 and protein expression in gill across metamorphosis show that the ca19 levels are highest in ammocoetes and decrease during metamorphosis while ca18 shows the opposite pattern with the highest levels in post-metamorphic juveniles. We propose that a unique molecular switch occurs during lamprey metamorphosis resulting in distinct gill carbonic anhydrases reflecting the contrasting life modes and habitats of these life-history stages.

  2. Los obispos del siglo XV

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    Sanz Sancho, Iluminado

    2002-12-01

    Full Text Available In spite of the importance of the diocese of Córdoba in the Later Middle Ages, an itemized study of its bishops has not still been made. We present the episcopal biographies of the XV century now, continuation of the episcopal biographies of the XIII-XIV centuries, shown up in Hispania Sacra, 54 (2002, 21-65.

    A pesar de la importancia de la diócesis de Córdoba en la Baja Edad Media, aún no se ha hecho un estudio pormenorizado de sus obispos. Presentamos ahora el episcopologio del siglo XV, continuación del episcopologio de los siglos XIIIXIV, aparecido en Hispania Sacra, 54 (2002, 21-56.

  3. Carbonic anhydrase inhibitors drug design.

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    McKenna, Robert; Supuran, Claudiu T

    2014-01-01

    Inhibition of the metalloenzyme carbonic anhydrase (CA, EC 4.2.1.1) has pharmacologic applications in the field of antiglaucoma, anticonvulsant, antiobesity, and anticancer agents but is also emerging for designing anti-infectives (antifungal and antibacterial agents) with a novel mechanism of action. As a consequence, the drug design of CA inhibitors (CAIs) is a very dynamic field. Sulfonamides and their isosteres (sulfamates/sulfamides) constitute the main class of CAIs which bind to the metal ion in the enzyme active site. Recently the dithiocarbamates, possessing a similar mechanism of action, were reported as a new class of inhibitors. Other families of CAIs possess a distinct mechanism of action: phenols, polyamines, some carboxylates, and sulfocoumarins anchor to the zinc-coordinated water molecule. Coumarins and five/six-membered lactones are prodrug inhibitors, binding in hydrolyzed form at the entrance of the active site cavity. Novel drug design strategies have been reported principally based on the tail approach for obtaining all these types of CAIs, which exploit more external binding regions within the enzyme active site (in addition to coordination to the metal ion), leading thus to isoform-selective compounds. Sugar-based tails as well as click chemistry were the most fruitful developments of the tail approach. Promising compounds that inhibit CAs from bacterial and fungal pathogens, of the dithiocarbamate, phenol and carboxylate types have also been reported.

  4. 碳酸酐酶Ⅸ(CA-Ⅸ)与HIF-1α在前列腺癌中的表达情况及相关性研究%The expression and correlation studies about Carbon anhydrase Ⅸ (CA-Ⅸ) and Hypoxia-inducible factor-1 alpha in prostate cancer

    Institute of Scientific and Technical Information of China (English)

    黄海; 韩金利; 姚友生; 谢文练; 黄健; 卢振权; 杜涛; 林天歆; 许可慰; 董文; 毕良宽; 郭正辉; 江春

    2012-01-01

    目的 探讨碳酸酐酶Ⅸ(CA-Ⅸ)及缺氧诱导因子-1α (HIF-1α)在前列腺癌不同分期分级中的表达及其内在联系情况. 方法 采用免疫组织化学S-P法及Western-blot检测正常前列腺组织、前列腺癌组织以及前列腺癌细胞系PC-3、Lncap中CA-Ⅸ及HIF-1α的表达情况,结合临床资料进行统计分析,评价CA-Ⅸ及HIF-1α表达情况与前列腺组织癌变分化程度之间的关系,同时分析两者之间的相关性.结果 在正常前列腺组织中CA-Ⅸ及HIF-1α基本不表达,在前列腺癌组织石蜡切片中,HIF处于高表达,其表达情况与前列腺癌病理分级相关.低分化的前列腺癌组织中HIF-1α的表达量高于高分化的前列腺癌组织.CA-Ⅸ在前列腺癌组织中表达率为37.5%,高于正常组织,与肿瘤分化程度无关.CA-Ⅸ及HIF-1α在前列腺癌组织中的表达情况具有相关性.结论 CA-Ⅸ及HIF-1α与前列腺癌的发生成正相关,而且两者在前列腺癌组织中的表达具有相关性,同时提示了以缺氧诱导因子通路为基础的分子机制在前列腺癌的演进中起到一定的作用.%Objective To study the expression and correlation of Carbon anhydrase Ⅸ (CA-Ⅸ) and Hypoxia-inducible factor-1 alpha (HIF-1α) in prostate cancer.Methods The immunohistochemistry of S-P and western-blot were used to detect the expression of Carbon anhydrase Ⅸ (CA-Ⅸ) and Hypoxia-inducible factor-1 alpha (HIF-1α) in normal prostate tissue,prostate cancer tissue,and prostate cancer cell lines PC-3,Lncap.Combined with clinical data,the statistical analysis on the evaluation of CA-Ⅸ and HIF-1α expression and prostate tissue differentiation degree relationship was done and the correlation between the two factor was analysed.Results In normal prostate tissue,CA-Ⅸ and HIF-1α almost did not express,but in prostate cancer tissue paraffin section,HIF-1α was at a high expression, and its expression had relationship with pathological

  5. Bioindication potential of carbonic anhydrase activity in anemones and corals.

    Science.gov (United States)

    Gilbert, A L; Guzmán, H M

    2001-09-01

    Activity levels of carbonic anhydrase (CA) were assessed in anemones Condylactis gigantea and Stichodactyla helianthus with laboratory exposures to copper, nickel, lead, and vanadium, and also in animals collected from polluted vs pristine field sites. CA activity was found to be decreased with increase in metal concentration and also in animals collected from the polluted field site. Preliminary assessments to adapt the CA assay for use in the widespread coral Montastraea cavernosa show decreased CA activity in specimens from the polluted field site and provide an avenue for future research aimed at more thoroughly describing coral CA activity for potential application in bioindication.

  6. Carbonic Anhydrases and Their Biotechnological Applications

    Directory of Open Access Journals (Sweden)

    Robert McKenna

    2013-08-01

    Full Text Available The carbonic anhydrases (CAs are mostly zinc-containing metalloenzymes which catalyze the reversible hydration/dehydration of carbon dioxide/bicarbonate. The CAs have been extensively studied because of their broad physiological importance in all kingdoms of life and clinical relevance as drug targets. In particular, human CA isoform II (HCA II has a catalytic efficiency of 108 M−1 s−1, approaching the diffusion limit. The high catalytic rate, relatively simple procedure of expression and purification, relative stability and extensive biophysical studies of HCA II has made it an exciting candidate to be incorporated into various biomedical applications such as artificial lungs, biosensors and CO2 sequestration systems, among others. This review highlights the current state of these applications, lists their advantages and limitations, and discusses their future development.

  7. Carbonic anhydrase from Apis mellifera: purification and inhibition by pesticides.

    Science.gov (United States)

    Soydan, Ercan; Güler, Ahmet; Bıyık, Selim; Şentürk, Murat; Supuran, Claudiu T; Ekinci, Deniz

    2017-12-01

    Carbonic anhydrase (CA) enzymes have been shown to play an important role in ion transport and in pH regulation in several organisms. Despite this information and the wealth of knowledge regarding the significance of CA enzymes, few studies have been reported about bee CA enzymes and the hazardous effects of chemicals. Using Apis mellifera as a model, this study aimed to determine the risk of pesticides on Apis mellifera Carbonic anhydrase enzyme (Am CA). CA was initially purified from Apis mellifera spermatheca for the first time in the literature. The enzyme was purified with an overall purification of ∼35-fold with a molecular weight of ∼32 kDa. The enzyme was then exposed to pesticides, including tebuconazole, propoxur, carbaryl, carbofuran, simazine and atrazine. The six pesticides dose-dependently inhibited in vitro AmCA activity at low micromolar concentrations. IC50 values for the pesticides were 0.0030, 0.0321, 0.0031, 0.0087, 0.0273 and 0.0165 μM, respectively. The AmCA inhibition mechanism of these compounds is unknown at this moment.

  8. The evolution of metazoan α-carbonic anhydrases and their roles in calcium carbonate biomineralization

    OpenAIRE

    Le Roy, Nathalie; Jackson, Daniel J.; Marie, Benjamin; Ramos-Silva, Paula; Marin, Frédéric

    2014-01-01

    The carbonic anhydrase (CA; EC 4.2.1.1) superfamily is a class of ubiquitous metallo-enzymes that catalyse the reversible hydration of carbon dioxide. The ?-CA family, present in all metazoan clades, is a key enzyme involved in a wide range of physiological functions including pH regulation, respiration, photosynthesis, and biocalcification. This paper reviews the evolution of the ?-CA family, with an emphasis on metazoan ?-CA members involved in biocalcification. Phylogenetic analyses reveal...

  9. Natural Product Polyamines That Inhibit Human Carbonic Anhydrases

    Directory of Open Access Journals (Sweden)

    Rohan A. Davis

    2014-01-01

    Full Text Available Natural product compound collections have proven an effective way to access chemical diversity and recent findings have identified phenolic, coumarin, and polyamine natural products as atypical chemotypes that inhibit carbonic anhydrases (CAs. CA enzymes are implicated as targets of variable drug therapeutic classes and the discovery of selective, drug-like CA inhibitors is essential. Just two natural product polyamines, spermine and spermidine, have until now been investigated as CA inhibitors. In this study, five more complex natural product polyamines 1–5, derived from either marine sponge or fungi, were considered for inhibition of six different human CA isozymes of interest in therapeutic drug development. All compounds share a simple polyamine core fragment, either spermine or spermidine, yet display substantially different structure activity relationships for CA inhibition. Notably, polyamines 1–5 were submicromolar inhibitors of the cancer drug target CA IX, this is more potent than either spermine or spermidine.

  10. Future Perspective in Carbonic Anhydrase Inhibitors and its Drugs

    Directory of Open Access Journals (Sweden)

    S.Petchimuthu

    2013-09-01

    Full Text Available Through this review it is contemplated that carbonic anhydrase inhibitors, were a traditional drugs of choice for the treatment of glaucoma with a myriad of side effects and inadequate topical effectiveness, may be formulated into a topically effective agent by utilizing various newer formulation approaches of ocular drug delivery. Even though the carbonic anhydrase inhibitor, acetazolamide (ACZ has a poor solubility and penetration power (BCS Class IV, various studies mentioned in the review indicate that it is possible to successfully formulate topically effective ACZ by using:(i High concentration of the drug, (ii Surfactant gel preparations of ACZ, (iii ACZ loaded into liposomes, (iv Cyclodextrins to increase the solubility and hence bioavailability of ACZ, and Viscolyzers and other polymers either alone or in combination with cyclodextrins. With the advent of newer topical carbonic anhydrase inhibitors (CAIs like dorzolamide and brinzolamide, a localized effect with fewer side effects is expected.But whenever absorbed systemically, a similar range of adverse effects (attributable to sulphonamides may occur upon use. Furthermore, oral ACZ is reported to be more physiologically effective than 2% dorzolamide hydrochloridead ministered topically, even though in isolated tissues dorzolamide appears to be the most active as it shows the lowest IC50 values for CA-II and CA-IV. Hence, there exists considerable scope for the development of more/equally effective and inexpensive topically effective formulations of ACZ. The use of various formulation technologies discussed in this review can provide a fresh impetus to research in this area.

  11. IgM natural autoantibodies against bromelain-treated mouse red blood cells recognise carbonic anhydrase.

    Science.gov (United States)

    Jonusys, A M; Cox, K O; Steele, E J

    1991-01-01

    Carbonic anhydrase (CA) from mouse erythrocyte membranes is recognised as an autoantigen in Western blotting experiments with FUB 1, a murine IgM monoclonal antibody that binds both phosphatidylcholine and bromelain-treated mouse red blood cells (BrMRBC). Serum from mice stimulated with lipopolysaccharide (LPS-serum) also recognises CA. From SDS-PAGE, and blotting experiments with whole mouse erythrocytes, we found two closely spaced glycoprotein bands in the 30 kD region that reacted with both FUB 1 and LPS-serum. One of the molecular weight markers, bovine carbonic anhydrase which is of a molecular weight of about 30 kD, electrophoresed in the same 30 kD region also reacted with these antibodies. Carbonic anhydrases from a range of mammalian species were found to be crossreactive with FUB 1 and LPS-serum by Western blotting, whereas human glycophorin A and human asialoglycophorin were not recognised by the antibodies. FUB 1 specifically recognises both native and denatured bovine carbonic anhydrase in ELISA assays. The serological identity of the determinants of CA and BrMRBC was confirmed by specific absorption of both FUB 1 and LPS-serum with BrMRBC and normal mouse erythrocytes. We propose that a native autoantigenic epitope on erythrocytes may be revealed by the proteolytic action of bromelain and that this determinant is associated, at least in part, with carbonic anhydrase.

  12. Pilot absorption experiments with carbonic anhydrase enhanced MDEA

    DEFF Research Database (Denmark)

    Gladis, Arne; F. Lomholdt, Niels; Fosbøl, Philip Loldrup

    2017-01-01

    -methyl-diethanolamine (MDEA) solvent, with and without the enzyme carbonic anhydrase (CA). The absorption experiments were performed at atmospheric pressure and agas phase carbon dioxide mole fraction of 0.13. During experiments liquid samples were withdrawn at each meter of column height and the solvent loading...... was determined by both a density method and the BaCl2 method. After the solvent was loaded to equilibrium it was heated up and reintroduced into the column, where CO2 was stripped off using air as stripping gas. The addition of CA increased the mass transfer significantly in all experiments. Lower absorption...

  13. PREFACE: Symmetries in Science XV

    Science.gov (United States)

    Schuch, Dieter; Ramek, Michael

    2012-08-01

    Logo Bregenz, the peaceful monastery of Mehrerau and the Opera on the Floating Stage again provided the setting for the international symposium 'Symmetries in Science'. The series which has been running for more than 30 years brings together leading theoreticians whose area of research is, in one way or another, related to symmetry. Since 1992 the meeting took place biannually in Brengez until 2003. In 2009, with the endorsement of the founder, Professor Bruno Gruber, we succeeded in re-establishing the series without external funding. The resounding success of that meeting encouraged us to continue in 2011 and, following on the enthusiasm and positive feedback of the participants, we expect to continue in 2013. Yet again, our meeting in 2011 was very international in flavour and brought together some 30 participants representing 12 nationalities, half of them from countries outside the European Union (from New Zealand to Mexico, Russia to Israel). The broad spectrum, a mixture of experienced experts and highly-motivated newcomers, the intensive exchange of ideas in a harmonious and relaxed atmosphere and the resulting joint projects are probably the secrets of why this meeting is considered to be so special to its participants. At the resumption in 2009 some leading experts and younger scientists from economically weak countries were unable to attend due to the lack of financial resources. This time, with the very worthy and unbureaucratic support of the 'Vereinigung von Freunden und Förderern der J W Goethe-Universität Frankfurt am Main' (in short: 'Friends and Supporters of the Frankfurt University'), it was possible for all candidates to participate. In particular some young, inspired scientists had the chance of presenting their work to a very competent, but also friendly, audience. We wish to thank the 'Freunde und Förderer' for supporting Symmetries in Science XV. Almost all participants contributed to the publication of this Conference Proceedings. There

  14. Molecular and biochemical characterization of carbonic anhydrases of Paracoccidioides

    Directory of Open Access Journals (Sweden)

    Mariana Vieira Tomazett

    Full Text Available Abstract Carbonic anhydrases (CA belong to the family of zinc metalloenzymes that catalyze the reversible hydration of carbon dioxide to bicarbonate. In the present work, we characterized the cDNAs of four Paracoccidioides CAs (CA1, CA2, CA3, and CA4. In the presence of CO2, there was not a significant increase in fungal ca1, ca2 and ca4 gene expression. The ca1 transcript was induced during the mycelium-to-yeast transition, while ca2 and ca4 gene expression was much higher in yeast cells, when compared to mycelium and mycelium-to-yeast transition. The ca1 transcript was induced in yeast cells recovered directly from liver and spleen of infected mice, while transcripts for ca2 and ca4 were down-regulated. Recombinant CA1 (rCA1 and CA4 (rCA4, with 33 kDa and 32 kDa respectively, were obtained from bacteria. The enzymes rCA1 (β-class and rCA4 (α-class were characterized regarding pH, temperature, ions and amino acids addition influence. Both enzymes were stable at pHs 7.5-8.5 and temperatures of 30-35 °C. The enzymes were dramatically inhibited by Hg+2 and activated by Zn+2, while only rCA4 was stimulated by Fe2+. Among the amino acids tested (all in L configuration, arginine, lysine, tryptophan and histidine enhanced residual activity of rCA1 and rCA4.

  15. Evolution of carbonic anhydrase in C4 plants.

    Science.gov (United States)

    Ludwig, Martha

    2016-06-01

    During the evolution of C4 photosynthesis, the intracellular location with most carbonic anhydrase (CA) activity has changed. In Flaveria, the loss of the sequence encoding a chloroplast transit peptide from an ancestral C3 CA ortholog confined the C4 isoform to the mesophyll cell cytosol. Recent studies indicate that sequence elements and histone modifications controlling the expression of C4-associated CAs were likely present in the C3 ancestral chromatin, enabling the evolution of the C4 pathway. Almost complete abolishment of maize CA activity yields no obvious phenotype at ambient CO2 levels. This contrasts with results for Flaveria CA mutants, and has opened discussion on the role of CA in the C4 carbon concentrating mechanism.

  16. Characterization of human carbonic anhydrase III from skeletal muscle.

    Science.gov (United States)

    Carter, N; Jeffery, S; Shiels, A; Edwards, Y; Tipler, T; Hopkinson, D A

    1979-10-01

    A third form of human carbonic anhydrase (CA III), found at high concentrations in skeletal muscle, has been purified and characterized. This isozyme shows relatively poor hydratase and esterase activities compared to the red cell isozymes, CA I and CA II, but is similar to these isozymes in subunit structure (monomer) and molecular size (28,000). CA III is liable to posttranslational modification by thiol group interaction. Monomeric secondary isozymes, sensitive to beta-mercaptoethanol, are found in both crude and purified material and can be generated in vitro by the addition of thiol reagents. Active dimeric isozymes, generated apparently by the formation of intermolecular disulfide bridges, also occur but account for only a small proportion of the total protein and appear only when the concentration of CA III is particularly high.

  17. Carbonic anhydrase 5 regulates acid-base homeostasis in zebrafish.

    Directory of Open Access Journals (Sweden)

    Ruben Postel

    Full Text Available The regulation of the acid-base balance in cells is essential for proper cellular homeostasis. Disturbed acid-base balance directly affects cellular physiology, which often results in various pathological conditions. In every living organism, the protein family of carbonic anhydrases regulate a broad variety of homeostatic processes. Here we describe the identification, mapping and cloning of a zebrafish carbonic anhydrase 5 (ca5 mutation, collapse of fins (cof, which causes initially a collapse of the medial fins followed by necrosis and rapid degeneration of the embryo. These phenotypical characteristics can be mimicked in wild-type embryos by acetazolamide treatment, suggesting that CA5 activity in zebrafish is essential for a proper development. In addition we show that CA5 regulates acid-base balance during embryonic development, since lowering the pH can compensate for the loss of CA5 activity. Identification of selective modulators of CA5 activity could have a major impact on the development of new therapeutics involved in the treatment of a variety of disorders.

  18. Enzymes for carbon sequestration: neutron crystallographic studies of carbonic anhydrase

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, S. Z., E-mail: zfisher@lanl.gov; Kovalevsky, A. Y. [Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Domsic, J. [Department of Biochemistry and Molecular Biology, PO Box 100245, University of Florida, Gainesville, FL 32610 (United States); Mustyakimov, M. [Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Silverman, D. N. [Department of Pharmacology and Therapeutics, PO Box 100267, University of Florida, Gainesville, FL 32610 (United States); McKenna, R. [Department of Biochemistry and Molecular Biology, PO Box 100245, University of Florida, Gainesville, FL 32610 (United States); Langan, P. [Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2010-11-01

    The first neutron crystal structure of carbonic anhydrase is presented. The structure reveals interesting and unexpected features of the active site that affect catalysis. Carbonic anhydrase (CA) is a ubiquitous metalloenzyme that catalyzes the reversible hydration of CO{sub 2} to form HCO{sub 3}{sup −} and H{sup +} using a Zn–hydroxide mechanism. The first part of catalysis involves CO{sub 2} hydration, while the second part deals with removing the excess proton that is formed during the first step. Proton transfer (PT) is thought to occur through a well ordered hydrogen-bonded network of waters that stretches from the metal center of CA to an internal proton shuttle, His64. These waters are oriented and ordered through a series of hydrogen-bonding interactions to hydrophilic residues that line the active site of CA. Neutron studies were conducted on wild-type human CA isoform II (HCA II) in order to better understand the nature and the orientation of the Zn-bound solvent (ZS), the charged state and conformation of His64, the hydrogen-bonding patterns and orientations of the water molecules that mediate PT and the ionization of hydrophilic residues in the active site that interact with the water network. Several interesting and unexpected features in the active site were observed which have implications for how PT proceeds in CA.

  19. Saccharin: a lead compound for structure-based drug design of carbonic anhydrase IX inhibitors.

    Science.gov (United States)

    Mahon, Brian P; Hendon, Alex M; Driscoll, Jenna M; Rankin, Gregory M; Poulsen, Sally-Ann; Supuran, Claudiu T; McKenna, Robert

    2015-02-15

    Carbonic anhydrase IX (CA IX) is a key modulator of aggressive tumor behavior and a prognostic marker and target for several cancers. Saccharin (SAC) based compounds may provide an avenue to overcome CA isoform specificity, as they display both nanomolar affinity and preferential binding, for CA IX compared to CA II (>50-fold for SAC and >1000-fold when SAC is conjugated to a carbohydrate moiety). The X-ray crystal structures of SAC and a SAC-carbohydrate conjugate bound to a CA IX-mimic are presented and compared to CA II. The structures provide substantial new insight into the mechanism of SAC selective CA isoform inhibition.

  20. Carbonic anhydrase activity in the red blood cells of sea level and high altitude natives.

    Science.gov (United States)

    Gamboa, J; Caceda, R; Gamboa, A; Monge-C, C

    2000-01-01

    Red blood cell carbonic anhydrase (CA) activity has not been studied in high altitude natives. Because CA is an intraerythocytic enzyme and high altitude natives are polycythemic, it is important to know if the activity of CA per red cell volume is different from that of their sea level counterparts. Blood was collected from healthy subjects living in Lima (150m) and from twelve subjects from Cerro de Pasco (4330m), and hematocrit and carbonic anhydrase activity were measured. As expected, the high altitude natives had significantly higher hematocrits than the sea level controls (p = 0.0002). No difference in the CA activity per milliliter of red cells was found between the two populations. There was no correlation between the hematocrit and CA activity.

  1. Capsaicin: A Potent Inhibitor of Carbonic Anhydrase Isoenzymes

    Directory of Open Access Journals (Sweden)

    Betul Arabaci

    2014-07-01

    Full Text Available Carbonic anhydrase (CA, EC 4.2.1.1 is a zinc containing metalloenzyme that catalyzes the rapid and reversible conversion of carbon dioxide (CO2 and water (H2O into a proton (H+ and bicarbonate (HCO3– ion. On the other hand, capsaicin is the main component in hot chili peppers and is used extensively used in spices, food additives and drugs; it is responsible for their spicy flavor and pungent taste. There are sixteen known CA isoforms in humans. Human CA isoenzymes I, and II (hCA I and hCA II are ubiquitous cytosolic isoforms. In this study, the inhibition properties of capsaicin against the slow cytosolic isoform hCA I, and the ubiquitous and dominant rapid cytosolic isozymes hCA II were studied. Both CA isozymes were inhibited by capsaicin in the micromolar range. This naturally bioactive compound has a Ki of 696.15 µM against hCA I, and of 208.37 µM against hCA II.

  2. Capsaicin: a potent inhibitor of carbonic anhydrase isoenzymes.

    Science.gov (United States)

    Arabaci, Betul; Gulcin, Ilhami; Alwasel, Saleh

    2014-07-10

    Carbonic anhydrase (CA, EC 4.2.1.1) is a zinc containing metalloenzyme that catalyzes the rapid and reversible conversion of carbon dioxide (CO2) and water (H2O) into a proton (H+) and bicarbonate (HCO3-) ion. On the other hand, capsaicin is the main component in hot chili peppers and is used extensively used in spices, food additives and drugs; it is responsible for their spicy flavor and pungent taste. There are sixteen known CA isoforms in humans. Human CA isoenzymes I, and II (hCA I and hCA II) are ubiquitous cytosolic isoforms. In this study, the inhibition properties of capsaicin against the slow cytosolic isoform hCA I, and the ubiquitous and dominant rapid cytosolic isozymes hCA II were studied. Both CA isozymes were inhibited by capsaicin in the micromolar range. This naturally bioactive compound has a Ki of 696.15 µM against hCA I, and of 208.37 µM against hCA II.

  3. Generation of nitric oxide from nitrite by carbonic anhydrase

    DEFF Research Database (Denmark)

    Aamand, Rasmus; Dalsgaard, Thomas; Jensen, Frank B;

    2009-01-01

    In catalyzing the reversible hydration of CO2 to bicarbonate and protons, the ubiquitous enzyme carbonic anhydrase (CA) plays a crucial role in CO2 transport, in acid-base balance, and in linking local acidosis to O2 unloading from hemoglobin. Considering the structural similarity between...... in the reaction induces vasodilation in aortic rings. This reaction occurs under normoxic and hypoxic conditions and in various tissues at physiological levels of CA and nitrite. Furthermore, two specific inhibitors of the CO2 hydration, dorzolamide and acetazolamide, increase the CA-catalyzed production...... of vasoactive NO from nitrite. This enhancing effect may explain the known vasodilating effects of these drugs and indicates that CO2 and nitrite bind differently to the enzyme active site. Kinetic analyses show a higher reaction rate at high pH, suggesting that anionic nitrite participates more effectively...

  4. The Structure of Carbonic Anhydrase IX Is Adapted for Low-pH Catalysis

    OpenAIRE

    Mahon, Brian P.; Bhatt, Avni; Socorro, Lilien; Driscoll, Jenna M.; Okoh, Cynthia; Lomelino, Carrie L.; Mboge, Mam Y.; Kurian, Justin J.; Tu, Chingkuang; Agbandje-McKenna, Mavis; Frost, Susan C; McKenna, Robert

    2016-01-01

    Human carbonic anhydrase IX (hCA IX) expression in many cancers is associated with hypoxic tumors and poor patient outcome. Inhibitors of hCA IX have been used as anticancer agents with some entering Phase I clinical trials. hCA IX is transmembrane protein whose catalytic domain faces the extracellular tumor milieu, which is typically associated with an acidic microenvironment. Here, we show that the catalytic domain of hCA IX (hCA IX-c) exhibits the necessary biochemical and biophysical prop...

  5. Carbonic anhydrases are upstream regulators of CO2-controlled stomatal movements in guard cells

    KAUST Repository

    Hu, Honghong

    2009-12-13

    The continuing rise in atmospheric CO2 causes stomatal pores in leaves to close and thus globally affects CO2 influx into plants, water use efficiency and leaf heat stress. However, the CO2-binding proteins that control this response remain unknown. Moreover, which cell type responds to CO2, mesophyll or guard cells, and whether photosynthesis mediates this response are matters of debate. We demonstrate that Arabidopsis thaliana double-mutant plants in the beta-carbonic anhydrases betaCA1 and betaCA4 show impaired CO2-regulation of stomatal movements and increased stomatal density, but retain functional abscisic-acid and blue-light responses. betaCA-mediated CO2-triggered stomatal movements are not, in first-order, linked to whole leaf photosynthesis and can function in guard cells. Furthermore, guard cell betaca-overexpressing plants exhibit instantaneous enhanced water use efficiency. Guard cell expression of mammalian alphaCAII complements the reduced sensitivity of ca1 ca4 plants, showing that carbonic anhydrase-mediated catalysis is an important mechanism for betaCA-mediated CO2-induced stomatal closure and patch clamp analyses indicate that CO2/HCO3- transfers the signal to anion channel regulation. These findings, together with ht1-2 (ref. 9) epistasis analysis demonstrate that carbonic anhydrases function early in the CO2 signalling pathway, which controls gas-exchange between plants and the atmosphere.

  6. Inhibition of carbonic anhydrase isoforms I, II, IX and XII with secondary sulfonamides incorporating benzothiazole scaffolds.

    Science.gov (United States)

    Petrou, Anthi; Geronikaki, Athina; Terzi, Emine; Guler, Ozen Ozensoy; Tuccinardi, Tiziano; Supuran, Claudiu T

    2016-12-01

    Carbonic anhydrases (CAs, EC 4.2.1.1) catalyze the fundamental reaction of CO2 hydration in all living organisms, being actively involved in the regulation of a plethora of patho/physiological conditions. A series of benzothiazole-based sulfonamides were synthesized and tested as possible CA inhibitors. Their inhibitory activity was assessed against the cytosolic human isoforms hCA I and hCA II and the transmembrane hCA IX and hCA XII. Several of the investigated derivatives showed interesting inhibition activity and selectivities for inhibiting hCA IX and hCA XII over the off-target ones hCA I and hCA II. Furthermore, computational procedures were used to investigate the binding mode of this class of compounds, within the active site of hCA IX.

  7. Carbonic anhydrase in calcified endoskeleton: novel activity in biocalcification in alcyonarian.

    Science.gov (United States)

    Rahman, M Azizur; Oomori, Tamotsu; Uehara, Tsuyoshi

    2008-01-01

    Carbonic anhydrase (CA) is a key enzyme in the chemical reaction of living organisms and has been found to be associated with calcification in a number of invertebrates including calcareous sponges, but until now no direct evidence has been advanced to show CA activity in alcyonarian corals. However, it is essential to understand the role of CA in the process of biocalcification in alcyonarian. Here we describe the novel activity of CA and its relationship to the formation of calcified hard tissues in alcyonarian coral, Lobophytum crassum. We find that two CA proteins, which were partially purified by electro-elution treatment, can control the morphology of CaCO(3) crystals and one of them is potentially involved in the process of biocalcification. Previously, we isolated CA from the total extract of alcyonarian, and further, we report here a single protein, which has both calcium-binding and CA activities and is responsible for CaCO(3) nucleation and crystal growth. This matrix protein inhibited the precipitation of CaCO(3) from a saturated solution containing CaCl(2) and NaHCO(3), indicating that it can act as a negative regulator for calcification in the sclerites of alcyonarians. The effect of an inhibitor on the enzyme activity was also examined. These findings strongly support the idea that carbonic anhydrase domain in alcyonarian is involved in the calcification process. Our observations strongly suggest that the matrix protein in alcyonarian coral is not only a structural protein but also a catalyst.

  8. Carbonic anhydrase isozymes Ⅸ and Ⅻ in gastric tumors

    Institute of Scientific and Technical Information of China (English)

    Mari Leppilampi; Juha Saarnio; Tuomo J. Karttunen; Jyrki Kivel(a); Silvia Pastorekov(a); Jaromir Pastorek; Abdul Waheed; William S. Sly; Seppo Parkkila

    2003-01-01

    AIM: To systematically study the expression of carbonic anhydrase (CA) isowmes Ⅸ and Ⅻ in gastric tumors.METHODS: We analyzed a representative series of specimens from non-neoplastic gastric mucosa and from various dysplastic and neoplastic gastric lesions for the expression of CA IX and XII. Immunohistochemical staining was performed using isozyme-specific antibodies and biotinstreptavidin complex method.RESULTS: CA IX was highly expressed in the normal gastric mucosa and remained positive in many gastric tumors. In adenomas, CA IX expression significantly decreased towards the high grade dysplasia. However, the expression resumed back to the normal level in well differentiated adenocarcinomas,while it again declined in carcinomas with less differentiation.In comparison, CA Ⅻ showed no or weak immunoreaction in the normal gastric mucosa and was slightly increased in tumors.CONCLUSION: These results demonstrate that CA Ⅸexpression is sustained in several types of gastric tumors.The variations observed in the CA Ⅸ levels support the concept that gastric adenomas and carcinomas are distinct entities and do not represent progressive steps of a single pathway.

  9. 4-Amino-substituted Benzenesulfonamides as Inhibitors of Human Carbonic Anhydrases

    Directory of Open Access Journals (Sweden)

    Kęstutis Rutkauskas

    2014-10-01

    Full Text Available A series of N-aryl-β-alanine derivatives and diazobenzenesulfonamides containing aliphatic rings were designed, synthesized, and their binding to carbonic anhydrases (CA I, II, VI, VII, XII, and XIII was studied by the fluorescent thermal shift assay and isothermal titration calorimetry. The results showed that 4-substituted diazobenzenesulfonamides were more potent CA binders than N-aryl-β-alanine derivatives. Most of the N-aryl-β-alanine derivatives showed better affinity for CA II while diazobenzenesulfonamides possessed nanomolar affinities towards CA I isozyme. X-ray crystallographic structures showed the modes of binding of both compound groups.

  10. Targeted mutagenesis of mitochondrial carbonic anhydrases VA and VB implicates both enzymes in ammonia detoxification and glucose metabolism

    OpenAIRE

    Shah, Gul N.; Rubbelke, Timothy S.; Hendin, Joshua; Nguyen, Hien; Waheed, Abdul; Shoemaker, James D.; Sly, William S.

    2013-01-01

    Prior studies with carbonic anhydrase (CA) inhibitors implicated mitochondrial CA in ureagenesis and gluconeogenesis. Subsequent studies identified two mitochondrial CAs. To distinguish the contribution of each enzyme, we studied the effects of targeted disruption of the murine CA genes, called Car5A and Car5B. The Car5A mutation had several deleterious consequences. Car5A null mice were smaller than wild-type littermates and bred poorly. However, on sodium–potassium citrate-supplemented wate...

  11. Co-production of carbonic anhydrase and phycobiliproteins by Spirulina sp. and Synechococcus nidulans.

    Science.gov (United States)

    Ores, Joana da Costa; Amarante, Marina Campos Assumpção de; Kalil, Susana Juliano

    2016-11-01

    The aim of this work was to study the co-production of the carbonic anhydrase, C-phycocyanin and allophycocyanin during cyanobacteria growth. Spirulina sp. LEB 18 demonstrated a high potential for simultaneously obtaining the three products, achieving a carbonic anhydrase (CA) productivity of 0.97U/L/d and the highest C-phycocyanin (PC, 5.9μg/mL/d) and allophycocyanin (APC, 4.3μg/mL/d) productivities. In the extraction study, high extraction yields were obtained from Spirulina using an ultrasonic homogenizer (CA: 25.5U/g; PC: 90mg/g; APC: 70mg/g). From the same biomass, it was possible to obtain three biomolecules that present high industrial value.

  12. Colocalization of carbonic anhydrase 9 expression and cell proliferation in human head and neck squamous cell carcinoma.

    NARCIS (Netherlands)

    Hoogsteen, I.J.; Marres, H.A.M.; Wijffels, K.I.E.M.; Rijken, P.F.J.W.; Peters, J.P.W.; Hoogen, F.J.A. van den; Oosterwijk, E.; Kogel, A.J. van der; Kaanders, J.H.A.M.

    2005-01-01

    PURPOSE: Tumor cells undergo a variety of biological changes under sustained hypoxic conditions, allowing cells to survive and retain their clonogenic potential. The purpose of this study is to relate the expression of the hypoxia marker carbonic anhydrase 9 (CA9) to the uptake of iododeoxyuridine (

  13. Thermostable Carbonic Anhydrases in Biotechnological Applications

    Directory of Open Access Journals (Sweden)

    Anna Di Fiore

    2015-07-01

    Full Text Available Carbonic anhydrases are ubiquitous metallo-enzymes which catalyze the reversible hydration of carbon dioxide in bicarbonate ions and protons. Recent years have seen an increasing interest in the utilization of these enzymes in CO2 capture and storage processes. However, since this use is greatly limited by the harsh conditions required in these processes, the employment of thermostable enzymes, both those isolated by thermophilic organisms and those obtained by protein engineering techniques, represents an interesting possibility. In this review we will provide an extensive description of the thermostable carbonic anhydrases so far reported and the main processes in which these enzymes have found an application.

  14. Targeting carbonic anhydrase to treat diabetic retinopathy: Emerging evidences and encouraging results

    Energy Technology Data Exchange (ETDEWEB)

    Weiwei, Zhang [Department of Endocrinology and Metabolism, HuaShan Hospital, Institute of Endocrinology and Diabetology, Shanghai Medical College, Fudan University, No. 12 Wulumuqi Road, Shanghai 200040 (China); Hu, Renming, E-mail: taylorzww@gmail.com [Department of Endocrinology and Metabolism, HuaShan Hospital, Institute of Endocrinology and Diabetology, Shanghai Medical College, Fudan University, No. 12 Wulumuqi Road, Shanghai 200040 (China)

    2009-12-18

    Diabetic retinopathy (DR) is the leading cause of vision loss among working-age populations in developed countries. Current treatment options are limited to tight glycemic, blood pressure control and destructive laser surgery. Carbonic anhydrases (CAs) are a group of enzymes involving in the rapid conversion of carbon dioxide to bicarbonate and protons. Emerging evidences reveal CA inhibitors hold the promise for the treatment of DR. This article summarizes encouraging results from clinical and animal studies, and reviews the possible mechanisms.

  15. Carbonic anhydrases in normal gastrointestinal tract and gastrointestinal tumours

    Institute of Scientific and Technical Information of China (English)

    Antti J. Kivel(a); Jyrki Kivel(a); Juha Saarnio; Seppo Parkkila

    2005-01-01

    Carbonic anhydrases (CAs) catalyse the hydration of CO2to bicarbonate at physiological pH. This chemical interconversion is crucial since HCO3- is the substrate for several biosynthetic reactions. This review is focused on the distribution and role of CA isoenzymes in both normal and pathological gastrointestinal (GI) tract tissues. It has been known for many years that CAs are widely present in the GI tract and play important roles in several physiological functions such as production of saliva, gastric acid, bile, and pancreatic juice as well as in absorption of salt and water in intestine. New information suggests that these enzymes participate in several processes that were not envisioned earlier. Especially, the recent reports on plasma membranebound isoenzymes Ⅸ and Ⅻ have raised considerable interest since they were reported to participate in cancer invasion and spread. They are induced by tumour hypoxia and may also play a role in von Hippel-Lindau (VHL)-mediated carcinogenesis.

  16. Genetics Home Reference: carbonic anhydrase VA deficiency

    Science.gov (United States)

    ... 19(3):199-229. Review. Citation on PubMed Shah GN, Rubbelke TS, Hendin J, Nguyen H, Waheed A, Shoemaker JD, Sly WS. Targeted mutagenesis of mitochondrial carbonic anhydrases VA and VB implicates both enzymes in ammonia detoxification and glucose ...

  17. Kinetic study of a novel thermo-stable α-carbonic anhydrase for biomimetic CO2 capture.

    Science.gov (United States)

    Russo, Maria Elena; Olivieri, Giuseppe; Capasso, Clemente; De Luca, Viviana; Marzocchella, Antonio; Salatino, Piero; Rossi, Mosè

    2013-09-10

    Biomimetic CO2 capture includes environmentally friendly solutions based on carbonic anhydrase (CA), an enzyme that increases CO2 absorption rate in conventional acid-gas scrubbing processes. The present contribution reports the characterization of a new recombinant carbonic anhydrase, SspCA, isolated from the thermophile bacterium Sulphurhydrogenibium yellowstonense sp. YO3AOP1. The kinetics of SspCA was characterized in terms of first order CO2 hydration rate according to a procedure based on CO2 absorption tests in a stirred cell apparatus. The first order kinetic constant at 25°C was 9.16 × 10(6) L/(mols). An appropriate investigation on SspCA stability was carried out to assess its long-term resistance to high temperatures as in all capture processes based on absorption/vacuum-desorption cycles. Its half-life was 53 and 8 days at 40 °C and 70 °C, respectively.

  18. Quantification of carbonic anhydrase gene expression in ventricle of hypertrophic and failing human heart

    Directory of Open Access Journals (Sweden)

    Alvarez Bernardo V

    2013-01-01

    Full Text Available Abstract Background Carbonic anhydrase enzymes (CA catalyze the reversible hydration of carbon dioxide to bicarbonate in mammalian cells. Trans-membrane transport of CA-produced bicarbonate contributes significantly to cellular pH regulation. A body of evidence implicates pH-regulatory processes in the hypertrophic growth pathway characteristic of hearts as they fail. In particular, Na+/H+ exchange (NHE activation is pro-hypertrophic and CA activity activates NHE. Recently Cardrase (6-ethoxyzolamide, a CA inhibitor, was found to prevent and revert agonist-stimulated cardiac hypertrophy (CH in cultured cardiomyocytes. Our goal thus was to determine whether hypertrophied human hearts have altered expression of CA isoforms. Methods We measured CA expression in hypertrophied human hearts to begin to examine the role of carbonic anhydrase in progression of human heart failure. Ventricular biopsies were obtained from patients undergoing cardiac surgery (CS, n = 14, or heart transplantation (HT, n = 13. CS patients presented mild/moderate concentric left ventricular hypertrophy and normal right ventricles, with preserved ventricular function; ejection fractions were ~60%. Conversely, HT patients with failing hearts presented CH or ventricular dilation accompanied by ventricular dysfunction and EF values of 20%. Non-hypertrophic, non-dilated ventricular samples served as controls. Results Expression of atrial and brain natriuretic peptide (ANP and BNP were markers of CH. Hypertrophic ventricles presented increased expression of CAII, CAIV, ANP, and BNP, mRNA levels, which increased in failing hearts, measured by quantitative real-time PCR. CAII, CAIV, and ANP protein expression also increased approximately two-fold in hypertrophic/dilated ventricles. Conclusions These results, combined with in vitro data that CA inhibition prevents and reverts CH, suggest that increased carbonic anhydrase expression is a prognostic molecular marker of cardiac

  19. A new peptide ligand for targeting human carbonic anhydrase IX, identified through the phage display technology.

    Directory of Open Access Journals (Sweden)

    Vasileios Askoxylakis

    Full Text Available UNLABELLED: Carbonic anhydrase IX (CAIX is a transmembrane enzyme found to be overexpressed in various tumors and associated with tumor hypoxia. Ligands binding this target may be used to visualize hypoxia, tumor manifestation or treat tumors by endoradiotherapy. METHODS: Phage display was performed with a 12 amino acid phage display library by panning against a recombinant extracellular domain of human carbonic anhydrase IX. The identified peptide CaIX-P1 was chemically synthesized and tested in vitro on various cell lines and in vivo in Balb/c nu/nu mice carrying subcutaneously transplanted tumors. Binding, kinetic and competition studies were performed on the CAIX positive human renal cell carcinoma cell line SKRC 52, the CAIX negative human renal cell carcinoma cell line CaKi 2, the human colorectal carcinoma cell line HCT 116 and on human umbilical vein endothelial cells (HUVEC. Organ distribution studies were carried out in mice, carrying SKRC 52 tumors. RNA expression of CAIX in HCT 116 and HUVEC cells was investigated by quantitative real time PCR. RESULTS: In vitro binding experiments of (125I-labeled-CaIX-P1 revealed an increased uptake of the radioligand in the CAIX positive renal cell carcinoma cell line SKRC 52. Binding of the radioligand in the colorectal carcinoma cell line HCT 116 increased with increasing cell density and correlated with the mRNA expression of CAIX. Radioligand uptake was inhibited up to 90% by the unlabeled CaIX-P1 peptide, but not by the negative control peptide octreotide at the same concentration. No binding was demonstrated in CAIX negative CaKi 2 and HUVEC cells. Organ distribution studies revealed a higher accumulation in SKRC 52 tumors than in heart, spleen, liver, muscle, intestinum and brain, but a lower uptake compared to blood and kidney. CONCLUSIONS: These data indicate that CaIX-P1 is a promising candidate for the development of new ligands targeting human carbonic anhydrase IX.

  20. Screening and docking studies of natural phenolic inhibitors of carbonic anhydrase

    Institute of Scientific and Technical Information of China (English)

    HUANG Huo-Qiang; PAN Xu-Lin; JI Chang-Jiu; ZENG Guang-Zhi; JIANG Li-Hua; FU Xiang; LIU Ji-Kai; HAO Xiao-Jiang; ZHANG Ying-Jun; TAN Ning-Hua

    2009-01-01

    Carbonic anhydrase Ⅱ (CAⅡ) is an Important enzyme complex with Zn2+, which is involved in many physiological and pathological processes, such as calcification, glaucoma and tumorigenicity. In order to search for novel inhibitors of CA Ⅱ, inhibition assay of carbonic anhydrase Ⅱ was performed, by which seven natural phenolic compounds, including four phenolics (grifolln, 4-O-methyl-grifolic acid, grifolic acid, and isovanillic acid) and three flavones (eriodictyol, quercetin and puerin A), showed in-hibitory activities against CAⅡ with IC50s in the range of 6.37-71.73 μmol/L. Grifolic acid is the most active one with IC50 of 6.37 μmol/L. These seven phenolic compounds were proved to be novel natural carbonic anhydrase Ⅱ inhibitors, which were obtained in flexible docking study with GOLD 3.0 soft-ware. Results indicated that the aliphatic chain and polar groups of hydroxyl and carboxyl are impor-tant to their inhibitory activities, providing a new insight into study on CA Ⅱ potent inhibitors.

  1. Comparison of inhibition effects of some benzoic acid derivatives on sheep heart carbonic anhydrase

    Science.gov (United States)

    Kiliç, Deryanur; Yildiz, Melike; Şentürk, Murat; Erdoǧan, Orhan; Küfrevioǧlu, Ömer Irfan

    2016-04-01

    Carbonic anhydrase (CA) is a family of metalloenzymes that requires Zn as a cofactor and catalyze the quick conversion of CO2 to HCO3- and H+. Inhibitors of the carbonic anhydrases (CAs) have medical usage of significant diseases such as glaucoma, epilepsy, gastroduodenal ulcers, acid-base disequilibria and neurological disorders. In the present study, inhibition of CA with some benzoic derivatives (1-6) were investigated. Sheep heart CA (shCA) enzyme was isolated by means of designed affinity chromatography gel (cellulose-benzyl-sulfanylamide) 42.45-fold in a yield of 44 % with 564.65 EU/mg. Purified shCA enzyme was used in vitro studies. In the studies, IC50 values were calculated for 3-aminobenzoic acid (1), 4-aminobenzoic acid (2), 2-hydroxybenzoic acid (3), 2-benzoylbenzoic acid (4), 2,3-dimethoxybenzoic acid (5), and 3,4,5-trimethoxybenzoic acid (6), showing the inhibition effects on the purified enzyme. Such molecules can be used as pioneer for discovery of novel effective CA inhibitors for medicinal chemistry applications.

  2. New natural product carbonic anhydrase inhibitors incorporating phenol moieties.

    Science.gov (United States)

    Karioti, Anastasia; Ceruso, Mariangela; Carta, Fabrizio; Bilia, Anna-Rita; Supuran, Claudiu T

    2015-11-15

    Carbonic anhydrases (CAs, EC 4.2.1.1) catalyze the fundamental reaction of CO2 hydration in all living organisms, being actively involved in the regulation of a plethora of patho/physiological conditions. They represent a typical example of enzyme convergent evolution, as six genetically unrelated families of such enzymes were described so far. The need to find selective CA inhibitors (CAIs) triggered the investigation of natural product libraries, which proved to be a valid source of agents with such an activity, as demonstrated for the phenols, polyamines and coumarins. Herein we report an in vitro inhibition study of human (h) CA isoforms hCAs I, II, IV, VII and XII with a panel of natural polyphenols including flavones, flavonols, flavanones, flavanols, isoflavones and depsides, some of which extracted from Quercus ilex and Salvia miltiorrhiza. Several of the investigated derivatives showed interesting inhibition activity and selectivities for inhibiting some important isoforms over the off-target ones hCA I and II.

  3. Carbonic Anhydrase: In the Driver's Seat for Bicarbonate Transport

    Directory of Open Access Journals (Sweden)

    Sterling D

    2001-07-01

    Full Text Available Carbonic anhydrases are a widely expressed family of enzymes that catalyze the reversible reaction: CO(2 + H(2O = HCO(3(- + H(+. These enzymes therefore both produce HCO(3(- for transport across membranes and consume HCO(3(- that has been transported across membranes. Thus these enzymes could be expected to have a key role in driving the transport of HCO(3(- across cells and epithelial layers. Plasma membrane anion exchange proteins (AE transport chloride and bicarbonate across most mammalian membranes in a one-for-one exchange reaction and act as a model for our understanding of HCO(3(- transport processes. Recently it was shown that AE1, found in erythrocytes and kidney, binds carbonic anhydrase II (CAII via the cytosolic C-terminal tail of AE1. To examine the physiological consequences of the interaction between CAII and AE1, we characterized Cl(-/HCO(3(- exchange activity in transfected HEK293 cells. Treatment of AE1-transfected cells with acetazolamide, a CAII inhibitor, almost fully inhibited anion exchange activity, indicating that endogenous CAII activity is essential for transport. Further experiments to examine the role of the AE1/CAII interaction will include measurements of the transport activity of AE1 following mutation of the CAII binding site. In a second approach a functionally inactive CA mutant, V143Y, will be co-expressed with AE1 in HEK293 cells. Since over expression of V143Y CAII would displace endogenous wild-type CAII from AE1, a loss of transport activity would be observed if binding to the AE1 C-terminus is required for transport.

  4. Synthesis, characterization and carbonic anhydrase inhibitory activity of novel benzothiazole derivatives.

    Science.gov (United States)

    Küçükbay, F Zehra; Buğday, Nesrin; Küçükbay, Hasan; Tanc, Muhammet; Supuran, Claudiu T

    2016-12-01

    N-protected amino acids were reacted with substituted benzothiazoles to give the corresponding N-protected amino acid-benzothiazole conjugates (60-89%). Their structures were confirmed by proton nuclear magnetic resonance ((1)H NMR), carbon-13 nuclear magnetic resonance ((13)C NMR), IR and elemental analysis. Their carbonic anhydrase (CA, EC 4.2.1.1) inhibitory activities were determined against two cytosolic human isoforms (hCA I and hCA II), one membrane-associated (hCA IV) and one transmembrane (hCA XII) enzyme by a stopped-flow CO2 hydrase assay method. The new compounds showed rather weak, micromolar inhibitory activity against most of these enzymes.

  5. Agents described in the Molecular Imaging and Contrast Agent Database for imaging carbonic anhydrase IX expression.

    Science.gov (United States)

    Sneddon, Deborah; Poulsen, Sally-Ann

    2014-10-01

    Carbonic anhydrase IX (CA IX) is selectively expressed in a range of hypoxic tumours and is a validated endogenous hypoxia marker with prognostic significance; hence, CA IX is of great interest as a molecular imaging target in oncology. In this review, we present an overview of the different imaging agents and imaging modalities that have been applied for the in vivo detection of CA IX. The imaging agents reviewed are all entries in the Molecular Imaging and Contrast Agent Database (MICAD) and comprise antibody, antibody fragments and small molecule imaging agents. The effectiveness of these agents for imaging CA IX in vivo gave variable performance; however, a number of agents proved very capable. As molecular imaging has become indispensable in current medical practice we anticipate that the clinical significance of CA IX will see continued development and improvements in imaging agents for targeting this enzyme.

  6. Catalase, carbonic anhydrase and xanthine oxidase activities in patients with mycosis fungoides.

    Science.gov (United States)

    Cengiz, Fatma Pelin; Beyaztas, Serap; Gokce, Basak; Arslan, Oktay; Guler, Ozen Ozensoy

    2015-04-01

    Mycosis fungoides (MF) is the most common form of cutaneous T-cell lymphoma. In several studies the relationship between catalase (CAT), human cytosolic carbonic anhydrases (CA; hCA-I and hCA-II) and xanthine oxidase (XO) enzyme activities have been investigated in various types of cancers but carbonic anhydrase, catalase and xanthine oxidase activities in patients with MF have not been previously reported. Therefore, in this preliminary study we aim to investigate CAT, CA and XO activities in patients with MF. This study enrolled 32 patients with MF and 26 healthy controls. According to the results, CA and CAT activities were significantly lower in patients with mycosis fungoides than controls (p < 0.001) (p < 0.001). There was no significant difference in XO activity between patient and control group (p = 0.601). Within these findings, we believe these enzyme activity levels might be a potentially important finding as an additional diagnostic biochemical tool for MF.

  7. Legionella pneumophila Carbonic Anhydrases: Underexplored Antibacterial Drug Targets

    Directory of Open Access Journals (Sweden)

    Claudiu T. Supuran

    2016-06-01

    Full Text Available Carbonic anhydrases (CAs, EC 4.2.1.1 are metalloenzymes which catalyze the hydration of carbon dioxide to bicarbonate and protons. Many pathogenic bacteria encode such enzymes belonging to the α-, β-, and/or γ-CA families. In the last decade, enzymes from some of these pathogens, including Legionella pneumophila, have been cloned and characterized in detail. These enzymes were shown to be efficient catalysts for CO2 hydration, with kcat values in the range of (3.4–8.3 × 105 s−1 and kcat/KM values of (4.7–8.5 × 107 M−1·s−1. In vitro inhibition studies with various classes of inhibitors, such as anions, sulfonamides and sulfamates, were also reported for the two β-CAs from this pathogen, LpCA1 and LpCA2. Inorganic anions were millimolar inhibitors, whereas diethyldithiocarbamate, sulfamate, sulfamide, phenylboronic acid, and phenylarsonic acid were micromolar ones. The best LpCA1 inhibitors were aminobenzolamide and structurally similar sulfonylated aromatic sulfonamides, as well as acetazolamide and ethoxzolamide (KIs in the range of 40.3–90.5 nM. The best LpCA2 inhibitors belonged to the same class of sulfonylated sulfonamides, together with acetazolamide, methazolamide, and dichlorophenamide (KIs in the range of 25.2–88.5 nM. Considering such preliminary results, the two bacterial CAs from this pathogen represent promising yet underexplored targets for obtaining antibacterials devoid of the resistance problems common to most of the clinically used antibiotics, but further studies are needed to validate them in vivo as drug targets.

  8. Mono- and di-halogenated histamine, histidine and carnosine derivatives are potent carbonic anhydrase I, II, VII, XII and XIV activators.

    Science.gov (United States)

    Saada, Mohamed-Chiheb; Vullo, Daniela; Montero, Jean-Louis; Scozzafava, Andrea; Supuran, Claudiu T; Winum, Jean-Yves

    2014-09-01

    Mono- and di-halogenated histamines, l-histidine methyl ester derivatives and carnosine derivatives incorporating chlorine, bromine and iodine were prepared and investigated as activators of five carbonic anhydrase (CA, EC 4.2.1.1) isoforms, the cytosolic hCA I, II and VII, and the transmembrane hCA XII and XIV. All of them were activated in a diverse manner by the investigated compounds, with a distinct activation profile.

  9. Carbonic anhydrase inhibitors with dual-tail moieties to match the hydrophobic and hydrophilic halves of the carbonic anhydrase active site.

    Science.gov (United States)

    Tanpure, Rajendra P; Ren, Bin; Peat, Thomas S; Bornaghi, Laurent F; Vullo, Daniela; Supuran, Claudiu T; Poulsen, Sally-Ann

    2015-02-12

    We present a new approach to carbonic anhydrase II (CA II) inhibitor design that enables close interrogation of the regions of the CA active site where there is the greatest variability in amino acid residues among the different CA isozymes. By appending dual tail groups onto the par excellence CA inhibitor acetazolamide, compounds that may interact with the distinct hydrophobic and hydrophilic halves of the CA II active site were prepared. The dual-tail combinations selected included (i) two hydrophobic moieties, (ii) two hydrophilic moieties, and (iii) one hydrophobic and one hydrophilic moiety. The CA enzyme inhibition profile as well as the protein X-ray crystal structure of compound 3, comprising one hydrophobic and one hydrophilic tail moiety, in complex with CA II is described. This novel dual-tail approach has provided an enhanced opportunity to more fully exploit interactions with the CA active site by enabling these molecules to interact with the distinct halves of the active site. In addition to the dual-tail compounds, a corresponding set of single-tail derivatives was synthesized, enabling a comparative analysis of the single-tail versus dual-tail compound CA inhibition profile.

  10. Screening and docking studies of natural phenolic inhibitors of carbonic anhydrase

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Carbonic anhydrase Ⅱ (CAⅡ) is an important enzyme complex with Zn2+,which is involved in many physiological and pathological processes, such as calcification, glaucoma and tumorigenicity. In order to search for novel inhibitors of CAⅡ, inhibition assay of carbonic anhydrase Ⅱ was performed, by which seven natural phenolic compounds, including four phenolics (grifolin, 4-O-methyl-grifolic acid, grifolic acid, and isovanillic acid) and three flavones (eriodictyol, quercetin and puerin A), showed in-hibitory activities against CAⅡ with IC50s in the range of 6.37-71.73 μmol/L. Grifolic acid is the most active one with IC50 of 6.37 μmol/L. These seven phenolic compounds were proved to be novel natural carbonic anhydrase Ⅱ inhibitors, which were obtained in flexible docking study with GOLD 3.0 soft-ware. Results indicated that the aliphatic chain and polar groups of hydroxyl and carboxyl are impor-tant to their inhibitory activities, providing a new insight into study on CA Ⅱ potent inhibitors.

  11. 25 CFR 36.42 - Standard XV-Counseling services.

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Standard XV-Counseling services. 36.42 Section 36.42... § 36.42 Standard XV—Counseling services. Each school shall offer student counseling services concerned with physical, social, emotional, intellectual, and vocational growth for each individual....

  12. Increased levels of carbonic anhydrase II in the developing Down syndrome brain.

    Science.gov (United States)

    Palminiello, Sonia; Kida, Elizabeth; Kaur, Kulbir; Walus, Marius; Wisniewski, Krystyna E; Wierzba-Bobrowicz, Teresa; Rabe, Ausma; Albertini, Giorgio; Golabek, Adam A

    2008-01-23

    By using a proteomic approach, we found increased levels of carbonic anhydrase II (CA II) in the brain of Ts65Dn mice, a mouse model for Down syndrome (DS). Further immunoblot analyses showed that the levels of CA II are increased not only in the brain of adult Ts65Dn mice but also in the brain of infants and young children with DS. Cellular localization of the enzyme in human brain, predominantly in the oligodendroglia and primitive vessels in fetal brain and in the oligodendroglia and some GABAergic neurons postnatally, was similar in DS subjects and controls. Given the role of CA II in regulation of electrolyte and water balance and pH homeostasis, up-regulation of CA II may reflect a compensatory mechanism mobilized in response to structural/functional abnormalities in the developing DS brain. However, this up-regulation may also have an unfavorable effect by increasing susceptibility to seizures of children with DS.

  13. Design of a carbonic anhydrase IX active-site mimic to screen inhibitors for possible anticancer properties.

    Science.gov (United States)

    Genis, Caroli; Sippel, Katherine H; Case, Nicolette; Cao, Wengang; Avvaru, Balendu Sankara; Tartaglia, Lawrence J; Govindasamy, Lakshmanan; Tu, Chingkuang; Agbandje-McKenna, Mavis; Silverman, David N; Rosser, Charles J; McKenna, Robert

    2009-02-17

    Recently, a convincing body of evidence has accumulated suggesting that the overexpression of carbonic anhydrase isozyme IX (CA IX) in some cancers contributes to the acidification of the extracellular matrix, which in turn promotes the growth and metastasis of the tumor. These observations have made CA IX an attractive drug target for the selective treatment of certain cancers. Currently, there is no available X-ray crystal structure of CA IX, and this lack of availability has hampered the rational design of selective CA IX inhibitors. In light of these observations and on the basis of structural alignment homology, using the crystal structure of carbonic anhydrase II (CA II) and the sequence of CA IX, a double mutant of CA II with Ala65 replaced by Ser and Asn67 replaced by Gln has been constructed to resemble the active site of CA IX. This CA IX mimic has been characterized kinetically using (18)O-exchange and structurally using X-ray crystallography, alone and in complex with five CA sulfonamide-based inhibitors (acetazolamide, benzolamide, chlorzolamide, ethoxzolamide, and methazolamide), and compared to CA II. This structural information has been evaluated by both inhibition studies and in vitro cytotoxicity assays and shows a correlated structure-activity relationship. Kinetic and structural studies of CA II and CA IX mimic reveal chlorzolamide to be a more potent inhibitor of CA IX, inducing an active-site conformational change upon binding. Additionally, chlorzolamide appears to be cytotoxic to prostate cancer cells. This preliminary study demonstrates that the CA IX mimic may provide a useful model to design more isozyme-specific CA IX inhibitors, which may lead to development of new therapeutic treatments of some cancers.

  14. Modification of carbonic anhydrase II with acetaldehyde, the first metabolite of ethanol, leads to decreased enzyme activity.

    OpenAIRE

    2008-01-01

    Abstract Background Acetaldehyde, the first metabolite of ethanol, can generate covalent modifications of proteins and cellular constituents. However, functional consequences of such modification remain poorly defined. In the present study, we examined acetaldehyde reaction with human carbonic anhydrase (CA) isozyme II, which has several features that make it a suitable target protein: It is widely expressed, its enzymatic activity can be monitored, its structural and catalytic properties are...

  15. Knock-down of hypoxia-induced carbonic anhydrases IX and XII radiosensitizes tumor cells by increasing intracellular acidosis

    OpenAIRE

    2013-01-01

    The relationship between acidosis within the tumor microenvironment and radioresistance of hypoxic tumor cells remains unclear. Previously we reported that hypoxia-induced carbonic anhydrases (CA) IX and CAXII constitute a robust intracellular pH (pHi)-regulating system that confers a survival advantage on hypoxic human colon carcinoma LS174Tr cells in acidic microenvironments. Here we investigate the role of acidosis, CAIX and CAXII knock-down in combination with ionizing radiation. Fibrobla...

  16. Expression of the CHOP-inducible carbonic anhydrase CAVI-b is required for BDNF-mediated protection from hypoxia

    OpenAIRE

    Matthews, Tori A.; Abel, Allyssa; Demme, Chris; Sherman, Teresa; Pan, Pei-wen; Halterman, Marc W.; Parkkila, Seppo; Nehrke, Keith

    2013-01-01

    Carbonic anhydrases (CAs) comprise a family of zinc-containing enzymes that catalyze the reversible hydration of carbon dioxide. CAs contribute to a myriad of physiological processes, including pH regulation, anion transport and water balance. To date, 16 known members of the mammalian alpha-CA family have been identified. Given that the catalytic family members share identical reaction chemistry, their physiologic roles are influenced greatly by their tissue and sub-cellular locations. CAVI ...

  17. Comparison of amino and epoxy functionalized SBA-15 used for carbonic anhydrase immobilization.

    Science.gov (United States)

    Fei, Xiaoyao; Chen, Shaoyun; Liu, Dai; Huang, Chunjie; Zhang, Yongchun

    2016-09-01

    Two functionalized SBA-15 [amine-functionalized SBA-15 (AFS) and epoxy-functionalized SBA-15 (GFS)] with different types of functional groups were synthesized by a hydrothermal process and post functionalized with 3-aminopropyltriethoxysilane (APTES) and 3-glycidyloxypropyltrimethoxysilane (GPTMS), respectively. They were used for the immobilization of carbonic anhydrase (CA). The physicochemical properties of the functionalized SBA-15 were characterized by X-ray powder diffraction (XRD), N2 adsorption-desorption, (13)C, (29)Si solid-state nuclear magnetic resonance (NMR) spectroscopy, and scanning electron microscopy (SEM). Before and after CA was immobilized on AFS and GFS, the effects of temperature and pH value on the enzyme activity, storage stability, and reusability were investigated using para-nitrophenyl acetate (p-NPA) assay. CA/GFS showed a better performance with respect to storage stability and reusability than CA/AFS. Moreover, the amount of CaCO3 precipitated over CA/AFS was less than that precipitated over CA/GFS, which was almost equal to that precipitated over the free CA. The results indicate that the epoxy group is a more suitable functional group for covalent bonding with CA than the amino group, and GFS is a promising support for CA immobilization.

  18. Human secreted carbonic anhydrase: cDNA cloning, nucleotide sequence, and hybridization histochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Aldred, P.; Fu, Ping; Barrett, G.; Penschow, J.D.; Wright, R.D.; Coghlan, J.P.; Fernley, R.T. (The Howard Florey Institute of Experimental Physiology and Medicine, Parkville, Victoria (Australia))

    1991-01-01

    Complementary DNA clones coding for the human secreted carbonic anhydrase isozyme (CAVI) have been isolated and their nucleotide sequences determined. These clones identify a 1.45-kb mRNA that is present in high levels in parotid submandibular salivary glands but absent in other tissues such as the sublingual gland, kidney, liver, and prostate gland. Hybridization histochemistry of human salivary glands shows mRNA for CA VI located in the acinar cells of these glands. The cDNA clones encode a protein of 308 amino acids that includes a 17 amino acid leader sequence typical of secreted proteins. The mature protein has 291 amino acids compared to 259 or 260 for the cytoplasmic isozymes, with most of the extra amino acids present as a carboxyl terminal extension. In comparison, sheep CA VI has a 45 amino acid extension. Overall the human CA VI protein has a sequence identity of 35 {percent} with human CA II, while residues involved in the active site of the enzymes have been conserved. The human and sheep secreted carbonic anhydrases have a sequence identity of 72 {percent}. This includes the two cysteine residues that are known to be involved in an intramolecular disulfide bond in the sheep CA VI. The enzyme is known to be glycosylated and three potential N-glycosylation sites (Asn-X-Thr/Ser) have been identified. Two of these are known to be glycosylated in sheep CA VI. Southern analysis of human DNA indicates that there is only one gene coding for CA VI.

  19. XV-15 Low-Noise Terminal Area Operations Testing

    Science.gov (United States)

    Edwards, B. D.

    1998-01-01

    Test procedures related to XV-15 noise tests conducted by NASA-Langley and Bell Helicopter Textron, Inc. are discussed. The tests. which took place during October and November 1995, near Waxahachie, Texas, documented the noise signature of the XV-15 tilt-rotor aircraft at a wide variety of flight conditions. The stated objectives were to: -provide a comprehensive acoustic database for NASA and U.S. Industry -validate noise prediction methodologies, and -develop and demonstrate low-noise flight profiles. The test consisted of two distinct phases. Phase 1 provided an acoustic database for validating analytical noise prediction techniques; Phase 2 directly measured noise contour information at a broad range of operating profiles, with emphasis on minimizing 'approach' noise. This report is limited to a documentation of the test procedures, flight conditions, microphone locations, meteorological conditions, and test personnel used in the test. The acoustic results are not included.

  20. Virtual screening of combinatorial library of novel benzenesulfonamides on mycobacterial carbonic anhydrase II

    Directory of Open Access Journals (Sweden)

    Dikant F.

    2016-12-01

    Full Text Available Combinatorial library of novel benzenesulfonamides was docked (Schrodinger Glide into mycobacterial carbonic anhydrase (mtCA II and human (hCA II isoforms with an aim to find drug candidates with selective activity on mtCA II. The predicted selectivity was calculated based on optimized MM-GBSA free energies for ligand enzyme interactions. Selectivity, LogP (o/w and interaction energy were used to calculate the selection index which determined the subset of best scoring molecules selected for further evaluation. Structure-activity relationship was found for fragment subsets, showing us the possible way regarding how to influence lipophilicity without affecting ligand-enzyme binding properties.

  1. Characterization of carbonic anhydrase XIII in the erythrocytes of the Burmese python, Python molurus bivittatus.

    Science.gov (United States)

    Esbaugh, A J; Secor, S M; Grosell, M

    2015-09-01

    Carbonic anhydrase (CA) is one of the most abundant proteins found in vertebrate erythrocytes with the majority of species expressing a low activity CA I and high activity CA II. However, several phylogenetic gaps remain in our understanding of the expansion of cytoplasmic CA in vertebrate erythrocytes. In particular, very little is known about isoforms from reptiles. The current study sought to characterize the erythrocyte isoforms from two squamate species, Python molurus and Nerodia rhombifer, which was combined with information from recent genome projects to address this important phylogenetic gap. Obtained sequences grouped closely with CA XIII in phylogenetic analyses. CA II mRNA transcripts were also found in erythrocytes, but found at less than half the levels of CA XIII. Structural analysis suggested similar biochemical activity as the respective mammalian isoforms, with CA XIII being a low activity isoform. Biochemical characterization verified that the majority of CA activity in the erythrocytes was due to a high activity CA II-like isoform; however, titration with copper supported the presence of two CA pools. The CA II-like pool accounted for 90 % of the total activity. To assess potential disparate roles of these isoforms a feeding stress was used to up-regulate CO2 excretion pathways. Significant up-regulation of CA II and the anion exchanger was observed; CA XIII was strongly down-regulated. While these results do not provide insight into the role of CA XIII in the erythrocytes, they do suggest that the presence of two isoforms is not simply a case of physiological redundancy.

  2. Malaria parasite carbonic anhydrase: inhibition of aromatic/heterocyclic sulfonamides and its therapeutic potential.

    Science.gov (United States)

    Krungkrai, Sudaratana R; Krungkrai, Jerapan

    2011-06-01

    Plasmodium falciparum (P. falciparum) is responsible for the majority of life-threatening cases of human malaria, causing 1.5-2.7 million annual deaths. The global emergence of drug-resistant malaria parasites necessitates identification and characterization of novel drug targets and their potential inhibitors. We identified the carbonic anhydrase (CA) genes in P. falciparum. The pfCA gene encodes anα-carbonic anhydrase, a Zn(2+)-metalloenzme, possessing catalytic properties distinct from that of the human host CA enzyme. The amino acid sequence of the pfCA enzyme is different from the analogous protozoan and human enzymes. A library of aromatic/heterocyclic sulfonamides possessing a large diversity of scaffolds were found to be very good inhibitors for the malarial enzyme at moderate-low micromolar and submicromolar inhibitions. The structure of the groups substituting the aromatic-ureido- or aromatic-azomethine fragment of the molecule and the length of the parent sulfonamide were critical parameters for the inhibitory properties of the sulfonamides. One derivative, that is, 4- (3, 4-dichlorophenylureido)thioureido-benzenesulfonamide (compound 10) was the most effective in vitro Plasmodium falciparum CA inhibitor, and was also the most effective antimalarial compound on the in vitro P. falciparum growth inhibition. The compound 10 was also effective in vivo antimalarial agent in mice infected with Plasmodium berghei, an animal model of drug testing for human malaria infection. It is therefore concluded that the sulphonamide inhibitors targeting the parasite CA may have potential for the development of novel therapies against human malaria.

  3. A class of sulfonamides with strong inhibitory action against the α-carbonic anhydrase from Trypanosoma cruzi.

    Science.gov (United States)

    Güzel-Akdemir, Özlen; Akdemir, Atilla; Pan, Peiwen; Vermelho, Alane B; Parkkila, Seppo; Scozzafava, Andrea; Capasso, Clemente; Supuran, Claudiu T

    2013-07-25

    Trypanosoma cruzi, the causative agent of Chagas disease, encodes for an α-carbonic anhydrase (CA, EC 4.2.1.1) possessing high catalytic activity (TcCA) which was recently characterized (Pan et al. J. Med. Chem. 2013, 56, 1761-1771). A new class of sulfonamides possessing low nanomolar/subnanomolar TcCA inhibitory activity is described here. Aromatic/heterocyclic sulfonamides incorporating halogeno/methoxyphenacetamido tails inhibited TcCA with KIs in the range of 0.5-12.5 nM, being less effective against the human off-target isoforms hCA I and II. A homology model of TcCA helped us to rationalize the excellent inhibition profile of these compounds against the protozoan enzyme, a putative new antitrypanosoma drug target. These compounds were ineffective antitrypanosomal agents in vivo due to penetrability problems of these highly polar molecules that possess sulfonamide moieties.

  4. Carbonic Anhydrase and Metalloderivatives: A Bioinorganic Chemistry Study

    Science.gov (United States)

    McQuate, Robert S.

    1977-01-01

    Discusses selected bioinorganic aspects of carbonic anhydrase and describes experiments that will reinforce the students' understanding of the presence and essential role that metal ions have in some biological systems. (SL)

  5. Transmembrane carbonic anhydrase isozymes IX and XII in the female mouse reproductive organs

    Directory of Open Access Journals (Sweden)

    Tomas Eija

    2004-10-01

    Full Text Available Abstract Background Carbonic anhydrase (CA classically catalyses the reversible hydration of dissolved CO2 to form bicarbonate ions and protons. The twelve active CA isozymes are thought to regulate a variety of cellular functions including several processes in the reproductive systems. Methods The present study was designed to investigate the expression of transmembrane CAs, CA IX and XII, in the mouse uterus, ovary and placenta. The expression of CA IX and XII was examined by immunoperoxidase staining method and western blotting. CA II and XIII served as positive controls since they are known to be present in the mouse reproductive tract. Results The data of our study indicated that CA XII is expressed in the mouse endometrium. Only very faint signal was observed in the corpus luteum of the ovary and the placenta remained mainly negative. CA IX showed weak reaction in the endometrial epithelium, while it was completely absent in the ovary and placenta. Conclusion The conservation of CA XII expression in both mouse and human endometrium suggests a role for this isozyme in reproductive physiology.

  6. Isatin-pyrazole benzenesulfonamide hybrids potently inhibit tumor-associated carbonic anhydrase isoforms IX and XII.

    Science.gov (United States)

    Ibrahim, Hany S; Abou-Seri, Sahar M; Tanc, Muhammet; Elaasser, Mahmoud M; Abdel-Aziz, Hatem A; Supuran, Claudiu T

    2015-10-20

    New series of benzenesulfonamide derivatives incorporating pyrazole and isatin moieties were prepared using celecoxib as lead molecule. Biological evaluation of the target compounds was performed against the metalloenzyme carbonic anhydrase (CA, EC 4.2.1.1) and more precisely against the human isoforms hCA I, II (cytosolic), IX and XII (transmembrane, tumor-associated enzymes). Most of the tested compounds efficiently inhibited hCA I, II and IX, with KIs of 2.5-102 nM, being more effective than the reference drug acetazolamide. Compounds 11e, 11f, 16e and 16f were found to inhibit hCA XII with Ki of 3.7, 6.5, 5.4 and 7.2 nM, respectively. Compounds 11e and 16e, with 5-NO2 substitution on the isatin ring, were found to be selective inhibitors of hCA IX and hCA XII. Docking studies revealed that the NO2 group of both compounds participate in interactions with Asp132 within the hCA IX active site, and with residues Lys67 and Asp130 in hCA XII, respectively.

  7. Influence of temperature and solvent concentration on the kinetics of the enzyme carbonic anhydrase in carbon capture technology

    DEFF Research Database (Denmark)

    Gladis, Arne; Deslauriers, Maria Gundersen; Fosbøl, Philip Loldrup

    2017-01-01

    In this study the effect of carbonic anhydrase addition on the absorption of CO2 was investigated in a wetted wall column apparatus. Four different solvents: the primary amine monoethanolamine (MEA), the sterically hindered primary amine 2-amino-2-methyl-1-propanol (AMP), the tertiary amine N......-methyl-diethanolamine (MDEA) and the carbonate salt solution K2CO3 were compared in concentrations from 5 to 50 wt% in a temperature range of 298–328 K with and without enzyme. Necessary mass transfer parameters such as liquid side mass transfer coefficient and solvent and enzyme reaction rates were determined...... and benchmarked to a 30 wt% MEA solution. The study reveals that the addition of the enzyme carbonic anhydrase (CA) dramatically increases the liquid side mass transfer coefficient for MDEA, and K2CO3; AMP has a moderate increase whereas MEA was unchanged. The results confirm that just bicarbonate forming systems...

  8. Characterization of a Mesorhizobium loti α-Type Carbonic Anhydrase and Its Role in Symbiotic Nitrogen Fixation▿

    OpenAIRE

    2009-01-01

    Carbonic anhydrase (CA) (EC 4.2.1.1) is a widespread enzyme catalyzing the reversible hydration of CO2 to bicarbonate, a reaction that participates in many biochemical and physiological processes. Mesorhizobium loti, the microsymbiont of the model legume Lotus japonicus, possesses on the symbiosis island a gene (msi040) encoding an α-type CA homologue, annotated as CAA1. In the present work, the CAA1 open reading frame from M. loti strain R7A was cloned, expressed, and biochemically character...

  9. Carbonic anhydrase: a key regulatory and detoxifying enzyme for Karst plants.

    Science.gov (United States)

    Müller, Werner E G; Qiang, Li; Schröder, Heinz C; Hönig, Natalie; Yuan, Daoxian; Grebenjuk, Vlad A; Mussino, Francesca; Giovine, Marco; Wang, Xiaohong

    2014-01-01

    Karstification is a rapid process during which calcidic stones/limestones undergo dissolution with the consequence of a desertification of karst regions. A slow-down of those dissolution processes of Ca-carbonate can be approached by a reforestation program using karst-resistant plants that can resist alkaline pH and higher bicarbonate (HCO₃⁻) concentrations in the soil. Carbonic anhydrases (CA) are enzymes that mediate a rapid and reversible interconversion of CO₂ and HCO₃⁻. In the present study, the steady-state expression of a CA gene, encoding for the plant carbonic anhydrase from the parsley Petroselinum crispum, is monitored. The studies were primarily been performed during germination of the seeds up to the 12/14-day-old embryos. The CA cDNA was cloned. Quantitative polymerase chain reaction (qPCR) analysis revealed that the gene expression level of the P. crispum CA is strongly and significantly affected at more alkaline pH in the growth medium (pH 8.3). This abolishing effect is counteracted both by addition of HCO₃⁻ and by addition of polyphosphate (polyP) to the culture medium. In response to polyP, the increased pH in the vacuoles of the growing plants is normalized. The effect of polyP let us to propose that this polymer acts as a buffer system that facilitates the adjustment of the pH in the cytoplasm. In addition, it is proposed that polyP has the potential to act, especially in the karst, as a fertilizer that allows the karstic plants to cope with the adverse pH and HCO₃⁻ condition in the soil.

  10. Inhibition of carbonic anhydrase II by thioxolone: a mechanistic and structural study.

    Science.gov (United States)

    Barrese, Albert A; Genis, Caroli; Fisher, S Zoe; Orwenyo, Jared N; Kumara, Mudalige Thilak; Dutta, Subodh K; Phillips, Eric; Kiddle, James J; Tu, Chingkuang; Silverman, David N; Govindasamy, Lakshmanan; Agbandje-McKenna, Mavis; McKenna, Robert; Tripp, Brian C

    2008-03-11

    This paper examines the functional mechanism of thioxolone, a compound recently identified as a weak inhibitor of human carbonic anhydrase II by Iyer et al. (2006) J. Biomol. Screening 11, 782-791 . Thioxolone lacks sulfonamide, sulfamate, or hydroxamate functional groups that are typically found in therapeutic carbonic anhydrase (CA) inhibitors, such as acetazolamide. Analytical chemistry and biochemical methods were used to investigate the fate of thioxolone upon binding to CA II, including Michaelis-Menten kinetics of 4-nitrophenyl acetate esterase cleavage, liquid chromatography-mass spectrometry (LC-MS), oxygen-18 isotope exchange studies, and X-ray crystallography. Thioxolone is proposed to be a prodrug inhibitor that is cleaved via a CA II zinc-hydroxide mechanism known to catalyze the hydrolysis of esters. When thioxolone binds in the active site of CA II, it is cleaved and forms 4-mercaptobenzene-1,3-diol via the intermediate S-(2,4-thiophenyl)hydrogen thiocarbonate. The esterase cleavage product binds to the zinc active site via the thiol group and is therefore the active CA inhibitor, while the intermediate is located at the rim of the active-site cavity. The time-dependence of this inhibition reaction was investigated in detail. Because this type of prodrug inhibitor mechanism depends on cleavage of ester bonds, this class of inhibitors may have advantages over sulfonamides in determining isozyme specificity. A preliminary structure-activity relationship study with a series of structural analogues of thioxolone yielded similar estimates of inhibition constants for most compounds, although two compounds with bromine groups at the C1 carbon of thioxolone were not inhibitory, suggesting a possible steric effect.

  11. Localization of putative carbonic anhydrases in two marine diatoms, Phaeodactylum tricornutum and Thalassiosira pseudonana.

    Science.gov (United States)

    Tachibana, Masaaki; Allen, Andrew E; Kikutani, Sae; Endo, Yuri; Bowler, Chris; Matsuda, Yusuke

    2011-09-01

    It is believed that intracellular carbonic anhydrases (CAs) are essential components of carbon concentrating mechanisms in microalgae. In this study, putative CA-encoding genes were identified in the genome sequences of the marine diatoms Phaeodactylum tricornutum and Thalassiosira pseudonana. Subsequently, the subcellular localizations of the encoded proteins were determined. Nine and thirteen CA sequences were found in the genomes of P. tricornutum and T. pseudonana, respectively. Two of the β-CA genes in P. tricornutum corresponded to ptca1 and ptca2 identified previously. Immunostaining transmission electron microscopy of a PtCA1:YFP fusion expressed in the cells of P. tricornutum clearly showed the localization of PtCA1 within the central part of the pyrenoid structure in the chloroplast. Besides these two β-CA genes, P. tricornutum likely contains five α- and two γ-CA genes, whereas T. pseudonana has three α-, five γ-, four δ-, and one ζ-CA genes. Semi-quantitative reverse transcription PCR performed on mRNA from the two diatoms grown in changing light and CO(2) conditions revealed that levels of six putative α- and γ-CA mRNAs in P. tricornutum did not change between cells grown in air-level CO(2) and 5% CO(2). However, mRNA levels of one putative α-CA gene, CA-VII in P. tricornutum, were reduced in the dark compared to that in the light. In T. pseudonana, mRNA accumulation levels of putative α-CA (CA-1), ζ-CA (CA-3) and δ-CA (CA-7) were analyzed and all levels found to be significantly reduced when cells were grown in 0.16% CO(2). Intercellular localizations of eight putative CAs were analyzed by expressing GFP fusion in P. tricornutum and T. pseudonana. In P. tricornutum, CA-I and II localized in the periplastidial compartment, CA-III, VI, VII were found in the chloroplast endoplasmic reticulum, and CA-VIII was localized in the mitochondria. On the other hand, T. pseudonana CA-1 localized in the stroma and CA-3 was found in the periplasm

  12. Inhibition of the β-class carbonic anhydrases from Mycobacterium tuberculosis with carboxylic acids.

    Science.gov (United States)

    Maresca, Alfonso; Vullo, Daniela; Scozzafava, Andrea; Manole, Gheorghe; Supuran, Claudiu T

    2013-04-01

    The growth of Mycobacterium tuberculosis is strongly inhibited by weak acids although the mechanism by which these compounds act is not completely understood. A series of substituted benzoic acids, nipecotic acid, ortho- and para-coumaric acid, caffeic acid and ferulic acid were investigated as inhibitors of three β-class carbonic anhydrases (CAs, EC 4.2.1.1) from this pathogen, mtCA 1 (Rv1284), mtCA 2 (Rv3588c) and mtCA 3 (Rv3273). All three enzymes were inhibited with efficacies between the submicromolar to the micromolar one, depending on the scaffold present in the carboxylic acid. mtCA 3 was the isoform mostly inhibited by these compounds (K(I)s in the range of 0.11-0.97 µM); followed by mtCA 2 (K(I)s in the range of 0.59-8.10 µM), whereas against mtCA 1, these carboxylic acids showed inhibition constants in the range of 2.25-7.13 µM. This class of relatively underexplored β-CA inhibitors warrant further in vivo studies, as they may have the potential for developing antimycobacterial agents with a diverse mechanism of action compared to the clinically used drugs for which many strains exhibit multi-drug or extensive multi-drug resistance.

  13. Carbonic anhydrase promotes the absorption rate of CO2 in post-combustion processes.

    Science.gov (United States)

    Vinoba, Mari; Bhagiyalakshmi, Margandan; Grace, Andrews Nirmala; Kim, Dae Hoon; Yoon, Yeoil; Nam, Sung Chan; Baek, Il Hyun; Jeong, Soon Kwan

    2013-05-09

    The rate of carbon dioxide (CO2) absorption by monoethanol amine (MEA), diethanol amine (DEA), N-methyl-2,2'-iminodiethanol (MDEA), and 2-amino-2-methyl 1-propanol (AMP) solutions was found to be enhanced by the addition of bovine carbonic anhydrase (CA), has been investigated using a vapor-liquid equilibrium (VLE) device. The enthalpy (-ΔHabs) of CO2 absorption and the absorption capacities of aqueous amines were measured in the presence and/or absence of CA enzyme via differential reaction calorimeter (DRC). The reaction temperature (ΔT) under adiabatic conditions was determined based on the DRC analysis. Bicarbonate and carbamate species formation mechanisms were elucidated by (1)H and (13)C NMR spectral analysis. The overall CO2 absorption rate (flux) and rate constant (kapp) followed the order MEA > DEA > AMP > MDEA in the absence or presence of CA. Hydration of CO2 by MDEA in the presence of CA directly produced bicarbonate, whereas AMP produced unstable carbamate intermediate, then underwent hydrolytic reaction and converted to bicarbonate. The MDEA > AMP > DEA > MEA reverse ordering of the enhanced CO2 flux and kapp in the presence of CA was due to bicarbonate formation by the tertiary and sterically hindered amines. Thus, CA increased the rate of CO2 absorption by MDEA by a factor of 3 relative to the rate of absorption by MDEA alone. The thermal effects suggested that CA yielded a higher activity at 40 °C.

  14. Carbonic anhydrase III regulates peroxisome proliferator-activated receptor-{gamma}2

    Energy Technology Data Exchange (ETDEWEB)

    Mitterberger, Maria C. [Cell Metabolism and Differentiation Research Group, Institute for Biomedical Aging Research of the Austrian Academy of Sciences, 6020 Innsbruck (Austria); Kim, Geumsoo [Laboratory of Biochemistry, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892-8012 (United States); Rostek, Ursula [Cell Metabolism and Differentiation Research Group, Institute for Biomedical Aging Research of the Austrian Academy of Sciences, 6020 Innsbruck (Austria); Levine, Rodney L. [Laboratory of Biochemistry, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892-8012 (United States); Zwerschke, Werner, E-mail: werner.zwerschke@oeaw.ac.at [Cell Metabolism and Differentiation Research Group, Institute for Biomedical Aging Research of the Austrian Academy of Sciences, 6020 Innsbruck (Austria)

    2012-05-01

    Carbonic anhydrase III (CAIII) is an isoenzyme of the CA family. Because of its low specific anhydrase activity, physiological functions in addition to hydrating CO{sub 2} have been proposed. CAIII expression is highly induced in adipogenesis and CAIII is the most abundant protein in adipose tissues. The function of CAIII in both preadipocytes and adipocytes is however unknown. In the present study we demonstrate that adipogenesis is greatly increased in mouse embryonic fibroblasts (MEFs) from CAIII knockout (KO) mice, as demonstrated by a greater than 10-fold increase in the induction of fatty acid-binding protein-4 (FABP4) and increased triglyceride formation in CAIII{sup -/-} MEFs compared with CAIII{sup +/+} cells. To address the underlying mechanism, we investigated the expression of the two adipogenic key regulators, peroxisome proliferator-activated receptor-{gamma}2 (PPAR{gamma}2) and CCAAT/enhancer binding protein-{alpha}. We found a considerable (approximately 1000-fold) increase in the PPAR{gamma}2 expression in the CAIII{sup -/-} MEFs. Furthermore, RNAi-mediated knockdown of endogenous CAIII in NIH 3T3-L1 preadipocytes resulted in a significant increase in the induction of PPAR{gamma}2 and FABP4. When both CAIII and PPAR{gamma}2 were knocked down, FABP4 was not induced. We conclude that down-regulation of CAIII in preadipocytes enhances adipogenesis and that CAIII is a regulator of adipogenic differentiation which acts at the level of PPAR{gamma}2 gene expression. -- Highlights: Black-Right-Pointing-Pointer We discover a novel function of Carbonic anhydrase III (CAIII). Black-Right-Pointing-Pointer We show that CAIII is a regulator of adipogenesis. Black-Right-Pointing-Pointer We demonstrate that CAIII acts at the level of PPAR{gamma}2 gene expression. Black-Right-Pointing-Pointer Our data contribute to a better understanding of the role of CAIII in fat tissue.

  15. Cadmium-Containing Carbonic Anhydrase CDCA1 in Marine Diatom Thalassiosira weissflogii

    Directory of Open Access Journals (Sweden)

    Vincenzo Alterio

    2015-03-01

    Full Text Available The Carbon Concentration Mechanism (CCM allows phytoplakton species to accumulate the dissolved inorganic carbon (DIC necessary for an efficient photosynthesis even under carbon dioxide limitation. In this mechanism of primary importance for diatoms, a key role is played by carbonic anhydrase (CA enzymes which catalyze the reversible hydration of CO2, thus taking part in the acquisition of inorganic carbon for photosynthesis. A novel CA, named CDCA1, has been recently discovered in the marine diatom Thalassiosira weissflogii. CDCA1 is a cambialistic enzyme since it naturally uses Cd2+ as catalytic metal ion, but if necessary can spontaneously exchange Cd2+ to Zn2+. Here, the biochemical and structural features of CDCA1 enzyme will be presented together with its putative biotechnological applications for the detection of metal ions in seawaters.

  16. Kinetics of Formation of Cobalt(II)- and Nickel(II) Carbonic Anhydrase.

    Science.gov (United States)

    McQuate, Robert S.; Reardon, John E.

    1978-01-01

    Discusses the kinetic behavior associated with the interaction of metal ions with apocarbonic anhydrase, focusing on the formation of two metallocarbonic anhydrase--the biochemically active Co(II) and the inactive Ni(II)derivatives. (GA)

  17. Arquitectura hospitalaria y cuidados durante los siglos XV al XIX

    OpenAIRE

    Castro Molina, Francisco Javier; Castro González, Maripaz; Megias Lizancos, Francisco; Martin Casañas, Felisa V.; Causapie Castro, Álvaro

    2012-01-01

    El presente texto pretende ofrecer un acercamiento a la arquitectura para la curación y el cuidado, revisando los diferentes modelos arquitectónicos, que desde el siglo XV se han venido desarrollando a lo largo de la Historia de la Humanidad para poder dar una respuesta a las necesidades de salud que se han originado hasta llegar a los nuevos ejemplos que surgen tras los descubrimientos científicos propios del siglo XIX, produciéndose un giro importante en la concepción del edificio hospitala...

  18. Knock-down of hypoxia-induced carbonic anhydrases IX and XII radiosensitizes tumor cells by increasing intracellular acidosis

    Directory of Open Access Journals (Sweden)

    Jérôme eDoyen

    2013-01-01

    Full Text Available The relationship between acidosis within the tumor microenvironment and radioresistance of hypoxic tumor cells remains unclear. Previously we reported that hypoxia-induced carbonic anhydrases CAIX and CAXII constitute a robust pHi-regulating system that confers a survival advantage on hypoxic human colon carcinoma LS174Tr cells in acidic microenvironments. Here we investigate the role of acidosis, CAIX and CAXII knock-down in combination with ionizing radiation. Fibroblasts cells (-/+ CAIX and LS174Tr cells (inducible knock-down for ca9/ca12 were analyzed for cell cycle phase distribution and survival after irradiation in extracellular pHo manipulations and hypoxia (1% O2 exposure. Radiotherapy was used to target ca9/ca12-silenced LS174Tr tumors grown in nude mice. We found that diminishing the pHi-regulating capacity of fibroblasts through inhibition of NHE-1 sensitize cells to radiation-induced cell death. Secondly, the pHi-regulating function of CAIX plays a key protective role in irradiated fibroblasts in an acidic environment as accompanied by a reduced number of cells in the radiosensitive phases of the cell cycle. Thirdly, we demonstrate that irradiation of LS174Tr spheroids, silenced for either ca9 or both ca9/ca12, showed a respective 50% and 75% increase in cell death as a result of a decrease in cell number in the radioresistant S phase and a disruption of CA-mediated pHi regulation. Finally, LS174Tr tumor progression was strongly decreased when ca9/ca12 silencing was combined with irradiation in vivo. These findings highlight the combinatory use of radiotherapy with targeting of the pHi-regulating carbonic anhydrases as an anti-cancer strategy.

  19. Multiple sources of carbonic anhydrase activity in pea thylakoids: soluble and membrane-bound forms.

    Science.gov (United States)

    Rudenko, Natalia N; Ignatova, Lyudmila K; Ivanov, Boris N

    2007-01-01

    Carbonic anhydrase (CA) activity of pea thylakoids, thylakoid membranes enriched with photosystem I (PSI-membranes), or photosystem II (PSII-membranes) as well as both supernatant and pellet after precipitation of thylakoids treated with detergent Triton X-100 were studied. CA activity of thylakoids in the presence of varying concentrations of Triton X-100 had two maxima, at Triton/chlorophyll (triton/Chl) ratios of 0.3 and 1.0. CA activities of PSI-membranes and PSII-membranes had only one maximum each, at Triton/Chl ratio 0.3 or 1.0, respectively. Two CAs with characteristics of the membrane-bound proteins and one CA with characteristics of the soluble proteins were found in the medium after thylakoids were incubated with Triton. One of the first two CAs had mobility in PAAG after native electrophoresis the same as that of CA residing in PSI-membranes, and the other CA had mobility the same as the mobility of CA residing in PSII-membranes, but the latter was different from CA situated in PSII core-complex (Ignatova et al. 2006 Biochemistry (Moscow) 71:525-532). The properties of the "soluble" CA removed from thylakoids were different from the properties of the known soluble CAs of plant cell: apparent molecular mass was about 262 kD and it was three orders more sensitive to the specific CA inhibitor, ethoxyzolamide, than soluble stromal CA. The data are discussed as indicating the presence of, at least, four CAs in pea thylakoids.

  20. Carbonic anhydrase activity in Arabidopsis thaliana thylakoid membrane and fragments enriched with PSI or PSII.

    Science.gov (United States)

    Ignatova, Lyudmila K; Rudenko, Natalia N; Mudrik, Vilen A; Fedorchuk, Tat'yana P; Ivanov, Boris N

    2011-12-01

    The procedure of isolating the thylakoids and the thylakoid membrane fragments enriched with either photosystem I or photosystem II (PSI- and PSII-membranes) from Arabidopsis thaliana leaves was developed. It differed from the one used with pea and spinach in durations of detergent treatment and centrifugation, and in concentrations of detergent and Mg(2+) in the media. Both the thylakoid and the fragments preserved carbonic anhydrase (CA) activities. Using nondenaturing electrophoresis followed by detection of CA activity in the gel stained with bromo thymol blue, one low molecular mass carrier of CA activity was found in the PSI-membranes, and two carriers, a low molecular mass one and a high molecular mass one, were found in the PSII-membranes. The proteins in the PSII-membranes differed in their sensitivity to acetazolamide (AA), a specific CA inhibitor. AA at 5 × 10(-7) M inhibited the CA activity of the high molecular mass protein but stimulated the activity of the low molecular mass carrier in the PSII-membranes. At the same concentration, AA moderately inhibited, by 30%, the CA activity of PSI-membranes. CA activity of the PSII-membranes was almost completely suppressed by the lipophilic CA inhibitor, ethoxyzolamide at 10(-9) M, whereas CA activity of the PSI-membranes was inhibited by this inhibitor even at 5 × 10(-7) M just the same as for AA. The observed distribution of CA activity in the thylakoid membranes from A. thaliana was close to the one found in the membranes of pea, evidencing the general pattern of CA activity in the thylakoid membranes of C3-plants.

  1. Antibodies reacting to carbonic anhydrase isozymes (I and II) and albumin in sera from dogs.

    Science.gov (United States)

    Nishita, Toshiho; Miyazaki, Rui; Miyazaki, Takae; Ochiai, Hideharu; Orito, Kensuke

    2016-06-01

    IgGs to carbonic anhydrase isozymes (CA-I and CA-II) and albumin were identified in dog serum. IgG titers were determined in the sera of asymptomatic dogs, and in dogs with atopic dermatitis, diarrhea and/or vomiting, diabetes and/or pancreatitis, kidney disease, hepatic disease, and thyroid gland disease, using ELISA. Low titres of IgG-reactive CA-I, CA-II, BSA, and CSA were found in the sera of healthy beagles. Compared with healthy beagles, there was a significant difference in the titers of antibodies against CA-I in asymptomatic dogs, dogs with diabetes and/or pancreatitis, or thyroid gland disease, or hepatic disease. Compared with healthy beagles, there was a significant difference in the antibody titer of anti-CA-II IgG in asymptomatic dogs and in those with hepatic disease. There was a significant difference in the antibody titer of anti-BSA IgG between healthy beagles and dogs with hepatic disease.

  2. Characterization of urease and carbonic anhydrase producing bacteria and their role in calcite precipitation.

    Science.gov (United States)

    Achal, Varenyam; Pan, Xiangliang

    2011-03-01

    Urease and carbonic anhydrase (CA) are key enzymes in the chemical reaction of living organisms and have been found to be associated with calcification in a number of microorganisms and invertebrates. Three bacterial strains designated as AP4, AP6, and AP9 were isolated from highly alkaline soil samples using the enrichment culture technique. On the basis of various physiological tests and 16S rRNA sequence analysis, these three bacteria were identified as Bacillus sp., B. megaterium, and B. simplex. Further, these Bacillus species have been characterized for the production of urease and CA in the process of biocalcification. One of the isolates, AP6 produced 553 U/ml of urease and 5.61 EU/ml CA. All the strains were able to produce significant amount of exopolymeric substances and biofilm. Further, efficacy of these strains was tested for calcite production ability and results were correlated with urease and CA. Isolate AP6 precipitated 2.26 mg calcite/cell dry mass (mg). Our observations strongly suggest that it is not only urease but CA also plays an important role in microbially induced calcium carbonate precipitation process. The current work demonstrates that urease and CA producing microbes can be utilized in biocalcification as a sealing agent for filling the gaps or cracks and fissures in constructed facilities and natural formations alike.

  3. Influence of pesticide exposure on carbonic anhydrase II from sheep stomach.

    Science.gov (United States)

    Kılınç, Namık; İşgör, Mehmet Mustafa; Şengül, Bülent; Beydemir, Şükrü

    2015-09-01

    Carbonic anhydrase (CA) is a widely distributed enzyme and has a crucial role in the cells, tissues and organs of living organisms. It is found that CA-II is one of the most abundant CA isoenzymes in the gastrointestinal system. It plays an important role in the gastric acid secretion in stomach. In this study, we purified CA-II isoenzyme from sheep stomach with a 615.2 purification fold, 78% purification yield and 5562.02 specific activity. Moreover, the in vitro effects of some commonly used pesticides including chlorpyrifos, cypermethrin, dichlorvos, glyphosate isopropylamine and lambda cyhalomethrin on the enzyme activity were investigated. Of these compounds, glyphosate isopropylamine and dichlorvos showed an inhibition on CA-II esterase activity. They have IC50 values of 0.155 µM and 2.690 µM and Ki values of 0.329 µM and 3.654 µM, respectively. Both glyphosate isopropylamine and dichlorvos inhibited CA-II isoenzyme in a noncompetitive manner.

  4. Linking Carbonic Anhydrase Abundance and Diversity in Soils to Ecological Function

    Science.gov (United States)

    Pang, E.; Meredith, L. K.; Welander, P. V.

    2015-12-01

    Carbonic anhydrase (CA) is an ancient enzyme widespread among bacteria, archaea, and eukarya that catalyzes the following reaction: CO2 + H2O ⇌ HCO3- + H+. Its functions are critical for key cellular processes such as concentrating CO2 for autotrophic growth, pH regulation, and pathogen survival in hosts. Currently, there are six known CA classes (α, β, γ, δ, η, ζ) arising from several distinct evolutionary lineages. CA are widespread in sequenced genomes, with many organisms containing multiple classes of CA or multiple CA of the same class. Soils host rich microbial communities with diverse and important ecological functions, but the diversity and abundance of CA in soils has not been explored. CA appears to play an important, but poorly understood, role in some biogeochemical cycles such as those of CO2 and its oxygen isotope composition and also carbonyl sulfide (COS), which are potential tracers in predictive carbon cycle models. Recognizing the prevalence and functional significance of CA in soils, we used a combined bioinformatics and molecular biology approach to address fundamental questions regarding the abundance, diversity, and function of CA in soils. To characterize the abundance and diversity of the different CA classes in soils, we analyzed existing soil metagenomic and metatranscriptomic data from the DOE Joint Genome Institute databases. Out of the six classes of CA, we only found the α, β, and γ classes to be present in soils, with the β class being the most abundant. We also looked at genomes of sequenced soil microorganisms to learn what combination of CA classes they contain, from which we can begin to predict the physiological role of CA. To characterize the functional roles of the different CA classes in soils, we collected soil samples from a variety of biomes with diverse chemical and physical properties and quantified the rate of two CA-mediated processes: soil uptake of COS and acceleration of the oxygen isotope exchange

  5. Atomic Data and Spectral Line Intensities for Ni XV

    Science.gov (United States)

    Landi, E.; Bhatia, A. K.

    2011-01-01

    Electron impact collision strengths, energy levels, oscillator strengths, and spontaneous radiative decay rates are calculated for Ni XV.Weinclude in the calculations the 9 lowest configurations, corresponding to 126 fine structure levels: 3s23p2, 3s3p3, 3s23p3d, 3p4, 3s3p23d, and 3s2 3p4l with l =, s, p, d, f. Collision strengths are calculated at five incident energies for all transitions: 7.8, 18.5, 33.5, 53.5, and 80.2 Ry above the threshold of each transition. An additional energy, very close to the transition threshold, has been added, whose value is between 0.004 and 0.28 Ry depending on the levels involved. Calculations have been carried out using the Flexible Atomic Code and the distorted-wave approximation. Excitation rate coefficients are calculated as a function of electron temperature by assuming a Maxwellian electron velocity distribution. Using the excitation rate coefficients and the radiative transition rates calculated in the present work, statistical equilibrium equations for level populations are solved at electron densities covering the 10(exp 8)-10(exp 14)/cu cm range and at an electron temperature of log T(sub e)(K) = 6.4, corresponding to the maximum abundance of Ni XV. Spectral line intensities are calculated, and their diagnostic relevance is discussed. This dataset will be made available in the next version of the CHIANTI database.

  6. Extraction of superoxide dismutase, catalase, and carbonic anhydrase from stroma-free red blood cell hemolysate for the preparation of the nanobiotechnological complex of polyhemoglobin-superoxide dismutase-catalase-carbonic anhydrase.

    Science.gov (United States)

    Guo, C; Gynn, M; Chang, T M S

    2015-06-01

    We report a novel method to simultaneously extract superoxide dismutase (SOD), catalase (CAT), and carbonic anhydrase (CA) from the same sample of red blood cells (RBCs). This avoids the need to use expensive commercial enzymes, thus enabling a cost-effective process for large-scale production of a nanobiotechnological polyHb-SOD-CAT-CA complex, with enhancement of all three red blood cell functions. An optimal concentration of phosphate buffer for ethanol-chloroform treatment results in good recovery of CAT, SOD, and CA after extraction. Different concentrations of the enzymes can be used to enhance the activity of polyHb-SOD-CAT-CA to 2, 4, or 6 times that of RBC.

  7. Toxicity and Physiological Actions of Carbonic Anhydrase Inhibitors to Aedes aegypti and Drosophila melanogaster

    Directory of Open Access Journals (Sweden)

    Sheena A. M. Francis

    2016-12-01

    Full Text Available The physiological role of carbonic anhydrases in pH and ion regulation is crucial to insect survival. We examined the toxic and neurophysiological effects of five carbonic anhydrase inhibitors (CAIs against Aedes aegypti. The 24 h larvicidal toxicities followed this rank order of potency: dichlorphenamide > methazolamide > acetazolamide = brinzolamide = dorzolamide. Larvicidal activity increased modestly in longer exposures, and affected larvae showed attenuated responses to probing without overt tremors, hyperexcitation, or convulsions. Acetazolamide and dichlorphenamide were toxic to adults when applied topically, but were of low potency and had an incomplete effect (<50% at 300 ng/mosquito even after injection. Dichlorphenamide was also the most toxic compound when fed to adult mosquitoes, and they displayed loss of posture and occasionally prolonged fluttering of the wings. Co-exposure with 500 ng of the synergist piperonyl butoxide (PBO increased the toxicity of dichlorphenamide ca. two-fold in feeding assays, indicating that low toxicity was not related to oxidative metabolism. Dichlorphenamide showed mild depolarizing and nerve discharge actions on insect neuromuscular and central nervous systems, respectively. These effects were increased in low buffer salines, indicating they were apparently related to loss of pH control in these tissues. Overall, sulfonamides displayed weak insecticidal properties on Aedes aegypti and are weak lead compounds.

  8. The structural comparison between membrane-associated human carbonic anhydrases provides insights into drug design of selective inhibitors.

    Science.gov (United States)

    Alterio, Vincenzo; Pan, Peiwen; Parkkila, Seppo; Buonanno, Martina; Supuran, Claudiu T; Monti, Simona M; De Simone, Giuseppina

    2014-07-01

    Carbonic anhydrase isoform XIV (CA XIV) is the last member of the human (h) CA family discovered so far, being localized in brain, kidneys, colon, small intestine, urinary bladder, liver, and spinal cord. It has recently been described as a possible drug target for treatment of epilepsy, some retinopathies as well as some skin tumors. Human carbonic anhydrase (hCA) XIV is a membrane-associated protein consisting of an N-terminal extracellular domain, a putative transmembrane region, and a small cytoplasmic tail. In this article, we report the expression, purification, and the crystallographic structure of the entire extracellular domain of this enzyme. The analysis of the structure revealed the typical α-CA fold, in which a 10-stranded β-sheet forms the core of the molecule, while the comparison with all the other membrane associated isoforms (hCAs IV, IX, and XII) allowed to identify the diverse oligomeric arrangement and the sequence and structural differences observed in the region 127-136 as the main factors to consider in the design of selective inhibitors for each one of the membrane associated α-CAs.

  9. C4 photosynthesis evolution in the transitional grass Neurachne: loss of a carbonic anhydrase chloroplast transit peptide.

    Science.gov (United States)

    Clayton, Harmony; Saladié, Montserrat; Rolland, Vivien; Sharwood, Robert E; Macfarlane, Terry; Ludwig, Martha

    2017-02-02

    Neurachne is the only known grass lineage containing closely related C3, C3-C4 intermediate and C4 species, making it an ideal taxon with which to study the evolution of C4 photosynthesis in the grasses. To begin dissecting the molecular changes that led to the evolution of C4 photosynthesis in this group, the cDNAs encoding four distinct β-carbonic anhydrase (CA) isoforms were characterized from leaf tissue of Neurachne munroi (C4), N. minor (C3-C4), and N. alopecuroidea (C3). Two genes (CA1 and CA2) each encode two different isoforms: CA1a, CA1b, CA2a and CA2b. Transcript analyses found CA1 mRNAs were significantly more abundant than transcripts from the CA2 gene in the leaves of each species examined, comprising approximately 99% of all β-CA transcripts measured. Localization experiments using green fluorescent protein fusion constructs showed that while CA1b is a cytosolic CA in all three species, the CA1a proteins are differentially localized. The N. alopecuroidea and N. minor CA1a isoforms were imported into chloroplasts of Nicotiana benthamiana leaf cells whereas N. munroi CA1a localized to the cytosol. Sequence analysis indicated an 11 amino acid deletion in the N-terminus of N. munroi CA1a relative to the C3 and C3-C4 proteins, suggesting chloroplast targeting of CA1a is the ancestral state, and that loss of a functional chloroplast transit peptide in N. munroi CA1a is associated with the evolution of C4 photosynthesis in Neurachne. Remarkably, this mechanism is homoplastic with evolution of the C4-associated CA in the dicotyledonous Flaveria, although the actual mutations in the two lineages differ.

  10. A High-Resolution Crystal Structure of a Psychrohalophilic α–Carbonic Anhydrase from Photobacterium profundum Reveals a Unique Dimer Interface

    Energy Technology Data Exchange (ETDEWEB)

    Somalinga, Vijayakumar; Buhrman, Greg; Arun, Ashikha; Rose, Robert B.; Grunden, Amy M. (NCSU)

    2016-12-09

    Bacterial α–carbonic anhydrases (α-CA) are zinc containing metalloenzymes that catalyze the rapid interconversion of CO2 to bicarbonate and a proton. We report the first crystal structure of a pyschrohalophilic α–CA from a deep-sea bacterium, Photobacterium profundum. Size exclusion chromatography of the purified P. profundum α–CA (PprCA) reveals that the protein is a heterogeneous mix of monomers and dimers. Furthermore, an “in-gel” carbonic anhydrase activity assay, also known as protonography, revealed two distinct bands corresponding to monomeric and dimeric forms of PprCA that are catalytically active. The crystal structure of PprCA was determined in its native form and reveals a highly conserved “knot-topology” that is characteristic of α–CA’s. Similar to other bacterial α–CA’s, PprCA also crystallized as a dimer. Furthermore, dimer interface analysis revealed the presence of a chloride ion (Cl-) in the interface which is unique to PprCA and has not been observed in any other α–CA’s characterized so far. Molecular dynamics simulation and chloride ion occupancy analysis shows 100% occupancy for the Cl- ion in the dimer interface. Zinc coordinating triple histidine residues, substrate binding hydrophobic patch residues, and the hydrophilic proton wire residues are highly conserved in PprCA and are identical to other well-studied α–CA’s.

  11. Identifying motor and sensory myelinated axons in rabbit peripheral nerves by histochemical staining for carbonic anhydrase and cholinesterase activities

    Science.gov (United States)

    Riley, Danny A.; Sanger, James R.; Matloub, Hani S.; Yousif, N. John; Bain, James L. W.

    1988-01-01

    Carbonic anhydrase (CA) and cholinesterase (CE) histochemical staining of rabbit spinal nerve roots and dorsal root ganglia demonstrated that among the reactive myeliated axons, with minor exceptions, sensory axons were CA positive and CE negative whereas motor axons were CA negative and CE positive. The high specificity was achieved by adjusting reaction conditions to stain subpopulations of myelinated axons selectively while leaving 50 percent or so unstained. Fixation with glutaraldehyde appeared necessary for achieving selectivity. Following sciatic nerve transection, the reciprocal staining pattern persisted in damaged axons and their regenerating processes which formed neuromas within the proximal nerve stump. Within the neuromas, CA-stained sensory processes were elaborated earlier and in greater numbers than CE-stained regenerating motor processes. The present results indicate that histochemical axon typing can be exploited to reveal heterogeneous responses of motor and sensory axons to injury.

  12. Synchrotron Radiation Provides a Plausible Explanation for the Generation of a Free Radical Adduct of Thioxolone in Mutant Carbonic Anhydrase II.

    Science.gov (United States)

    Sippel, Katherine H; Genis, Caroli; Govindasamy, Lakshmanan; Agbandje-McKenna, Mavis; Kiddle, James J; Tripp, Brian C; McKenna, Robert

    2010-10-07

    Thioxolone acts as a prodrug in the presence of carbonic anhydrase II (CA II), whereby the molecule is cleaved by thioester hydrolysis to the carbonic anhydrase inhibitor, 4-mercaptobenzene-1,3-diol (TH0). Thioxolone was soaked into the proton transfer mutant H64A of CA II in an effort to capture a reaction intermediate via X-ray crystallography. Structure determination of the 1.2 Å resolution data revealed the TH0 had been modified to a 4,4'-disulfanediyldibenzene-1,3-diol, a product of crystallization conditions, and a zinc ligated 2,4-dihydroxybenzenesulfenic acid, most likely induced by radiation damage. Neither ligand was likely a result of an enzymatic mechanism.

  13. Metal Complexes of 1,3,4-Thiadiazole-2,5-Disulfonamide are Strong Dual Carbonic Anhydrase Inhibitors, although the Ligand Possesses very Weak such Properties

    Science.gov (United States)

    Supuran, Claudiu T.

    1995-01-01

    Coordination compounds of Co(II), Ni(II), Cu(II), Zn(II), and Cd(II) with 1,3,4-thiadiazole-2,5-disulfonamide as ligand were synthesized and characterized by IR and UV spectroscopy, conductimetry and thermogravimetry. The parent ligand is a very weak carbonic anhydrase (CA) inhibitor, although it constituted the lead for developing important classes of diuretics. The complex derivatives behave as much stronger CA inhibitors, with IC50 values around 10−8M against isozyme CA II, and 10−7 M against isozyme CAI. PMID:18472784

  14. Metal Complexes of 1,3,4-Thiadiazole-2,5-Disulfonamide are Strong Dual Carbonic Anhydrase Inhibitors, although the Ligand Possesses very Weak such Properties.

    Science.gov (United States)

    Supuran, C T

    1995-01-01

    Coordination compounds of Co(II), Ni(II), Cu(II), Zn(II), and Cd(II) with 1,3,4-thiadiazole-2,5-disulfonamide as ligand were synthesized and characterized by IR and UV spectroscopy, conductimetry and thermogravimetry. The parent ligand is a very weak carbonic anhydrase (CA) inhibitor, although it constituted the lead for developing important classes of diuretics. The complex derivatives behave as much stronger CA inhibitors, with IC(50) values around 10(-8)M against isozyme CA II, and 10(-7) M against isozyme CAI.

  15. Coumarin or benzoxazinone based novel carbonic anhydrase inhibitors: synthesis, molecular docking and anticonvulsant studies.

    Science.gov (United States)

    Karataş, Mert Olgun; Uslu, Harun; Sarı, Suat; Alagöz, Mehmet Abdullah; Karakurt, Arzu; Alıcı, Bülent; Bilen, Cigdem; Yavuz, Emre; Gencer, Nahit; Arslan, Oktay

    2016-10-01

    Among many others, coumarin derivatives are known to show human carbonic anhydrase (hCA) inhibitory activity. Since hCA inhibition is one of the underlying mechanisms that account for the activities of some antiepileptic drugs (AEDs), hCA inhibitors are expected to have anti-seizure properties. There are also several studies reporting compounds with an imidazole and/or benzimidazole moiety which exert these pharmacological properties. In this study, we prepared fifteen novel coumarin-bearing imidazolium and benzimidazolium chloride, nine novel benzoxazinone-bearing imidazolium and benzimidazolium chloride derivatives and evaluated their hCA inhibitory activities and along with fourteen previously synthesized derivatives we scanned their anticonvulsant effects. As all compounds inhibited purified hCA isoforms I and II, some of them also proved protective against Maximal electroshock seizure (MES) and ScMet induced seizures in mice. Molecular docking studies with selected coumarin derivatives have revealed that these compounds bind to the active pocket of the enzyme in a similar fashion to that previously described for coumarin derivatives.

  16. Innovative molecular diagnosis of Trichinella species based on β-carbonic anhydrase genomic sequence.

    Science.gov (United States)

    Zolfaghari Emameh, Reza; Kuuslahti, Marianne; Näreaho, Anu; Sukura, Antti; Parkkila, Seppo

    2016-03-01

    Trichinellosis is a helminthic infection where different species of Trichinella nematodes are the causative agents. Several molecular assays have been designed to aid diagnostics of trichinellosis. These assays are mostly complex and expensive. The genomes of Trichinella species contain certain parasite-specific genes, which can be detected by polymerase chain reaction (PCR) methods. We selected β-carbonic anhydrase (β-CA) gene as a target, because it is present in many parasites genomes but absent in vertebrates. We developed a novel β-CA gene-based method for detection of Trichinella larvae in biological samples. We first identified a β-CA protein sequence from Trichinella spiralis by bioinformatic tools using β-CAs from Caenorhabditis elegans and Drosophila melanogaster. Thereafter, 16 sets of designed primers were tested to detect β-CA genomic sequences from three species of Trichinella, including T. spiralis, Trichinella pseudospiralis and Trichinella nativa. Among all 16 sets of designed primers, the primer set No. 2 efficiently amplified β-CA genomic sequences from T. spiralis, T. pseudospiralis and T. nativa without any false-positive amplicons from other parasite samples including Toxoplasma gondii, Toxocara cati and Parascaris equorum. This robust and straightforward method could be useful for meat inspection in slaughterhouses, quality control by food authorities and medical laboratories.

  17. The role of carbonic anhydrase in C4 photosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Studer, Anthony [Life Sciences Research Foundation, Baltimore, MD (United States)

    2015-10-01

    Current pressures on the global food supply have accelerated the urgency for a second green revolution using novel and sustainable approaches to increase crop yield and efficiency. This proposal outlines experiments to address fundamental questions regarding the biology of C4 photosynthesis, the method of carbon fixation utilized by the most productive food, feed and bioenergy crops. Carbonic anhydrase (CA) has been implicated in multiple cellular functions including nitrogen metabolism, water use efficiency, and photosynthesis. CA catalyzes the first dedicated step in C4 photosynthesis, the hydration of CO2 into bicarbonate, and is potentially rate limiting in C4 grasses. Using insertional mutagenesis, we have generated CA mutants in maize, and propose the characterization of these mutants using phenotypic, physiological, and transcriptomic profiling to assay the plant’s response to altered CA activity. In addition, florescent protein tagging experiments will be employed to study the subcellular localization of CA paralogs, providing critical data for modeling carbon fixation in C4 plants. Finally, I propose parallel experiments in Setaria viridis to explore its relevance as model C4 grass. Using a multifaceted approach, this proposal addresses important questions in basic biology, as well as the need for translation research in response to looming global food challenges.

  18. Synthesis and carbonic anhydrase inhibitory properties of amino acid - coumarin/quinolinone conjugates incorporating glycine, alanine and phenylalanine moieties.

    Science.gov (United States)

    Küçükbay, F Zehra; Küçükbay, Hasan; Tanc, Muhammet; Supuran, Claudiu T

    2016-12-01

    N-Protected amino acids (Gly, Ala and Phe) were reacted with amino substituted coumarin and quinolinone derivatives, leading to the corresponding N-protected amino acid-coumarin/quinolinone conjugates. The carbonic anhydrase (CA, EC 4.2.1.1) inhibitory activity of the new compounds was assessed against various human (h) isoforms, such as hCA I, hCA II, hCA IV and hCA XII. The quinolinone conjugates were inactive as enzyme inhibitors, whereas the coumarins were ineffective hCA I/II inhibitors (KIs > 50 μM) but were submicromolar hCA IV and XII inhibitors, with inhibition constants ranging between 92 nM and 1.19 μM for hCA IV, and between 0.11 and 0.79 μM for hCA XII. These coumarin derivatives, as many others reported earlier, thus show an interesting selective inhibitory profile for the membrane-bound over the cytosolic CA isoforms.

  19. Crisis feudal y nuevo orden social : Vizcaya, siglo XV

    Directory of Open Access Journals (Sweden)

    Javier Enríquez Fernández

    1989-01-01

    Full Text Available El siglo XV supuso para Vizcaya, y para el País Vasco en conjunto, un periodo de transformación y cristalización social. No obstante, y al igual que sucede en las demás áreas europeas, la sociedad vizcaína parte de unos presupuestos básicos que la historiografía tradicional ha tendido a olvidar en unos casos, a soslayar en otros, o a malinterpretar introduciendo elementos que en la Vizcaya del Cuatrocientos apenas estaban esbozados. Así, se ha dado excesiva importancia a las urbes, contraponiéndolas, en una lucha un tanto confusa, al mundo campesino.

  20. Ordenanzas municipales de Ourense en el siglo XV: estudio introductorio

    Directory of Open Access Journals (Sweden)

    Enjo Babío, Ascensión

    2006-12-01

    Full Text Available The medieval municipal ordinances reflect the worry of the council by the daily problems and the decisions adopted to resolve them. In Ourense, a group of ordinances corresponding to the fifteenth century are preserved and they show the decisions adopted by the council in matter of urban and rural police, salubriousness, provision, funeral rites, etc. They permit also a detailed study about their structure and their elaboration procedure.

    La ordenanzas municipales medievales reflejan la preocupación del concejo por los problemas cotidianos y las decisiones adoptadas para resolverlos. En Ourense, se conservan un grupo de ordenanzas correspondientes al siglo XV que muestran las decisiones adoptadas por el concejo en materia de policía urbana y rural, salubridad, abastecimiento, exequias, etc., y que permiten un estudio detallado acerca de su estructura y procedimiento de elaboración.

  1. Carbonic Anhydrase I Is Recognized by an SOD1 Antibody upon Biotinylation of Human Spinal Cord Extracts

    Directory of Open Access Journals (Sweden)

    Robert Bowser

    2010-10-01

    Full Text Available We recently reported the presence of a novel 32 kDa protein immunoreactive to a copper, zinc superoxide dismutase (SOD1 antibody within the spinal cord of patients with amyotrophic lateral sclerosis (ALS. This unique protein species was generated by biotinylation of spinal cord tissue extracts to detect conformational changes of SOD1 specific to ALS patients. To further characterize this protein, we enriched the protein by column chromatography and determined its protein identity by mass spectrometry. The protein that gave rise to the 32 kDa species upon biotinylation was identified as carbonic anhydrase I (CA I. Biotinylation of CA I from ALS spinal cord resulted in the generation of a novel epitope recognized by the SOD1 antibody. This epitope could also be generated by biotinylation of extracts from cultured cells expressing human CA I. Peptide competition assays identified the amino acid sequence in carbonic anhydrase I responsible for binding the SOD1 antibody. We conclude that chemical modifications used to identify pathogenic protein conformations can lead to the identification of unanticipated proteins that may participate in disease pathogenesis.

  2. Molecular and biochemical analysis of the beta class carbonic anhydrases in Caenorhabditis elegans.

    Science.gov (United States)

    Fasseas, Michael K; Tsikou, Daniela; Flemetakis, Emmanouil; Katinakis, Panagiotis

    2010-07-01

    The beta class of the carbonic anhydrase (CA) enzyme family has been found in plants, yeast, bacteria and algae, but not in animals. Also, little is known concerning the CAs of C. elegans. Genes possibly encoding beta-CAs were revealed by in silico analysis of the C. elegans genome. Amino acid sequence and 3D structure analysis revealed a resemblance to both plant and cab-type beta-CAs. Temporal expression patterns of the two genes, as well as changes in expression levels under different atmospheric conditions (stress) were analyzed by real-time RT-PCR. Recombinant enzymes, expressed in E. coli were used for in vitro measurement of CA activity, while a yeast complementation experiment was performed in order to assess their ability to complement the function of S. crevisieae beta-CA (NCE103) in vivo. RNAi by feeding was performed on wild-type populations that were then examined for a visible phenotype under normal or various stress conditions (pH, CO(2)/O(2)). Two genes possibly encoding beta-CAs were revealed (bca-1 and y116a8c.28). Their products contain elements of both plant and cab-type CAs. Both assays showed that Y116a8c.28 is an active CA. Both genes showed significant levels of transcript accumulation during development, while they also responded to the stress conditions. No visible phenotype was scored under normal or stress conditions.

  3. Sulfonamide inhibition studies of the β-carbonic anhydrase from the pathogenic bacterium Vibrio cholerae.

    Science.gov (United States)

    Del Prete, Sonia; Vullo, Daniela; De Luca, Viviana; Carginale, Vincenzo; Ferraroni, Marta; Osman, Sameh M; AlOthman, Zeid; Supuran, Claudiu T; Capasso, Clemente

    2016-03-01

    The genome of the pathogenic bacterium Vibrio cholerae encodes for three carbonic anhydrases (CAs, EC 4.2.1.1) belonging to the α-, β- and γ-classes. VchCA, the α-CA from this species was investigated earlier, whereas the β-class enzyme, VchCAβ was recently cloned, characterized kinetically and its X-ray crystal structure reported by this group. Here we report an inhibition study with sulfonamides and one sulfamate of this enzyme. The best VchCAβ inhibitors were deacetylated acetazolamide and methazolamide and hydrochlorothiazide, which showed inhibition constants of 68.2-87.0nM. Other compounds, with medium potency against VchCAβ, (KIs in the range of 275-463nM), were sulfanilamide, metanilamide, sulthiame and saccharin whereas the clinically used agents such as acetazolamide, methazolamide, ethoxzolamide, dorzolamide, zonisamide and celecoxib were micromolar inhibitors (KIs in the range of 4.51-8.57μM). Identification of potent and possibly selective inhibitors of VchCA and VchCAβ over the human CA isoforms, may lead to pharmacological tools useful for understanding the physiological role(s) of this under-investigated enzymes.

  4. Oxygen Regulation of a Nodule-Located Carbonic Anhydrase in Alfalfa1

    Science.gov (United States)

    Gálvez, Susana; Hirsch, Ann M.; Wycoff, Keith L.; Hunt, Stephen; Layzell, David B.; Kondorosi, Adam; Crespi, Martin

    2000-01-01

    Control of the permeability to oxygen is critical for the function of symbiotic nitrogen fixation in legume nodules. The inner cortex (IC) seems to be a primary site for this regulation. In alfalfa (Medicago sativa) nodules, expression of the Msca1 gene encoding a carbonic anhydrase (CA) was previously found to be restricted to the IC. We have now raised antibodies against recombinant Msca1 protein and used them, together with antibodies raised against potato leaf CA, to demonstrate the presence of two forms of CA in mature nodules. Each antibody recognizes a different CA isoform in nodule tissues. Immunolocalization revealed that leaf-related CAs were localized primarily in the nitrogen-fixing zone, whereas the Msca1 protein was restricted exclusively to the IC region, in indeterminate and determinate nodules. In alfalfa nodules grown at various O2 concentrations, an inverse correlation was observed between the external oxygen pressure and Msca1 protein content in the IC, the site of the putative diffusion barrier. Thus Msca1 is a molecular target of physiological processes occurring in the IC cells involved in gas exchange in the nodule. PMID:11080283

  5. Mutant carbonic anhydrase 4 impairs pH regulation and causes retinal photoreceptor degeneration.

    Science.gov (United States)

    Yang, Zhenglin; Alvarez, Bernardo V; Chakarova, Christina; Jiang, Li; Karan, Goutam; Frederick, Jeanne M; Zhao, Yu; Sauvé, Yves; Li, Xi; Zrenner, Eberhart; Wissinger, Bernd; Hollander, Anneke I Den; Katz, Bradley; Baehr, Wolfgang; Cremers, Frans P; Casey, Joseph R; Bhattacharya, Shomi S; Zhang, Kang

    2005-01-15

    Retina and retinal pigment epithelium (RPE) belong to the metabolically most active tissues in the human body. Efficient removal of acid load from retina and RPE is a critical function mediated by the choriocapillaris. However, the mechanism by which pH homeostasis is maintained is largely unknown. Here, we show that a functional complex of carbonic anhydrase 4 (CA4) and Na+/bicarbonate co-transporter 1 (NBC1) is specifically expressed in the choriocapillaris and that missense mutations in CA4 linked to autosomal dominant rod-cone dystrophy disrupt NBC1-mediated HCO3- transport. Our results identify a novel pathogenic pathway in which a defect in a functional complex involved in maintaining pH balances, but not expressed in retina or RPE, leads to photoreceptor degeneration. The importance of a functional CA4 for survival of photoreceptors implies that CA inhibitors, which are widely used as medications, particularly in the treatment of glaucoma, may have long-term adverse effects on vision.

  6. High-resolution structure of human carbonic anhydrase II complexed with acetazolamide reveals insights into inhibitor drug design.

    Science.gov (United States)

    Sippel, Katherine H; Robbins, Arthur H; Domsic, John; Genis, Caroli; Agbandje-McKenna, Mavis; McKenna, Robert

    2009-10-01

    The crystal structure of human carbonic anhydrase II (CA II) complexed with the inhibitor acetazolamide (AZM) has been determined at 1.1 A resolution and refined to an R(cryst) of 11.2% and an R(free) of 14.7%. As observed in previous CA II-inhibitor complexes, AZM binds directly to the zinc and makes several key interactions with active-site residues. The high-resolution data also showed a glycerol molecule adjacent to the AZM in the active site and two additional AZMs that are adventitiously bound on the surface of the enzyme. The co-binding of AZM and glycerol in the active site demonstrate that given an appropriate ring orientation and substituents, an isozyme-specific CA inhibitor may be developed.

  7. Effects of reduced carbonic anhydrase activity on CO2 assimilation rates in Setaria viridis: a transgenic analysis.

    Science.gov (United States)

    Osborn, Hannah L; Alonso-Cantabrana, Hugo; Sharwood, Robert E; Covshoff, Sarah; Evans, John R; Furbank, Robert T; von Caemmerer, Susanne

    2017-01-01

    In C4 species, the major β-carbonic anhydrase (β-CA) localized in the mesophyll cytosol catalyses the hydration of CO2 to HCO3(-), which phosphoenolpyruvate carboxylase uses in the first step of C4 photosynthesis. To address the role of CA in C4 photosynthesis, we generated transgenic Setaria viridis depleted in β-CA. Independent lines were identified with as little as 13% of wild-type CA. No photosynthetic defect was observed in the transformed lines at ambient CO2 partial pressure (pCO2). At low pCO2, a strong correlation between CO2 assimilation rates and CA hydration rates was observed. C(18)O(16)O isotope discrimination was used to estimate the mesophyll conductance to CO2 diffusion from the intercellular air space to the mesophyll cytosol (gm) in control plants, which allowed us to calculate CA activities in the mesophyll cytosol (Cm). This revealed a strong relationship between the initial slope of the response of the CO2 assimilation rate to cytosolic pCO2 (ACm) and cytosolic CA activity. However, the relationship between the initial slope of the response of CO2 assimilation to intercellular pCO2 (ACi) and cytosolic CA activity was curvilinear. This indicated that in S. viridis, mesophyll conductance may be a contributing limiting factor alongside CA activity to CO2 assimilation rates at low pCO2.

  8. Structural basis of the oxidative activation of the carboxysomal [gamma]-carbonic anhydrase, CcmM

    Energy Technology Data Exchange (ETDEWEB)

    Peña, Kerry L.; Castel, Stephane E.; de Araujo, Charlotte; Espie, George S.; Kimber, Matthew S. (Guelph); (Toronto)

    2010-04-26

    Cyanobacterial RuBisCO is sequestered in large, icosahedral, protein-bounded microcompartments called carboxysomes. Bicarbonate is pumped into the cytosol, diffuses into the carboxysome through small pores in its shell, and is then converted to CO{sub 2} by carbonic anhydrase (CA) prior to fixation. Paradoxically, many {beta}-cyanobacteria, including Thermosynechococcus elongatus BP-1, lack the conventional carboxysomal {beta}-CA, ccaA. The N-terminal domain of the carboxysomal protein CcmM is homologous to {gamma}-CA from Methanosarcina thermophila (Cam) but recombinant CcmM derived from ccaA-containing cyanobacteria show no CA activity. We demonstrate here that either full length CcmM from T. elongatus, or a construct truncated after 209 residues (CcmM209), is active as a CA - the first catalytically active bacterial {gamma}-CA reported. The 2.0 {angstrom} structure of CcmM209 reveals a trimeric, left-handed {beta}-helix structure that closely resembles Cam, except that residues 198-207 form a third {alpha}-helix stabilized by an essential Cys194-Cys200 disulfide bond. Deleting residues 194-209 (CcmM193) results in an inactive protein whose 1.1 {angstrom} structure shows disordering of the N- and C-termini, and reorganization of the trimeric interface and active site. Under reducing conditions, CcmM209 is similarly partially disordered and inactive as a CA. CcmM protein in fresh E. coli cell extracts is inactive, implying that the cellular reducing machinery can reduce and inactivate CcmM, while diamide, a thiol oxidizing agent, activates the enzyme. Thus, like membrane-bound eukaryotic cellular compartments, the {beta}-carboxysome appears to be able to maintain an oxidizing interior by precluding the entry of thioredoxin and other endogenous reducing agents.

  9. Characterization of the first beta-class carbonic anhydrase from an arthropod (Drosophila melanogaster and phylogenetic analysis of beta-class carbonic anhydrases in invertebrates

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    Niederhauser Barbara

    2010-07-01

    Full Text Available Abstract Background The β-carbonic anhydrase (CA, EC 4.2.1.1 enzymes have been reported in a variety of organisms, but their existence in animals has been unclear. The purpose of the present study was to perform extensive sequence analysis to show that the β-CAs are present in invertebrates and to clone and characterize a member of this enzyme family from a representative model organism of the animal kingdom, e.g., Drosophila melanogaster. Results The novel β-CA gene, here named DmBCA, was identified from FlyBase, and its orthologs were searched and reconstructed from sequence databases, confirming the presence of β-CA sequences in 55 metazoan species. The corresponding recombinant enzyme was produced in Sf9 insect cells, purified, kinetically characterized, and its inhibition was investigated with a series of simple, inorganic anions. Holoenzyme molecular mass was defined by dynamic light scattering analysis and gel filtration, and the results suggested that the holoenzyme is a dimer. Double immunostaining confirmed predictions based on sequence analysis and localized DmBCA protein to mitochondria. The enzyme showed high CO2 hydratase activity, with a kcat of 9.5 × 105 s-1 and a kcat/KM of 1.1 × 108 M-1s-1. DmBCA was appreciably inhibited by the clinically-used sulfonamide acetazolamide, with an inhibition constant of 49 nM. It was moderately inhibited by halides, pseudohalides, hydrogen sulfide, bisulfite and sulfate (KI values of 0.67 - 1.36 mM and more potently by sulfamide (KI of 0.15 mM. Bicarbonate, nitrate, nitrite and phenylarsonic/boronic acids were much weaker inhibitors (KIs of 26.9 - 43.7 mM. Conclusions The Drosophila β-CA represents a highly active mitochondrial enzyme that is a potential model enzyme for anti-parasitic drug development.

  10. Identification of two carbonic anhydrases in the mantle of the European Abalone Haliotis tuberculata (Gastropoda, Haliotidae): phylogenetic implications.

    Science.gov (United States)

    LE Roy, Nathalie; Marie, Benjamin; Gaume, Béatrice; Guichard, Nathalie; Delgado, Sidney; Zanella-Cléon, Isabelle; Becchi, Michel; Auzoux-Bordenave, Stéphanie; Sire, Jean-Yves; Marin, Frédéric

    2012-07-01

    Carbonic anhydrases (CAs) represent a diversified family of metalloenzymes that reversibly catalyze the hydration of carbon dioxide. They are involved in a wide range of functions, among which is the formation of CaCO(3) skeletons in metazoans. In the shell-forming mantle tissues of mollusks, the location of the CA catalytic activity is elusive and gives birth to contradicting views. In the present paper, using the European abalone Haliotis tuberculata, a key model gastropod in biomineralization studies, we identified and characterized two CAs (htCA1 and htCA2) that are specific of the shell-forming mantle tissue. We analyzed them in a phylogenetic context. Combining various approaches, including proteomics, activity tests, and in silico analyses, we showed that htCA1 is secreted but is not incorporated in the organic matrix of the abalone shell and that htCA2 is transmembrane. Together with previous studies dealing with molluskan CAs, our findings suggest two possible modes of action for shell mineralization: the first mode applies to, for example, the bivalves Unio pictorum and Pinctada fucata, and involves a true CA activity in their shell matrix; the second mode corresponds to, for example, the European abalone, and does not include CA activity in the shell matrix. Our work provides new insight on the diversity of the extracellular macromolecular tools used for shell biomineralization study in mollusks.

  11. Synthesis, characterization and in vitro inhibition of metal complexes of pyrazole based sulfonamide on human erythrocyte carbonic anhydrase isozymes I and II.

    Science.gov (United States)

    Büyükkıdan, Nurgün; Büyükkıdan, Bülent; Bülbül, Metin; Kasımoğulları, Rahmi; Mert, Samet

    2017-12-01

    Sulfonamides represent an important class of biologically active compounds. A sulfonamide possessing carbonic anhydrase (CA) inhibitory properties obtained from a pyrazole based sulfonamide, ethyl 1-(3-nitrophenyl)-5-phenyl-3-((5-sulfamoyl-1,3,4-thiadiazol-2-yl)carbamoyl)-1H-pyrazole-4-carboxylate (1), and its metal complexes with the Ni(II) for (2), Cu(II) for (3) and Zn(II) for (4) have been synthesized. The structures of metal complexes (2-4) were established on the basis of their elemental analysis, (1)H NMR, IR, UV-Vis and MS spectral data. The inhibition of two human carbonic anhydrase (hCA, EC 4.2.1.1) isoenzymes I and II, with 1 and synthesized complexes (2-4) and acetazolamide (AAZ) as a control compound was investigated in vitro by using the hydratase and esterase assays. The complexes 2, 3 and 4 showed inhibition constant in the range 0.1460-0.3930 µM for hCA-I and 0.0740-0.0980 µM for hCA-II, and they had effective more inhibitory activity on hCA-I and hCA-II than corresponding free ligand 1 and than AAZ.

  12. Research progress of carbon dioxide capture by using carbonic anhydrase%碳酸酐酶用于二氧化碳捕集的研究进展

    Institute of Scientific and Technical Information of China (English)

    王静

    2012-01-01

    碳酸酐酶(CA)可以加速捕集化石燃料燃烧产生的二氧化碳,从而降低CO2的排放量.主要介绍了CA的来源、活性、稳定性及作用.分析了使用新型生物方法对二氧化碳进行捕集和储存的优缺点,并对下一步的工作进行了展望.%It has been demonstrated that carbonic anhydrase has the potential of accelerating of carbon dioxide capture from fossil fuel and reduce the discharge of carbon dioxide. The source, activity, stability and functions of carbonic anhydrase are mainly presented. In addition, the advantages and disadvantages of using new biological for carbon dioxide capture and storage are discussed and analyzed, and the further study is prospected.

  13. El deporte en la ciudad de Sevilla durante el siglo XV=Sports in Seville during the XVth century

    Directory of Open Access Journals (Sweden)

    Gonzalo Ramírez Macías

    2013-03-01

    Full Text Available Esta investigación tiene como finalidad fundamental conocer y caracterizar los deportes que eran practicados durante el siglo XV en la ciudad de Sevilla, una de las capitales castellanas que más prosperidad experimentó en esa centuria. La primera parte de este estudio está dedicada a justificar y fundamentar la investigación, en la segunda parte se expone la metodología de investigación propuesta, la cual tiene un carácter novedoso dentro de la historia del deporte. En tercer lugar se presentan y analizan los resultados obtenidos en el estudio, que indican que los deportes practicados durante el siglo XV en la ciudad de Sevilla eran: juego de cañas, correr la sortija, correr monte, justas, torneos, carreras pedestres, carreras a caballo y correr toros. Finalmente se exponen las conclusiones de la investigación las cuales se fundamentan en los resultados de la misma y en las aportaciones de otros estudios anteriores.--------------------------------------------------------------------------The main purpose of this research is to know and characterize the sports practised during the XVth century in Seville, one of the most prosperous Castilian capitals at that time. The first part of this research is devoted to its justification and basis, whereas the second part puts forward the research methodology suggested, which has a new nature within the history of Sports. Thirdly, the results obtained in the research are presented and analysed, what points out that the sports practised during the XVth Century in Seville were: cane games,*correr la sortija, **correr monte, jousts, tournaments, races, horse races and bull races. Finally, the research conclusions are expounded, which are based on its results and on other contributions from previous researches.*Correr la sortija: A game in which two players riding horses had to catch a ring with a spear.**Correr monte: to hunt

  14. Interaction of anions with a newly characterized alpha carbonic anhydrase from Halomonas sp.

    Science.gov (United States)

    Orhan, Furkan; Şentürk, Murat; Supuran, Claudiu T

    2016-12-01

    The inhibition and characterization of the α-class carbonic anhydrase (CA, EC 4.2.1.1) from the Halomonas sp. are reported for the first time. The enzyme was purified 91-fold with a yield of 39%, and a specific activity of 600 U/mg proteins was obtained. It has an optimum pH at 7.5, an optimum ionic strength at 20 mM and an optimum temperature at 20 °C. The following anions, SCN(-), Br(-), Cl(-), I(-), [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text] showed inhibitory effects on the hydratase activity of the enzyme. Sulfate, sulfide, azide, nitrate, nitrite and iodide exhibited the strongest inhibitory activity, in the micromolar range (KI-s of 5.5-15.5 µM). SCN(-), Br(-), Cl(-), [Formula: see text] were moderate inhibitors, whereas other anions showed only weak activities. Our findings indicate that these anions inhibit the Halomonas sp. CA (HmCA) enzyme in a similar manner to other α-CAs from mammals investigated earlier, but the susceptibility to various anions differs significantly between the Halomonas sp. and other organism CAs.

  15. Carbon dioxide capture using Escherichia coli expressing carbonic anhydrase in a foam bioreactor.

    Science.gov (United States)

    Watson, Stuart K; Han, Zhenlin; Su, Wei Wen; Deshusses, Marc A; Kan, Eunsung

    2016-12-01

    The present study reports CO2 capture and conversion to bicarbonate using Escherichia coli expressing carbonic anhydrase (CA) on its cell surface in a novel foam bioreactor. The very large gas-liquid interfacial area in the foam bioreactor promoted rapid CO2 absorption while the CO2 in the aqueous phase was subsequently converted to bicarbonate ions by the CA. CO2 gas removal in air was investigated at various conditions such as gas velocity, cell density and CO2 inlet concentration. Regimes for kinetic and mass transfer limitations were defined. Very high removal rates of CO2 were observed: 9570 g CO2 m(-3) bioreactor h(-1) and a CO2 removal efficiency of 93% at 4% inlet CO2 when the gas retention time was 24 s, and cell concentration was 4 gdw L(-1). These performances are superior to earlier reports of experimental bioreactors using CA for CO2 capture. Overall, this bioreactor system has significant potential as an alternative CO2 capture technology.

  16. Synthesis and Evaluation of New Phthalazine Urea and Thiourea Derivatives as Carbonic Anhydrase Inhibitors

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    Nurcan Berber

    2013-01-01

    Full Text Available A new series of phthalazine substituted urea and thiourea derivatives were synthesized, and their inhibitory effects on the activity of purified human carbonic anhydrases (hCAs I and II were evaluated. 2H-Indazolo[2,1-b]phthalazine-trione derivative (1 was prepared with 4-nitrobenzaldehyde, dimedone, and phthalhydrazide in the presence of TFA in DMF, and nitro group was reduced to amine derivative (2 with SnCl2·2H2O. The compound was reacted with isocyanates and isothiocyanates to get the final products (3a–p. The results showed that all the synthesized compounds inhibited the CA isoenzymes activity. 3a (IC50 = 6.40 µM for hCA I and 6.13 µM for hCA II has the most inhibitory effect. The synthesized compounds are very bulky to be able to bind near the zinc ion, and they much more probably bind as the coumarin derivatives.

  17. Engineering de novo disulfide bond in bacterial α-type carbonic anhydrase for thermostable carbon sequestration

    Science.gov (United States)

    Jo, Byung Hoon; Park, Tae Yoon; Park, Hyun June; Yeon, Young Joo; Yoo, Young Je; Cha, Hyung Joon

    2016-07-01

    Exploiting carbonic anhydrase (CA), an enzyme that rapidly catalyzes carbon dioxide hydration, is an attractive biomimetic route for carbon sequestration due to its environmental compatibility and potential economic viability. However, the industrial applications of CA are strongly hampered by the unstable nature of enzymes. In this work, we introduced in silico designed, de novo disulfide bond in a bacterial α-type CA to enhance thermostability. Three variants were selected and expressed in Escherichia coli with an additional disulfide bridge. One of the variants showed great enhancement in terms of both kinetic and thermodynamic stabilities. This improvement could be attributed to the loss of conformational entropy of the unfolded state, showing increased rigidity. The variant showed an upward-shifted optimal temperature and appeared to be thermoactivated, which compensated for the lowered activity at 25 °C. Collectively, the variant constructed by the rapid and effective de novo disulfide engineering can be used as an efficient biocatalyst for carbon sequestration under high temperature conditions.

  18. SWATH-based proteomics identified carbonic anhydrase 2 as a potential diagnosis biomarker for nasopharyngeal carcinoma

    Science.gov (United States)

    Luo, Yanzhang; Mok, Tin Seak; Lin, Xiuxian; Zhang, Wanling; Cui, Yizhi; Guo, Jiahui; Chen, Xing; Zhang, Tao; Wang, Tong

    2017-01-01

    Nasopharyngeal carcinoma (NPC) is a serious threat to public health, and the biomarker discovery is of urgent needs. The data-independent mode (DIA) based sequential window acquisition of all theoretical fragment-ion spectra (SWATH) mass spectrometry (MS) has been proved to be precise in protein quantitation and efficient for cancer biomarker researches. In this study, we performed the first SWATH-MS analysis comparing the NPC and normal tissues. Spike-in stable isotope labeling by amino acids in cell culture (super-SILAC) MS was used as a shotgun reference. We identified and quantified 1414 proteins across all SWATH-MS analyses. We found that SWATH-MS had a unique feature to preferentially detect proteins with smaller molecular weights than either super-SILAC MS or human proteome background. With SWATH-MS, 29 significant differentially express proteins (DEPs) were identified. Among them, carbonic anhydrase 2 (CA2) was selected for further validation per novelty, MS quality and other supporting rationale. With the tissue microarray analysis, we found that CA2 had an AUC of 0.94 in differentiating NPC from normal tissue samples. In conclusion, SWATH-MS has unique features in proteome analysis, and it leads to the identification of CA2 as a potentially new diagnostic biomarker for NPC. PMID:28117408

  19. Structural insight into activity enhancement and inhibition of H64A carbonic anhydrase II by imidazoles

    Directory of Open Access Journals (Sweden)

    Mayank Aggarwal

    2014-03-01

    Full Text Available Human carbonic anhydrases (CAs are zinc metalloenzymes that catalyze the hydration and dehydration of CO2 and HCO3−, respectively. The reaction follows a ping-pong mechanism, in which the rate-limiting step is the transfer of a proton from the zinc-bound solvent (OH−/H2O in/out of the active site via His64, which is widely believed to be the proton-shuttling residue. The decreased catalytic activity (∼20-fold lower with respect to the wild type of a variant of CA II in which His64 is replaced with Ala (H64A CA II can be enhanced by exogenous proton donors/acceptors, usually derivatives of imidazoles and pyridines, to almost the wild-type level. X-ray crystal structures of H64A CA II in complex with four imidazole derivatives (imidazole, 1-methylimidazole, 2-methylimidazole and 4-methylimidazole have been determined and reveal multiple binding sites. Two of these imidazole binding sites have been identified that mimic the positions of the `in' and `out' rotamers of His64 in wild-type CA II, while another directly inhibits catalysis by displacing the zinc-bound solvent. The data presented here not only corroborate the importance of the imidazole side chain of His64 in proton transfer during CA catalysis, but also provide a complete structural understanding of the mechanism by which imidazoles enhance (and inhibit when used at higher concentrations the activity of H64A CA II.

  20. Plague Epidemic s in Syria b etween XIII - XV. Centuries

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    Esra ATMACA

    2015-07-01

    Full Text Available Epidemic diseases that cause mass death has been one of the greatest fears of the society in the past century Usually due to poor living conditions, poverty, the inadequate treatment. Plague is one of them. Plague word is sometimes used synonymously with t he word tâûn, sometimes considered to be a greater sense of the Word plague. These outbreaks occured repeatedly in human society and many times occured between XIII - XV. centuries. Our research aims to examine the plague occured in Syria in the Mamluk state domination discussed period. One of the outbreaks have occured in the period between the years 1347 - 1351. Epidemic was looming at the same time with the European named the black death or large extinction. Many people have been killed in Syria as in other places where the epidemic has spread. Rumors about them are given in the source is situated in the form of the issuance of the number of people who died in one day and sometimes the total number of deaths took place at a given date range. In this study, we aimed to determine which is more severe than the others in the outbreak, to assess the rumor about the number of deaths from this cause, to reveal the difficulties of the funeral of the dead, to uncover practices that people do to get rid of this disease.

  1. The role of carbonic anhydrase in hepatic glucose production.

    Science.gov (United States)

    Ismail, Ibrahim Salihu

    2016-12-14

    Considerable efforts are being made daily to discover novel therapeutic targets to better understand the mechanism for designing drugs in treating diabetes. Inhibition of hepatic gluconeogenesis by metformin remains the first line of oral therapy for managing type 2 diabetes. The link between rise in blood lactate level and reduction of hepatic glucose production with metformin usage remains to be determined. Carbonic anhydrase is proposed to be the link connecting blood lactate accumulation and inhibition of hepatic gluconeogenesis and thus could serve as a new therapeutic target for reducing hepatic glucose production. Understanding the link between rise in blood lactate level and the role of carbonic anhydrase in lactate uptake will be essential towards the development of a promising new antidiabetic medication.

  2. Synthesis and in Vivo Biological Evaluation of (68)Ga-Labeled Carbonic Anhydrase IX Targeting Small Molecules for Positron Emission Tomography.

    Science.gov (United States)

    Sneddon, Deborah; Niemans, Raymon; Bauwens, Matthias; Yaromina, Ala; van Kuijk, Simon J A; Lieuwes, Natasja G; Biemans, Rianne; Pooters, Ivo; Pellegrini, Paul A; Lengkeek, Nigel A; Greguric, Ivan; Tonissen, Kathryn F; Supuran, Claudiu T; Lambin, Philippe; Dubois, Ludwig; Poulsen, Sally-Ann

    2016-07-14

    Tumor hypoxia contributes resistance to chemo- and radiotherapy, while oxygenated tumors are sensitive to these treatments. The indirect detection of hypoxic tumors is possible by targeting carbonic anhydrase IX (CA IX), an enzyme overexpressed in hypoxic tumors, with sulfonamide-based imaging agents. In this study, we present the design and synthesis of novel gallium-radiolabeled small-molecule sulfonamides targeting CA IX. The compounds display favorable in vivo pharmacokinetics and stability. We demonstrate that our lead compound, [(68)Ga]-2, discriminates CA IX-expressing tumors in vivo in a mouse xenograft model using positron emission tomography (PET). This compound shows specific tumor accumulation and low uptake in blood and clears intact to the urine. These findings were reproduced in a second study using PET/computed tomography. Small molecules investigated to date utilizing (68)Ga for preclinical CA IX imaging are scarce, and this is one of the first effective (68)Ga compounds reported for PET imaging of CA IX.

  3. Regulation of expression and biochemical characterization of a beta-class carbonic anhydrase from the plant growth-promoting rhizobacterium, Azospirillum brasilense Sp7.

    Science.gov (United States)

    Kaur, Simarjot; Mishra, Mukti Nath; Tripathi, Anil K

    2009-10-01

    Carbonic anhydrase (CA; [EC 4.2.1.1]) is a ubiquitous enzyme catalysing the reversible hydration of CO(2) to bicarbonate, a reaction that supports various biochemical and physiological functions. Genome analysis of Azospirillum brasilense, a nonphotosynthetic, nitrogen-fixing, rhizobacterium, revealed an ORF with homology to beta-class carbonic anhydrases (CAs). Biochemical characteristics of the beta-class CA of A. brasilense, analysed after cloning the gene (designated as bca), overexpressing in Escherichia coli and purifying the protein by affinity purification, revealed that the native recombinant enzyme is a homotetramer, inhibited by the known CA inhibitors. CA activity in A. brasilense cell extracts, reverse transcriptase (RT)-PCR and Western blot analyses showed that bca was constitutively expressed under aerobic conditions. Lower beta-galactosidase activity in A. brasilense cells harbouring bca promoter: lacZ fusion during the stationary phase or during growth on 3% CO(2) enriched air or at acidic pH indicated that the transcription of bca was downregulated by the stationary phase, elevated CO(2) levels and acidic pH conditions. These observations were also supported by RT-PCR analysis. Thus, beta-CA in A. brasilense seems to be required for scavenging CO(2) from the ambient air and the requirement of CO(2) hydration seems to be higher for the cultures growing exponentially at neutral to alkaline pH.

  4. Thermodynamics of binding of a sulfonamide inhibitor to metal-mutated carbonic anhydrase as studied by affinity capillary electrophoresis.

    Science.gov (United States)

    Sato, Yosuke; Hoshino, Hitoshi; Iki, Nobuhiko

    2015-09-01

    By affinity capillary electrophoresis (ACE), the thermodynamic binding constants of a sulfonamide (SA) inhibitor to bovine carbonic anhydrase II (CA) and metal mutated variants (M-CAs) were evaluated. 1-(4-Aminosulfonylphenylazo)-2-naphthol-6,8-disulfonate was used as the SA in the electrophoretic buffer for ACE. The Scatchard analysis of the dependence of the electrophoretic mobility of native CA on the SA concentration provided the binding constant to be Kb=(2.29±0.05)×10(6) M(-1) (at pH8.4, 25°C). On the other hand, apoCA showed far smaller value [Kb=(3.76±0.14)×10(2) M(-1)], suggesting that the coordination of SA to the Zn(II) center controlled the binding thermodynamics. The ACE of M-CAs showed the same behaviors as native CA but with different Kb values. For example, Co-CA adopting the same tetrahedral coordination geometry as native CA exhibited the largest Kb value [(2.55±0.05)×10(6) M(-1)] among the M-CAs. In contrast, Mn- and Ni-CA, which adopted the octahedral coordination geometry, had Kb values that were about two orders of magnitude lower. Because the hydrophobic cavity of CA around the active center pre-organized the orientation of SA, thereby fixing the ligating NH(-) moiety to the apex of the tetrahedron supported by three basal His3 of CA, metals such as Zn and Co at the center of M-CA gave the most stable CA-SA complex. However, pre-organization was not favored for octahedral geometry. Thus, pre-organization of SA was the key to facilitating the tetrahedral coordination geometry of the Zn(II) active center of CA.

  5. In vivo imaging and quantification of carbonic anhydrase IX expression as an endogenous biomarker of tumor hypoxia.

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    Bagna Bao

    Full Text Available Carbonic anhydrase IX (CA IX is a transmembrane protein that has been shown to be greatly upregulated under conditions of hypoxia in many tumor cell lines. Tumor hypoxia is associated with impaired efficacy of cancer therapies making CA IX a valuable target for preclinical and diagnostic imaging. We have developed a quantitative in vivo optical imaging method for detection of CA IX as a marker of tumor hypoxia based on a near-infrared (NIR fluorescent derivative of the CA IX inhibitor acetazolamide (AZ. The agent (HS680 showed single digit nanomolar inhibition of CA IX as well as selectivity over other CA isoforms and demonstrated up to 25-fold upregulation of fluorescent CA IX signal in hypoxic versus normoxic cells, which could be blocked by 60%-70% with unlabeled AZ. CA IX negative cell lines (HCT-116 and MDA-MB-231, as well as a non-binding control agent on CA IX positive cells, showed low fluorescent signal under both conditions. In vivo FMT imaging showed tumor accumulation and excellent tumor definition from 6-24 hours. In vivo selectivity was confirmed by pretreatment of the mice with unlabeled AZ resulting in >65% signal inhibition. HS680 tumor signal was further upregulated >2X in tumors by maintaining tumor-bearing mice in a low oxygen (8% atmosphere. Importantly, intravenously injected HS680 signal was co-localized specifically with both CA IX antibody and pimonidazole (Pimo, and was located away from non-hypoxic regions indicated by a Hoechst stain. Thus, we have established a spatial correlation of fluorescence signal obtained by non-invasive, tomographic imaging of HS680 with regions of hypoxia and CA IX expression. These results illustrate the potential of HS680 and combined with FMT imaging to non-invasively quantify CA IX expression as a hypoxia biomarker, crucial to the study of the underlying biology of hypoxic tumors and the development and monitoring of novel anti-cancer therapies.

  6. Inhibition of carbonic anhydrase from Trypanosoma cruzi for the management of Chagas disease: an underexplored therapeutic opportunity.

    Science.gov (United States)

    Supuran, Claudiu T

    2016-01-01

    An α-carbonic anhydrases (CAs, EC 4.2.1.1) was recently discovered, cloned and characterized in the genome of the protozoan parasite Trypanosoma cruzi, the causative agent of Chagas disease, a neglected but widespread tropical disease. Inhibition of this α-CAs (TcCA) with anions, sulfonamides, sulfamates, thiols and hydroxamates has been investigated in detail, with several low nanomolar in vitro inhibitors. Although the sulfonamides were the best in vitro inhibitors, they showed no ex vivo anti-T. cruzi activity, due to poor penetration. However, some thiols and hydroxamates acting as low nanomolar TcCA inhibitors also showed significant antitrypanosomal ex vivo activity, making this enzyme an attractive yet underexplored drug target for the management of Chagas disease.

  7. A sucrose-binding site provides a lead towards an isoform-specific inhibitor of the cancer-associated enzyme carbonic anhydrase IX.

    Science.gov (United States)

    Pinard, Melissa A; Aggarwal, Mayank; Mahon, Brian P; Tu, Chingkuang; McKenna, Robert

    2015-10-01

    Human carbonic anhydrase (CA; EC 4.2.1.1) isoform IX (CA IX) is an extracellular zinc metalloenzyme that catalyzes the reversible hydration of CO2 to HCO3(-), thereby playing a role in pH regulation. The majority of normal functioning cells exhibit low-level expression of CA IX. However, in cancer cells CA IX is upregulated as a consequence of a metabolic transition known as the Warburg effect. The upregulation of CA IX for cancer progression has drawn interest in it being a potential therapeutic target. CA IX is a transmembrane protein, and its purification, yield and crystallization have proven challenging to structure-based drug design, whereas the closely related cytosolic soluble isoform CA II can be expressed and crystallized with ease. Therefore, we have utilized structural alignments and site-directed mutagenesis to engineer a CA II that mimics the active site of CA IX. In this paper, the X-ray crystal structure of this CA IX mimic in complex with sucrose is presented and has been refined to a resolution of 1.5 Å, an Rcryst of 18.0% and an Rfree of 21.2%. The binding of sucrose at the entrance to the active site of the CA IX mimic, and not CA II, in a non-inhibitory mechanism provides a novel carbohydrate moiety binding site that could be further exploited to design isoform-specific inhibitors of CA IX.

  8. The selective expression of carbonic anhydrase genes of Aspergillus nidulans in response to changes in mineral nutrition and CO2 concentration.

    Science.gov (United States)

    Xiao, Leilei; Lian, Bin; Dong, Cuiling; Liu, Fanghua

    2016-02-01

    Carbonic anhydrase (CA) plays an important role in the formation and evolution of life. However, to our knowledge, there has been no report on CA isoenzyme function differentiation in fungi. Two different CA gene sequences in Aspergillus nidulans with clear genetic background provide us a favorable basis for studying function differentiation of CA isoenzymes. Heterologously expressed CA1 was used to test its weathering ability on silicate minerals and real-time quantitative PCR was used to detect expression of the CA1 and CA2 genes at different CO2 concentrations and in the presence of different potassium sources. The northern blot method was applied to confirm the result of CA1 gene expression. Heterologously expressed CA1 significantly promoted dissolution of biotite and wollastonite, and CA1 gene expression increased significantly in response to soluble K-deficiency. The northern blot test further showed that CA1 participated in K-feldspar weathering. In addition, the results showed that CA2 was primary involved in adapting to CO2 concentration change. Taken together, A. nidulans can choose different CA to meet their survival needs, which imply that some environmental microbes have evolved different CAs to adapt to changes in CO2 concentration and acquire mineral nutrition so that they can better adapt to environmental changes. Inversely, their adaption may impact mineral weathering and/or CO2 concentration, and even global change.

  9. H,K-ATPase and carbonic anhydrase response to chronic systemic rat gastric hypoxia

    Directory of Open Access Journals (Sweden)

    Ulfah Lutfiah

    2015-11-01

    Full Text Available Background: Hypoxia may induce gastric ulcer associated with excessive hidrogen chloride (HCl secretion. Synthesis of HCl involves 2 enzymes, H,K-ATPase and carbonic anhydrase (CA. This study aimed to clarify the underlying cause of gastric ulcer in chronic hypoxic condition, by investigating the H,K-ATPase and CA9 response in rats.Methods: This study was an in vivo experiment, to know the relationship between hypoxia to expression of H,K-ATPase and CA9 mRNA, and H,K-ATPase and total CA specific activity of chronic systemic rat gastric hypoxia. The result was compared to control. Data was analyzed by SPSS. If the data distribution was normal and homogeneous, ANOVA and LSD post-hoc test were used. However, if the distribution was not normal and not homogeneous, and still as such after transformation, data was treated in non-parametric using Kruskal-Wallis and Mann Whitney test. Twenty five male Sprague-Dawley rats were divided into 5 groups: rats undergoing hypoxia for 1, 3, 5, and 7 days placed in hypoxia chamber (10% O2, 90% N2, and one control group. Following this treatment, stomach of the rats was extracted and homogenized. Expression of H,K-ATPase and CA9 mRNA was measured using real time RT-PCR. Specific activity of H,K-ATPase was measured using phosphate standard solution, and specific activity of total CA was measured using p-nitrophenol solution.Results: The expression of H,K-ATPase mRNA was higher in the first day (2.159, and drastically lowered from the third to seventh day (0.289; 0.108; 0.062. Specific activities of H,K-ATPase was slightly higher in the first day (0.765, then was lowered in the third (0.685 and fifth day (0.655, and was higher in the seventh day (0.884. The expression of CA9 mRNA was lowered progressively from the first to seventh day (0.84; 0.766; 0.736; 0.343. Specific activities of total CA was low in the first day (0.083, and was higher from the third to seventh day (0.111; 0.136; 0.144.Conclusion: In hypoxia

  10. A new class of quinazoline-sulfonamides acting as efficient inhibitors against the α-carbonic anhydrase from Trypanosoma cruzi.

    Science.gov (United States)

    Alafeefy, Ahmed M; Ceruso, Mariangela; Al-Jaber, Nabila A; Parkkila, Seppo; Vermelho, Alane Beatriz; Supuran, Claudiu T

    2015-01-01

    The protozoan parasite Trypanosoma cruzi is the agent responsible for trypanosomiasis (Chagas disease) in humans and other animals. It has been recently reported that this pathogen encodes for an α-class carbonic anhydrase (CA, EC 4.2.1.1), denominated TcCA, which was shown to be crucial for its life cycle. Inhibition studies of a class of 4-oxoquinazoline containing a benzensulfonamide moiety and their 4-thioxo bioisosteres against the protozoan enzyme TcCA are described here. Most of 4-oxoquinazoline sulfonamides showed nanomolar TcCA inhibition activity with K(I)s in the same order of magnitude of acetazolamide (AAZ), whereas their thioxo bioisosters showed moderate anti-Trypanosoma CA potency with K(I)s in the micromolar range. The discovery of compounds incorporating a 4-oxoquinazoline ring as a low-nanomolar TcCA inhibitor is quite promising and it may be useful for developing anti-Trypanosoma agents with a novel mechanism of action compared to the clinically used drugs (such as benznidazole, nifurtimox) for which significant resistance and serious adverse effects due to their high-toxicity appeared.

  11. Carbonic anhydrase activity in the vas deferens of the cotton leafworm - Spodoptera littoralis (Lepidoptera: Noctuidae) controlled by circadian clock.

    Science.gov (United States)

    Kotwica, J; Ciuk, M A; Joachimiak, E; Rowinski, S; Cymborowski, B; Bebas, P

    2006-11-01

    The male reproductive tract of Lepidoptera is an ideal model for the study of the physiological role of peripheral clocks in insects. The latter are significant in the generation and coordination of rhythmic phenomena which facilitate the initial stages of sperm capacitation. This process requires the maintenance of pH in the upper vas deferens (UVD) aided by, among others, H+-ATPase. Our aim was to determine the potential involvement of carbonic anhydrase (CA) in this process, an enzyme tasked with generating protons subsequently utilized by H+-ATPase to acidify the UVD milieu in S. littoralis, during the time when the lumen of this organ is filled with sperm. We attempted to answer the question whether CA activity can be controlled by the biological oscillator present in the male reproductive tract of the cotton leafworm. Using PAGE zymography, the presence of CA was demonstrated in the UVD wall, but not in the luminal fluid nor in the sperm. Using histochemistry, it was shown that CA is active in the UVD epithelium, and that this activity varies throughout the day and is most likely controlled by an endogenous biological clock. Conversely, the application of CA inhibitors, acetazolamide and sodium thiocyanate, in conjunction with an analysis of H+-ATPase activity in the acidification the UVD environment shows that CA most likely does not play a direct role in the regulation of the pH in this organ.

  12. Molecular and biochemical analysis of the α class carbonic anhydrases in Caenorhabditis elegans.

    Science.gov (United States)

    Fasseas, Michael K; Tsikou, Daniela; Flemetakis, Emmanouil; Katinakis, Panagiotis

    2011-03-01

    In this study, in silico analysis of the Caenorhabditis elegans genome revealed six genes (cah-1, cah-2, cah-3, cah-4, cah-5, and cah-6) possibly encoding α class CAs (carbonic anhydrase). Real-time RT-PCR analysis revealed the temporal expression pattern of each gene, as well as changes in expression levels under different atmospheric conditions (stress). Cah-3 and cah-4 showed the highest levels of transcript accumulation, while most genes responded to the stress conditions. Yeast complementation showed that cah-3 was able to complement the function of Saccharomyces cerevisiae CA (NCE103) in vivo. Recombinant CAH-3, CAH-4a and CAH-5 enzymes, expressed in Escherichia coli were used for in vitro measurement of CA activity. However, in vitro activity was only detectable for CAH-4a. RNAi by feeding was performed on wild-type C. elegans for all genes. The worms were examined for a visible phenotype under normal and stress conditions (pH, CO(2)/O(2)). Silencing cah-3 and cah-4 may reduce the life-span of the worms (at 22 °C).

  13. How to get into bones: proton pump and carbonic anhydrase in Osedax boneworms.

    Science.gov (United States)

    Tresguerres, Martin; Katz, Sigrid; Rouse, Greg W

    2013-06-22

    Osedax are gutless siboglinid worms that thrive on vertebrate bones lying on the ocean floor, mainly those of whales. The posterior body of female Osedax penetrates into the bone forming extensions known as 'roots', which host heterotrophic symbiotic bacteria in bacteriocytes beneath the epidermis. The Osedax root epithelium presumably absorbs bone collagen and/or lipids, which are metabolized by the symbiotic bacteria that in turn serve for Osedax's nutrition. Here, we show that Osedax roots express extremely high amounts of vacuolar-H(+)-ATPase (VHA), which is located in the apical membrane and in cytoplasmic vesicles of root and ovisac epithelial cells. The enzyme carbonic anhydrase (CA), which catalyses the hydration of CO2 into H(+) and HCO3(-), is also expressed in roots and throughout Osedax body. These results suggest Osedax roots have massive acid-secreting capacity via VHA, fuelled by H(+) derived from the CA-catalysed hydration of CO2 produced by aerobic metabolism. We propose the secreted acid dissolves the bone carbonate matrix to then allow the absorption of bone-derived nutrients across the skin. In an exciting example of convergent evolution, this model for acid secretion is remarkably similar to mammalian osteoclast cells. However, while osteoclasts dissolve bone for repairing and remodelling, the Osedax root epithelium secretes acid to dissolve foreign bone to access nutrients.

  14. Genetic polymorphisms in the carbonic anhydrase VI gene and dental caries susceptibility.

    Science.gov (United States)

    Li, Z-Q; Hu, X-P; Zhou, J-Y; Xie, X-D; Zhang, J-M

    2015-06-01

    We investigated the role of 7 single nucleotide polymorphisms in the carbonic anhydrase (CA) VI gene (rs2274328, rs17032907, rs11576766, rs2274333, rs10864376, rs3765964, and rs6680186) and the possible association between these polymorphisms and dental caries susceptibility in a Northwestern Chinese population. We collected samples from 164 high caries experience and 191 very low caries experience and conducted a case-control study according to the number of decayed, missing, and filled teeth index and genotyped the 7 polymorphisms using a 384-well plate format with the Sequenom MassARRAY platform. Individuals carrying the rs17032907 TT genotype were more likely to have an increased risk of dental caries compared with carriers of the C/C genotype in the co-dominant model, with an odds ratio (95% confidence interval) of 2.144 (1.096-4.195). We also found that the haplotype (ACA) (rs2274328, rs17032907 and rs11576766) was associated with a low number of decayed, missing, and filled teeth index with an odds ratio (95% confidence interval) of 0.635 (0.440-0.918). However, we found no association between dental caries susceptibility and the rs2274328, rs11576766, rs2274333, rs10864376, rs3765964, and rs6680186 polymorphisms and other haplotypes. The rs17032907 genetic variant and the haplotype (ACA) of CA VI may be associated with dental caries susceptibility.

  15. Effect of sulfonamides as carbonic anhydrase VA and VB inhibitors on mitochondrial metabolic energy conversion.

    Science.gov (United States)

    Arechederra, Robert L; Waheed, Abdul; Sly, William S; Supuran, Claudiu T; Minteer, Shelley D

    2013-03-15

    Obesity is quickly becoming an increasing problem in the developed world. One of the major fundamental causes of obesity and diabetes is mitochondria dysfunction due to faulty metabolic pathways which alter the metabolic substrate flux resulting in the development of these diseases. This paper examines the role of mitochondrial carbonic anhydrase (CA) isozymes in the metabolism of pyruvate, acetate, and succinate when specific isozyme inhibitors are present. Using a sensitive electrochemical approach of wired mitochondria to analytically measure metabolic energy conversion, we determine the resulting metabolic difference after addition of an inhibitory compound. We found that certain sulfonamide analogues displayed broad spectrum inhibition of metabolism, where others only had significant effect on some metabolic pathways. Pyruvate metabolism always displayed the most dramatically affected metabolism by the sulfonamides followed by fatty acid metabolism, and then finally succinate metabolism. This allows for the possibility of using designed sulfonamide analogues to target specific mitochondrial CA isozymes in order to subtly shift metabolism and glucogenesis flux to treat obesity and diabetes.

  16. Weapons and armament on the miniatures of Tabriz miniature school of the XV - XVI centuries

    OpenAIRE

    AHMADOV SABUHI AHMAD OGLU

    2015-01-01

    Tabriz miniature school is an important part of the art of the Middle East. The article discusses battle miniatures in which medieval artists reliably and historical accuracy depicted various weapons and armament. These miniatures can serve as an important historical source for the study of weapons of the XV XVI centuries. The main purpose of this article is to give the proof of these miniatures of art school which can be considered as a source for the study of arms and armament of the XV XVI...

  17. Structural elucidation of the hormonal inhibition mechanism of the bile acid cholate on human carbonic anhydrase II

    Energy Technology Data Exchange (ETDEWEB)

    Boone, Christopher D. [University of Florida, PO Box 100267, Gainesville, FL 32610 (United States); Tu, Chingkuang [University of Florida, PO Box 100245, Gainesville, FL 32610 (United States); McKenna, Robert, E-mail: rmckenna@ufl.edu [University of Florida, PO Box 100267, Gainesville, FL 32610 (United States)

    2014-06-01

    The structure of human carbonic anhydrase II in complex with cholate has been determined to 1.54 Å resolution. Elucidation of the novel inhibition mechanism of cholate will aid in the development of a nonsulfur-containing, isoform-specific therapeutic agent. The carbonic anhydrases (CAs) are a family of mostly zinc metalloenzymes that catalyze the reversible hydration/dehydration of CO{sub 2} into bicarbonate and a proton. Human isoform CA II (HCA II) is abundant in the surface epithelial cells of the gastric mucosa, where it serves an important role in cytoprotection through bicarbonate secretion. Physiological inhibition of HCA II via the bile acids contributes to mucosal injury in ulcerogenic conditions. This study details the weak biophysical interactions associated with the binding of a primary bile acid, cholate, to HCA II. The X-ray crystallographic structure determined to 1.54 Å resolution revealed that cholate does not make any direct hydrogen-bond interactions with HCA II, but instead reconfigures the well ordered water network within the active site to promote indirect binding to the enzyme. Structural knowledge of the binding interactions of this nonsulfur-containing inhibitor with HCA II could provide the template design for high-affinity, isoform-specific therapeutic agents for a variety of diseases/pathological states, including cancer, glaucoma, epilepsy and osteoporosis.

  18. Flight control system development for the XV - 15 tiltrotor aircraft%XV-15倾转旋翼飞机飞行控制系统概述

    Institute of Scientific and Technical Information of China (English)

    朱源

    2005-01-01

    XV-15倾转旋翼飞机兼有直升机垂直起降、空中悬停及固定翼飞机高速巡航的优点,因而在军用和民用飞机中有着广泛的应用前景.XV-15的机体结构和普通飞机一样,但在翼尖安装可以倾转的发动机短舱和旋翼.该飞机控制系统结合旋翼控制和固定翼控制,通过自动控制系统和推力管理系统来辅助飞行员对飞机的控制.主要介绍了主飞行控制系统和辅助控制系统的控制特点.

  19. Activity and stability of immobilized carbonic anhydrase for promoting CO2 absorption into a carbonate solution for post-combustion CO2 capture

    Science.gov (United States)

    Zhang, S.; Zhang, Z.; Lu, Y.; Rostam-Abadi, M.; Jones, A.

    2011-01-01

    An Integrated Vacuum Carbonate Absorption Process (IVCAP) currently under development could significantly reduce the energy consumed when capturing CO2 from the flue gases of coal-fired power plants. The biocatalyst carbonic anhydrase (CA) has been found to effectively promote the absorption of CO2 into the potassium carbonate solution that would be used in the IVCAP. Two CA enzymes were immobilized onto three selected support materials having different pore structures. The thermal stability of the immobilized CA enzymes was significantly greater than their free counterparts. For example, the immobilized enzymes retained at least 60% of their initial activities after 90days at 50??C compared to about 30% for their free counterparts under the same conditions. The immobilized CA also had significantly improved resistance to concentrations of sulfate (0.4M), nitrate (0.05M) and chloride (0.3M) typically found in flue gas scrubbing liquids than their free counterparts. ?? 2011 Elsevier Ltd.

  20. PREFACE: XV Mexican School of Particles and Fields

    Science.gov (United States)

    Salazar, Humberto; Napsuciale Mendivil, Mauro; Delepine, David

    2013-11-01

    The XV Mexican School of Particles and Fields was held at Puebla, Mexico at The Old and beautiful building of the Colegio Carolino from 6-15 September 2013. It gathered more than 132 national physicists, and 10 from other countries. This school lasted seven days and consisted of pedagogical lectures, discussions and poster sessions. Experimental, and theoretical developments were presented by distinguished physicists; addressing the most recent results in particle and field physics. The school lectures included topics on collider physics, neutrino physics, physics beyond the standard model, astroparticle physics, effective theories among others. The highlight topic of the conference was the discovery of the new boson, announced on 4 July 2012 by the LHC. The discovery of a particle consistent with the long-sought Higgs boson, considered one of the most important discoveries of the 21st Century, was fully addressed. The particle represented the final piece of the standard model. The searching methods and latest results were extensively presented as well as the detector design. The physics implications of the discovery and the future of searches for physics BSM, like SUSY, were covered. The topical conference included: 'Recent results on Higgs' by John Ellis, 'The CMS experiment, Highlights and Performance' by Tiziano Camporesi (CMS spokesperson), and 'LHC physics program by Emilio' Meschi (LHC physics coordinator). For many of the participants, however, the highlight of the school may have been the Sunday excursion to the Large Millimeter Telescope and HAWC Observatory, two of the world's largest astrophysics experiments in their field. We thank all the lecturers for making this a timely and informative school. Thanks to all who encouraged the discussions and stimulated the flow of information during the question time and the discussion sessions. Finally, the School and these Proceedings would have not been possible without the efforts of the sponsors as well as the

  1. PREFACE: XV International Seminar on Physics and Chemistry of Solids

    Science.gov (United States)

    Kotur, Bogdan; Brągiel, Piotr

    2011-03-01

                      Logo     Logo The XV International Seminar on Physics and Chemistry of Solids (ISPCS15) was held from 7-10 June 2009 in Szklarska Poręba. Over eighty participants joined together in this mountain resort, at the foot of Szrenica peak, in the Polish part of the Sudety range. The majority or participants, in accordance with Seminar tradition, were from Ukraine and Poland. The pleasant and warm atmosphere created by the organizers was conducive to fruitful discussions, making new contacts and to joyful gatherings with friends. Even the rainy weather could not change that. Lectures and communications mainly covered the fields of solid state physics and chemistry, and possible applications. This time, however, a new section was introduced - one devoted to modern topics in liquid chemistry. Sometimes such a look over the borders of scientific specialties leads to interesting insights and original research solutions. Some of the papers presented during ISPCS15 are collected in this volume. Their diversity is representative of both the scope and character of this Seminar. The majority of the papers are research reports, but a review article and a paper focussed on problems connected with environmental protection are also included. This Conference has functioned for over a decade due to the permanent support of the rectors of both co-organizing universities: Professor Ivan Vakarchuk from Ivan Franko National University of Lviv and Professor Zygmunt Bąk from Jan Dlugosz University in Częstochowa. It is our pleasure, on behalf of the all participants of the past Seminars, to express our gratitude for this assistance. We would also like to thank all the invited speakers who kindly accepted our invitation, namely Professors Roman Gladyshevskii (Ivan Franko National University, Lviv, Ukraine), Mihaela Gulea (Laboratoire de Chimie Moleculare et Thioorganique, CAEN, France), Osama I Abd El-Salam (National Research

  2. Cloning, expression and biochemical characterization of a β-carbonic anhydrase from the soil bacterium Enterobacter sp. B13.

    Science.gov (United States)

    Eminoğlu, Ayşenur; Vullo, Daniela; Aşık, Aycan; Çolak, Dilşat Nigar; Supuran, Claudiu T; Çanakçı, Sabriye; Osman Beldüz, Ali

    2016-12-01

    A recombinant carbonic anhydrase (CA, EC 4.2.1.1) from the soil-dwelling bacterium Enterobacter sp. B13 was cloned and purified by Co(2+) affinity chromatography. Bioinformatic analysis showed that the new enzyme (denominated here B13-CA) belongs to the β-class CAs and to possess 95% homology with the ortholog enzyme from Escherichia coli encoded by the can gene, whereas its sequence homology with the other such enzyme from E. coli (encoded by the cynT gene) was of 33%. B13-CA was characterized kinetically as a catalyst for carbon dioxide hydration to bicarbonate and protons. The enzyme shows a significant catalytic activity, with the following kinetic parameters at 20 °C and pH of 8.3: kcat of 4.8 × 10(5) s(-1) and kcat/Km of 5.6 × 10(7) M(-1) × s(-1). This activity was potently inhibited by acetazolamide which showed a KI of 78.9 nM. Although only this compound was investigated for the moment as B13-CA inhibitor, further studies may reveal new classes of inhibitors/activators of this enzyme which may show biomedical or environmental applications, considering the posssible role of this enzyme in CaCO3 biomineralization processes.

  3. Role of Carbonic Anhydrase as an Activator in Carbonate Rock Dissolution and Its Implication for Atmospheric CO2 Sink

    Institute of Scientific and Technical Information of China (English)

    刘再华

    2001-01-01

    The conversion of CO2 into H+ and is a relatively slow reaction. Hence, its kinetics may be rate determining in carbonate rock dissolution. Carbonic anhydrase (CA), which is widespread in nature, was used to catalyze the CO2 conversion process in dissolution experiments of limestone and dolomite. It was found that the rate of dissolution increases by a factor of about 10 after the addition of CA at a high CO2 partial pressure (Pco2) for limestone and about 3 at low Pco2 for dolomite. This shows that reappraisal is necessary for the importance of chemical weathering (including carbonate rock dissolution and silicate weathering) in the atmospheric CO2 sink and the mysterious missing sink in carbon cycling. It is doubtless that previous studies of weathering underestimated weathering rates due to the ignorance of CA as an activator in weathering, thus the contribution of weathering to the atmospheric CO2 sink is also underestimated. This finding also shows the need to examine the situ distribution and activity of CA in different waters and to investigate the role of CA in weathering.``

  4. Density functional theory study of proton transfer in carbonic anhydrase

    Institute of Scientific and Technical Information of China (English)

    ZHANG Lidong; XIE Daiqian

    2005-01-01

    Proton transfer in carbonic anhydrase II has been studied at the B3LYP/6-31G(D) level. The active site model consists of the zinc ion, four histidine residues, two threonine residues, and three water molecules. Our calculations showed that the proton of the zinc-bound water molecule could be transferred to the nearest water molecule and an intermediate containing H3O+ is then formed. The intermediate is only 1.3 kJ·mol-1 above the reactant complex, whereas the barrier height for the proton transfer is about 8.1 kJ·mol-1.

  5. Biochemical characterization of the native α-carbonic anhydrase purified from the mantle of the Mediterranean mussel, Mytilus galloprovincialis.

    Science.gov (United States)

    Perfetto, Rosa; Del Prete, Sonia; Vullo, Daniela; Sansone, Giovanni; Barone, Carmela; Rossi, Mosè; Supuran, Claudiu T; Capasso, Clemente

    2017-12-01

    A α-carbonic anhydrase (CA, EC 4.2.1.1) has been purified and characterized biochemically from the mollusk Mytilus galloprovincialis. As in most mollusks, this α-CA is involved in the biomineralization processes leading to the precipitation of calcium carbonate in the mussel shell. The new enzyme had a molecular weight of 50 kDa, which is roughly two times higher than that of a monomeric α-class enzyme. Thus, Mytilus galloprovincialis α-CA is either a dimer, or similar to the Tridacna gigas CA described earlier, may have two different CA domains in its polypeptide chain. The Mytilus galloprovincialis α-CA sequence contained the three His residues acting as zinc ligands and the gate-keeper residues present in all α-CAs (Glu106-Thr199), but had a Lys in position 64 and not a His as proton shuttling residue, being thus similar to the human isoform hCA III. This probably explains the relatively low catalytic activity of Mytilus galloprovincialis α-CA, with the following kinetic parameters for the CO2 hydration reaction: kcat = 4.1 × 10(5) s(-1) and kcat/Km of 3.6 × 10(7) M(-1) × s(-1). The enzyme activity was poorly inhibited by the sulfonamide acetazolamide, with a KI of 380 nM. This study is one of the few describing in detail the biochemical characterization of a molluskan CA and may be useful for understanding in detail the phylogeny of these enzymes, their role in biocalcification processes and their potential use in the biomimetic capture of the CO2.

  6. El Libro Temas Médicos. Tomo XV

    Directory of Open Access Journals (Sweden)

    Alberto Albornoz Plata

    1996-04-01

    Full Text Available

    Para presentar a ustedes el Libro Temas Médicos volumen XV, órgano oficial de la Academia, deseo recordar que esta publicación cumple hoy 25 años de existencia ininterrumpida, ya que los tomos I y II fueron publicados en 1970. De esta manera estamos celebrando realmente las “Bodas de Plata” de esta publicación.

    Quiero agradecer en la forma más sincera las frases muy amables que me dedica nuestro diligente Presidente de la Academia, doctor Gilberto Rueda Pérez, en el Prólogo.

    Una breve historia de Temas Médicos es la siguiente: En 1968 fui elegido Tesorero de la Junta Directiva que presidía el doctor Guillermo Uribe Cuella; el doctor Augusto Gast Galvis era el Vicepresidente y el doctor Héctor Pedraza, Secretario; traía la experiencia de la Sociedad Colombiana de Gastroenterología, en donde fui Editor de los Libros 11/ al XIII de Temas Escogidos de Gastroenterología, que hoy día ya se han publicado hasta el Tomo XXV: hablé directamente con el profesor Uribe Cualla, informándole sobre el interés para que la Academia publicara un libro anual o cada dos años y yo me encargaría de todo: Buscar la financiación y editarlo; acogió muy bien mi idea y así publiqué los Tomos 1 (de 600 páginas y el Tomo 1/ (de 870 páginas; en el Prólogo del Tomo 1 dice el doctor Uribe: “… así que este Volumen que lleva el título de Temas Médicos debe considerarse como la continuación de la Revista Médica que por mucho tiempo editó la Academia y que por razones de diversa índole hace ya un tiempo prolongado no se publica …”. Estos libros fueron publicados en 1970.

    En forma progresiva fui el Editor de los Temas siguientes, siendo también Tesorero en la Presidencia de Juan Pablo Llinás; en 1973 se publicó el Tomo VJJ conmemorativo a los cien años de fundada la Academia; posteriorme.nte con la Presidencia de Santiago Triana Cortés, Guillermo Rueda Montaña, César Augusto Pantoja, Hernando Groot, Pablo G

  7. Building reactive copper centers in human carbonic anhydrase II.

    Science.gov (United States)

    Song, He; Weitz, Andrew C; Hendrich, Michael P; Lewis, Edwin A; Emerson, Joseph P

    2013-08-01

    Reengineering metalloproteins to generate new biologically relevant metal centers is an effective a way to test our understanding of the structural and mechanistic features that steer chemical transformations in biological systems. Here, we report thermodynamic data characterizing the formation of two type-2 copper sites in carbonic anhydrase and experimental evidence showing one of these new, copper centers has characteristics similar to a variety of well-characterized copper centers in synthetic models and enzymatic systems. Human carbonic anhydrase II is known to bind two Cu(2+) ions; these binding events were explored using modern isothermal titration calorimetry techniques that have become a proven method to accurately measure metal-binding thermodynamic parameters. The two Cu(2+)-binding events have different affinities (K a approximately 5 × 10(12) and 1 × 10(10)), and both are enthalpically driven processes. Reconstituting these Cu(2+) sites under a range of conditions has allowed us to assign the Cu(2+)-binding event to the three-histidine, native, metal-binding site. Our initial efforts to characterize these Cu(2+) sites have yielded data that show distinctive (and noncoupled) EPR signals associated with each copper-binding site and that this reconstituted enzyme can activate hydrogen peroxide to catalyze the oxidation of 2-aminophenol.

  8. Azobenzene-based inhibitors of human carbonic anhydrase II

    Directory of Open Access Journals (Sweden)

    Leander Simon Runtsch

    2015-07-01

    Full Text Available Aryl sulfonamides are a widely used drug class for the inhibition of carbonic anhydrases. In the context of our program of photochromic pharmacophores we were interested in the exploration of azobenzene-containing sulfonamides to block the catalytic activity of human carbonic anhydrase II (hCAII. Herein, we report the synthesis and in vitro evaluation of a small library of nine photochromic sulfonamides towards hCAII. All molecules are azobenzene-4-sulfonamides, which are substituted by different functional groups in the 4´-position and were characterized by X-ray crystallography. We aimed to investigate the influence of electron-donating or electron-withdrawing substituents on the inhibitory constant Ki. With the aid of an hCAII crystal structure bound to one of the synthesized azobenzenes, we found that the electronic structure does not strongly affect inhibition. Taken together, all compounds are strong blockers of hCAII with Ki = 25–65 nM that are potentially photochromic and thus combine studies from chemical synthesis, crystallography and enzyme kinetics.

  9. Exclusive localization of carbonic anhydrase in bacteriocytes of the deep-sea clam Calyptogena okutanii with thioautotrophic symbiotic bacteria.

    Science.gov (United States)

    Hongo, Yuki; Nakamura, Yoshimitsu; Shimamura, Shigeru; Takaki, Yoshihiro; Uematsu, Katsuyuki; Toyofuku, Takashi; Hirayama, Hisako; Takai, Ken; Nakazawa, Masatoshi; Maruyama, Tadashi; Yoshida, Takao

    2013-12-01

    Deep-sea Calyptogena clams harbor thioautotrophic intracellular symbiotic bacteria in their gill epithelial cells. The symbiont fixes CO2 to synthesize organic compounds. Carbonic anhydrase (CA) from the host catalyzes the reaction CO2 + H2O ↔ HCO3(-) + H(+), and is assumed to facilitate inorganic carbon (Ci) uptake and transport to the symbiont. However, the localization of CA in gill tissue remains unknown. We therefore analyzed mRNA sequences, proteins and CA activity in Calyptogena okutanii using expression sequence tag, SDS-PAGE and LC-MS/MS. We found that acetazolamide-sensitive soluble CA was abundantly expressed in the gill tissue of C. okutanii, and the enzyme was purified by affinity chromatography. Mouse monoclonal antibodies against the CA of C. okutanii were used in western blot analysis and immunofluorescence staining of the gill tissues of C. okutanii, which showed that CA was exclusively localized in the symbiont-harboring cells (bacteriocytes) in gill epithelial cells. Western blot analysis and measurement of activity showed that CA was abundantly (26-72% of total soluble protein) detected in the gill tissues of not only Calyptogena clams but also deep-sea Bathymodiolus mussels that harbor thioautotrophic or methanotrophic symbiotic bacteria, but was not detected in a non-symbiotic mussel, Mytilus sp. The present study showed that CA is abundant in the gill tissues of deep-sea symbiotic bivalves and specifically localizes in the cytoplasm of bacteriocytes of C. okutanii. This indicates that the Ci supply process to symbionts in the vacuole (symbiosome) in bacteriocytes is essential for symbiosis.

  10. The archetype gamma-class carbonic anhydrase (Cam) contains iron when synthesized in vivo.

    Science.gov (United States)

    Macauley, Sheridan R; Zimmerman, Sabrina A; Apolinario, Ethel E; Evilia, Caryn; Hou, Ya-Ming; Ferry, James G; Sowers, Kevin R

    2009-02-10

    A recombinant protein overproduction system was developed in Methanosarcina acetivorans to facilitate biochemical characterization of oxygen-sensitive metalloenzymes from strictly anaerobic species in the Archaea domain. The system was used to overproduce the archetype of the independently evolved gamma-class carbonic anhydrase. The overproduced enzyme was oxygen sensitive and had full incorporation of iron instead of zinc observed when overproduced in Escherichia coli. This, the first report of in vivo iron incorporation for any carbonic anhydrase, supports the need to reevaluate the role of iron in all classes of carbonic anhydrases derived from anaerobic environments.

  11. Renal carbonic anhydrases are involved in the reabsorption of endogenous nitrite.

    Science.gov (United States)

    Chobanyan-Jürgens, Kristine; Schwarz, Alexandra; Böhmer, Anke; Beckmann, Bibiana; Gutzki, Frank-Mathias; Michaelsen, Jan T; Stichtenoth, Dirk O; Tsikas, Dimitrios

    2012-02-15

    Nitrite (ONO(-)) exerts nitric oxide (NO)-related biological actions and its concentration in the circulation may be of particular importance. Nitrite is excreted in the urine. Hence, the kidney may play an important role in nitrite/NO homeostasis in the vasculature. We investigated a possible involvement of renal carbonic anhydrases (CAs) in endogenous nitrite reabsorption in the proximal tubule. The potent CA inhibitor acetazolamide was administered orally to six healthy volunteers (5 mg/kg) and nitrite was measured in spot urine samples before and after administration. Acetazolamide increased abruptly nitrite excretion in the urine, strongly suggesting that renal CAs are involved in nitrite reabsorption in healthy humans. Additional in vitro experiments support our hypothesis that nitrite reacts with CO(2), analogous to the reaction of peroxynitrite (ONOO(-)) with CO(2), to form acid-labile nitrito carbonate [ONOC(O)O(-)]. We assume that this reaction is catalyzed by CAs and that nitrito carbonate represents the nitrite form that is actively transported into the kidney. The significance of nitrite reabsorption in the kidney and the underlying mechanisms, notably a direct involvement of CAs in the reaction between nitrite and CO(2), remain to be elucidated.

  12. Sulfonamide inhibition studies of the γ-carbonic anhydrase from the Antarctic bacterium Colwellia psychrerythraea.

    Science.gov (United States)

    Vullo, Daniela; De Luca, Viviana; Del Prete, Sonia; Carginale, Vincenzo; Scozzafava, Andrea; Osman, Sameh M; AlOthman, Zeid; Capasso, Clemente; Supuran, Claudiu T

    2016-02-15

    The Antarctic bacterium Colwellia psychrerythraea encodes for a γ-class carbonic anhydrase (CA, EC 4.2.1.1), which was cloned, purified and characterized. The enzyme (CpsCAγ) has a moderate catalytic activity for the physiologic reaction of CO2 hydration to bicarbonate and protons, with a k(cat) 6.0×10(5) s(-1) and a k(cat)/K(m) of 4.7×10(6) M(-1) s(-1). A series of sulfonamides and a sulfamate were investigated as inhibitors of the new enzyme. The best inhibitor was metanilamide (K(I) of 83.5 nM) followed by indisulam, valdecoxib, celecoxib, sulthiame and hydrochlorothiazide (K(I)s ranging between 343 and 491 nM). Acetazolamide, methazolamide as well as other aromatic/heterocyclic derivatives showed inhibition constants between 502 and 7660 nM. The present study may shed some more light regarding the role that γ-CAs play in the life cycle of psychrophilic bacteria as the Antarctic one investigated here, by allowing the identification of inhibitors which may be useful as pharmacologic tools.

  13. Inhibition of the alpha- and beta-carbonic anhydrases from the gastric pathogen Helycobacter pylori with anions.

    Science.gov (United States)

    Maresca, Alfonso; Vullo, Daniela; Scozzafava, Andrea; Supuran, Claudiu T

    2013-04-01

    The gastric pathogen Helicobacter pylori encodes two carbonic anhydrases (CAs, EC 4.2.1.1), an α- and a β-class one, hpαCA and hpβCA, crucial for its survival in the acidic environment from the stomach. Sulfonamides, strong inhibitors of these enzymes, block the growth of the pathogen, in vitro and in vivo. Here we report the inhibition of the two H. pylori CAs with inorganic and complex anions and other molecules interacting with zinc proteins. hpαCA was inhibited in the low micromolar range by diethyldithiocarbamate, sulfamide, sulfamic acid, phenylboronic acid, and in the submillimolar one by cyanide, cyanate, hydrogen sulfide, divanadate, tellurate, perruthenate, selenocyanide, trithiocarbonate, iminodisulfonate. hpβCA generally showed a stronger inhibition with most of these anions, with several low micromolar and many submillimolar inhibitors detected. These inhibitors may be used as leads for developing anti-H. pylori agents with a diverse mechanism of action compared to clinically used antibiotics.

  14. Impacts of Elevated CO2 Concentration on Biochemical Composition,Carbonic Anhydrase, and Nitrate Reductase Activity of Freshwater Green Algae

    Institute of Scientific and Technical Information of China (English)

    Jian-Rong XIA; Kun-Shan GAO

    2005-01-01

    To investigate the biochemical response of freshwater green algae to elevated CO2 concentrations,Chlorella pyrenoidosa Chick and Chlamydomonas reinhardtii Dang cells were cultured at different CO2concentrations within the range 3-186 μmol/L and the biochemical composition, carbonic anhydrase (CA),and nitrate reductase activities of the cells were investigated. Chlorophylls (Chl), carotenoids, carbonhydrate,and protein contents were enhanced to varying extents with increasing CO2 concentration from 3-186μmol/L. The CO2 enrichment significantly increased the Chl a/Chl b ratio in Chlorella pyrenoidosa, but not in Chlamydomonas reinhardtii. The CO2 concentration had significant effects on CA and nitrate reductase activity. Elevating CO2 concentration to 186 μmol/L caused a decline in intracellular and extracellullar CA activity. Nitrate reductase activity, under either light or dark conditions, in C. reinhardtii and C. pyrenoidosa was also significantly decreased with CO2 enrichment. From this study, it can be concluded that CO2enrichment can affect biochemical composition, CA, and nitrate reductase activity, and that the biochemical response was species dependent.

  15. Poly(amidoamine) dendrimers show carbonic anhydrase inhibitory activity against α-, β-, γ- and η-class enzymes.

    Science.gov (United States)

    Carta, Fabrizio; Osman, Sameh M; Vullo, Daniela; AlOthman, Zeid; Del Prete, Sonia; Capasso, Clemente; Supuran, Claudiu T

    2015-11-01

    Four generations of poly(amidoamine) (PAMAM) dendrimers incorporating benzenesulfonamide moieties were investigated as inhibitors of carbonic anhydrases (CAs, EC 4.2.1.1) belonging to the α-, β-, γ- and η-classes which are present in pathogenic bacteria, fungi or protozoa. The following bacterial, fungal and protozoan organisms were included in the study: Vibrio cholerae, Trypanosoma cruzi, Leishmania donovani chagasi, Porphyromonas gingivalis, Cryptococcus neoformans, Candida glabrata, and Plasmodium falciparum. The eight pathozymes present in these organisms were efficiently inhibited by the four generations PAMAM-sulfonamide dendrimers, but multivalency effects were highly variable among the different enzyme classes. The Vibrio enzyme VchCA was best inhibited by the G3 dendrimer incorporating 32 sulfamoyl moieties. The Trypanosoma enzyme TcCA on the other hand was best inhibited by the first generation dendrimer G0 (with 4 sulfamoyl groups), whereas for other enzymes the optimal inhibitory power was observed for the G1 or G2 dendrimers, with 8 and 16 sulfonamide functionalities. This study thus proves that the multivalency may be highly relevant for enzyme inhibition for some but not all CAs from pathogenic organisms. On the other hand, some dendrimers investigated here showed a better inhibitory power compared to acetazolamide for enzymes from widespread pathogens, such as the η-CA from Plasmodium falciparum. Overall, the main conclusion is that this class of molecules may lead to important developments in the field of anti-infective CA inhibitors.

  16. Carbonic anhydrase inhibitors: Design, synthesis, kinetic, docking and molecular dynamics analysis of novel glycine and phenylalanine sulfonamide derivatives.

    Science.gov (United States)

    Fidan, İsmail; Salmas, Ramin Ekhteiari; Arslan, Mehmet; Şentürk, Murat; Durdagi, Serdar; Ekinci, Deniz; Şentürk, Esra; Coşgun, Sedat; Supuran, Claudiu T

    2015-12-01

    The inhibition of two human cytosolic carbonic anhydrase isozymes I and II, with some novel glycine and phenylalanine sulfonamide derivatives were investigated. Newly synthesized compounds G1-4 and P1-4 showed effective inhibition profiles with KI values in the range of 14.66-315μM for hCA I and of 18.31-143.8μM against hCA II, respectively. In order to investigate the binding mechanisms of these inhibitors, in silico docking studies were applied. Atomistic molecular dynamic simulations were performed for docking poses which utilize to illustrate the inhibition mechanism of used inhibitors into active site of CAII. These sulfonamide containing compounds generally were competitive inhibitors with 4-nitrophenylacetate as substrate. Some investigated compounds here showed effective hCA II inhibitory effects, in the same range as the clinically used sulfonamide, sulfanilamide or mafenide and might be used as leads for generating enzyme inhibitors possibly targeting other CA isoforms which have not been yet assayed for their interactions with such agents.

  17. Cloning, characterization and anion inhibition study of a β-class carbonic anhydrase from the caries producing pathogen Streptococcus mutans.

    Science.gov (United States)

    Dedeoglu, Nurcan; De Luca, Viviana; Isik, Semra; Yildirim, Hatice; Kockar, Feray; Capasso, Clemente; Supuran, Claudiu T

    2015-07-01

    The oral pathogenic bacterium involved in human dental caries formation Streptococcus mutans, encodes for two carbonic anhydrase (CA, EC 4.2.1.1) one belonging to the α- and the other one to the β-class. This last enzyme (SmuCA) has been cloned, characterized and investigated for its inhibition profile with a major class of CA inhibitors, the inorganic anions. Here we show that SmuCA has a good catalytic activity for the CO2 hydration reaction, with kcat 4.2×10(5)s(-1) and kcat/Km of 5.8×10(7)M(-1)×s(-1), being inhibited by cyanate, carbonate, stannate, divannadate and diethyldithiocarbamate in the submillimolar range (KIs of 0.30-0.64mM) and more efficiently by sulfamide, sulfamate, phenylboronic acid and phenylarsonic acid (KIs of 15-46μM). The anion inhibition profile of the S. mutans enzyme is very different from other α- and β-CAs investigated earlier. Identification of effective inhibitors of this new enzyme may lead to pharmacological tools useful for understanding the role of S. mutans CAs in dental caries formation, and eventually the development of pharmacological agents with a new mechanism of antibacterial action.

  18. Gene encoding γ-carbonic anhydrase is cotranscribed with argC and induced in response to stationary phase and high CO2 in Azospirillum brasilense Sp7

    Directory of Open Access Journals (Sweden)

    Mishra Mukti N

    2010-07-01

    Full Text Available Abstract Background Carbonic anhydrase (CA is a ubiquitous enzyme catalyzing the reversible hydration of CO2 to bicarbonate, a reaction underlying diverse biochemical and physiological processes. Gamma class carbonic anhydrases (γ-CAs are widespread in prokaryotes but their physiological roles remain elusive. At present, only γ-CA of Methanosarcina thermophila (Cam has been shown to have CA activity. Genome analysis of a rhizobacterium Azospirillum brasilense, revealed occurrence of ORFs encoding one β-CA and two γ-CAs. Results One of the putative γ-CA encoding genes of A. brasilense was cloned and overexpressed in E. coli. Electrometric assays for CA activity of the whole cell extracts overexpressing recombinant GCA1 did not show CO2 hydration activity. Reverse transcription-PCR analysis indicated that gca1 in A. brasilense is co-transcribed with its upstream gene annotated as argC, which encodes a putative N-acetyl-γ-glutamate-phosphate reductase. 5'-RACE also demonstrated that there was no transcription start site between argC and gca1, and the transcription start site located upstream of argC transcribed both the genes (argC-gca1. Using transcriptional fusions of argC-gca1 upstream region with promoterless lacZ, we further demonstrated that gca1 upstream region did not have any promoter and its transcription occurred from a promoter located in the argC upstream region. The transcription of argC-gca1 operon was upregulated in stationary phase and at elevated CO2 atmosphere. Conclusions This study shows lack of CO2 hydration activity in a recombinant protein expressed from a gene predicted to encode a γ-carbonic anhydrase in A. brasilense although it cross reacts with anti-Cam antibody raised against a well characterized γ-CA. The organization and regulation of this gene along with the putative argC gene suggests its involvement in arginine biosynthetic pathway instead of the predicted CO2 hydration.

  19. Evidence for an early evolutionary emergence of γ-type carbonic anhydrases as components of mitochondrial respiratory complex I

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    Gray Michael W

    2010-06-01

    Full Text Available Abstract Background The complexity of mitochondrial complex I (CI; NADH:ubiquinone oxidoreductase has increased considerably relative to the homologous complex in bacteria. Comparative analyses of CI composition in animals, fungi and land plants/green algae suggest that novel components of mitochondrial CI include a set of 18 proteins common to all eukaryotes and a variable number of lineage-specific subunits. In plants and green algae, several purportedly plant-specific proteins homologous to γ-type carbonic anhydrasesCA have been identified as components of CI. However, relatively little is known about CI composition in the unicellular protists, the characterizations of which are essential to our understanding of CI evolution. Results We have performed a tandem mass spectrometric characterization of CI from the amoeboid protozoon Acanthamoeba castellanii. Among the proteins identified were two γCA homologs, AcCa1 and AcCa2, demonstrating that γCA proteins are not specific to plants/green algae. In fact, through bioinformatics searches we detected γCA homologs in diverse protist lineages, and several of these homologs are predicted to possess N-terminal mitochondrial targeting peptides. Conclusions The detection of γCAs in CI of Acanthamoeba, considered to be a closer relative of animals and fungi than plants, suggests that γCA proteins may have been an ancestral feature of mitochondrial CI, rather than a novel, plant-specific addition. This assertion is supported by the presence of genes encoding γCAs in the nuclear genomes of a wide variety of eukaryotes. Together, these findings emphasize the importance of a phylogenetically broad characterization of CI for elucidating CI evolution in eukaryotes.

  20. Carbonic anhydrase IX, a hypoxia-induced catalytic component of the pH regulating machinery in tumors.

    Science.gov (United States)

    Sedlakova, Olga; Svastova, Eliska; Takacova, Martina; Kopacek, Juraj; Pastorek, Jaromir; Pastorekova, Silvia

    2014-01-08

    Acidic tissue microenvironment contributes to tumor progression via multiple effects including the activation of angiogenic factors and proteases, reduced cell-cell adhesion, increased migration and invasion, etc. In addition, intratumoral acidosis can influence the uptake of anticancer drugs and modulate the response of tumors to conventional therapy. Acidification of the tumor microenvironment often develops due to hypoxia-triggered oncogenic metabolism, which leads to the extensive production of lactate, protons, and carbon dioxide. In order to avoid intracellular accumulation of the acidic metabolic products, which is incompatible with the survival and proliferation, tumor cells activate molecular machinery that regulates pH by driving transmembrane inside-out and outside-in ion fluxes. Carbonic anhydrase IX (CA IX) is a hypoxia-induced catalytic component of the bicarbonate import arm of this machinery. Through its catalytic activity, CA IX directly participates in many acidosis-induced features of tumor phenotype as demonstrated by manipulating its expression and/or by in vitro mutagenesis. CA IX can function as a survival factor protecting tumor cells from hypoxia and acidosis, as a pro-migratory factor facilitating cell movement and invasion, as a signaling molecule transducing extracellular signals to intracellular pathways (including major signaling and metabolic cascades) and converting intracellular signals to extracellular effects on adhesion, proteolysis, and other processes. These functional implications of CA IX in cancer are supported by numerous clinical studies demonstrating the association of CA IX with various clinical correlates and markers of aggressive tumor behavior. Although our understanding of the many faces of CA IX is still incomplete, existing knowledge supports the view that CA IX is a biologically and clinically relevant molecule, exploitable in anticancer strategies aimed at targeting adaptive responses to hypoxia and/or acidosis.

  1. Optic nerve oxygen tension in pigs and the effect of carbonic anhydrase inhibitors

    DEFF Research Database (Denmark)

    Stefánsson, E; Jensen, P K; Eysteinsson, T;

    1999-01-01

    To evaluate how the oxygen tension of the optic nerve (ONP(O)2) is affected by the administration of the carbonic anhydrase inhibitors dorzolamide and acetazolamide and by alterations in oxygen and carbon dioxide in the breathing mixture....

  2. Phosphorylation controls the localization and activation of the lumenal carbonic anhydrase in Chlamydomonas reinhardtii.

    Directory of Open Access Journals (Sweden)

    Amaya Blanco-Rivero

    Full Text Available BACKGROUND: Cah3 is the only carbonic anhydrase (CA isoform located in the thylakoid lumen of Chlamydomonas reinhardtii. Previous studies demonstrated its association with the donor side of the photosystem II (PSII where it is required for the optimal function of the water oxidizing complex. However this enzyme has also been frequently proposed to perform a critical function in inorganic carbon acquisition and CO(2 fixation and all mutants lacking Cah3 exhibit very poor growth after transfer to low CO(2 conditions. RESULTS/CONCLUSIONS: In the present work we demonstrate that after transfer to low CO(2, Cah3 is phosphorylated and that phosphorylation is correlated to changes in its localization and its increase in activity. When C. reinhardtii wild-type cells were acclimated to limiting CO(2 conditions, the Cah3 activity increased about 5-6 fold. Under these conditions, there were no detectable changes in the level of the Cah3 polypeptide. The increase in activity was specifically inhibited in the presence of Staurosporine, a protein kinase inhibitor, suggesting that the Cah3 protein was post-translationally regulated via phosphorylation. Immunoprecipitation and in vitro dephosphorylation experiments confirm this hypothesis. In vivo phosphorylation analysis of thylakoid polypeptides indicates that there was a 3-fold increase in the phosphorylation signal of the Cah3 polypeptide within the first two hours after transfer to low CO(2 conditions. The increase in the phosphorylation signal was correlated with changes in the intracellular localization of the Cah3 protein. Under high CO(2 conditions, the Cah3 protein was only associated with the donor side of PSII in the stroma thylakoids. In contrast, in cells grown at limiting CO(2 the protein was partly concentrated in the thylakoids crossing the pyrenoid, which did not contain PSII and were surrounded by Rubisco molecules. SIGNIFICANCE: This is the first report of a CA being post

  3. Carbonic anhydrase inhibition increases retinal oxygen tension and dilates retinal vessels

    DEFF Research Database (Denmark)

    Pedersen, Daniella Bach; Koch Jensen, Peter; la Cour, Morten

    2005-01-01

    Carbonic anhydrase inhibitors (CAIs) increase blood flow in the brain and probably also in the optic nerve and retina. Additionally they elevate the oxygen tension in the optic nerve in the pig. We propose that they also raise the oxygen tension in the retina. We studied the oxygen tension...... in the pig retina and optic nerve before and after dorzolamide injection. Also the retinal vessel diameters during carbonic anhydrase inhibition were studied....

  4. Carbonic anhydrase inhibition increases retinal oxygen tension and dilates retinal vessels

    DEFF Research Database (Denmark)

    Pedersen, Daniella Bach; Koch Jensen, Peter; la Cour, Morten;

    2005-01-01

    Carbonic anhydrase inhibitors (CAIs) increase blood flow in the brain and probably also in the optic nerve and retina. Additionally they elevate the oxygen tension in the optic nerve in the pig. We propose that they also raise the oxygen tension in the retina. We studied the oxygen tension in the...... in the pig retina and optic nerve before and after dorzolamide injection. Also the retinal vessel diameters during carbonic anhydrase inhibition were studied....

  5. Inhibition of carbonic anhydrase isoforms I, II, IX and XII with novel Schiff bases: identification of selective inhibitors for the tumor-associated isoforms over the cytosolic ones.

    Science.gov (United States)

    Sarikaya, Busra; Ceruso, Mariangela; Carta, Fabrizio; Supuran, Claudiu T

    2014-11-01

    A series of new Schiff bases was obtained from sulfanilamide, 3-fluorosulfanilamide or 4-(2-aminoethyl)-benzenesulfonamide and aromatic/heterocyclic aldehydes incorporating both hydrophobic and hydrophilic moieties. The obtained sulfonamides were investigated as inhibitors of four physiologically relevant carbonic anhydrase (CA, EC 4.2.1.1) isoforms, the cytosolic CA I and II, as well as the transmembrane, tumor-associated CA IX and XII. Most derivatives were medium potency or weak hCA I/II inhibitors, but several of them showed nanomolar affinity for CA IX and/or XII, making them an interesting example of isoform-selective compounds. The nature of the aryl/hetaryl moiety present in the initial aldehyde was the main factor influencing potency and isoform selectivity. The best and most CA IX-selective compounds incorporated moieties such as 4-methylthiophenyl, 4-cyanophenyl-, 4-(2-pyridyl)-phenyl and the 4-aminoethylbenzenesulfonamide scaffold. The best hCA XII inhibitors, also showing selectivity for this isoform, incorporated 2-methoxy-4-nitrophenyl-, 2,3,5,6-tetrafluorophenyl and 4-(2-pyridyl)-phenyl functionalities and were also derivatives of 4-aminoethylbenzenesulfonamide. The sulfanilamide and 3-fluorosulfanilamide derived Schiff bases were less active compared to the corresponding 4-aminoethyl-benzenesulfonamide derivatives. As hCA IX/XII selective inhibition is attractive for obtaining antitumor agents/diagnostic tools with a new mechanism of action, compounds of the type described here may be considered interesting preclinical candidates.

  6. Design and synthesis of benzothiazole-6-sulfonamides acting as highly potent inhibitors of carbonic anhydrase isoforms I, II, IX and XII.

    Science.gov (United States)

    Ibrahim, Diaa A; Lasheen, Deena S; Zaky, Maysoun Y; Ibrahim, Amany W; Vullo, Daniela; Ceruso, Mariangela; Supuran, Claudiu T; Abou El Ella, Dalal A

    2015-08-01

    A series of novel 2-aminobenzothiazole derivatives bearing sulfonamide at position 6 was designed, synthesized and investigated as inhibitors of four isoforms of the metalloenzyme carbonic anhydrase (CA, EC 4.2.1.1), the cytosolic CA I and II, and the tumor-associated isozymes CA IX and XII. Docking and binding energy studies were carried out to reveal details regarding the favorable interactions between the scaffolds of these new inhibitors and the active sites of the investigated CA isoforms. Most of the novel compounds were acting as highly potent inhibitors of the tumor-associated hCA IX and hCA XII with KIs in the nanomolar range. The ubiquitous and dominant rapid cytosolic isozyme hCA II was also inhibited with KIs ranging from 3.5 to 45.4 nM. The favorable interactions between some of the new compounds and the active site of different CA isoforms were delineated by using molecular docking which may be useful for designing compounds with high affinity and selectivity for some CAs with biomedical applications.

  7. Carbonic Anhydrase: An Efficient Enzyme with Possible Global Implications

    Directory of Open Access Journals (Sweden)

    Christopher D. Boone

    2013-01-01

    Full Text Available As the global atmospheric emissions of carbon dioxide (CO2 and other greenhouse gases continue to grow to record-setting levels, so do the demands for an efficient and inexpensive carbon sequestration system. Concurrently, the first-world dependence on crude oil and natural gas provokes concerns for long-term availability and emphasizes the need for alternative fuel sources. At the forefront of both of these research areas are a family of enzymes known as the carbonic anhydrases (CAs, which reversibly catalyze the hydration of CO2 into bicarbonate. CAs are among the fastest enzymes known, which have a maximum catalytic efficiency approaching the diffusion limit of 108 M−1s−1. As such, CAs are being utilized in various industrial and research settings to help lower CO2 atmospheric emissions and promote biofuel production. This review will highlight some of the recent accomplishments in these areas along with a discussion on their current limitations.

  8. Carbonic anhydrase in Escherichia coli. A product of the cyn operon.

    Science.gov (United States)

    Guilloton, M B; Korte, J J; Lamblin, A F; Fuchs, J A; Anderson, P M

    1992-02-25

    The product of the cynT gene of the cyn operon in Escherichia coli has been identified as a carbonic anhydrase. The cyn operon also includes the gene cynS, encoding the enzyme cyanase. Cyanase catalyzes the reaction of cyanate with bicarbonate to give ammonia and carbon dioxide. The carbonic anhydrase was isolated from an Escherichia coli strain overexpressing the cynT gene and characterized. The purified enzyme was shown to contain 1 Zn2+/subunit (24 kDa) and was found to behave as an oligomer in solution; the presence of bicarbonate resulted in partial dissociation of the oligomeric enzyme. The kinetic properties of the enzyme are similar to those of carbonic anhydrases from other species, including inhibition by sulfonamides and cyanate. The amino acid sequence shows a high degree of identity with the sequences of two plant carbonic anhydrases. but not with animal and algal carbonic anhydrases. Since carbon dioxide formed in the bicarbonate-dependent decomposition of cyanate diffuses out of the cell faster than it would be hydrated to bicarbonate, the apparent function of the induced carbonic anhydrase is to catalyze hydration of carbon dioxide and thus prevent depletion of cellular bicarbonate.

  9. Complexes With Biologically Active Ligands. Part 111. Synthesis and Carbonic Anhydrase Inhibitory Activity of Metal Complexes of 4,5-Disubstituted-3-Mercapto-1,2,4-Triazole Derivatives

    Science.gov (United States)

    Scozzafava, Andrea; Cavazza, Christine; Saramet, Ioana; Briganti, Fabrizio; Banciu, Mircea D.

    1998-01-01

    Complexes containing five 4,5-disubstituted-3-mercapto-1,2,4-triazoles and Zn(II), Hg(II) and Cu(I) were synthesized and characterized by standard procedures (elemental analysis; IR, electronic and NMR spectroscopy, conductimetry and TG analysis). Both the thione as well as the thiolate forms of the ligands were evidenced to interact with the metal ions in the prepared complexes. The original mercaptans and their metal complexes behave as inhibitors of three carbonic anhydrase (CA) isozymes, CA I, II and IV, but did not lower intraocular pressure in rabbits in animal models of glaucoma. PMID:18475819

  10. Complexes with biologically active ligands. Part 11. Synthesis and carbonic anhydrase inhibitory activity of metal complexes of 4,5-disubstituted-3-mercapto-1,2,4-triazole derivatives.

    Science.gov (United States)

    Scozzafava, A; Cavazza, C; Supuran, C T; Saramet, I; Briganti, F; Banciu, M D

    1998-01-01

    Complexes containing five 4,5-disubstituted-3-mercapto-1,2,4-triazoles and Zn(II), Hg(II) and Cu(I) were synthesized and characterized by standard procedures (elemental analysis; IR, electronic and NMR spectroscopy, conductimetry and TG analysis). Both the thione as well as the thiolate forms of the ligands were evidenced to interact with the metal ions in the prepared complexes. The original mercaptans and their metal complexes behave as inhibitors of three carbonic anhydrase (CA) isozymes, CA I, II and IV, but did not lower intraocular pressure in rabbits in animal models of glaucoma.

  11. Bio-sequestration of CO2 Using Carbonic Anhydrase in situ Encapsulated Inside Electrospun Hollow Fibers%静电纺丝制备中空纤维原位固定化碳酸酐酶用于二氧化碳的吸收

    Institute of Scientific and Technical Information of China (English)

    崔建东; 李莹; 姬晓元; 边红杰; 张羽飞; 苏志国; 马光辉; 张松平

    2014-01-01

    Carbonic anhydrase catalyzed bio-sequestration of CO2 to form HCO-3 , followed by trapping as solid CaCO3 is one of the most promising technologies for CO2 capturing. The effects of reaction condition on the CO2 hydration using free carbonic anhydrase were systematically investigated. In order to improve the stability of the enzyme and facility its recycling, the carbonic anhydrase was in situ encapsulated inside hollow fibers via a novel co-axial electrospinning technology. Compared with the free enzyme, the immobilized carbonic an-hydrase showed much improved thermal stability and suffered much reduced inhibitory effects from cation ions, such as Cu2+ and Fe3+. After 11 reuses, the immobilized enzyme retained about 81. 9% of its original activity by comparing the amount of formed CaCO3 precipitation. In the presence of immobilized carbonic anhydrase, both calcite and vaterite CaCO3 solid were formed;while in the absence of enzyme or with free carbonic anhy-drase, only calcite CaCO3 was observed.%考察了游离碳酸酐酶吸收CO2水合体系反应条件,并通过同轴共纺静电纺丝技术制备出中空结构纤维,实现了碳酸酐酶在中空纤维中的原位包埋,提高了酶的稳定性并便于回收和重复利用.实验结果表明,固定化碳酸酐酶的热稳定性显著增强,受Cu2+和Fe3+等金属离子的抑制作用大幅度降低.连续使用11次后所生成的CaCO3沉淀量仍能达到首次使用的81.9%.固定化酶体系生成的CaCO3沉淀包括方解石型和球文石型2种晶形,而无酶和加入游离碳酸酐酶的反应体系则主要生成方解石型CaCO3沉淀.

  12. Sulfonamide inhibition studies of the β-carbonic anhydrase from the newly discovered bacterium Enterobacter sp. B13.

    Science.gov (United States)

    Eminoğlu, Ayşenur; Vullo, Daniela; Aşık, Aycan; Çolak, Dilşat Nigar; Çanakçı, Sabriye; Beldüz, Ali Osman; Supuran, Claudiu T

    2016-04-01

    The genome of the newly identified bacterium Enterobacter sp. B13 encodes for a β-class carbonic anhydrases (CAs, EC 4.2.1.1), EspCA. This enzyme was recently cloned, and characterized kinetically by this group (J. Enzyme Inhib. Med. Chem. 2016, 31). Here we report an inhibition study with sulfonamides and sulfamates of this enzyme. The best EspCA inhibitors were some sulfanylated sulfonamides with elongated molecules, metanilamide, 4-aminoalkyl-benzenesulfonamides, acetazolamide, and deacetylated methazolamide (KIs in the range of 58.7-96.5nM). Clinically used agents such as methazolamide, ethoxzolamide, dorzolamide, brinzolamide, benzolamide, zonisamide, sulthiame, sulpiride, topiramate and valdecoxib were slightly less effective inhibitors (KIs in the range of 103-138nM). Saccharin, celecoxib, dichlorophenamide and many simple benzenesulfonamides were even less effective as EspCA inhibitors, with KIs in the range of 384-938nM. Identification of effective inhibitors of this bacterial enzyme may lead to pharmacological tools useful for understanding the physiological role(s) of the β-class CAs in bacterial pathogenicity/virulence.

  13. Intrinsic thermodynamics of 4-substituted-2,3,5,6-tetrafluorobenzenesulfonamide binding to carbonic anhydrases by isothermal titration calorimetry.

    Science.gov (United States)

    Zubrienė, Asta; Smirnovienė, Joana; Smirnov, Alexey; Morkūnaitė, Vaida; Michailovienė, Vilma; Jachno, Jelena; Juozapaitienė, Vaida; Norvaišas, Povilas; Manakova, Elena; Gražulis, Saulius; Matulis, Daumantas

    2015-10-01

    Para substituted tetrafluorobenzenesulfonamides bind to carbonic anhydrases (CAs) extremely tightly and exhibit some of the strongest known protein-small ligand interactions, reaching an intrinsic affinity of 2 pM as determined by displacement isothermal titration calorimetry (ITC). The enthalpy and entropy of binding to five CA isoforms were measured by ITC in two buffers of different protonation enthalpies. The pKa values of compound sulfonamide groups were measured potentiometrically and spectrophotometrically, and enthalpies of protonation were measured by ITC in order to evaluate the proton linkage contributions to the observed binding thermodynamics. Intrinsic means the affinity of a sulfonamide anion for the Zn bound water form of CAs. Fluorination of the benzene ring significantly enhanced the observed affinities as it increased the fraction of deprotonated ligand while having little impact on intrinsic affinities. Intrinsic enthalpy contributions to the binding affinity were dominant over entropy and were more exothermic for CA I than for other CA isoforms. Thermodynamic measurements together with the X-ray crystallographic structures of protein-ligand complexes enabled analysis of structure-activity relationships in this enzyme ligand system.

  14. Carbonic Anhydrase VI Gene Polymorphism rs2274327 Relationship Between Salivary Parameters and Dental-Oral Health Status in Children.

    Science.gov (United States)

    Sengul, Fatih; Kilic, Munevver; Gurbuz, Taskin; Tasdemir, Sener

    2016-08-01

    The aim of this study was to research carbonic anhydrase (CA) VI one single-nucleotide polymorphism (SNP) and its potential association with dental-oral health status (dental caries, Plaque Index (PI) and Gingival Index (GI)) and salivary parameters (salivary buffering capacity, salivary flow rate (SFR)) in children. A total of 178 children were divided into two groups: non-carious (n = 70, 34 boys and 36 girls) and carious (n = 108, 47 boys and 61 girls). The clinical evaluations were performed according to the decayed, missing, and filled teeth (dmft/DMFT) index by a specialist. Clinical parameters including PI, GI, and simplified oral hygiene index (OHI-S) were recorded. Salivary pH (SpH) was measured using pH paper. Blood samples and unstimulated whole saliva were collected, and SFR was calculated. The CA VI rs2274327 polymorphism was determined by a LightSNiP assay on the realtime PCR system. The frequencies of rs2274327 were not significant between groups (p > 0.05). There was a positive correlation between OHI-S and SpH in the carious and non-carious groups (p OHI-S, PI, GI, SFR, and SpH (p > 0.05). CA VI SNP (rs2274327) had no statistically significant association with OHI-S, PI, GI, SFR, and SpH in the children.

  15. Cloning, characterization and anion inhibition studies of a γ-carbonic anhydrase from the Antarctic bacterium Colwellia psychrerythraea.

    Science.gov (United States)

    De Luca, Viviana; Vullo, Daniela; Del Prete, Sonia; Carginale, Vincenzo; Osman, Sameh M; AlOthman, Zeid; Supuran, Claudiu T; Capasso, Clemente

    2016-02-15

    We have cloned, purified and characterized the γ-carbonic anhydrase (CA, EC 4.2.1.1) present in the genome of the Antarctic bacterium Colwellia psychrerythraea, which is an obligate psychrophile. The enzyme shows a significant catalytic activity for the physiologic reaction of CO2 hydration to bicarbonate and protons, with the following kinetic parameters: kcat of 6.0×10(5)s(-1) and a kcat/Km of 4.7×10(6)M(-1)×s(-1). This activity was inhibited by the sulfonamide CA inhibitor (CAI) acetazolamide, with a KI of 502nM. A range of anions was also investigated for their inhibitory action against the new enzyme CpsCA. Perchlorate, tetrafluoroborate, fluoride and bromide were not inhibitory, whereas cyanate, thiocyanate, cyanide, hydrogensulfide, carbonate and bicarbonate showed KIs in the range of 1.4-4.4mM. Diethyldithiocarbamate was a better inhibitor (KI of 0.58mM) whereas sulfamide, sulfamate, phenylboronic acid and phenylarsonic acid were the most effective inhibitors detected, with KIs ranging between 8 and 38μM. The present study may shed some more light regarding the role that γ-CAs play in the life cycle of psychrophilic bacteria as the Antarctic one investigated here.

  16. Carbonic anhydrase inhibitors. Inhibition of the beta-class enzyme from the pathogenic yeast Candida glabrata with anions.

    Science.gov (United States)

    Innocenti, Alessio; Leewattanapasuk, Worraanong; Mühlschlegel, Fritz A; Mastrolorenzo, Antonio; Supuran, Claudiu T

    2009-08-15

    A beta-carbonic anhydrase (CA, EC 4.2.1.1), the protein encoded by the NCE103 gene of Candida glabrata which also present in Candida albicans and Saccharomycescerevisiae, was cloned, purified, characterized kinetically and investigated for its inhibition by a series simple, inorganic anions such as halogenides, pseudohalogenides, bicarbonate, carbonate, nitrate, nitrite, hydrogen sulfide, bisulfite, perchlorate, sulfate and some isosteric species. The enzyme showed significant CO(2) hydrase activity, with a k(cat) of 3.8 x 10(5)s(-1) and k(cat)/K(M) of 4.8 x 10(7)M(-1)s(-1). The Cà glabrata CA (CgCA) was moderately inhibited by metal poisons (cyanide, azide, cyanate, thiocyanate, K(I)s of 0.60-1.12 mM) but strongly inhibited by bicarbonate, nitrate, nitrite and phenylarsonic acid (K(I)s of 86-98 microM). The other anions investigated showed inhibition constants in the low millimolar range, with the exception of bromide and iodide (K(I)s of 27-42 mM).

  17. Carbonic anhydrase inhibitors. Inhibition of the beta-class enzyme from the yeast Saccharomyces cerevisiae with anions.

    Science.gov (United States)

    Isik, Semra; Kockar, Feray; Arslan, Oktay; Guler, Ozen Ozensoy; Innocenti, Alessio; Supuran, Claudiu T

    2008-12-15

    The protein encoded by the Nce103 gene of Saccharomyces cerevisiae, a beta-carbonic anhydrase (CA, EC 4.2.1.1) designated as scCA, has been cloned, purified, characterized kinetically, and investigated for its inhibition with a series simple, inorganic anions such as halogenides, pseudohalogenides, bicarbonate, carbonate, nitrate, nitrite, hydrogen sulfide, bisulfite, perchlorate, sulfate, and some of its isosteric species. The enzyme showed high CO(2) hydrase activity, with a k(cat) of 9.4x10(5) s(-1) and k(cat)/K(m) of 9.8x10(7) M(-1) s(-1). scCA was weakly inhibited by metal poisons (cyanide, azide, cyanate, thiocyanate, K(I)s of 16.8-55.6 mM) and strongly inhibited by bromide, iodide, and sulfamide (K(I)s of 8.7-10.8 microM). The other investigated anions showed inhibition constants in the low millimolar range.

  18. Biomimetic CO2 capture using a highly thermostable bacterial α-carbonic anhydrase immobilized on a polyurethane foam.

    Science.gov (United States)

    Migliardini, Fortunato; De Luca, Viviana; Carginale, Vincenzo; Rossi, Mosè; Corbo, Pasquale; Supuran, Claudiu T; Capasso, Clemente

    2014-02-01

    The biomimetic approach represents an interesting strategy for carbon dioxide (CO2) capture, offering advantages over other methods, due to its specificity for CO2 and its eco-compatibility, as it allows concentration of CO2 from other gases, and its conversion to water soluble ions. This approach uses microorganisms capable of fixing CO2 through metabolic pathways or via the use of an enzyme, such as carbonic anhydrase (CA, EC 4.2.1.1). Recently, our group cloned and purified a novel bacterial α-CA, named SspCA, from the thermophilic bacteria, Sulfurihydrogenibium yellowstonense YO3AOP1 living in hot springs at temperatures of up to 110 °C. This enzyme showed an exceptional thermal stability, retaining its high catalytic activity for the CO2 hydration reaction even after being heated at 70 °C for several hours. In the present paper, the SspCA was immobilized within a polyurethane (PU) foam. The immobilized enzyme was found to be catalytically active and showed a long-term stability. A bioreactor containing the "PU-immobilized enzyme" (PU-SspCA) as shredded foam was used for experimental tests aimed to verify the CO2 capture capability in conditions close to those of a power plant application. In this bioreactor, a gas phase, containing CO2, was put into contact with a liquid phase under conditions, where CO2 contained in the gas phase was absorbed and efficiently converted into bicarbonate by the extremo-α-CA.

  19. Effect of egg turning and incubation time on carbonic anhydrase gene expression in the blastoderm of the Japanese quail (Coturnix c. japonica).

    Science.gov (United States)

    De Winter, P; Sugden, D; Baggott, G K

    2008-09-01

    1. The gene expression of carbonic anhydrase, a key enzyme for the production of sub-embryonic fluid (SEF), was assessed in turned and unturned eggs of the Japanese quail. The plasma membrane-associated isoforms CA IV, CA IX, CA XII, CA XIV, and the cytoplasmic isoform CA II, were investigated in the extra-embryonic tissue of the blastoderm and in embryonic blood. 2. Eggs were incubated at 37.6 degrees C, c.60% RH, and turned hourly (90 degrees ) or left unturned. From 48 to 96 h of incubation mRNA was extracted from blastoderm tissue, reverse-transcribed to cDNA and quantified by real-time qPCR using gene-specific primers. Blood collected at 96 h was processed identically. 3. Blastoderm CA IV gene expression increased with the period of incubation only in turned eggs, with maxima at 84 and 96 h of incubation. Only very low levels were found in blood. 4. Blastoderm CA II gene expression was greatest at 48 and 54 h of incubation, subsequently declining to much lower levels and unaffected by turning. Blood CA II gene expression was about 25-fold greater than in the blastoderm. 5. The expression of CA IX in the blastoderm was the highest of all isoforms, yet unaffected by turning. CA XII did not amplify and CA XIV was present at unquantifiable low levels. 6. It is concluded that only gene expression for CA IV is sensitive to egg turning, and that increased CA IV gene expression could account for the additional SEF mass found at 84 to 96 h of incubation in embryos of turned eggs.

  20. How does the exchange of one oxygen atom with sulfur affect the catalytic cycle of carbonic anhydrase?

    Science.gov (United States)

    Schenk, Stephan; Kesselmeier, Jürgen; Anders, Ernst

    2004-06-21

    We have extended our investigations of the carbonic anhydrase (CA) cycle with the model system [(H(3)N)(3)ZnOH](+) and CO(2) by studying further heterocumulenes and catalysts. We investigated the hydration of COS, an atmospheric trace gas. This reaction plays an important role in the global COS cycle since biological consumption, that is, uptake by higher plants, algae, lichens, and soil, represents the dominant terrestrial sink for this gas. In this context, CA has been identified by a member of our group as the key enzyme for the consumption of COS by conversion into CO(2) and H(2)S. We investigated the hydration mechanism of COS by using density functional theory to elucidate the details of the catalytic cycle. Calculations were first performed for the uncatalyzed gas phase reaction. The rate-determining step for direct reaction of COS with H(2)O has an energy barrier of deltaG=53.2 kcal mol(-1). We then employed the CA model system [(H(3)N)(3)ZnOH](+) (1) and studied the effect on the catalytic hydration mechanism of replacing an oxygen atom with sulfur. When COS enters the carbonic anhydrase cycle, the sulfur atom is incorporated into the catalyst to yield [(H(3)N)(3)ZnSH](+) (27) and CO(2). The activation energy of the nucleophilic attack on COS, which is the rate-determining step, is somewhat higher (20.1 kcal mol(-1) in the gas phase) than that previously reported for CO(2). The sulfur-containing model 27 is also capable of catalyzing the reaction of CO(2) to produce thiocarbonic acid. A larger barrier has to be overcome for the reaction of 27 with CO(2) compared to that for the reaction of 1 with CO(2). At a well-defined stage of this cycle, a different reaction path can emerge: a water molecule helps to regenerate the original catalyst 1 from 27, a process accompanied by the formation of thiocarbonic acid. We finally demonstrate that nature selected a surprisingly elegant and efficient group of reactants, the [L(3)ZnOH](+)/CO(2)/H(2)O system, that helps

  1. Inhibition of hypoxia-inducible carbonic anhydrase-IX enhances hexokinase Ⅱ inhibitor-induced hepatocellular carcinoma cell apoptosis

    Institute of Scientific and Technical Information of China (English)

    Su-jong YU; Hyo-suk LEE; Jung-hwan YOON; Jeong-hoon LEE; Sun-jung MYUNG; Eun-sun JANG; Min-sun KWAK; Eun-ju CHO; Ja-june JANG; Yoon-jun KIM

    2011-01-01

    Aim: The hypoxic condition within large or infiltrative hypovascular tumors produces intracellular acidification, which could activate many signaling pathways and augment cancer cell growth and invasion. Carbonic anhydrase-Ⅸ (CA-Ⅸ) is an enzyme lowering pH. This study is to examine whether hypoxia induces CA-Ⅸ in hepatocellular carcinoma (HCC) cells, and to evaluate its clinical implication in HCC patients.Methods: Human HCC cell lines (Huh-7 and HepG2 cells) were used, and cell growth was assessed using MTS assay. CA-IX expression and apoptotic/kinase signaling were evaluated using immunoblotting. The cells were transfected with CA-Ⅸ-specific siRNA, or treated with its inhibitor 4-(2-aminoethyl) benzenesulfonamide (CAI#1), and/or the hexokinase Ⅱ inhibitor, 3-bromopyruvate (3-BP). A clinic pathological analysis of 69 patients who underwent an HCC resection was performed using a tissue array.Results: Incubation of HCC cells under hypoxia (1% 02, 5% C02, 94% N2) for 36 h significantly increased CA-IX expression level. CAI#1(400 μmol/L) or CA-IX siRNA (100 μmol/L) did not influence HCC cell growth and induce apoptosis. However, CAI#1 or CA-IX siRNA at these concentrations enhanced the apoptosis induced by 3-BP (100 μmol/L). This enhancement was attributed to increased ER stress and JNK activation, as compared with 3-BP alone. Furthermore, a clinic pathological analysis of 69 HCC patients revealed that tumor CA-Ⅸ intensity was inversely related to E-cadherin intensity.Conclusion: Inhibition of hypoxia-induced CA-Ⅸ enhances hexokinase Ⅱ inhibitor-induced HCC apoptosis. Furthermore, CA-IX expres sion profiles may have prognostic implications in HCC patients. Thus, the inhibition of CA-Ⅸ, in combination with a hexokinase Ⅱ inhibitor, may be therapeutically useful in patients with HCCs that are aggressively growing in a hypoxic environment.

  2. Carbonic anhydrase inhibitors. Inhibition of human cytosolic isoforms I and II with (reduced) Schiff's bases incorporating sulfonamide, carboxylate and carboxymethyl moieties.

    Science.gov (United States)

    Nasr, Gihane; Cristian, Alina; Barboiu, Mihail; Vullo, Daniella; Winum, Jean-Yves; Supuran, Claudiu T

    2014-05-15

    A library of Schiff bases was synthesized by condensation of aromatic amines incorporating sulfonamide, carboxylic acid or carboxymethyl functionalities as Zn(2+)-binding groups, with aromatic aldehydes incorporating tert-butyl, hydroxy and/or methoxy groups. The corresponding amines were thereafter obtained by reduction of the imines. These compounds were assayed for the inhibition of two cytosolic human carbonic anhydrase (hCA, EC 4.2.1.1) isoenzymes, hCA I and II. The Ki values of the Schiff bases were in the range of 7.0-21,400nM against hCA II and of 52-8600nM against hCA I, respectively. The corresponding amines showed Ki values in the range of 8.6nM-5.3μM against hCA II, and of 18.7-251nM against hCA I, respectively. Unlike the imines, the reduced Schiff bases are stable to hydrolysis and several low-nanomolar inhibitors were detected, most of them incorporating sulfonamide groups. Some carboxylates also showed interesting CA inhibitory properties. Such hydrosoluble derivatives may show pharmacologic applications.

  3. Evidence from simultaneous intracellular- and surface-pH transients that carbonic anhydrase IV enhances CO2 fluxes across Xenopus oocyte plasma membranes.

    Science.gov (United States)

    Musa-Aziz, Raif; Occhipinti, Rossana; Boron, Walter F

    2014-11-01

    Human carbonic anhydrase IV (CA IV) is GPI-anchored to the outer membrane surface, catalyzing CO2/HCO3 (-) hydration-dehydration. We examined effects of heterologously expressed CA IV on intracellular-pH (pHi) and surface-pH (pHS) transients caused by exposing oocytes to CO2/HCO3 (-)/pH 7.50. CO2 influx causes a sustained pHi fall and a transient pHS rise; CO2 efflux does the opposite. Both during CO2 addition and removal, CA IV increases magnitudes of maximal rate of pHi change (dpHi/dt)max, and maximal pHS change (ΔpHS) and decreases time constants for pHi changes (τpHi ) and pHS relaxations (τpHS ). Decreases in time constants indicate that CA IV enhances CO2 fluxes. Extracellular acetazolamide blocks all CA IV effects, but not those of injected CA II. Injected acetazolamide partially reduces CA IV effects. Thus, extracellular CA is required for, and the equivalent of cytosol-accessible CA augments, the effects of CA IV. Increasing the concentration of the extracellular non-CO2/HCO3 (-) buffer (i.e., HEPES), in the presence of extracellular CA or at high [CO2], accelerates CO2 influx. Simultaneous measurements with two pHS electrodes, one on the oocyte meridian perpendicular to the axis of flow and one downstream from the direction of extracellular-solution flow, reveal that the downstream electrode has a larger (i.e., slower) τpHS , indicating [CO2] asymmetry over the oocyte surface. A reaction-diffusion mathematical model (third paper in series) accounts for the above general features, and supports the conclusion that extracellular CA, which replenishes entering CO2 or consumes exiting CO2 at the extracellular surface, enhances the gradient driving CO2 influx across the cell membrane.

  4. Design and Synthesis of Novel Nonsteroidal Anti-Inflammatory Drugs and Carbonic Anhydrase Inhibitors Hybrids (NSAIDs-CAIs) for the Treatment of Rheumatoid Arthritis.

    Science.gov (United States)

    Bua, Silvia; Di Cesare Mannelli, Lorenzo; Vullo, Daniela; Ghelardini, Carla; Bartolucci, Gianluca; Scozzafava, Andrea; Supuran, Claudiu T; Carta, Fabrizio

    2017-02-09

    We report the synthesis of a series of hybrid compounds incorporating 6- and 7-substituted coumarins (carbonic anhydrase, CA inhibitors) derivatized with clinically used NSAIDs (indomethacin, sulindac, ketoprofen, ibuprofen, diclofenac, ketorolac, etc., cyclooxygenase inhibitors) as agents for the management of rheumatoid arthritis (RA). Most compounds were effective in inhibiting the RA overexpressed hCA IX and XII, with KI values in the low nanomolar-subnanomolar ranges. The antihyperalgesic activity of such compounds was assessed by means of the paw-pressure and incapacitance tests using an in vivo RA model. Among all tested compounds, the 7-coumarine hybrid with ibuprofen showed potent and persistent antihyperalgesic effect up to 60 min after administration.

  5. Hemoglobin level predicts outcome for vulvar cancer patients independent of GLUT-1 and CA-IX expression in tumor tissue.

    NARCIS (Netherlands)

    Nieuwenhof, H.P. van de; Hullu, J.A. de; Kaanders, J.H.A.M.; Bulten, J.; Massuger, L.F.A.G.; Kempen, L.C.L.T. van

    2010-01-01

    Intratumoral hypoxia has been associated with poor prognosis in several solid tumors. The aim of this study was to determine whether the hypoxia-associated markers glucose transporter (GLUT)-1 and carbonic anhydrase (CA)-IX expression and preoperative hemoglobin (Hb) levels correlate with presence o

  6. Expression patterns and subcellular localization of carbonic anhydrases are developmentally regulated during tooth formation.

    Directory of Open Access Journals (Sweden)

    Claes-Göran Reibring

    Full Text Available Carbonic anhydrases (CAs play fundamental roles in several physiological events, and emerging evidence points at their involvement in an array of disorders, including cancer. The expression of CAs in the different cells of teeth is unknown, let alone their expression patterns during odontogenesis. As a first step towards understanding the role of CAs during odontogenesis, we used immunohistochemistry, histochemistry and in situ hybridization to reveal hitherto unknown dynamic distribution patterns of eight CAs in mice. The most salient findings include expression of CAII/Car2 not only in maturation-stage ameloblasts (MA but also in the papillary layer, dental papilla mesenchyme, odontoblasts and the epithelial rests of Malassez. We uncovered that the latter form lace-like networks around incisors; hitherto these have been known to occur only in molars. All CAs studied were produced by MA, however CAIV, CAIX and CARPXI proteins were distinctly enriched in the ruffled membrane of the ruffled MA but exhibited a homogeneous distribution in smooth-ended MA. While CAIV, CAVI/Car6, CAIX, CARPXI and CAXIV were produced by all odontoblasts, CAIII distribution displayed a striking asymmetry, in that it was virtually confined to odontoblasts in the root of molars and root analog of incisors. Remarkably, from initiation until near completion of odontogenesis and in several other tissues, CAXIII localized mainly in intracellular punctae/vesicles that we show to overlap with LAMP-1- and LAMP-2-positive vesicles, suggesting that CAXIII localizes within lysosomes. We showed that expression of CAs in developing teeth is not confined to cells involved in biomineralization, pointing at their participation in other biological events. Finally, we uncovered novel sites of CA expression, including the developing brain and eye, the olfactory epithelium, melanoblasts, tongue, notochord, nucleus pulposus and sebaceous glands. Our study provides important information for

  7. Non-destructive measurement of carbonic anhydrase activity and the oxygen isotope composition of soil water

    Science.gov (United States)

    Jones, Sam; Sauze, Joana; Ogée, Jérôme; Wohl, Steven; Bosc, Alexandre; Wingate, Lisa

    2016-04-01

    Carbonic anhydrases are a group of metalloenzymes that catalyse the hydration of aqueous carbon dioxide (CO2). The expression of carbonic anhydrase by bacteria, archaea and eukarya has been linked to a variety of important biological processes including pH regulation, substrate supply and biomineralisation. As oxygen isotopes are exchanged between CO2 and water during hydration, the presence of carbonic anhydrase in plants and soil organisms also influences the oxygen isotope budget of atmospheric CO2. Leaf and soil water pools have distinct oxygen isotope compositions, owing to differences in pool sizes and evaporation rates, which are imparted on CO2during hydration. These differences in the isotopic signature of CO2 interacting with leaves and soil can be used to partition the contribution of photosynthesis and soil respiration to net terrestrial CO2 exchange. However, this relies on our knowledge of soil carbonic anhydrase activity and currently, the prevalence and function of these enzymes in soils is poorly understood. Isotopic approaches used to estimate soil carbonic anhydrase activity typically involve the inversion of models describing the oxygen isotope composition of CO2 fluxes to solve for the apparent, potentially catalysed, rate of oxygen exchange during hydration. This requires information about the composition of CO2 in isotopic equilibrium with soil water obtained from destructive, depth-resolved soil water sampling. This can represent a significant challenge in data collection given the considerable potential for spatial and temporal variability in the isotopic composition of soil water and limited a priori information with respect to the appropriate sampling resolution and depth. We investigated whether we could circumvent this requirement by constraining carbonic anhydrase activity and the composition of soil water in isotopic equilibrium with CO2 by solving simultaneously the mass balance for two soil CO2 steady states differing only in the

  8. Evidence for the involvement of carbonic anhydrase and urease in calcium carbonate formation in the gravity-sensing organ of Aplysia californica

    Science.gov (United States)

    Pedrozo, H. A.; Schwartz, Z.; Dean, D. D.; Harrison, J. L.; Campbell, J. W.; Wiederhold, M. L.; Boyan, B. D.

    1997-01-01

    To better understand the mechanisms that could modulate the formation of otoconia, calcium carbonate granules in the inner ear of vertebrate species, we examined statoconia formation in the gravity-sensing organ, the statocyst, of the gastropod mollusk Aplysia californica using an in vitro organ culture model. We determined the type of calcium carbonate present in the statoconia and investigated the role of carbonic anhydrase (CA) and urease in regulating statocyst pH as well as the role of protein synthesis and urease in statoconia production and homeostasis in vitro. The type of mineral present in statoconia was found to be aragonitic calcium carbonate. When the CA inhibitor, acetazolamide (AZ), was added to cultures of statocysts, the pH initially (30 min) increased and then decreased. The urease inhibitor, acetohydroxamic acid (AHA), decreased statocyst pH. Simultaneous addition of AZ and AHA caused a decrease in pH. Inhibition of urease activity also reduced total statoconia number, but had no effect on statoconia volume. Inhibition of protein synthesis reduced statoconia production and increased statoconia volume. In a previous study, inhibition of CA was shown to decrease statoconia production. Taken together, these data show that urease and CA play a role in regulating statocyst pH and the formation and maintenance of statoconia. CA produces carbonate ion for calcium carbonate formation and urease neutralizes the acid formed due to CA action, by production of ammonia.

  9. Anion inhibition studies of the α-carbonic anhydrase from the protozoan pathogen Trypanosoma cruzi, the causative agent of Chagas disease.

    Science.gov (United States)

    Pan, Peiwen; Vermelho, Alane Beatriz; Scozzafava, Andrea; Parkkila, Seppo; Capasso, Clemente; Supuran, Claudiu T

    2013-08-01

    The protozoan pathogen Trypanosoma cruzi, the causative agent of Chagas disease, encodes an α-class carbonic anhydrase (CA, EC 4.2.1.1), TcCA, which was recently shown to be crucial for its life cycle. Thiols, a class of strong TcCA inhibitors, were also shown to block the growth of the pathogen in vitro. Here we report the inhibition of TcCA by inorganic and complex anions and other molecules interacting with zinc proteins, such as sulfamide, sulfamic acid, phenylboronic/arsonic acids. TcCA was inhibited in the low micromolar range by iodide, cyanate, thiocyanate, hydrogensulfide and trithiocarbonate (KIs in the range of 44-93 μM), but the best inhibitor was diethyldithiocarbamate (KI=5 μM). Sulfamide showed an inhibition constant of 120 μM, but sulfamic acid was much less effective (KI of 10.6 mM). The discovery of diethyldithiocarbamate as a low micromolar TcCA inhibitor may be useful to detect leads for developing anti-Trypanosoma agents with a diverse mechanism of action compared to clinically used drugs (benznidazole, nifurtimox) for which significant resistance emerged.

  10. Synthesis of 5-amino-1,3,4-thiadiazole-2-sulphonamide derivatives and their inhibition effects on human carbonic anhydrase isozymes.

    Science.gov (United States)

    Kasımoğulları, Rahmi; Bülbül, Metin; Mert, Samet; Güleryüz, Hülya

    2011-04-01

    In this study, some novel inhibitors were synthesised from the further stage reactions of 4-benzoyl-1-(4-nitrophenyl)-5-phenyl-1H-pyrazole-3-carbonyl chloride with 5-amino-1,3,4-thiadiazole-2-sulphonamide 1 (inhibitor 1). They were characterised by elemental and spectral (¹H NMR, ¹³C NMR, IR) analyses. Human carbonic anhydrase isoenzymes (hCA-I and hCA-II) were purified from erythrocyte cells by affinity chromatography. The inhibitory effects of inhibitor 1, acetazolamide (2) and the 11 newly synthesised amides (8-18) on the hydratase and esterase activities of these isoenzymes (hCA-I and hCA-II) were studied in vitro. In relation to these activities, the inhibition equilibrium constants (K(i)) were determined. The K(i) values for the new compounds (8-18) were observed to be well below that of the parent compound inhibitor 1 and were also compared to 2 under the same experimental conditions. The comparison of the newly synthesised amides to inhibitor 1 and to 2 indicated that the new derivatives preferentially inhibited hCA-II and were more potent inhibitors of hCA-II than the parent inhibitor 1 and 2.

  11. Carbonic anhydrase activity and photosynthetic rate in the tree species Paulownia tomentosa Steud. Effect of dimethylsulfoxide treatment and zinc accumulation in leaves.

    Science.gov (United States)

    Lazova, Galia N; Naidenova, Tsveta; Velinova, Katya

    2004-03-01

    The enzyme carbonic anhydrase (CA) (EC 4.2.1.1) catalyzes the reversible conversion of CO2 to HCO3- and has been shown to be involved in photosynthesis. The enzyme has been shown in animals, plants, eubacteria and viruses, but similar reports on the evidence for CA activity in tree plants does not be appear to be available. In the preliminary analyses of the work, the CA activity in leaf extracts from the tree species Paulownia tomentosa Steud. (introduced in Bulgaria) is described. A connection between CA activity and the rate of photosynthetic CO2 fixation is shown. In the second portion of the work, the effect of 10(-4) mol/L and 10(-2) mol/L dimethylsulfoxide (DMSO) on the zinc accumulation in leaves is demonstrated. It is suggested that CA activity is an indicator of the level of physiologically active zinc in leaves of P. tomentosa Steud. A connection between the process of zinc accumulation in leaves and the activity of the enzymes CA and glycolate oxidase (GO) (EC 1.1.3.1) is established.

  12. Catecholamine-induced vasoconstriction is sensitive to carbonic anhydrase I activation

    Directory of Open Access Journals (Sweden)

    Puscas I.

    2001-01-01

    Full Text Available We studied the relationship between alpha- and beta-adrenergic agonists and the activity of carbonic anhydrase I and II in erythrocyte, clinical and vessel studies. Kinetic studies were performed. Adrenergic agonists increased erythrocyte carbonic anhydrase as follows: adrenaline by 75%, noradrenaline by 68%, isoprenaline by 55%, and orciprenaline by 62%. The kinetic data indicated a non-competitive mechanism of action. In clinical studies carbonic anhydrase I from erythrocytes increased by 87% after noradrenaline administration, by 71% after orciprenaline and by 82% after isoprenaline. The increase in carbonic anhydrase I paralleled the increase in blood pressure. Similar results were obtained in vessel studies on piglet vascular smooth muscle. We believe that adrenergic agonists may have a dual mechanism of action: the first one consists of a catecholamine action on its receptor with the formation of a stimulus-receptor complex. The second mechanism proposed completes the first one. By this second component of the mechanism, the same stimulus directly acts on the carbonic anhydrase I isozyme (that might be functionally coupled with adrenergic receptors, so that its activation ensures an adequate pH for stimulus-receptor coupling for signal transduction into the cell, resulting in vasoconstriction.

  13. Inhibition studies of bacterial, fungal and protozoan β-class carbonic anhydrases with Schiff bases incorporating sulfonamide moieties.

    Science.gov (United States)

    Ceruso, Mariangela; Carta, Fabrizio; Osman, Sameh M; Alothman, Zeid; Monti, Simona Maria; Supuran, Claudiu T

    2015-08-01

    A series of new Schiff bases derived from sulfanilamide, 3-fluorosulfanilamide or 4-(2-aminoethyl)-benzenesulfonamide containing either a hydrophobic or a hydrophilic tail, have been investigated as inhibitors of three β-carbonic anhydrases (CA, EC 4.2.1.1) from three different microorganisms. Their antifungal, antibacterial and antiprotozoan activities have been determined against the pathogenic fungus Cryptococcus neoformans, the bacterial pathogen Brucella suis and the protozoan parasite Leishmania donovani chagasi, responsible for Leishmaniasis. The results of these inhibition studies show that all three enzymes were efficiently inhibited by the Schiff base sulfonamides with KI values in the nanomolar or submicromolar range, depending on the nature of the tail, coming from the aryl/heteroaryl moiety present in the starting aldehyde employed in the synthesis. Furthermore, the compounds hereby investigated revealed high β-CAs selectivity over the ubiquitous, physiologically relevant and off-target human isoforms (CA I and II) and to be more potent as antifungal and antibacterial than as antiprotozoan potential drugs.

  14. The importance of carbonic anhydrase II in red blood cells during exposure of chicken embryos to CO2.

    Science.gov (United States)

    Everaert, N; Willemsen, H; Hulikova, A; Brown, H; Decuypere, E; Swietach, P; Bruggeman, V

    2010-07-31

    The importance of carbonic anhydrase (CA) during exposure of chicken embryos to CO(2) during the second half of incubation was investigated. The protein abundance and activity of CAII in erythrocytes was significantly higher in CO(2)-exposed embryos compared to normal conditions. Daily injections of acetazolamide (ATZ), an inhibitor of CA, increased blood P(CO2) and decreased blood pH in both control and CO(2)-incubated embryos. ATZ increased blood bicarbonate concentration in embryos exposed to normal atmosphere and in day-12 embryos exposed to high CO(2). The tendency of an increased blood potassium concentration in ATZ-injected embryos under standard atmospheric conditions might indicate that protons were exchanged with intracellular potassium. However, there was no evidence for such an exchange in CO(2)-incubated ATZ-treated embryos. This study shows for the first time that chicken embryos adapt to CO(2) during the second half of incubation by increasing CAII protein expression and function in red blood cells. This response may serve to "buffer" elevated CO(2) levels.

  15. Expression of the CHOP-inducible carbonic anhydrase CAVI-b is required for BDNF-mediated protection from hypoxia.

    Science.gov (United States)

    Matthews, Tori A; Abel, Allyssa; Demme, Chris; Sherman, Teresa; Pan, Pei-wen; Halterman, Marc W; Parkkila, Seppo; Nehrke, Keith

    2014-01-16

    Carbonic anhydrases (CAs) comprise a family of zinc-containing enzymes that catalyze the reversible hydration of carbon dioxide. CAs contribute to a myriad of physiological processes, including pH regulation, anion transport and water balance. To date, 16 known members of the mammalian alpha-CA family have been identified. Given that the catalytic family members share identical reaction chemistry, their physiologic roles are influenced greatly by their tissue and sub-cellular locations. CAVI is the lone secreted CA and exists in both saliva and the gastrointestinal mucosa. An alternative, stress-inducible isoform of CAVI (CAVI-b) has been shown to be expressed from a cryptic promoter that is activated by the CCAAT/Enhancer-Binding Protein Homologous Protein (CHOP). The CAVI-b isoform is not secreted and is currently of unknown physiological function. Here we use neuronal models, including a model derived using Car6 and CHOP gene ablations, to delineate a role for CAVI-b in ischemic protection. Our results demonstrate that CAVI-b expression, which is increased through CHOP-signaling in response to unfolded protein stress, is also increased by oxygen-glucose deprivation (OGD). While enforced expression of CAVI-b is not sufficient to protect against ischemia, CHOP regulation of CAVI-b is necessary for adaptive changes mediated by BDNF that reduce subsequent ischemic damage. These results suggest that CAVI-b comprises a necessary component of a larger adaptive signaling pathway downstream of CHOP.

  16. Cloning, characterization and sulfonamide inhibition studies of an α-carbonic anhydrase from the living fossil sponge Astrosclera willeyana.

    Science.gov (United States)

    Ohradanova, Anna; Vullo, Daniela; Pastorekova, Silvia; Pastorek, Jaromir; Jackson, Daniel J; Wörheide, Gert; Supuran, Claudiu T

    2012-02-15

    The α-carbonic anhydrase (CA, EC 4.2.1.1) Astrosclerin-3 previously isolated from the living fossil sponge Astrosclera willeyana (Jackson et al., Science 2007, 316, 1893), was cloned, kinetically characterized and investigated for its inhibition properties with sulfonamides and sulfamates. Astrosclerin-3 has a high catalytic activity for the CO(2) hydration reaction to bicarbonate and protons (k(cat) of 9.0×10(5) s(-1) and k(cat)/K(m) of 1.1×10(8) M(-1) × s(-1)), and is inhibited by various aromatic/heterocyclic sulfonamides and sulfamates with inhibition constants in the range of 2.9 nM-8.85 μM. Astrosclerin, and the human isoform CA II, display similar kinetic properties and affinities for sulfonamide inhibitors, despite more than 550 million years of independent evolution. Because Astrosclerin-3 is involved in biocalcification, the inhibitors characterized here may be used to gain insights into such processes in other metazoans.

  17. Variable involvement of the perivascular retinal tissue in carbonic anhydrase inhibitor induced relaxation of porcine retinal arterioles in vitro

    DEFF Research Database (Denmark)

    Kehler, Anne Katrine; Holmgaard, Kim; Hessellund, Anders;

    2007-01-01

    PURPOSE: Inhibition of carbonic anhydrase in the eye is an important treatment modality for reducing the intraocular pressure in glaucoma. However, evidence suggests that carbonic anhydrase inhibition also exerts a relaxing effect on the vessels in the optic nerve, and it has been suggested...

  18. Functional role of a putative carbonic anhydrase II-binding domain in the electrogenic Na+ -HCO₃- cotransporter NBCe1 expressed in Xenopus oocytes.

    Science.gov (United States)

    Yamada, Hideomi; Horita, Shoko; Suzuki, Masashi; Fujita, Toshiro; Seki, George

    2011-01-01

    The electrogenic Na+ -HCO₃⁻ cotransporter NBCe1 plays essential roles in the regulation of systemic and/or local pH. Homozygous inactivating mutations in NBCe1 cause proximal renal tubular acidosis associated with ocular abnormalities. We recently showed that defective membrane expression of NBCe1, caused by several mutations such as Delta65bp (S982NfsX4), is also associated with familial migraine. The Delta65bp mutant is quite unique in that it lacks a putative carbonic anhydrase (CA) II-binding domain but still shows an apparently normal transport activity in Xenopus oocytes. In this addendum, we show that the co-expression of CAII together with the wild-type NBCe1 or the Delta65bp mutant does not enhance the NBCe1 activities in oocytes. Moreover, a carbonic anhydrase inhibitor acetazolamide fails to inhibit the wild-type or the Delta65bp activities co-expressed with CAII. These results indicate that a bicarbonate transport metabolon proposed for the interaction between CAII and NBCe1 does not work at least in Xenopus oocytes.

  19. Electromagnetic and Light Scattering by Nonspherical Particles XV: Celebrating 150 Years of Maxwell's Electromagnetics

    Science.gov (United States)

    Macke, Andreas; Mishchenko, Michael I.

    2015-01-01

    The 15th Electromagnetic and Light Scattering Conference (ELS-XV) was held in Leipzig, Germany from 21 to 26 of June 2015. This conference built on the great success of the previous meetings held in Amsterdam (1995), Helsinki(1997) [2], New York City(1998) [3], Vigo (1999),Halifax (2000), Gainesville (2002), Bremen (2003), Salobreña (2005), St. Petersburg (2006), Bodrum (2007), Hatfield (2008), Helsinki (2010), Taormina (2011), and Lille as well as the workshops held in Bremen (1996,1998) and Moscow (1997). As usual, the main objective of this conference was to bring together scientists, engineers, and PhD students studying various aspects of electromagnetic scattering and to provide a relaxed atmosphere for in-depth discussion of theory, measurements, and applications. Furthermore, ELS-XV supported the United Nations "Year of Light" and celebrated the150th anniversary of Maxwell's electromagnetics. Maxwell's paper on "A Dynamical Theory of the Electromagnetic Field" was published in1865 and has widely been acknowledged as one of the supreme achievements in the history of science. The conference was attended by136 scientists from 22 countries. The scientific program included two plenary lectures, 16 invited reviews, 88 contributed oral talks, and 70 poster presentations. The program and the abstracts of conference presentations are available at the conference website http://www.els-xv-2015.net/home.html. Following the well-established ELS practice and with Elsevier's encouragement, we solicited full-size papers for a topical issue of the Journal of Quantitative Spectroscopy and Radiative Transfer (JQSRT). The result of this collective effort is now in the reader's hands. As always, every invited review and regular paper included in this topical issue has undergone the same rigorous peer review process as any other manuscript published in the JQSRT.

  20. Carbonic anhydrase levels and internal lacunar CO/sub 2/ concentrations in aquatic macrophytes

    Energy Technology Data Exchange (ETDEWEB)

    Weaver, C.I.

    1979-01-01

    Carbonic anhydrase levels were examined in a variety of aquatic macrophytes from different habitats. In general, carbonic anhydrase levels increased across the habitat gradient such that activities were low in submersed aquatic macrophytes and high in emergent macrophytes with floating-leaved and free-floating plants exhibiting intermediate activities. Internal lacunar CO/sub 2/ concentrations were analyzed in relation to carbonic anhydrase activities. There was no correlation between these two parameters. Internal CO/sub 2/ concentrations ranged from low to high in submersed macrophytes, but were low in floating-leaved and emergent macrophytes. The observed internal CO/sub 2/ concentrations are discussed in relation to the individual morphologies of the plants and the environments in which they occurred.

  1. Crystal structure and kinetic studies of a tetrameric type II β-carbonic anhydrase from the pathogenic bacterium Vibrio cholerae.

    Science.gov (United States)

    Ferraroni, Marta; Del Prete, Sonia; Vullo, Daniela; Capasso, Clemente; Supuran, Claudiu T

    2015-12-01

    Carbonic anhydrase (CA) is a zinc enzyme that catalyzes the reversible conversion of carbon dioxide to bicarbonate (hydrogen carbonate) and a proton. CAs have been extensively investigated owing to their involvement in numerous physiological and pathological processes. Currently, CA inhibitors are widely used as antiglaucoma, anticancer and anti-obesity drugs and for the treatment of neurological disorders. Recently, the potential use of CA inhibitors to fight infections caused by protozoa, fungi and bacteria has emerged as a new research direction. In this article, the cloning and kinetic characterization of the β-CA from Vibrio cholerae (VchCAβ) are reported. The X-ray crystal structure of this new enzyme was solved at 1.9 Å resolution from a crystal that was perfectly merohedrally twinned, revealing a tetrameric type II β-CA with a closed active site in which the zinc is tetrahedrally coordinated to Cys42, Asp44, His98 and Cys101. The substrate bicarbonate was found bound in a noncatalytic binding pocket close to the zinc ion, as reported for a few other β-CAs, such as those from Escherichia coli and Haemophilus influenzae. At pH 8.3, the enzyme showed a significant catalytic activity for the physiological reaction of the hydration of CO2 to bicarbonate and protons, with the following kinetic parameters: a kcat of 3.34 × 10(5) s(-1) and a kcat/Km of 4.1 × 10(7) M(-1) s(-1). The new enzyme, on the other hand, was poorly inhibited by acetazolamide (Ki of 4.5 µM). As this bacterial pathogen encodes at least three CAs, an α-CA, a β-CA and a γ-CA, these enzymes probably play an important role in the life cycle and pathogenicity of Vibrio, and it cannot be excluded that interference with their activity may be exploited therapeutically to obtain antibiotics with a different mechanism of action.

  2. Carbonic Anhydrase and Zinc in Plant Physiology Anhidrasa Carbónica y Zinc en Fisiología Vegetal

    Directory of Open Access Journals (Sweden)

    Dalila Jacqueline Escudero-Almanza

    2012-03-01

    Full Text Available Carbonic anhydrase (CA (EC: 2.4.1.1 catalyzes the rapid conversion of carbon dioxide plus water into a proton and the bicarbonate ion (HCO3- that can be found in prokaryotes and higher organisms; it is represented by four different families. Carbonic anhydrase is a metalloenzyme that requires Zn as a cofactor and is involved in diverse biological processes including pH regulation, CO2 transfer, ionic exchange, respiration, CO2 photosynthetic fixation, and stomatal closure. Therefore, the review includes relevant aspects about CA morphology, oligomerization, and structural differences in the active site. On the other hand, we consider the general characteristics of Zn, its geometry, reactions, and physiology. We then consider the CA catalysis mechanism that is carried out by the metal ion and where Zn acts as a cofactor. Zinc deficiency can inhibit growth and protein synthesis, and there is evidence that it reduces the CA content in some plants, which is a relationship addressed in this review. In leaves, CA represents 20.1% of total soluble protein, while it is the second most abundant in the chloroplast after ribulose 1,5-disphosphate carboxylase/oxygenase (RuBisCO. This facilitates the supply of CO2 to the phosphoenolpyruvate carboxylase in C4 and CAM plants and RuBisCO in C3 plants.La anhidrasa carbónica (CA (EC: 4.2.1.1 cataliza la conversión rápida de dióxido de carbono más agua en un protón y el ion bicarbonato (HCO3-; la cual puede encontrarse en procariotas y en organismos superiores y está representada por cuatro familias distintas. La CA es una metaloenzima que requiere Zn como cofactor y está implicada en diversos procesos biológicos, incluyendo la regulación del pH, la transferencia de CO2, intercambio iónico, la respiración, la fijación fotosintética de CO2, y el cierre estomático. Por lo cual, la revisión incluye aspectos relevantes sobre la morfología de laAC, su oligomerización y diferencias estructurales en el

  3. A physiological role for cyanate-induced carbonic anhydrase in Escherichia coli.

    OpenAIRE

    Guilloton, M B; Lamblin, A F; Kozliak, E I; Gerami-Nejad, M; Tu, C.; Silverman, D.; Anderson, P. M.; Fuchs, J A

    1993-01-01

    Cyanate induces expression of the cyn operon in Escherichia coli. The cyn operon includes the gene cynS, encoding cyanase, which catalyzes the reaction of cyanate with bicarbonate to give ammonia and carbon dioxide. A carbonic anhydrase activity was recently found to be encoded by the cynT gene, the first gene of the cyn operon; it was proposed that carbonic anhydrase prevents depletion of bicarbonate during cyanate decomposition due to loss of CO2 by diffusion out of the cell (M. B. Guilloto...

  4. Carbonic anhydrase mimics for enhanced CO2 absorption in an amine-based capture solvent.

    Science.gov (United States)

    Kelsey, Rachael A; Miller, David A; Parkin, Sean R; Liu, Kun; Remias, Joe E; Yang, Yue; Lightstone, Felice C; Liu, Kunlei; Lippert, Cameron A; Odom, Susan A

    2016-01-07

    Two new small-molecule enzyme mimics of carbonic anhydrase were prepared and characterized. These complexes contain the salen-like ligand bis(hydroxyphenyl)phenanthroline. This ligand is similar to the salen-type ligands previously incorporated into carbonic anhydrase mimics but contains no hydrolyzable imine groups and therefore serves as a promising ligand scaffold for the synthesis of a more robust CO2 hydration catalyst. These homogeneous catalysts were investigated for CO2 hydration in concentrated primary amine solutions through which a dilute CO2 (14%) fluid stream was flowed and showed exceptional activity for increased CO2 absorption rates.

  5. Electromagnetic and light scattering by nonspherical particles XV: Celebrating 150 years of Maxwell's electromagnetics

    Science.gov (United States)

    Macke, Andreas; Mishchenko, Michael I.

    2016-07-01

    The 15th Electromagnetic and Light Scattering Conference (ELS-XV) was held in Leipzig, Germany from 21 to 26 of June 2015 (Fig. 1). This conference built on the great success of the previous meetings held in Amsterdam (1995) [1], Helsinki (1997) [2], New York City (1998) [3], Vigo (1999), Halifax (2000) [4], Gainesville (2002) [5], Bremen (2003) [6], Salobreña (2005) [7], St. Petersburg (2006) [8], Bodrum (2007) [9], Hatfield (2008) [10], Helsinki (2010) [11], Taormina (2011) [12], and Lille [13] as well as the workshops held in Bremen (1996, 1998) and Moscow (1997). As usual, the main objective of this conference was to bring together scientists, engineers, and PhD students studying various aspects of electromagnetic scattering and to provide a relaxed atmosphere for in-depth discussion of theory, measurements, and applications. Furthermore, ELS-XV supported the United Nations "Year of Light" and celebrated the 150th anniversary of Maxwell's electromagnetics. Maxwell's paper on "A Dynamical Theory of the Electromagnetic Field" [14] was published in 1865 and has widely been acknowledged as one of the supreme achievements in the history of science.

  6. Cultivos agrícolas en la Ribeira Sacra durante los siglos XIV y XV

    Directory of Open Access Journals (Sweden)

    José Antonio López Sabatel

    2007-01-01

    Full Text Available Este artículo pretende una aproximación al espacio agrario de la Ribeira Sacra a lo largo de los siglos XIV y XV a través de sus diferentes cultivos. La vid, las tierras de cereal, así como la huerta, el linar y el nabal se articularán en consonancia no sólo con las diversas estrategias del campesinado para garantizar su subsistencia, sino también con los condicionantes económicos propios de este periodo histórico.This article tries to approach to the agrarian area of the Sacred Ribeira throughout the XIV and XV centuries across its different cultivations. The grapevine, the cereal fields, as well as the kitchen garden, the flax field and the turnip field will be joint together, according not only with the varied strategies of the peasants to guarantee their subsistence, but also with the particular economic limitations of this historical period.

  7. Generation of nitric oxide from nitrite by carbonic anhydrase:

    DEFF Research Database (Denmark)

    Aamand, Rasmus; Dalsgaard, Thomas; Jensen, Frank Bo;

    2009-01-01

    bicarbonate and nitrite, we hypothesized that CA uses nitrite as a substrate to produce the potent vasodilator nitric oxide (NO) to increase local blood flow to metabolically active tissues. Here we show that CA readily reacts with nitrite to generate NO, particularly at low pH, and that the NO produced...

  8. Characterization of a Mesorhizobium loti α-Type Carbonic Anhydrase and Its Role in Symbiotic Nitrogen Fixation▿

    Science.gov (United States)

    Kalloniati, Chrysanthi; Tsikou, Daniela; Lampiri, Vasiliki; Fotelli, Mariangela N.; Rennenberg, Heinz; Chatzipavlidis, Iordanis; Fasseas, Costas; Katinakis, Panagiotis; Flemetakis, Emmanouil

    2009-01-01

    Carbonic anhydrase (CA) (EC 4.2.1.1) is a widespread enzyme catalyzing the reversible hydration of CO2 to bicarbonate, a reaction that participates in many biochemical and physiological processes. Mesorhizobium loti, the microsymbiont of the model legume Lotus japonicus, possesses on the symbiosis island a gene (msi040) encoding an α-type CA homologue, annotated as CAA1. In the present work, the CAA1 open reading frame from M. loti strain R7A was cloned, expressed, and biochemically characterized, and it was proven to be an active α-CA. The biochemical and physiological roles of the CAA1 gene in free-living and symbiotic rhizobia were examined by using an M. loti R7A disruption mutant strain. Our analysis revealed that CAA1 is expressed in both nitrogen-fixing bacteroids and free-living bacteria during growth in batch cultures, where gene expression was induced by increased medium pH. L. japonicus plants inoculated with the CAA1 mutant strain showed no differences in top-plant traits and nutritional status but consistently formed a higher number of nodules exhibiting higher fresh weight, N content, nitrogenase activity, and δ13C abundance. Based on these results, we propose that although CAA1 is not essential for nodule development and symbiotic nitrogen fixation, it may participate in an auxiliary mechanism that buffers the bacteroid periplasm, creating an environment favorable for NH3 protonation, thus facilitating its diffusion and transport to the plant. In addition, changes in the nodule δ13C abundance suggest the recycling of at least part of the HCO3− produced by CAA1. PMID:19218391

  9. Characterization of a Mesorhizobium loti alpha-type carbonic anhydrase and its role in symbiotic nitrogen fixation.

    Science.gov (United States)

    Kalloniati, Chrysanthi; Tsikou, Daniela; Lampiri, Vasiliki; Fotelli, Mariangela N; Rennenberg, Heinz; Chatzipavlidis, Iordanis; Fasseas, Costas; Katinakis, Panagiotis; Flemetakis, Emmanouil

    2009-04-01

    Carbonic anhydrase (CA) (EC 4.2.1.1) is a widespread enzyme catalyzing the reversible hydration of CO(2) to bicarbonate, a reaction that participates in many biochemical and physiological processes. Mesorhizobium loti, the microsymbiont of the model legume Lotus japonicus, possesses on the symbiosis island a gene (msi040) encoding an alpha-type CA homologue, annotated as CAA1. In the present work, the CAA1 open reading frame from M. loti strain R7A was cloned, expressed, and biochemically characterized, and it was proven to be an active alpha-CA. The biochemical and physiological roles of the CAA1 gene in free-living and symbiotic rhizobia were examined by using an M. loti R7A disruption mutant strain. Our analysis revealed that CAA1 is expressed in both nitrogen-fixing bacteroids and free-living bacteria during growth in batch cultures, where gene expression was induced by increased medium pH. L. japonicus plants inoculated with the CAA1 mutant strain showed no differences in top-plant traits and nutritional status but consistently formed a higher number of nodules exhibiting higher fresh weight, N content, nitrogenase activity, and delta(13)C abundance. Based on these results, we propose that although CAA1 is not essential for nodule development and symbiotic nitrogen fixation, it may participate in an auxiliary mechanism that buffers the bacteroid periplasm, creating an environment favorable for NH(3) protonation, thus facilitating its diffusion and transport to the plant. In addition, changes in the nodule delta(13)C abundance suggest the recycling of at least part of the HCO(3)(-) produced by CAA1.

  10. T tubules and surface membranes provide equally effective pathways of carbonic anhydrase-facilitated lactic acid transport in skeletal muscle.

    Directory of Open Access Journals (Sweden)

    Janine Hallerdei

    Full Text Available We have studied lactic acid transport in the fast mouse extensor digitorum longus muscles (EDL by intracellular and cell surface pH microelectrodes. The role of membrane-bound carbonic anhydrases (CA of EDL in lactic acid transport was investigated by measuring lactate flux in muscles from wildtype, CAIV-, CAIX- and CAXIV-single ko, CAIV-CAXIV double ko and CAIV-CAIX-CAXIV-triple ko mice. This was complemented by immunocytochemical studies of the subcellular localization of CAIV, CAIX and CAXIV in mouse EDL. We find that CAXIV and CAIX single ko EDL exhibit markedly but not maximally reduced lactate fluxes, whereas triple ko and double ko EDL show maximal or near-maximal inhibition of CA-dependent lactate flux. Interpretation of the flux measurements in the light of the immunocytochemical results leads to the following conclusions. CAXIV, which is homogeneously distributed across the surface membrane of EDL fibers, facilitates lactic acid transport across this membrane. CAIX, which is associated only with T tubular membranes, facilitates lactic acid transport across the T tubule membrane. The removal of lactic acid from the lumen of T tubuli towards the interstitial space involves a CO2-HCO3- diffusional shuttle that is maintained cooperatively by CAIX within the T tubule and, besides CAXIV, by the CAIV, which is strategically located at the opening of the T tubules. The data suggest that about half the CA-dependent muscular lactate flux occurs across the surface membrane, while the other half occurs across the membranes of the T tubuli.

  11. Targeted mutagenesis of mitochondrial carbonic anhydrases VA and VB implicates both enzymes in ammonia detoxification and glucose metabolism.

    Science.gov (United States)

    Shah, Gul N; Rubbelke, Timothy S; Hendin, Joshua; Nguyen, Hien; Waheed, Abdul; Shoemaker, James D; Sly, William S

    2013-04-30

    Prior studies with carbonic anhydrase (CA) inhibitors implicated mitochondrial CA in ureagenesis and gluconeogenesis. Subsequent studies identified two mitochondrial CAs. To distinguish the contribution of each enzyme, we studied the effects of targeted disruption of the murine CA genes, called Car5A and Car5B. The Car5A mutation had several deleterious consequences. Car5A null mice were smaller than wild-type littermates and bred poorly. However, on sodium-potassium citrate-supplemented water, they produced offspring in expected numbers. Their blood ammonia concentrations were markedly elevated, but their fasting blood sugars were normal. By contrast, Car5B null mice showed normal growth and normal blood ammonia levels. They too had normal fasting blood sugars. Car5A/B double-knockout (DKO) mice showed additional abnormalities. Impaired growth was more severe than for Car5A null mice. Hyperammonemia was even greater as well. Although fertile, DKO animals were produced in less-than-predicted numbers even when supplemented with sodium-potassium citrate in their drinking water. Survival after weaning was also reduced, especially for males. In addition, fasting blood glucose levels for DKO mice were significantly lower than for controls (153 ± 33 vs. 230 ± 24 mg/dL). The enhanced hyperammonemia and lower fasting blood sugar, which are both seen in the DKO mice, indicate that both Car5A and Car5B contribute to both ammonia detoxification (ureagenesis) and regulation of fasting blood sugar (gluconeogenesis). Car5A, which is expressed mainly in liver, clearly has the predominant role in ammonia detoxification. The contribution of Car5B to ureagenesis and gluconeogenesis was evident only on a Car5A null background.

  12. The impact of Carbonic Anhydrase on the partitioning of leaf and soil CO18O and COS gas exchange across scales

    Science.gov (United States)

    Wingate, L.; Wehr, R. A.; Commane, R.; Ogee, J.; Sauze, J.; Jones, S.; Launois, T.; Wohl, S.; Whelan, M.; Meredith, L. K.; Genty, B.; Gimeno, T.; Kesselmeier, J.; Bosc, A.; Cuntz, M.; Munger, J. W.; Nelson, D. D.; Saleska, S. R.; Wofsy, S. C.; Zahniser, M. S.

    2015-12-01

    Photosynthesis (GPP), the largest CO2 flux to the land surface, is currently estimated with considerable uncertainty at between 100-175 Pg C yr-1. More robust estimates of global GPP could be obtained from the atmospheric budgets of other valuable tracers, such as carbonyl sulfide (COS) or the oxygen isotopic composition (δ18O) of atmospheric CO2. However, quantifying GPP using these tracers hinges on a better understanding of how soil micro-organisms modify the atmospheric concentrations of CO18O and COS at large scales. In particular, understanding better the role and activity of the enzyme Carbonic Anhydrase (CA) in soil micro-organisms is critical. We present novel datasets and model simulations demonstrating the progress in the collection of multi-tracer field datasets and how a new generation of multi-tracer land surface models can provide valuable constraints on photosynthesis and respiration across scales.

  13. 22 CFR 124.15 - Special Export Controls for Defense Articles and Defense Services Controlled under Category XV...

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Special Export Controls for Defense Articles...-SHORE PROCUREMENT AND OTHER DEFENSE SERVICES § 124.15 Special Export Controls for Defense Articles and Defense Services Controlled under Category XV: Space Systems and Space Launches. (a) The export of...

  14. Basement Membrane Zone Collagens XV and XVIII/Proteoglycans Mediate Leukocyte Influx in Renal Ischemia/Reperfusion

    NARCIS (Netherlands)

    Zaferani, Azadeh; Talsma, Ditmer T.; Yazdani, Saleh; Celie, Johanna W. A. M.; Aikio, Mari; Heljasvaara, Ritva; Navis, Gerjan J.; Pihlajaniemi, Taina; van den Born, Jacob

    2014-01-01

    Collagen type XV and XVIII are proteoglycans found in the basement membrane zones of endothelial and epithelial cells, and known for their cryptic anti-angiogenic domains named restin and endostatin, respectively. Mutations or deletions of these collagens are associated with eye, muscle and microves

  15. Neutron structure of human carbonic anhydrase II in complex with methazolamide: mapping the solvent and hydrogen-bonding patterns of an effective clinical drug

    Directory of Open Access Journals (Sweden)

    Mayank Aggarwal

    2016-09-01

    Full Text Available Carbonic anhydrases (CAs; EC 4.2.1.1 catalyze the interconversion of CO2 and HCO3−, and their inhibitors have long been used as diuretics and as a therapeutic treatment for many disorders such as glaucoma and epilepsy. Acetazolamide (AZM and methazolamide (MZM, a methyl derivative of AZM are two of the classical CA inhibitory drugs that have been used clinically for decades. The jointly refined X-ray/neutron structure of MZM in complex with human CA isoform II (hCA II has been determined to a resolution of 2.2 Å with an Rcryst of ∼16.0%. Presented in this article, along with only the second neutron structure of a clinical drug-bound hCA, is an in-depth structural comparison and analyses of differences in hydrogen-bonding network, water-molecule orientation and solvent displacement that take place upon the binding of AZM and MZM in the active site of hCA II. Even though MZM is slightly more hydrophobic and displaces more waters than AZM, the overall binding affinity (Ki for both of the drugs against hCA II is similar (∼10 nM. The plausible reasons behind this finding have also been discussed using molecular dynamics and X-ray crystal structures of hCA II–MZM determined at cryotemperature and room temperature. This study not only allows a direct comparison of the hydrogen bonding, protonation states and solvent orientation/displacement of AZM and MZM, but also shows the significant effect that the methyl derivative has on the solvent organization in the hCA II active site.

  16. Carboxysomal carbonic anhydrases: Structure and role in microbial CO2 fixation

    Energy Technology Data Exchange (ETDEWEB)

    Cannon, Gordon C.; Heinhorst, Sabine; Kerfeld, Cheryl A.

    2010-06-23

    Cyanobacteria and some chemoautotrophic bacteria are able to grow in environments with limiting CO2 concentrations by employing a CO2-concentrating mechanism (CCM) that allows them to accumulate inorganic carbon in their cytoplasm to concentrations several orders of magnitude higher than that on the outside. The final step of this process takes place in polyhedral protein microcompartments known as carboxysomes, which contain the majority of the CO2-fixing enzyme, RubisCO. The efficiency of CO2 fixation by the sequestered RubisCO is enhanced by co-localization with a specialized carbonic anhydrase that catalyzes dehydration of the cytoplasmic bicarbonate and ensures saturation of RubisCO with its substrate, CO2. There are two genetically distinct carboxysome types that differ in their protein composition and in the carbonic anhydrase(s) they employ. Here we review the existing information concerning the genomics, structure and enzymology of these uniquely adapted carbonic anhydrases, which are of fundamental importance in the global carbon cycle.

  17. Antibody inhibiting enzymatic activity of tumour-associated carbonic anhydrase isoform IX

    NARCIS (Netherlands)

    Murri-Plesko, M.T.; Hulikova, A.; Oosterwijk, E.; Scott, A.M.; Zortea, A.; Harris, A.L.; Ritter, G.; Old, L.; Bauer, S.; Swietach, P.; Renner, C.

    2011-01-01

    Carbonic anhydrase IX (CAIX) is a hypoxia-induced, membrane-tethered enzyme that is highly expressed in many cancers. It catalyses the hydration of CO(2) to HCO(3)(-) and H(+), and the reverse dehydration reaction. Recent studies have shown an important role for CAIX in pH regulation and it has been

  18. The CA domain of the respiratory complex I is required for normal embryogenesis in Arabidopsis thaliana.

    Science.gov (United States)

    Córdoba, Juan Pablo; Marchetti, Fernanda; Soto, Débora; Martin, María Victoria; Pagnussat, Gabriela Carolina; Zabaleta, Eduardo

    2016-03-01

    The NADH-ubiquinone oxidoreductase [complex I (CI), EC 1.6.5.3] of the mitochondrial respiratory chain is the principal entry point of electrons, and vital in maintaining metabolism and the redox balance. In a variety of eukaryotic organisms, except animal and fungi (Opisthokonta), it contains an extra domain composed of putative gamma carbonic anhydrases subunits, named the CA domain, which was proposed to be essential for complex I assembly. There are two kinds of carbonic anhydrase subunits: CAs (of which there are three) and carbonic anhydrase-like proteins (CALs) (of which there are two). In plants, the CA domain has been linked to photorespiration. In this work, we report that Arabidopsis mutant plants affected in two specific CA subunits show a lethal phenotype. Double homozygous knockouts ca1ca2 embryos show a significant developmental delay compared to the non-homozygous embryos, which show a wild-type (WT) phenotype in the same silique. Mutant embryos show impaired mitochondrial membrane potential and mitochondrial reactive oxygen species (ROS) accumulation. The characteristic embryo greening does not take place and fewer but larger oil bodies are present. Although seeds look dark brown and wrinkled, they are able to germinate 12 d later than WT seeds. However, they die immediately, most likely due to oxidative stress.Since the CA domain is required for complex I biogenesis, it is predicted that in ca1ca2 mutants no complex I could be formed, triggering the lethal phenotype. The in vivo composition of a functional CA domain is proposed.

  19. Characterization and anions inhibition studies of an α-carbonic anhydrase from the teleost fish Dicentrarchus labrax.

    Science.gov (United States)

    Ekinci, Deniz; Ceyhun, Saltuk Buğrahan; Sentürk, Murat; Erdem, Deryanur; Küfrevioğlu, Omer İrfan; Supuran, Claudiu T

    2011-01-15

    Carbonic anhydrase (CA; EC 4.2.1.1) was purified from the gill of the teleost fish Dicentrarchus labrax (European seabass). The purification procedure consisted of a single step affinity chromatography on Sepharose 4B-tyrosine-sulfanilamide. The enzyme was purified 84.9-fold with a yield of 58%, and a specific activity of 838.9 U/mg proteins. It has an optimum pH at 8.0; an optimum temperature at 10°C. The kinetic parameters of this enzyme were determined for its esterase activity, with 4-nitrophenyl acetate (NPA) as substrate. The following anions, H₂NSO₃⁻, I⁻, SCN⁻, NO₃⁻, NO₂⁻, N₃⁻, Br⁻, Cl⁻, SO₄²⁻, and F⁻ showed inhibitory effects on the enzyme. Sulfamic acid, iodide, and thiocyanate exhibited the strongest inhibitory action, in the micromolar range (K(i)s of 87-187 μM). NO₃⁻, NO₂⁻ and N₃⁻ were moderate inhibitors, whereas other anions showed only weak actions. All tested anions inhibited the enzyme in a competitive manner. Our findings indicate that these anions inhibit the fish enzyme in a similar manner to other α-CAs from mammals investigated earlier, but the susceptibility to various anions differs significantly between the fish and mammalian CAs.

  20. Intrinsic Thermodynamics and Structures of 2,4- and 3,4-Substituted Fluorinated Benzenesulfonamides Binding to Carbonic Anhydrases.

    Science.gov (United States)

    Zubrienė, Asta; Smirnov, Alexey; Dudutienė, Virginija; Timm, David D; Matulienė, Jurgita; Michailovienė, Vilma; Zakšauskas, Audrius; Manakova, Elena; Gražulis, Saulius; Matulis, Daumantas

    2017-01-20

    The goal of rational drug design is to understand structure-thermodynamics correlations in order to predict the chemical structure of a drug that would exhibit excellent affinity and selectivity for a target protein. In this study we explored the contribution of added functionalities of benzenesulfonamide inhibitors to the intrinsic binding affinity, enthalpy, and entropy for recombinant human carbonic anhydrases (CA) CA I, CA II, CA VII, CA IX, CA XII, and CA XIII. The binding enthalpies of compounds possessing similar chemical structures and affinities were found to be very different, spanning a range from -90 to +10 kJ mol(-1) , and are compensated by a similar opposing entropy contribution. The intrinsic parameters of binding were determined by subtracting the linked protonation reactions. The sulfonamide group pKa values of the compounds were measured spectrophotometrically, and the protonation enthalpies were measured by isothermal titration calorimetry (ITC). Herein we describe the development of meta- or ortho-substituted fluorinated benzenesulfonamides toward the highly potent compound 10 h, which exhibits an observed dissociation constant value of 43 pm and an intrinsic dissociation constant value of 1.1 pm toward CA IX, an anticancer target that is highly overexpressed in various tumors. Fluorescence thermal shift assays, ITC, and X-ray crystallography were all applied in this work.

  1. Cloning, characterization, and sulfonamide and thiol inhibition studies of an α-carbonic anhydrase from Trypanosoma cruzi, the causative agent of Chagas disease.

    Science.gov (United States)

    Pan, Peiwen; Vermelho, Alane Beatriz; Capaci Rodrigues, Giseli; Scozzafava, Andrea; Tolvanen, Martti E E; Parkkila, Seppo; Capasso, Clemente; Supuran, Claudiu T

    2013-02-28

    An α-carbonic anhydrase (CA, EC 4.2.1.1) has been identified, cloned, and characterized from the unicellular protozoan Trypanosoma cruzi, the causative agent of Chagas disease. The enzyme (TcCA) has a very high catalytic activity for the CO2 hydration reaction, being similar kinetically to the human (h) isoform hCA II, although it is devoid of the His64 proton shuttle. A large number of aromatic/heterocyclic sulfonamides and some 5-mercapto-1,3,4-thiadiazoles were investigated as TcCA inhibitors. The aromatic sulfonamides were weak inhibitors (K(I) values of 192 nM to 84 μM), whereas some heterocyclic compounds inhibited the enzyme with K(I) values in the range 61.6-93.6 nM. The thiols were the most potent in vitro inhibitors (K(I) values of 21.1-79.0 nM), and some of them also inhibited the epimastigotes growth of two T. cruzi strains in vivo.

  2. 3D QSAR studies, pharmacophore modeling, and virtual screening of diarylpyrazole-benzenesulfonamide derivatives as a template to obtain new inhibitors, using human carbonic anhydrase II as a model protein.

    Science.gov (United States)

    Entezari Heravi, Yeganeh; Sereshti, Hassan; Saboury, Ali Akbar; Ghasemi, Jahan; Amirmostofian, Marzieh; Supuran, Claudiu T

    2017-12-01

    A 3D-QSAR modeling was performed on a series of diarylpyrazole-benzenesulfonamide derivatives acting as inhibitors of the metalloenzyme carbonic anhydrase (CA, EC 4.2.1.1). The compounds were collected from two datasets with the same scaffold, and utilized as a template for a new pharmacophore model to screen the ZINC database of commercially available derivatives. The datasets were divided into training, test, and validation sets. As the first step, comparative molecular field analysis (CoMFA), CoMFA region focusing and comparative molecular similarity indices analysis (CoMSIA) in parallel with docking studies were applied to a set of 41 human (h) CA II inhibitors. The validity and the prediction capacity of the resulting models were evaluated by leave-one-out (LOO) cross-validation approach. The reliability of the model for the prediction of possibly new CA inhibitors was also tested.

  3. Inhibition of bacterial carbonic anhydrases and zinc proteases: from orphan targets to innovative new antibiotic drugs.

    Science.gov (United States)

    Supuran, C T

    2012-01-01

    Zinc-containing enzymes, such as carbonic anhydrases (CAs) and metalloproteases (MPs) play critical functions in bacteria, being involved in various steps of their life cycle, which are important for survival, colonization, acquisition of nutrients for growth and proliferation, facilitation of dissemination, invasion and pathogenicity. The development of resistance to many classes of clinically used antibiotics emphasizes the need of new antibacterial drug targets to be explored. There is a wealth of data regarding bacterial CAs and zinc MPs present in many pathogenic species, such as Neisseria spp., Helycobacter pylori Escherichia coli, Mycobacterium tuberculosis, Brucella spp., Streptococcus pneumoniae, Salmonella enterica, Haemophilus influenzae, Listeria spp, Vibrio spp., Pseudomonas aeruginosa, Legionella pneumophila, Streptomyces spp., Clostridium spp., Enterococcus spp., etc. Some of these enzymes have been cloned, purified and characterized by crystallographic techniques. However, for the moment, few potent and specific inhibitors for bacterial MPs have been reported except for Clostridium histolyticum collagenase, botulinum and tetanus neurotoxin and anthrax lethal factor, which will be reviewed in this article. Bacteria encode α-,β-, and/or γ-CA families, but up to now only the first two classes have been investigated in some detail in different species. The α-CAs from Neisseria spp. and H. pylori as well as the β-class enzymes from E. coli, H. pylori, M. tuberculosis, Brucella spp., S. pneumoniae, S. enterica and H. influenzae have been cloned and characterized. The catalytic/inhibition mechanisms of these CAs are well understood as X-ray crystal structures are available for some of them, but no adducts of these enzymes with inhibitors have been characterized so far. In vitro and in vivo studies with various classes of inhibitors, such as anions, sulfonamides and sulfamates have been reported. Only for Neisseria spp., H. pylori, B. suis and S

  4. Expression of transmembrane carbonic anhydrases, CAIX and CAXII, in human development

    Directory of Open Access Journals (Sweden)

    Lerman Michael I

    2009-03-01

    Full Text Available Abstract Background Transmembrane CAIX and CAXII are members of the alpha carbonic anhydrase (CA family. They play a crucial role in differentiation, proliferation, and pH regulation. Expression of CAIX and CAXII proteins in tumor tissues is primarily induced by hypoxia and this is particularly true for CAIX, which is regulated by the transcription factor, hypoxia inducible factor-1 (HIF-1. Their distributions in normal adult human tissues are restricted to highly specialized cells that are not always hypoxic. The human fetus exists in a relatively hypoxic environment. We examined expression of CAIX, CAXII and HIF-1α in the developing human fetus and postnatal tissues to determine whether expression of CAIX and CAXII is exclusively regulated by HIF-1. Results The co-localization of CAIX and HIF-1α was limited to certain cell types in embryonic and early fetal tissues. Those cells comprised the primitive mesenchyma or involved chondrogenesis and skin development. Transient CAIX expression was limited to immature tissues of mesodermal origin and the skin and ependymal cells. The only tissues that persistently expressed CAIX protein were coelomic epithelium (mesothelium and its remnants, the epithelium of the stomach and biliary tree, glands and crypt cells of duodenum and small intestine, and the cells located at those sites previously identified as harboring adult stem cells in, for example, the skin and large intestine. In many instances co-localization of CAIX and HIF-1α was not evident. CAXII expression is restricted to cells involved in secretion and water absorption such as parietal cells of the stomach, acinar cells of the salivary glands and pancreas, epithelium of the large intestine, and renal tubules. Co-localization of CAXII with CAIX or HIF-1α was not observed. Conclusion The study has showed that: 1 HIF-1α and CAIX expression co- localized in many, but not all, of the embryonic and early fetal tissues; 2 There is no evidence of

  5. Referencias a las armas utilizadas en las luchas nobiliarias gallegas en el siglo XV

    Directory of Open Access Journals (Sweden)

    Fraga Díez, Guillermo Federico Carlos

    1988-12-01

    Full Text Available Como modestísima aportación al tema, recogemos las referencias que figuran en un documento del año 1524, pero que aluden a sucesos ocurridos a finales del siglo xv. Se trata del recuento —efectuado en presencia del notario Antonio del Corral— de las armas existentes en quince fortalezas de la dignidad arzobispal de Santiago. Como sería muy prolijo enumerar el armamento de cada fortaleza una por una, hacemos una relación general de dichas armas, con alguna ligera anotación que encontramos en otras fuentes de la época referentes a la utilización de tales armas, llamando la atención sobre la coexistencia de las que podríamos llamar tradicionales con las nuevas de fuego.

  6. Geothermal Program Review XV: proceedings. Role of Research in the Changing World of Energy Supply

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-01-01

    The U.S. Department of Energy`s Office of Geothermal Technologies conducted its annual Program Review XV in Berkeley, March 24-26, 1997. The geothermal community came together for an in-depth review of the federally-sponsored geothermal research and development program. This year`s theme focussed on {open_quotes}The Role of Research in the Changing World of Energy Supply.{close_quotes} This annual conference is designed to promote technology transfer by bringing together DOE-sponsored researchers; utility representatives; geothermal developers; equipment and service suppliers; representatives from local, state, and federal agencies; and others with an interest in geothermal energy. Separate abstracts have been indexed to the database for contributions to this conference.

  7. La deuda pública de los municipios aragoneses en los siglos XIV y XV

    Directory of Open Access Journals (Sweden)

    Abella Samitier, Juan

    2009-06-01

    Full Text Available This article aims at studying the origin of public debt in Aragon in the 14th century and its development in the 15th century. Hence, the dire state of municipal finances, the reasons that led city and town councils to run into debt, cuts and rises in interest rates, and some the most important issues of public debt will be fully discussed and analysed.

    El objeto de este artículo es estudiar los orígenes de la deuda pública de los municipios aragoneses en el siglo XIV y su evolución en el siglo XV. En este sentido, se analiza especialmente la cronología de las principales emisiones, los cambios en los tipos de interés y las causas que obligaron a las ciudades y villas del reino a endeudarse.

  8. Advanced AFCS developments on the XV-15 tilt rotor research aircraft. [Automatic Flight Control System

    Science.gov (United States)

    Churchill, G. B.; Gerdes, R. M.

    1984-01-01

    The design criteria and control and handling qualities of the Automatic Flight Control System (AFCS), developed in the framework of the XV-15 tilt-rotor research aircraft, are evaluated, differentiating between the stability and control criteria. A technically aggressive SCAS control law was implemented, demonstrating that significant benefits accrue when stability criteria are separated from design criteria; the design analyses for application of the control law are presented, and the limit bandwidth for stabilization in hovering flight is shown to be defined by rotor or control lag functions. Flight tests of the aircraft resulted in a rating of 3 on the Cooper-Harper scale; a possibility of achieving a rating of 2 is expected if the system is applied to the yaw and heave control modes.

  9. Georgios Sphrantzes or how to become an archon in Byzantium in the XV century

    Directory of Open Access Journals (Sweden)

    Nikolić Maja

    2010-01-01

    Full Text Available The historical work by Georgios Sphrantzes, his Memoirs, illustrates, through information on his life and career, the way in which a person could enter the higher social circles in XV century Byzantium. Usually, these persons were referred to in sources as "archons" and some of them as the emperor’s "oikeioi", which involved a specific kind of personal and close relationship with the ruler and, in this case, a dynasty. Furthermore, "Sphrantzes" work provides data on some late Byzantine phenomena, for instance, not only the imperial "oikos", but those of the emperor’s brothers as well, and indicates the existence of the same hierarchy in the "ospitia" of the despotai.

  10. A physiological role for cyanate-induced carbonic anhydrase in Escherichia coli.

    Science.gov (United States)

    Guilloton, M B; Lamblin, A F; Kozliak, E I; Gerami-Nejad, M; Tu, C; Silverman, D; Anderson, P M; Fuchs, J A

    1993-03-01

    Cyanate induces expression of the cyn operon in Escherichia coli. The cyn operon includes the gene cynS, encoding cyanase, which catalyzes the reaction of cyanate with bicarbonate to give ammonia and carbon dioxide. A carbonic anhydrase activity was recently found to be encoded by the cynT gene, the first gene of the cyn operon; it was proposed that carbonic anhydrase prevents depletion of bicarbonate during cyanate decomposition due to loss of CO2 by diffusion out of the cell (M. B. Guilloton, J. J. Korte, A. F. Lamblin, J. A. Fuchs, and P. M. Anderson, J. Biol. Chem. 267:3731-3734, 1992). The function of the product of the third gene of this operon, cynX, is unknown. In the study reported here, the physiological roles of cynT and cynX were investigated by construction of chromosomal mutants in which each of the three genes was rendered inactive. The delta cynT chromosomal mutant expressed an active cyanase but no active carbonic anhydrase. In contrast to the wild-type strain, the growth of the delta cynT strain was inhibited by cyanate, and the mutant strain was unable to degrade cyanate and therefore could not use cyanate as the sole nitrogen source when grown at a partial CO2 pressures (pCO2) of 0.03% (air). At a high pCO2 (3%), however, the delta cynT strain behaved like the wild-type strain; it was significantly less sensitive to the toxic effects of cyanate and could degrade cyanate and use cyanate as the sole nitrogen source for growth. These results are consistent with the proposed function for carbonic anhydrase. The chromosomal mutant carrying cynS::kan expressed induced carbonic anhydrase activity but no active cyanase. The cynS::kan mutant was found to be much less sensitive to cyanate than the delta cynT mutant at a low pCO2, indicating that bicarbonate depletion due to the reaction of bicarbonate with cyanate catalyzed by cyanase is more deleterious to growth than direct inhibition by cyanate. Mutants carrying a nonfunctional cynX gene (cynX::kan and

  11. Intrinsic Thermodynamics and Structure Correlation of Benzenesulfonamides with a Pyrimidine Moiety Binding to Carbonic Anhydrases I, II, VII, XII, and XIII.

    Directory of Open Access Journals (Sweden)

    Miglė Kišonaitė

    Full Text Available The early stage of drug discovery is often based on selecting the highest affinity lead compound. To this end the structural and energetic characterization of the binding reaction is important. The binding energetics can be resolved into enthalpic and entropic contributions to the binding Gibbs free energy. Most compound binding reactions are coupled to the absorption or release of protons by the protein or the compound. A distinction between the observed and intrinsic parameters of the binding energetics requires the dissection of the protonation/deprotonation processes. Since only the intrinsic parameters can be correlated with molecular structural perturbations associated with complex formation, it is these parameters that are required for rational drug design. Carbonic anhydrase (CA isoforms are important therapeutic targets to treat a range of disorders including glaucoma, obesity, epilepsy, and cancer. For effective treatment isoform-specific inhibitors are needed. In this work we investigated the binding and protonation energetics of sixteen [(2-pyrimidinylthioacetyl]benzenesulfonamide CA inhibitors using isothermal titration calorimetry and fluorescent thermal shift assay. The compounds were built by combining four sulfonamide headgroups with four tailgroups yielding 16 compounds. Their intrinsic binding thermodynamics showed the limitations of the functional group energetic additivity approach used in fragment-based drug design, especially at the level of enthalpies and entropies of binding. Combined with high resolution crystal structural data correlations were drawn between the chemical functional groups on selected inhibitors and intrinsic thermodynamic parameters of CA-inhibitor complex formation.

  12. Analytical aeroelastic stability considerations and conversion loads for an XV-15 tilt-rotor in a wind tunnel simulation

    Science.gov (United States)

    Kottapalli, Sesi; Meza, Victor

    1992-01-01

    A rotorcraft analysis is conducted to assess tilt-rotor stability and conversion loads for the XV-15 rotor with metal blades within its specified test envelope. A 38-DOF flutter analysis based on the code by Johnson (1988) is developed to simulate a wind-tunnel test in which the rotor torque is constant and thereby study stability. The same analytical model provides the simulated loads including hub loads, blade loads, and oscillatory pitch-link loads with attention given to the nonuniform inflow through the proprotor in the presence of the wing. Tilt-rotor stability during the cruise mode is found to be sensitive to coupling effects in the control system stiffness, and a stability problem is identified in the XV-15 Advanced Technology Blades. The present analysis demonstrates that the tilt-rotor is stable within the specified test envelope of the NASA 40 x 80-ft wind tunnel.

  13. Structure and Metal Exchange in the Cadmium Carbonic anhydrase of Marine Diatoms

    Energy Technology Data Exchange (ETDEWEB)

    Xu,Y.; Feng, l.; Jeffrey, P.; Shi, Y.; Morel, F.

    2008-01-01

    Carbonic anhydrase, a zinc enzyme found in organisms from all kingdoms, catalyses the reversible hydration of carbon dioxide and is used for inorganic carbon acquisition by phytoplankton. In the oceans, where zinc is nearly depleted, diatoms use cadmium as a catalytic metal atom in cadmium carbonic anhydrase (CDCA). Here we report the crystal structures of CDCA in four distinct forms: cadmium-bound, zinc-bound, metal-free and acetate-bound. Despite lack of sequence homology, CDCA is a structural mimic of a functional {beta}-carbonic anhydrase dimer, with striking similarity in the spatial organization of the active site residues. CDCA readily exchanges cadmium and zinc at its active site--an apparently unique adaptation to oceanic life that is explained by a stable opening of the metal coordinating site in the absence of metal. Given the central role of diatoms in exporting carbon to the deep sea, their use of cadmium in an enzyme critical for carbon acquisition establishes a remarkable link between the global cycles of cadmium and carbon.

  14. Carbonic anhydrase 2-like and Na⁺-K⁺-ATPase α gene expression in medaka (Oryzias latipes) under carbonate alkalinity stress.

    Science.gov (United States)

    Yao, Zongli; Lai, Qifang; Hao, Zhuoran; Chen, Ling; Lin, Tingting; Zhou, Kai; Wang, Hui

    2015-12-01

    High carbonate alkalinity is one of the major stress factors for living organisms in saline-alkaline water areas. Acute and chronic effects of carbonate alkalinity on expression of two genes, carbonic anhydrase 2-like (CA2-like) and Na(+)-K(+)-ATPase α subunit (NKA-α) mRNA in medaka (Oryzias latipes) were evaluated to better understand the responses important for coping with a carbonate alkalinity stress. In the acute exposure experiment, the expression of CA2-like and NKA-α mRNA in the gill and kidney of medaka were examined from 0 h to 7 days exposed to 30.4 mM carbonate alkalinity water. Exposure to high carbonate alkalinity resulted in a transitory alkalosis, followed by a transient increase in gill and kidney CA2-like and NKA-α mRNA expression. In the chronic exposure experiment, the expression of these two genes was examined in the gill and kidney at 50 days post-exposure to six different carbonate alkalinity concentrations ranging from 1.5 to 30.4 mM. Gill and kidney CA2-like mRNA levels in 30.4 mM were approximately 10 and 30 times higher than that of the control (1.5 mM), respectively. Less differences were found in NKA-α expression in the 50-days exposure. The results indicate that when transferred to high carbonate alkalinity water, a transitory alkalosis may occur in medaka, followed by compensatory acid-base and ion regulatory responses. Thus, CA2-like and NKA-α are at least two of the important factors that contribute to the regulation of alkalinity stress.

  15. Type XV collagen in human colonic adenocarcinomas has a different distribution than other basement membrane zone proteins.

    Science.gov (United States)

    Amenta, P S; Briggs, K; Xu, K; Gamboa, E; Jukkola, A F; Li, D; Myers, J C

    2000-03-01

    In situ carcinomas must penetrate their own basement membrane to be classified as invasive, and subsequently infiltrate surrounding connective tissue and cross vascular basement membranes to metastasize hematogenously. Accordingly, in many studies, integral basement membrane components, including type IV collagen, laminin, and heparan sulfate proteoglycan, have been localized in a spectrum of tumors to gain insight into their role in neoplasia. A number of recently identified extracellular matrix molecules and isoforms of the aforementioned proteins have been localized to the basement membrane zone, illustrating another level of biochemical heterogeneity in these structures. As the complexity of these matrices becomes more apparent, their roles in maintaining homeostasis and in tumor biology falls into question. Of the new group of collagens localized to the basement membrane zone, type XV was the first to be characterized (Cell Tissue Res, 286:493-505, 1996). This nonfibrillar collagen has a nearly ubiquitous distribution in normal human tissues via a strong association with basement membrane zones, suggesting that it functions to adhere basement membrane to the underlying stroma. To begin investigation of this protein in malignant tumors, we have localized type XV in human colonic adenocarcinomas and compared its distribution with that of type IV collagen and laminin. Collagens XV and IV and laminin were found in all normal and colonic epithelial, muscle, fat, neural, and vascular basement membrane zones, as shown previously. In moderately differentiated, invasive adenocarcinomas, laminin and type IV collagen were sometimes observed as continuous, linear deposits around some of the malignant glands, but more often they were seen in either discontinuous deposits or were completely absent. In contrast, type XV collagen was characterized as virtually absent from the basement membrane zones of malignant glandular elements in moderately differentiated tumors

  16. Las galeras mercantiles de Florencia en el Reino de Granada en el siglo XV

    Directory of Open Access Journals (Sweden)

    González Arévalo, Raúl

    2011-06-01

    Full Text Available Florence developped a statal galleys system in the 15th century. The present article analyzes its role in the Kingdom of Granada, in the Florentine Sea Consuls’ orders as well as in the privet documentation. Thus, we study aspects as different as the insertion of the Nasrid ports in the Florentine navigation lines, freight charges envisaged and the news about the mercantile practice. What emerges is a hitherto unknown image about the role of the Tuscan galleys in the external commercial organization of the Granadan territory.

    Florencia desarrolló un sistema estatal de galeras en el siglo XV. El presente artículo analiza su papel en el Reino de Granada, tanto en las órdenes del Consulado del Mar florentino como en la documentación privada. Así, se estudian aspectos tan dispares como la inserción de los puertos nazaríes en las líneas de navegación florentinas, los fletes previstos y las noticias sobre la práctica mercantil. Emerge una imagen inédita sobre el papel de las galeras toscanas en la articulación comercial exterior del territorio granadino.

  17. Los ingresos extraordinarios del Reino de Galicia en el siglo XV

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    Rubio Martínez, Amparo

    2010-12-01

    Full Text Available Study of the extraordinary taxes that are levied in the kingdom of Galicia during the fifteenth century. First attention is given to the collection of actual orders during the reigns of John II and Henry IV, then move on to explore other ways of collecting taxes and extraordinary contribution of the Brotherhood and its replacement, from 1498, for extraordinary services approved by the Cortes of the kingdom.

    Estudio de los impuestos extraordinarios que se recaudan en el reino de Galicia durante todo el siglo XV. En primer lugar se presta atención a la recaudación de los pedidos reales durante los reinados de Juan II y Enrique IV, para pasar después a analizar otras formas de recaudación de tributos extraordinarios como la contribución de la Hermandad y su sustitución, a partir de 1498, por los servicios extraordinarios aprobados por las Cortes del reino.

  18. Eclesiásticos en la diplomacia castellana en el siglo XV

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    Villarroel González, Óscar

    2010-12-01

    Full Text Available The clergymen were, along the Middle Ages, usually members of the diplomatic services of the Monarchy. The fact of know the Latin was, among other things, the key that were suitable to work for the Monarchy in this kind of tasks. This study analyzes the figure of the clergymen who played in diplomatic works in the fifteenth century. It analyzes who, why and how they were chosen for these tasks, attending on his studies and hierarchy.

    Los eclesiásticos participaron de forma activa y recurrente en la diplomacia durante lo siglos medievales. Su dominio del latín, entre otras cosas, fue clave en el hecho de que fuesen personajes idóneos para colaborar con la Monarquía en tales cometidos. En el presente estudio se analiza la figura de los eclesiásticos que desempeñaron labores diplomáticas en Castilla en el siglo XV. Se analiza quiénes, cómo y por qué fueron elegidos para esas tareas, atendiendo a su formación y su jerarquía eclesiástica.

  19. Una fuente para el estudio de las luchas nobiliarias en la Galicia del siglo XV

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    Rodríguez González, Angel

    1988-12-01

    Full Text Available Aunque la situación de los territorios que formaban la monarquía castellana del siglo XV no ofrece, ni mucho menos, un cuadro de pacífica convivencia, ha quedado estereotipada como tierra de revuelta permanente el reino de Galicia, y así se recoge en todos los textos cronísticos de la Baja Edad Media española. Sin ser una excepción, hemos de admitir, sin embargo, que tal estado responde a una realidad, y así se pone de manifiesto en una crónica gallega que, a pesar de su importancia, no ha sido recogida en la historia de la historiografía española. Nos referimos a Vasco de Aponte, autor de una Relación de algunas Casas y Linages del Reino de Galicia , que se escribió en la primera mitad del siglo xvi. Su autor fue escudero de la Casa de Andrade y su obra adolece de imprecisiones cronológicas, pero, como se ha dicho de él, fue un magnífico historiador «porque ni siquiera pretendió serlo».

  20. Artesanos vidrieros en Mallorca. Relaciones y conexiones con el levante Peninsular (siglos XIV-XV

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    Capellà Galmés, Miquel Àngel

    2014-12-01

    Full Text Available This paper analyses the production cycle of glass, and the artisans who worked it, in the city of Majorca during the 14th and 15th centuries. It also studies the relationships established with Barcelona and other areas in the Crown of Aragon for glass production and trade in the gothic period. Based on archival documentation, this paper studies the locations and structure of kilns, the source of the raw materials used in the manufacturing and, fi nally, the models of organisation and family relations of the glassmakers.En este artículo se analiza el ciclo productivo del vidrio y los artesanos que en él intervinieron en la Ciutat de Mallorca durante los siglos XIV y XV. También es fundamental fijar las relaciones que se establecieron con Barcelona y otras zonas de la Corona de Aragón, en el marco de la producción y del comercio del vidrio en época gótica. Se estudia, mediante la documentación de archivo, la localización de los hornos, su estructura, así como el origen de las materias primas utilizadas en la fabricación y, finalmente, los modelos de organización y relaciones familiares de los vidrieros.

  1. (Una visión del medioambiente en los siglos XV al XVIII

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    José Ojeda Nieto

    2005-01-01

    Full Text Available Entre los siglos XV y XVIII los oriolanos persiguieron a lobos y pájaros. Buscaban el exterminio del predador para acabar con los desmanes en los rebaños de ganado y con el temor ancestral, revivido constantemente en cuentos y leyendas. Mataban pájaros porque su proliferación reducía las cosechas. Se trataba de controlar, cuando no eliminar, unos competidores desleales. A la historia del medioambiente le corresponde señalar no solo los fenómenos de transformación y degradación del espacio, también la relación antrópica con las demás especies. La relación hombre-lobos y pájaros, y aún las ratas, en la Orihuela de los siglos señalados, constituye un modelo de análisis que compete también al campo de las ciencias humanas.

  2. The synthesis of novel pyrazole-3,4-dicarboxamides bearing 5-amino-1,3,4-thiadiazole-2-sulfonamide moiety with effective inhibitory activity against the isoforms of human cytosolic carbonic anhydrase I and II.

    Science.gov (United States)

    Mert, Samet; Alım, Zuhal; İşgör, Mehmet Mustafa; Beydemir, Şükrü; Kasımoğulları, Rahmi

    2016-10-01

    A series of 1-(3-substituted-phenyl)-5-phenyl-N(3),N(4)-bis(5-sulfamoyl-1,3,4-thiadiazol-2-yl)-1H-pyrazole-3,4-dicarboxamides (4-15) were synthesized. The structures of these pyrazole-sulfonamides were confirmed by FT-IR, (1)H NMR, (13)C NMR and elemental analysis methods. Human cytosolic carbonic anhydrase (CA, EC 4.2.1.1) isozymes (hCA I and II) were purified from erythrocyte cells by affinity chromatography. The inhibitory effects of newly synthesized derivatives (4-15) were investigated in vitro on esterase activities of these isozymes. The Ki values were determined as 0.119-3.999μM for hCA I and 0.084-0.878μM for hCA II. The results showed that the compound 6 for hCA I and the compound 11 for hCA II had the highest inhibitory effect. Beside that, the compound 8 had the lowest inhibition effect on both isozymes.

  3. Recombinant thermoactive phosphoenolpyruvate carboxylase (PEPC) from Thermosynechococcus elongatus and its coupling with mesophilic/thermophilic bacterial carbonic anhydrases (CAs) for the conversion of CO2 to oxaloacetate.

    Science.gov (United States)

    Del Prete, Sonia; De Luca, Viviana; Capasso, Clemente; Supuran, Claudiu T; Carginale, Vincenzo

    2016-01-15

    With the continuous increase of atmospheric CO2 in the last decades, efficient methods for carbon capture, sequestration, and utilization are urgently required. The possibility of converting CO2 into useful chemicals could be a good strategy to both decreasing the CO2 concentration and for achieving an efficient exploitation of this cheap carbon source. Recently, several single- and multi-enzyme systems for the catalytic conversion of CO2 mainly to bicarbonate have been implemented. In order to design and construct a catalytic system for the conversion of CO2 to organic molecules, we implemented an in vitro multienzyme system using mesophilic and thermophilic enzymes. The system, in fact, was constituted by a recombinant phosphoenolpyruvate carboxylase (PEPC) from the thermophilic cyanobacterium Thermosynechococcus elongatus, in combination with mesophilic/thermophilic bacterial carbonic anhydrases (CAs), for converting CO2 into oxaloacetate, a compound of potential utility in industrial processes. The catalytic procedure is in two steps: the conversion of CO2 into bicarbonate by CA, followed by the carboxylation of phosphoenolpyruvate with bicarbonate, catalyzed by PEPC, with formation of oxaloacetate (OAA). All tested CAs, belonging to α-, β-, and γ-CA classes, were able to increase OAA production compared to procedures when only PEPC was used. Interestingly, the efficiency of the CAs tested in OAA production was in good agreement with the kinetic parameters for the CO2 hydration reaction of these enzymes. This PEPC also revealed to be thermoactive and thermostable, and when coupled with the extremely thermostable CA from Sulphurhydrogenibium azorense (SazCA) the production of OAA was achieved even if the two enzymes were exposed to temperatures up to 60 °C, suggesting a possible role of the two coupled enzymes in biotechnological processes.

  4. V-H+ -ATPase translocation during blood alkalosis in dogfish gills: interaction with carbonic anhydrase and involvement in the postfeeding alkaline tide.

    Science.gov (United States)

    Tresguerres, Martin; Parks, Scott K; Wood, Chris M; Goss, Greg G

    2007-05-01

    We investigated the involvement of carbonic anhydrase (CA) in mediating V-H(+)-ATPase translocation into the basolateral membrane in gills of alkalotic Squalus acanthias. Immunolabeling revealed that CA is localized in the same cells as V-H(+)-ATPase. Blood plasma from dogfish injected with acetazolamide [30 mg/kg at time (t) = 0 and 6 h] and infused with NaHCO(3) for 12 h (1,000 microeq.kg(-1).h(-1)) had significantly higher plasma HCO(3)(-) concentration than fish that were infused with NaHCO(3) alone (28.72 +/- 0.41 vs. 6.57 +/- 2.47 mmol/l, n = 3), whereas blood pH was similar in both treatments (8.03 +/- 0.11 vs. 8.04 +/- 0.11 pH units at t = 12 h). CA inhibition impaired V-H(+)-ATPase translocation into the basolateral membrane, as estimated from immunolabeled gill sections and Western blotting on gill cell membranes (0.24 +/- 0.08 vs. 1.00 +/- 0.28 arbitrary units, n = 3; P < 0.05). We investigated V-H(+)-ATPase translocation during a postfeeding alkalosis ("alkaline tide"). Gill samples were taken 24-26 h after dogfish were fed to satiety in a natural-like feeding regime. Immunolabeled gill sections revealed that V-H(+)-ATPase translocated to the basolateral membrane in the postfed fish. Confirming this result, V-H(+)-ATPase abundance was twofold higher in gill cell membranes of the postfed fish than in fasted fish (n = 4-5; P < 0.05). These results indicate that 1) intracellular H(+) or HCO(3)(-) produced by CA (and not blood pH or HCO(3)(-)) is likely the stimulus that triggers the V-H(+)-ATPase translocation into the basolateral membrane in alkalotic fish and 2) V-H(+)-ATPase translocation is important for enhanced HCO(3)(-) secretion during a naturally occurring postfeeding alkalosis.

  5. Expression of proteins encoded by the Escherichia coli cyn operon: carbon dioxide-enhanced degradation of carbonic anhydrase.

    Science.gov (United States)

    Kozliak, E I; Guilloton, M B; Gerami-Nejad, M; Fuchs, J A; Anderson, P M

    1994-09-01

    Cyanase catalyzes the reaction of cyanate with bicarbonate to give 2CO2. The cynS gene encoding cyanase, together with the cynT gene for carbonic anhydrase, is part of the cyn operon, the expression of which is induced in Escherichia coli by cyanate. The physiological role of carbonic anhydrase is to prevent depletion of cellular bicarbonate during cyanate decomposition due to loss of CO2 (M.B. Guilloton, A.F. Lamblin, E. I. Kozliak, M. Gerami-Nejad, C. Tu, D. Silverman, P.M. Anderson, and J.A. Fuchs, J. Bacteriol. 175:1443-1451, 1993). A delta cynT mutant strain was extremely sensitive to inhibition of growth by cyanate and did not catalyze decomposition of cyanate (even though an active cyanase was expressed) when grown at a low pCO2 (in air) but had a Cyn+ phenotype at a high pCO2. Here the expression of these two enzymes in this unusual system for cyanate degradation was characterized in more detail. Both enzymes were found to be located in the cytosol and to be present at approximately equal levels in the presence of cyanate. A delta cynT mutant strain could be complemented with high levels of expressed human carbonic anhydrase II; however, the mutant defect was not completely abolished, perhaps because the E. coli carbonic anhydrase is significantly less susceptible to inhibition by cyanate than mammalian carbonic anhydrases. The induced E. coli carbonic anhydrase appears to be particularly adapted to its function in cyanate degradation. Active cyanase remained in cells grown in the presence of either low or high pCO2 after the inducer cyanate was depleted; in contrast, carbonic anhydrase protein was degraded very rapidly (minutes) at a high pCO2 but much more slowly (hours) at a low pCO2. A physiological significance of these observations is suggested by the observation that expression of carbonic anhydrase at a high pCO2 decreased the growth rate.

  6. THEATER AS AN EDUCATIONAL TOOL IN THE HUMANISTIC PEDAGOGY OF THE XV-XVI CENTURIES

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    Zinaida A. LURIE

    2016-01-01

    Full Text Available The article discusses the concept of theater and drama of the German humanists of the XV-XVI centuries. The author marks out the main stages of development of humanistic literature and highlights several key arguments for studying drama and organizing performances that could be found in texts of Christian humanists. Basically, the last were associated with methodology of teaching and moralizing. Both philological and pedagogical arguments, mainly of applied character, considering theater and drama as effective learning tools were reflected in works of Erasmus of Rotterdam, and later become a formula typical for statutes of the Protestant schools. However, it is the didactic concept of theater as a tool of preaching that is of the most importance. The author focuses on Philip Melanchthon, a reformer and a humanist, who in his comments on classical theater consistently developed the idea of the interpretation of dramatic texts through the light of Christian ethics and dogmatic. The most precious are his comments on Terence's comedies. The author shows, how the humanist ideas complemented ones of the late classical rhetorician Aelius Donat, who also had analyzed text of Roman comediograth in the light of Christian thought. In particular, Melanchthon's submission of dramatic genres, comedy and tragedy, is studied. It differed from one of Donat and reflected the influence of Aristotle. Despite certain internal contradictions and difficulties in matching pagan comedies with Christianity, his work is to be interpreted as the key theatrical concept of the period. It is the Melanchthon's comedies that formed the idea of the perfect theater, which found expression in the consistent Protestant drama of XVI century.

  7. Carbonic Anhydrase as Pollution Biomarker: An Ancient Enzyme with a New Use

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    Trifone Schettino

    2012-11-01

    Full Text Available The measurement of cellular and sub-cellular responses to chemical contaminants (referred to as biomarkers in living organisms represents a recent tool in environmental monitoring. The review focuses on carbonic anhydrase, a ubiquitous metalloenzyme which plays key roles in a wide variety of physiological processes involving CO2 and HCO3−. In the last decade a number of studies have demonstrated the sensitivity of this enzyme to pollutants such as heavy metals and organic chemicals in both humans and wildlife. The review analyses these studies and discusses the potentiality of this enzyme as novel biomarker in environmental monitoring and assessment.

  8. Carbonic Anhydrase Enhanced Carbon Capture: Kinetic Measurements and Pilot Plant Trials

    DEFF Research Database (Denmark)

    Gladis, Arne; Deslauriers, Maria Gundersen; Fosbøl, Philip Loldrup

    In this study the effect of carbonic anhydrase addition on the absorption of CO2 was investigated in a wetted wall column apparatus. Four different solvents: MEA (a primary amine), AMP (a sterically hindered primary amine), MDEA (a tertiary amine) and K2CO3 a carbonate salt solution were tested...... in concentrations from 5 to 50 wt%. Necessary mass transfer parameters such as liquid side mass transfer coefficient and solvent and enzyme reaction rates were determined in a temperature range from 298 to 328 K and benchmarked to a 30 wt% MEA solution. The study reveals that the addition of the enzyme carbonic...

  9. Cuantification poblacional de lobo marino Comun (Otaria flavescens) en el litoral de la XV, I y II Regiones.

    OpenAIRE

    Contreras Von Meyer, Francisco; Bartheld Villagra, José Luis; Moreno Gómez, Felipe; Torres, Juan Pablo; Montecinos, Mario

    2014-01-01

    Este informe fue desarrollado en respuesta al censo de Lobos Marinos desarrollado en la XV Región de Arica y Parinacota, I Región de Tarapacá y II Región de Antofagasta.Con el fin de actualizar la información que existe de las poblaciones de Otaria flavescens en la zona Norte de Chile (se efectuaron dos censos, el primero durante la temporada post-reproductiva del año 2012 y el segundo durante la temporada reproductiva del año 2013. Los censos fueron ejecutados mediante dos metodo...

  10. Formation of Na1+xV3O8 Nanoribbon Thin Film from V2O5 Xerogel on Sodium Silicate Glass Substrate

    Institute of Scientific and Technical Information of China (English)

    GUO Yi; XU Jin-jie; LI Jun; YANG Wen-sheng

    2007-01-01

    Na1+xV3O8 nanoribbon thin film was successfully fabricated by annealing the V2O5 xerogel film on sodium silicate glass substrate at 450 ℃. It has been identified that the amount of sodium ions diffused into the V2O5 xerogel film increases with the high temperature of annealing treatment. The sodium glass substrate serves as a limited sodium source to induce the transformation from V2O5 to Na1+xV3O8.

  11. "Una noria gótica en el claustro de la catedral de Toledo" in El siglo XV y la diversidad de las artes.

    OpenAIRE

    Passini, Jean; Yuste Galán, Amalia

    2011-01-01

    Amalia Ma Yuste Galán (UCM), aut. http://librosartemedieval.blogspot.com/2010/10/el-siglo-xv-y-la-diversidad-de-las.html; Tras la observación y análisis de una de estrecha cámara, situada bajo la panda sur del claustro, y su relación con el resto de construcciones, proponemos que la noria de la que se habla en siglo XV estaba instalaba en esta original estructura rectangular que se comunica con el antiguo aljibe de la mezquita mayor toledana. La importancia de esta máquina para sacar agua se ...

  12. Modelling the impact of soil Carbonic Anhydrase on the net ecosystem exchange of OCS at Harvard forest using the MuSICA model

    Science.gov (United States)

    Launois, Thomas; Ogée, Jérôme; Commane, Roisin; Wehr, Rchard; Meredith, Laura; Munger, Bill; Nelson, David; Saleska, Scott; Wofsy, Steve; Zahniser, Mark; Wingate, Lisa

    2016-04-01

    The exchange of CO2 between the terrestrial biosphere and the atmosphere is driven by photosynthetic uptake and respiratory loss, two fluxes currently estimated with considerable uncertainty at large scales. Model predictions indicate that these biosphere fluxes will be modified in the future as CO2 concentrations and temperatures increase; however, it still unclear to what extent. To address this challenge there is a need for better constraints on land surface model parameterisations. Additional atmospheric tracers of large-scale CO2 fluxes have been identified as potential candidates for this task. In particular carbonyl sulphide (OCS) has been proposed as a complementary tracer of gross photosynthesis over land, since OCS uptake by plants is dominated by carbonic anhydrase (CA) activity, an enzyme abundant in leaves that catalyses CO2 hydration during photosynthesis. However, although the mass budget at the ecosystem is dominated by the flux of OCS into leaves, some OCS is also exchanged between the atmosphere and the soil and this component of the budget requires constraining. In this study, we adapted the process-based isotope-enabled model MuSICA (Multi-layer Simulator of the Interactions between a vegetation Canopy and the Atmosphere) to include the transport, reaction, diffusion and production of OCS within a forested ecosystem. This model was combined with 3 years (2011-2013) of in situ measurements of OCS atmospheric concentration profiles and fluxes at the Harvard Forest (Massachussets, USA) to test hypotheses on the mechanisms responsible for CA-driven uptake by leaves and soils as well as possible OCS emissions during litter decomposition. Model simulations over the three years captured well the impact of diurnally and seasonally varying environmental conditions on the net ecosystem OCS flux. A sensitivity analysis on soil CA activity and soil OCS emission rates was also performed to quantify their impact on the vertical profiles of OCS inside the

  13. Carbonic anhydrase II increases the activity of the human electrogenic Na+/HCO3- cotransporter.

    Science.gov (United States)

    Becker, Holger M; Deitmer, Joachim W

    2007-05-04

    Several acid/base-coupled membrane transporters, such as the electrogenic sodium-bicarbonate cotransporter (NBCe1), have been shown to bind to different carbonic anhydrase isoforms to create a "transport metabolon." We have expressed NBCe1 derived from human kidney in oocytes of Xenopus leavis and determined its transport activity by recording the membrane current in voltage clamp, and the cytosolic H(+) and Na(+) concentrations using ion-selective microelectrodes. When carbonic anhydrase isoform II (CAII) had been injected into oocytes, the membrane current and the rate of cytosolic Na(+) rise, indicative for NBCe1 activity, increased significantly with the amount of injected CAII (2-200 ng). The CAII inhibitor ethoxyzolamide reversed the effects of CAII on the NBCe1 activity. Co-expressing wild-type CAII or NH(2)-terminal mutant CAII together with NBCe1 provided similar results, whereas co-expressing the catalytically inactive CAII mutant V143Y had no effect on NBCe1 activity. Mass spectrometric analysis and the rate of cytosolic H(+) change following addition of CO(2)/HCO(3)(-) confirmed the catalytic activity of injected and expressed CAII in oocytes. Our results show that the transport capacity of NBCe1 is enhanced by the catalytic activity of CAII, in line with the notion that CAII forms a transport metabolon with NBCe1.

  14. Zinc Transfer Kinetics of Metallothioneins and Their Fragmentswith Apo-carbonic Anhydrase

    Institute of Scientific and Technical Information of China (English)

    HUANG, Zhong-Xian; LIU, Fang; ZHENG, Qi; YU, Wen-Hao

    2001-01-01

    Tne zinc transfer reactions from Zn7-MT-I, Zn7-MT-Ⅱ, Zn4α fragment (MT-I) and Zn4-α fragment (MT-Ⅱ) to apo-carbonic anhydrase have been studied. In each reaction, no more than one zinc ion per molecule is involved in metal transfer.Zn7-MT-I and Zn7-MT-Ⅱ donate zinc to apo-carbonic anhydrase and de novo constitute it at a comparable efficiency,while Zn7-MT-Ⅱ exhibits a little faster rate. Surprisingiy,Zinc is released from Zn4-α fragment (MT-Ⅱ) with a much faster rate than from Zn4-α fragment (MT-I), whose rate is close to that of Zn7-MT-I. The reason for the difference is still unknown. Introducing complex compounds into this system may give rise to an effect on the reaction. The transfer from Zn7-MT-Ⅱ in the presence of reduced glutathione shows little difference compare to the control, suggesting that the reduced glutathione is not involved in zinc transfer process. However,glutathione disulfide does accelerate this zinc transfer reaction remarkably, indicating that the oxidative factors contribute to zinc rlease from metallothioneins.

  15. Synthesis of novel bisindolylmethanes: New carbonic anhydrase II inhibitors, docking, and 3D pharmacophore studies.

    Science.gov (United States)

    Imran, Syahrul; Taha, Muhammad; Ismail, Nor Hadiani; Fayyaz, Sharmeen; Khan, Khalid Mohammed; Choudhary, Muhammad Iqbal

    2016-10-01

    In this study, 45 bisindolylmethanes having sulfonamide moiety had been synthesized through 3 steps. In vitro assay for inhibition of carbonic anhydrase showed that some of the compounds having sulfonamide moiety are capable of inhibiting carbonic anhydrase II. Bisindoles having halogens at fifth position showed better inhibitory activity as compared to unsubstituted bisindoles. The results obtained from in vitro inhibitory activity were subjected through 3D QSAR and docking studies to identify important features contributing to the activity and further improve the structure. Pharmacophore studies suggest that bisindolylmethane moiety is contributing significantly towards the inhibition activity. Docking studies showed that compounds having nitro substituent (5g and 5i) were found to be able interact with Zn(2+) ion, Thr199, His94, His96, and His119, which interferes with the ZnOHThr199Glu106 hydrogen bond network. Bulky nitro substituent at ortho position for compound 5g prevents the compound from interacting with other residues like Thr199 and Thr200. Methyl substituent at ortho position for Compound 5i induces less steric hindrance effect, thus allowing second oxygen atom of sulfonamide to interact with Thr199 (2.51Å). Hydrogen bonding between NH on indole ring with Glu69 might have increased stability of ligand-receptor complex.

  16. Biochemistry and physiology of the β class carbonic anhydrase (Cpb) from Clostridium perfringens strain 13.

    Science.gov (United States)

    Kumar, R Siva Sai; Hendrick, William; Correll, Jared B; Patterson, Andrew D; Melville, Stephen B; Ferry, James G

    2013-05-01

    The carbonic anhydrase (Cpb) from Clostridium perfringens strain 13, the only carbonic anhydrase encoded in the genome, was characterized both biochemically and physiologically. Heterologously produced and purified Cpb was shown to belong to the type I subclass of the β class, the first β class enzyme investigated from a strictly anaerobic species of the domain Bacteria. Kinetic analyses revealed a two-step, ping-pong, zinc-hydroxide mechanism of catalysis with Km and kcat/Km values of 3.1 mM CO₂ and 4.8 × 10⁶ s⁻¹ M⁻¹, respectively. Analyses of a cpb deletion mutant of C. perfringens strain HN13 showed that Cpb is strictly required for growth when cultured in semidefined medium and an atmosphere without CO₂. The growth of the mutant was the same as that of the parent wild-type strain when cultured in nutrient-rich media with or without CO₂ in the atmosphere, although elimination of glucose resulted in decreased production of acetate, propionate, and butyrate. The results suggest a role for Cpb in anaplerotic CO₂ fixation reactions by supplying bicarbonate to carboxylases. Potential roles in competitive fitness are discussed.

  17. Indomethacin lowers optic nerve oxygen tension and reduces the effect of carbonic anhydrase inhibition and carbon dioxide breathing

    DEFF Research Database (Denmark)

    Pedersen, D B; Eysteinsson, T; Stefánsson, E

    2004-01-01

    Prostaglandins are important in blood flow regulation. Carbon dioxide (CO(2)) breathing and carbonic anhydrase inhibition increase the oxygen tension in the retina and optic nerve. To study the mechanism of this effect and the role of cyclo-oxygenase in the regulation of optic nerve oxygen tensio...

  18. Carbonic Anhydrase Inhibitors for the Treatment of Cystic Macular Lesions in Children With X-Linked Juvenile Retinoschisis

    NARCIS (Netherlands)

    Verbakel, S.K.; Ven, J.P.H. van de; Blanc, L.M.P. le; Groenewoud, J.M.M.; Jong, E.K.; Klevering, B.J.; Hoyng, C.B.

    2016-01-01

    Purpose: Little is known regarding the therapeutic effect of carbonic anhydrase inhibitors (CAIs) in the management of cystic macular lesions in children with X-linked juvenile retinoschisis (XLRS) despite the fact that this disease often manifests during childhood. Therefore, our goal was to determ

  19. Update and critical appraisal of combined timolol and carbonic anhydrase inhibitors and the effect on ocular blood flow in glaucoma patients.

    Science.gov (United States)

    Moss, Adam M; Harris, Alon; Siesky, Brent; Rusia, Deepam; Williamson, Kathleen M; Shoshani, Yochai

    2010-04-26

    Topical hypotensive therapy with both timolol and carbonic anhydrase inhibitors has been shown to be efficacious at reducing intraocular pressure. Many prospective studies have also suggested that carbonic anhydrase inhibitors augment ocular blood flow and vascular regulation independent of their hypotensive effects. Although consistent in their findings, these studies must be cautiously interpreted due to the limitations of study design and specific blood flow imaging modalities. The purpose of this review is to appraise and critically evaluate the current body of literature investigating the effects of combined treatment with topical carbonic anhydrase inhibitors and timolol in patients with glaucoma with respect to ocular blood flow, visual function, and optic nerve head structure.

  20. La expansión del siglo XV: rivalidad luso-castellana

    Directory of Open Access Journals (Sweden)

    Romero Portilla, Paz

    2003-12-01

    Full Text Available : During the 15th century the Castilian kingdom continued its territorial expansion towards the south —except for some military campaigns in the peninsula—, and towards the North of Africa and the Atlantic islands where they faced up with the Portuguese dominion. This movement propitiated a rivalry that was kept until the signature of the treaty of Alcáçobas in 1479. In this period of time the political relationships between the two kingdoms were, in general, harmonic and friendly, but the discrepancies concerning the Atlantic area split them and it derived in several conflicts. In these, nearly 50 years, of rivalry between Castile and Portugal, we find different political positions in relation with the territorial expansion and with the pontifical documents that gave support to both parts. By this means, we can see the development of the legal-moral doctrine that would be used in subsequent discoveries and conquests in the New World.

    Durante el siglo XV el reino castellano continuó su expansión territorial hacia el sur y, salvo algunas campañas en suelo peninsular, hacia el Norte de África y las islas atlánticas donde se enfrentó con los intereses portugueses, originándose una rivalidad que no cesó hasta la firma del tratado de Alcáçobas en 1479. Durante este tiempo la política entre ambos reinos fue, en general, de amistad y armonía, pero la cuestión atlántica los distanció y fue origen de importantes conflictos. En estos casi cincuenta años de rivalidad entre Portugal y Castilla encontramos diferentes posturas políticas respecto a la expansión territorial y documentos pontificios que apoyan a ambas partes. Asimismo advertimos cómo se fue desarrollando una doctrina jurídico-moral que posteriormente sería utilizada en los descubrimientos y conquistas en el Nuevo Mundo.

  1. Palabras y gestos de compromiso: los reyes castellanos y sus juramentos (siglo XV

    Directory of Open Access Journals (Sweden)

    Ana Isabel CARRASCO MANCHADO

    2007-06-01

    Full Text Available Parmi les paroles prononcées par les rois au cours de leur règne, il y a celles qui expriment l’engagement : serment, promesses, vœux et hommages… Ces engagements verbaux, en tant qu’actes de paroles, se chargent d’une importante signification politique lorsqu’un roi en est l’émetteur. En raison des conditions dans lesquelles elles sont prononcées, dans un contexte public et toujours politique, et de leur efficacité rituelle, ces paroles constituent un champ privilégié pour étudier les fonctions de la parole royale. Le présent article se veut être une première approche des « paroles d’engagement » prononcées par les rois castillans au cours du XVe siècle à partir de leur mention dans les chroniques, de leur rôle dans la construction d’une image royale, des contextes qui donnent lieu à l’expression de ce type de parole royale (serments institutionnels, promesses liées à la lutte politique…, du sens de la gamme linguistique sur laquelle joue un roi pour exprimer son engagement et de la place de cette dernière dans la construction de l’autorité royale.Entre las palabras pronunciadas por los reyes a lo largo de su reinado se encuentran las que expresan compromiso: juramentos, promesas, votos, homenajes… Estos compromisos verbales, como actos de habla, se hallan plagados de sentido político cuando es el rey el emisor. Por sus condiciones de su pronunciación, en un contexto público y siempre político y por su eficacia ritual suponen un ámbito privilegiado para el estudio de las funciones del habla regia. El objetivo de este artículo es realizar una aproximación a las “palabras de compromiso” expresadas por los reyes castellanos en el siglo XV, tratando de valorar su presencia en el discurso cronístico; su relación con la construcción de la imagen del monarca; los contextos que suelen dar lugar a expresiones de este tipo de palabra regia (juramentos institucionales; promesas ligadas a la

  2. La descendencia del Liber regum en la Castilla de los siglos XIV-XV

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    Jean-Pierre Jardin

    2010-06-01

    Full Text Available La influencia del Liber regum en los siglos que siguieron su redacción fue objeto de estudios penetrantes de Luis Filipe Lindley Cintra, el cual puso en evidencia la utilización de la obra como fuente parcial del Poema de Fernán González (s. XIII y del Laberinto de Fortuna de Juan de Mena (s. XV. En la continuidad de estos estudios, nos proponemos poner de realce la utilización de la sección del Liber regum dedicada a la época antigua como fuente de al menos dos sumas de crónicas del siglo XIV. En conclusión de este estudio, intentaremos comprender por qué esta obrita, perteneciente a un género historiográfico menor, pudo seguir ejerciendo tal influencia en un momento en el que otras fuentes, de mayor prestigio, podían fácilmente utilizarse.L’influence du Liber regum dans les siècles qui ont suivi sa rédaction a fait l’objet d’études pénétrantes de Luis Filipe Lindley Cintra. Celui-ci a mis en évidence l’utilisation de l’ouvrage comme source partielle du Poema de Fernán González (XIIIe siècle et du Laberinto de Fortuna de Juan de Mena (XVe. Dans la continuité de ces études, nous nous proposons de mettre en évidence l’utilisation de la section du Liber regum consacrée à l’époque antique comme source d’au moins deux sommes de chroniques du XIVe siècle. En conclusion de cette étude, nous essaierons de comprendre pourquoi ce modeste ouvrage relevant d’un genre historiographique mineur a pu continuer à exercer une telle influence à une époque où d’autres sources, de plus grand prestige, étaient disponibles.

  3. Effect of pH and light on population growth and activity of extracellular carbonic anhydrase in two species of dinoflagellates%pH及光照对两种赤潮甲藻种群生长和胞外碳酸酐酶活性的影响

    Institute of Scientific and Technical Information of China (English)

    戴芳芳; 周成旭; 严小军

    2011-01-01

    研究了pH和光照强度对两种赤潮甲藻(Prorocentrum donghaiense和Karlodinium micrum)的种群生长及其胞外碳酸酐酶(CA)活性的影响.结果表明,pH7.5、光照强度30 μmol/(m2.s)是两种微藻的最适种群生长条件,在种群生长的最适pH和光照强度下,胞外CA活性最大.最适培养条件下,两种甲藻胞外碳酸酐酶活性随着种群生长周期而变化,指数生长期至平台期CA酶活增加,平台期至衰退期CA酶活降低,平台期胞外CA活性最大.%The effects of pH and light intensity on population growth and extracellular carbonic anhydrase ( CA) activity in two species of dinoflagellates (Prorocenlnim donghaieme and Karlodinium micrum) were studied. The results show that pH 7. 5 and 30μmol/( m2 · s) irradiance which triggered the optimum population growth, were the conditions that favored the highest activity of extracellular CA in the two dinoflagellates. Under the optimum cultivation conditions,the extracellular carbonic anhydrase activity in the two dinoflagellates varies with the population growth phases. CA activities were increased from exponential phase to the stationary phase and decreased form stationary phase to the decline phase. The highest extracellular CA activity occurred at the stationary phase. The significance of the population growth related CA activity in population dynamics of the two dinoflagellates was also discussed.

  4. A pilot study on potential plasma hypoxia markers in the radiotherapy of non-small cell lung cancer. Osteopontin, carbonic anhydrase IX and vascular endothelial growth factor

    Energy Technology Data Exchange (ETDEWEB)

    Ostheimer, C.; Bache, M.; Guettler, A.; Vordermark, D. [Martin-Luther-University Halle-Wittenberg, Department of Radiation Oncology, Halle (Saale) (Germany); Kotzsch, M. [Technical University Dresden, Department of Pathology, Dresden (Germany)

    2014-03-15

    Hypoxic radioresistance plays a critical role in the radiotherapy of cancer and adversely impacts prognosis and treatment response. This prospective study investigated the interrelationship and the prognostic significance of several hypoxia-related proteins in non-small cell lung cancer (NSCLC) patients treated by radiotherapy ± chemotherapy. Pretreatment osteopontin (OPN), vascular endothelial growth factor (VEGF) and carbonic anhydrase IX (CA IX) plasma levels were determined by ELISA in 55 NSCLC (M0) patients receiving 66 Gy curative-intent radiotherapy or chemoradiation. Marker correlation, association with clinicopathological parameters and the prognostic value of a biomarker combination was evaluated. All biomarkers were linearly correlated and linked to different clinical parameters including lung function, weight loss (OPN), gross tumor volume (VEGF) and T stage (CA IX). High OPN (p = 0.03), VEGF (p = 0.02) and CA IX (p = 0.04) values were significantly associated with poor survival. Double marker combination additively increased the risk of death by a factor of 2 and high plasma levels of the triple combination OPN/VEGF/CA IX yielded a 5.9-fold risk of death (p = 0.009). The combined assessment of OPN/VEGF/CA IX correlated independently with prognosis (p = 0.03) in a multivariate Cox regression model including N stage, T stage and GTV. This pilot study suggests that a co-detection augments the prognostic value of single markers and that the integration of OPN, VEGF and CA IX into a hypoxic biomarker profile for the identification of patients with largely hypoxic and radioresistant tumors should be further evaluated. (orig.) [German] Hypoxische Radioresistenz spielt eine kritische Rolle in der Radiotherapie maligner Tumoren und beeinflusst Prognose und Therapieansprechen negativ. Diese prospektive Studie untersuchte den Zusammenhang und die prognostische Bedeutung einiger hypoxieassoziierter Proteine bei Patienten mit nicht-kleinzelligem Bronchialkarzinom

  5. Update and critical appraisal of combined timolol and carbonic anhydrase inhibitors and the effect on ocular blood flow in glaucoma patients

    Directory of Open Access Journals (Sweden)

    Adam M Moss

    2010-03-01

    Full Text Available Adam M Moss, Alon Harris, Brent Siesky, Deepam Rusia, Kathleen M Williamson, Yochai ShoshaniDepartment of Ophthalmology, Indiana University School of Medicine, Indianapolis, Indiana, USAAbstract: Topical hypotensive therapy with both timolol and carbonic anhydrase inhibitors has been shown to be efficacious at reducing intraocular pressure. Many prospective studies have also suggested that carbonic anhydrase inhibitors augment ocular blood flow and vascular regulation independent of their hypotensive effects. Although consistent in their findings, these studies must be cautiously interpreted due to the limitations of study design and specific blood flow imaging modalities. The purpose of this review is to appraise and critically evaluate the current body of literature investigating the effects of combined treatment with topical carbonic anhydrase inhibitors and timolol in patients with glaucoma with respect to ocular blood flow, visual function, and optic nerve head structure.Keywords: ocular blood flow, carbonic anhydrase inhibitor, timolol, glaucoma, visual function, optic nerve head

  6. Intracellular pH homeostasis and serotonin-induced pH changes in Calliphora salivary glands: the contribution of V-ATPase and carbonic anhydrase.

    Science.gov (United States)

    Schewe, Bettina; Schmälzlin, Elmar; Walz, Bernd

    2008-03-01

    Blowfly salivary gland cells have a vacuolar-type H(+)-ATPase (V-ATPase) in their apical membrane that energizes secretion of a KCl-rich saliva upon stimulation with serotonin (5-hydroxytryptamine, 5-HT). We have used BCECF to study microfluometrically whether V-ATPase and carbonic anhydrase (CA) are involved in intracellular pH (pH(i)) regulation, and we have localized CA activity by histochemistry. We show: (1) mean pH(i) in salivary gland cells is 7.5+/-0.3 pH units (N=96), higher than that expected from passive H(+) distribution; (2) low 5-HT concentrations (0.3-3 nmol l(-1)) induce a dose-dependent acidification of up to 0.2 pH units, with 5-HT concentrations >10 nmol l(-1), causing monophasic or multiphasic pH changes; (3) the acidifying effect of 5-HT is mimicked by bath application of cAMP, forskolin or IBMX; (4) salivary gland cells exhibit CA activity; (5) CA inhibition with acetazolamide and V-ATPase inhibition with concanamycin A lead to a slow acidification of steady-state pH(i); (6) 5-HT stimuli in the presence of acetazolamide induce an alkalinization that can be decreased by simultaneous application of the V-ATPase inhibitor concanamycin A; (7) concanamycin A removes alkali-going components from multiphasic 5-HT-induced pH changes; (8) NHE activity and a Cl(-)-dependent process are involved in generating 5-HT-induced pH changes; (9) the salivary glands probably contain a Na(+)-driven amino acid transporter. We conclude that V-ATPase and CA contribute to steady-state pH(i) regulation and 5-HT-induced outward H(+) pumping does not cause an alkalinization of pH(i) because of cytosolic H(+) accumulation attributable to stimulated cellular respiration and AE activity, masking the alkalizing effect of V-ATPase-mediated acid extrusion.

  7. Conformational effects on the circular dichroism of Human Carbonic Anhydrase II: a multilevel computational study.

    Directory of Open Access Journals (Sweden)

    Tatyana G Karabencheva-Christova

    Full Text Available Circular Dichroism (CD spectroscopy is a powerful method for investigating conformational changes in proteins and therefore has numerous applications in structural and molecular biology. Here a computational investigation of the CD spectrum of the Human Carbonic Anhydrase II (HCAII, with main focus on the near-UV CD spectra of the wild-type enzyme and it seven tryptophan mutant forms, is presented and compared to experimental studies. Multilevel computational methods (Molecular Dynamics, Semiempirical Quantum Mechanics, Time-Dependent Density Functional Theory were applied in order to gain insight into the mechanisms of interaction between the aromatic chromophores within the protein environment and understand how the conformational flexibility of the protein influences these mechanisms. The analysis suggests that combining CD semi empirical calculations, crystal structures and molecular dynamics (MD could help in achieving a better agreement between the computed and experimental protein spectra and provide some unique insight into the dynamic nature of the mechanisms of chromophore interactions.

  8. Oxygen-18 incorporation into malic acid during nocturnal carbon dioxide fixation in crassulacean acid metabolism plants: a new approach to estimating in vivo carbonic anhydrase activity

    Energy Technology Data Exchange (ETDEWEB)

    Holtum, J.A.M.; Summons, R.; Roeske, C.A.; Comins, H.N.; O' Leary, M.H.

    1984-01-01

    Crassulacean acid metabolism (CAM) plants fix carbon dioxide at night by the carboxylation of phosphoenolpyruvate. If CO2 fixation is conducted with TC YO2, then in the absence of carbonic anhydrase, the malate formed by dark CO2 fixation should also contain high levels of carbon-13 and oxygen-18. Conversely, if carbonic anhydrase is present and highly active, oxygen exchange between CO2 and cellular H2O will occur more rapidly than carboxylation, and the ( TC) malate formed will contain little or no oxygen-18 above the natural abundance level. The presence of oxygen-18 in these molecules can be detected either by nuclear magnetic resonance or by mass spectrometry. Studies of phosphoenolpyruvate carboxylase in the presence and absence of carbonic anhydrase in vitro confirm the validity of the method. When CAM plants are studied by this method, we find that most species show incorporation of a significant amount of oxygen-18. Comparison of these results with results of isotope fractionation and gas exchange studies permits calculation of the in vivo activity of carbonic anhydrase toward HCO3 compared with that of phosphoenolpyruvate carboxylase. The ratio (carbonic anhydrase activity/phosphoenolpyruvate carboxylase activity) is species dependent and varies from a low of about 7 for Ananas comosus to values near 20 for Hoya carnosa and Bryophyllum pinnatum, 40 for Kalanchoee daigremontiana, and 100 or greater for Bryophyllum tubiflorum, Kalanchoee serrata, and Kalanchoae tomentosa. Carbonic anhydrase activity increases relative to phosphoenolpyruvate carboxylase activity at higher temperature. 37 references, 2 figures, 8 tables.

  9. Carbonic anhydrase inhibitors modify intracellular pH transients and contractions of rat middle cerebral arteries during CO2/HCO3(-) fluctuations.

    Science.gov (United States)

    Rasmussen, Jacob K; Boedtkjer, Ebbe

    2017-01-01

    The CO2/HCO3(-) buffer minimizes pH changes in response to acid-base loads, HCO3(-) provides substrate for Na(+),HCO3(-)-cotransporters and Cl(-)/HCO3(-)-exchangers, and H(+) and HCO3(-) modify vasomotor responses during acid-base disturbances. We show here that rat middle cerebral arteries express cytosolic, mitochondrial, extracellular, and secreted carbonic anhydrase isoforms that catalyze equilibration of the CO2/HCO3(-) buffer. Switching from CO2/HCO3(-)-free to CO2/HCO3(-)-containing extracellular solution results in initial intracellular acidification due to hydration of CO2 followed by gradual alkalinization due to cellular HCO3(-) uptake. Carbonic anhydrase inhibition decelerates the initial acidification and attenuates the associated transient vasoconstriction without affecting intracellular pH or artery tone at steady-state. Na(+),HCO3(-)-cotransport and Na(+)/H(+)-exchange activity after NH4(+)-prepulse-induced intracellular acidification are unaffected by carbonic anhydrase inhibition. Extracellular surface pH transients induced by transmembrane NH3 flux are evident under CO2/HCO3(-)-free conditions but absent when the buffer capacity and apparent H(+) mobility increase in the presence of CO2/HCO3(-) even after the inhibition of carbonic anhydrases. We conclude that (a) intracellular carbonic anhydrase activity accentuates pH transients and vasoconstriction in response to acute elevations of pCO2, (b) CO2/HCO3(-) minimizes extracellular surface pH transients without requiring carbonic anhydrase activity, and

  10. Retórica y poética en la gramática del siglo XV

    OpenAIRE

    2006-01-01

    La enseñanza de la gramática en el siglo XV centra su atención en la búsqueda de los medios que permitan el acceso a una lengua que ya no se habla, la lengua latina, de la forma más directa, práctica, breve y eficaz. Fruto de esta preocupación son los compendios gramaticales que muchos maestros de gramática, con una clara intención pedagógica, preparan aunando temas no sólo gramaticales sino que también extraídos de la teoría retórica. Siguiendo, pues, los diferentes capítul...

  11. Changes of Carbonic Anhydrase Activities in Tomato Leaves under Drought Stress%干旱胁迫下番茄叶片碳酸酐酶活性的变化

    Institute of Scientific and Technical Information of China (English)

    孙卫红; 吴秋霞; 温新宇; 何华纲; 吴沿友; 丁佳俊; 封丽娜

    2015-01-01

    Carbonic anhydrase (CA) catalyzes the reversible hydration of CO2, and it is an important photosyn-thetic enzyme which take part in the CO2 conduction and get into the carboxylation site. The CA activity has a great effect on photosynthesis and water use efifciency. In order to study the effect of expression of CA gene on the plant photosynthesis and plant water potential in tomato (Lycopersicon esculentum), the expression of cytoso-lic CA gene in tomato leaves under drought stress were determined by Northern blotting. And the CA enzyme ac-tivity, photosynthetic rate and water potential in tomato leaves under drought stress were also determined. The re-sults showed that the expression of cytosolic CA gene in tomato leaves was induced by drought stress. With the time of drought stress, the CA activity increased and then fell, and the changes were basically similar to that of CA gene expression. Net photosynthetic rate and water potential of tomato leaves decreased with the degree of drought and the treatment time. However, the CA activity, net photosynthetic rate and water potential changed slightly with the soil relative water content of 75%. The results indicated that there was a certain corresponding relationship be-tween the changes of water potential and photosynthetic rate in tomato leaves and the change of CA activity.%碳酸酐酶(carbonic anhydrase, CA)催化CO2的可逆水合反应,是参与CO2传导而进入羧化位点的重要光合酶,其活性高低对植物水分利用及光合作用有较大影响。为了研究干旱胁迫下番茄CA表达活性变化对植株光合作用及水分利用的影响,本文利用Northern杂交检测番茄叶片的胞质CA基因在干旱胁迫下的表达;测定干旱胁迫下番茄叶片CA活性、光合速率和叶片水势变化。结果表明,番茄叶片胞质CA基因受干旱胁迫诱导;CA活性随着干旱胁迫时间延长而发生由低至高再回落的变化,且变化规律基本与CA基因相似。番

  12. Putting the pieces into place: Properties of intact zinc metallothionein 1A determined from interaction of its isolated domains with carbonic anhydrase.

    Science.gov (United States)

    Pinter, Tyler B J; Stillman, Martin J

    2015-11-01

    Mammalian metallothioneins (MTs) bind up to seven Zn(2+) using a large number of cysteine residues relative to their small size and can act as zinc-chaperones. In metal-saturated Zn7-MTs, the seven zinc ions are co-ordinated tetrahedrally into two distinct clusters separated by a linker; the N-terminal β-domain [(Zn3Cys9)(3-)] and C-terminal α-domain [(Zn4Cys11)(3-)]. We report on the competitive zinc metalation of apo-carbonic anhydrase [CA; metal-free CA (apo-CA)] in the presence of apo-metallothionein 1A domain fragments to identify domain specific determinants of zinc binding and zinc donation in the intact two-domain Znn-βαMT1A (human metallothionein 1A isoform; n=0-7). The apo-CA is shown to compete effectively only with Zn2-3-βMT and Zn4-αMT. Detailed modelling of the ESI mass spectral data have revealed the zinc-binding affinities of each of the zinc-binding sites in the two isolated fragments. The three calculated equilibrium zinc affinities [log(KF)] of the isolated β-domain were: 12.2, 11.7 and 11.4 and the four isolated α-domain affinities were: 13.5, 13.2, 12.7 and 12.6. These data provide guidance in identification of the location of the strongest-bound and weakest-bound zinc in the intact two-domain Zn7βαMT. The β-domain has the weakest zinc-binding site and this is where zinc ions are donated from in the Zn7-βαMT. The α-domain with the highest affinity binds the first zinc, which we propose leads to an unscrambling of the cysteine ligands from the apo-peptide bundle. We propose that stabilization of the intact Zn6-MT and Zn7-MT, relative to that of the sum of the separated fragments, is due to the availability of additional cysteine ligand orientations (through interdomain interactions) to support the clustered structures.

  13. La tecnología sedera en Valencia a la luz de unas ordenanzas inéditas del siglo XV

    Directory of Open Access Journals (Sweden)

    Navarro Espinach, Germán

    2011-12-01

    Full Text Available Study of an unpublished book of ordinances of the 15th to 17th centuries pertaining to the silk velvets weavers of Valencia, conserved in The Hispanic Society of America in New York. Its comparison with the Valencian silk ordinances that we already know provides new information on 15th century textile technology.

    Estudio de un libro inédito de ordenanzas de los siglos XV-XVII perteneciente a los tejedores de terciopelos de seda de Valencia, conservado en The Hispanic Society of America de Nueva York. Su comparación con las ordenanzas valencianas de la seda conocidas hasta ahora ofrece nuevos datos sobre la tecnología textil del siglo XV.

  14. Allosteric reversion of Haemophilus influenzae β-carbonic anhydrase via a proline shift.

    Science.gov (United States)

    Hoffmann, Katherine M; Million-Perez, H Rachael; Merkhofer, Richard; Nicholson, Hilary; Rowlett, Roger S

    2015-01-20

    Haemophilus influenzae β-carbonic anhydrase (HICA) has been reverse-engineered in the allosteric site region to resemble the nonallosteric Pisum sativum enzyme in order to identify critical features of allostery and intersusbunit communication. Three variants (W39V/G41A, P48S/A49P, and W39V/G41A/P48S/A49P) were identified, through a comparison with a crystal structure of nonallosteric P. sativum β-carbonic anhydrase (PSCA, PDB 1EKJ ), to potentially revert HICA to a nonallosteric enzyme. The W39V/G41A and P48S/A49P mutations decreased the apparent kcat/Km proton dependence from 4 to 2 and 1, respectively, increasing the overall maximal kcat/Km to 16 ± 2 μM(-1) s(-1) (380% of wild type) and 17 ± 3 μM(-1) s(-1) (405% of wild type). The pKa values of the metal-bound water molecule based on the pH-rate profile kinetics (8.32 ± 0.04 for W39V/G41A and 8.3 ± 0.1 for P48S/A49P) were also slightly higher than that for the wild-type enzyme (7.74 ± 0.04). The P48S/A49P variant has lost all pH-rate cooperativity. The W39V/G41A/P48S/A49P variant's kinetics were unusual and were fit with a log-linear function with a slope 0.9 ± 0.2. The crystal structure of the W39V/G41A variant revealed an active site very similar to the T-state wild-type oligomer with bicarbonate trapped in the escort site. By contrast, the X-ray crystal structure of a proline shift variant (P48S/A49P) reveals that it has adopted an active site conformation nearly identical to that of nonallosteric β-carbonic anhydrase (R-state) for one chain, including a tight association with the dimer-exchanged N-terminal helices; the second chain in the asymmetric unit is associated in a biologically relevant oligomer, but it adopts a T-state conformation that is not capped by dimer-exchanged N-terminal helices. The hybrid R/T nature of HICA P48S/A49P structurally recapitulates the interruption of pH-rate cooperativity observed for this variant. Comparison of the conformations of the R and T chains of P48S/A49P

  15. NH4+浓度对黄色短杆菌XV0505发酵生产L-缬氨酸的影响%Effect of NH4+concentration on L-valine fermentation by Brevibacterium flavum XV0505

    Institute of Scientific and Technical Information of China (English)

    冯宁; 白亚磊; 徐庆阳; 谢希贤; 陈宁

    2011-01-01

    以L-缬氨酸(L-Val)生产菌黄色短杆菌XV0505为供试菌株,以(NH4)2SO4为唯一添加N源,考察不同NH4+浓度对发酵过程中菌体干质量、L-Val产量和葡萄糖消耗速率以及菌体内代谢流量的影响.研究表明:NH4+浓度过高或不足都会影响发酵水平,降低L-Val的产量.合适的初始NH4+浓度为225 mmol/L,产酸期NH4+维持浓度为35mmol/L时,有利菌体产酸.在此NH4+浓度下,在30L发酵罐发酵60h,发酵液中菌体生物量和L-Val质量浓度分别可达22.35和59.12g/L.%The ammonium sulfate was selected as the only feeding nitrogen source in the L-valine fermentation process by Brevibacterium flavum XV0505. Effects of different N H4+ concentrations on biomass,yield of L-valine,glucose consumption rate and the metabolic flux were studied in a 30 L fermentor. Results showed that excessive or insufficient concentrations of NH4+ would adversely affect the yield of L-valine and bacterial growth. Therefore,the appropriate additive dosage of NH4+ (225 mmol/l) was determined,and L-valine production was increased by keeping low NH4+ concentration(35 mmol/L) in the synthesis period of L-valine. With the optimum additional dosage of NH4+ , the yields of L-valine and DCW were up to 59. 12 and 22. 35 g/L (60 h) in the 30 L fermentor.

  16. La moneda castellana en los manuales de mercaderías y tratados de aritmética italianos bajomedievales (siglos XIII-XV)

    OpenAIRE

    2007-01-01

    El presente artículo analiza el conocimiento sobre la moneda y el sistema monetario vigentes en Castilla en la Baja Edad Media en los manuales de mercadería y los tratados de aritmética italianos de los siglos XIII al XV. The present paper analyzes the knowledge of money and money system in Castile in the Late Middle Ages in the Italian pratiche di mercatura and treaties of Arithmetics from the XIIIth to XVth Centuries.

  17. Fluoroalkyl and alkyl chains have similar hydrophobicities in binding to the "hydrophobic wall" of carbonic anhydrase.

    Science.gov (United States)

    Mecinović, Jasmin; Snyder, Phillip W; Mirica, Katherine A; Bai, Serena; Mack, Eric T; Kwant, Richard L; Moustakas, Demetri T; Héroux, Annie; Whitesides, George M

    2011-09-07

    The hydrophobic effect, the free-energetically favorable association of nonpolar solutes in water, makes a dominant contribution to binding of many systems of ligands and proteins. The objective of this study was to examine the hydrophobic effect in biomolecular recognition using two chemically different but structurally similar hydrophobic groups, aliphatic hydrocarbons and aliphatic fluorocarbons, and to determine whether the hydrophobicity of the two groups could be distinguished by thermodynamic and biostructural analysis. This paper uses isothermal titration calorimetry (ITC) to examine the thermodynamics of binding of benzenesulfonamides substituted in the para position with alkyl and fluoroalkyl chains (H(2)NSO(2)C(6)H(4)-CONHCH(2)(CX(2))(n)CX(3), n = 0-4, X = H, F) to human carbonic anhydrase II (HCA II). Both alkyl and fluoroalkyl substituents contribute favorably to the enthalpy and the entropy of binding; these contributions increase as the length of chain of the hydrophobic substituent increases. Crystallography of the protein-ligand complexes indicates that the benzenesulfonamide groups of all ligands examined bind with similar geometry, that the tail groups associate with the hydrophobic wall of HCA II (which is made up of the side chains of residues Phe131, Val135, Pro202, and Leu204), and that the structure of the protein is indistinguishable for all but one of the complexes (the longest member of the fluoroalkyl series). Analysis of the thermodynamics of binding as a function of structure is compatible with the hypothesis that hydrophobic binding of both alkyl and fluoroalkyl chains to hydrophobic surface of carbonic anhydrase is due primarily to the release of nonoptimally hydrogen-bonded water molecules that hydrate the binding cavity (including the hydrophobic wall) of HCA II and to the release of water molecules that surround the hydrophobic chain of the ligands. This study defines the balance of enthalpic and entropic contributions to the

  18. La Segunda Partida en los debates políticos de la Castilla del siglo XV

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    José Manuel NIETO SORIA

    2008-05-01

    Full Text Available Desde el punto de vista del desarrollo de la construcción de modelos políticos, puede afirmarse que el siglo XV en Castilla es el siglo de la Segunda partida. Apenas comenzado el reinado de Juan II y, sobre todo, a partir del ascenso como gran privado del rey de don Álvaro de Luna, la Segunda partida se situará en el centro del debate político, bien para conseguir una máxima aproximación a sus planteamientos, o bien para reivindicar la necesidad de evitarlos. Si los dos grandes temas políticos de la Castilla del siglo XV fueron el modelo de monarquía y el perfil caballeresco de la nobleza, tanto uno como otro asunto se abordaron mediante la concesión del máximo protagonismo al texto alfonsino.Du point de vue du processus de construction des modèles politiques, on peut affirmer que le XVe siècle castillan est le siècle de la Deuxième Partie. Dès le début du règne de Jean II et, surtout, à partir de l’ascension de Don Álvaro de Luna comme grand favori du roi, la Deuxième Partie se situera au centre du débat politique, tantôt pour permettre de cibler au plus près ses enjeux, tantôt pour revendiquer la nécessité de les éluder. Si les deux grandes questions politiques de la Castille du XVe siècle furent le modèle de la monarchie et le profil chevaleresque de la noblesse, on les aborda aussi bien l’une que l’autre en faisant jouer un rôle de premier plan au texte alphonsin.

  19. Synthesis, characterization, computational studies, antimicrobial activities and carbonic anhydrase inhibitor effects of 2-hydroxy acetophenone-N-methyl p-toluenesulfonylhydrazone and its Co(II), Pd(II), Pt(II) complexes

    Science.gov (United States)

    Özbek, Neslihan; Alyar, Saliha; Memmi, Burcu Koçak; Gündüzalp, Ayla Balaban; Bahçeci, Zafer; Alyar, Hamit

    2017-01-01

    2-Hydroxyacetophenone-N-methyl p-toluenesulfonylhydrazone (afptsmh) derived from p-toluenesulfonicacid-1-methylhydrazide (ptsmh) and its Co(II), Pd(II), Pt(II) complexes were synthesized for the first time. Synthesized compounds were characterized by spectroscopic methods (FT-IR, 1Hsbnd 13C NMR, LC-MS, UV-vis), magnetic susceptibility and conductivity measurements. 1H and 13C shielding tensors for crystal structure of ligand were calculated with GIAO/DFT/B3LYP/6-311++G(d,p) methods in CDCl3. The vibrational band assignments were performed at B3LYP/6-311++G(d,p) theory level combined with scaled quantum mechanics force field (SQMFF) methodology. The antibacterial activities of synthesized compounds were studied against some Gram positive and Gram negative bacteria by using microdilution and disc diffusion methods. In vitro enzyme inhibitory effects of the compounds were measured by UV-vis spectrophotometer. The enzyme activities against human carbonic anhydrase II (hCA II) were evaluated as IC50 (the half maximal inhibitory concentration) values. It was found that afptsmh and its metal complexes have inhibitory effects on hCA II isoenzyme. General esterase activities were determined using alpha and beta naphtyl acetate substrates (α- and β-NAs) of Drosophila melanogaster (D. melanogaster). Activity results show that afptsmh does not strongly affect the bacteria strains and also shows poor inhibitory activity against hCAII isoenzyme whereas all complexes posses higher biological activities.

  20. Spectroscopic and MD simulation studies on unfolding processes of mitochondrial carbonic anhydrase VA induced by urea.

    Science.gov (United States)

    Idrees, Danish; Prakash, Amresh; Haque, Md Anzarul; Islam, Asimul; Ahmad, Faizan; Hassan, Md Imtaiyaz

    2016-09-01

    Carbonic anhydrase VA (CAVA) is primarily expressed in the mitochondria and involved in numerous physiological processes including lipogenesis, insulin secretion from pancreatic cells, ureagenesis, gluconeogenesis and neuronal transmission. To understand the biophysical properties of CAVA, we carried out a reversible urea-induced isothermal denaturation at pH 7.0 and 25°C. Spectroscopic probes, [θ]222 (mean residue ellipticity at 222 nm), F344 (Trp-fluorescence emission intensity at 344 nm) and Δε280 (difference absorption at 280 nm) were used to monitor the effect of urea on the structure and stability of CAVA. The urea-induced reversible denaturation curves were used to estimate [Formula: see text], Gibbs free energy in the absence of urea; Cm, the mid-point of the denaturation curve, i.e. molar urea concentration ([urea]) at which ΔGD = 0; and m, the slope (=∂ΔGD/∂[urea]). Coincidence of normalized transition curves of all optical properties suggests that unfolding/refolding of CAVA is a two-state process. We further performed 40 ns molecular dynamics simulation of CAVA to see the dynamics at different urea concentrations. An excellent agreement was observed between in silico and in vitro studies.

  1. A Carbonic Anhydrase Serves as an Important Acid-Base Regulator in Pacific Oyster Crassostrea gigas Exposed to Elevated CO2: Implication for Physiological Responses of Mollusk to Ocean Acidification.

    Science.gov (United States)

    Wang, Xiudan; Wang, Mengqiang; Jia, Zhihao; Qiu, Limei; Wang, Lingling; Zhang, Anguo; Song, Linsheng

    2017-02-01

    Carbonic anhydrases (CAs) have been demonstrated to play an important role in acid-base regulation in vertebrates. However, the classification and modulatory function of CAs in marine invertebrates, especially their responses to ocean acidification remain largely unknown. Here, a cytosolic α-CA (designated as CgCAII-1) was characterized from Pacific oyster Crassostrea gigas and its molecular activities against CO2 exposure were investigated. CgCAII-1 possessed a conserved CA catalytic domain, with high similarity to invertebrate cytoplasmic or mitochondrial α-CAs. Recombinant CgCAII-1 could convert CO2 to HCO3(-) with calculated activity as 0.54 × 10(3) U/mg, which could be inhibited by acetazolamide (AZ). The mRNA transcripts of CgCAII-1 in muscle, mantle, hepatopancreas, gill, and hemocytes increased significantly after exposure to elevated CO2. CgCAII-1 could interact with the hemocyte membrane proteins and the distribution of CgCAII-1 protein became more concentrated and dense in gill and mantle under CO2 exposure. The intracellular pH (pHi) of hemocytes under CO2 exposure increased significantly (p CO2 exposure. The impact of CO2 exposure on CA activity coupled with the mRNA expression level and protein translocation of CgCAII-1 provided evidences that CgCAII-1 could respond to ocean acidification and participate in acid-base regulation. Such cytoplasmic CA-based physiological regulation mechanism might explain other physiological responses of marine organisms to OA.

  2. Impacts of CA9 gene polymorphisms on urothelial cell carcinoma susceptibility and clinicopathologic characteristics in Taiwan.

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    Shian-Shiang Wang

    Full Text Available BACKGROUND: Carbonic anhydrase 9 (CA9 is reportedly overexpressed in several types of carcinomas and is generally considered a marker of malignancy. The current study explored the effect of CA9 gene polymorphisms on the susceptibility of developing urothelial cell carcinoma (UCC and the clinicopathological status. METHODOLOGY AND PRINCIPAL FINDINGS: A total of 442 participants, including 221 healthy people and 221 patients with UCC, were recruited for this study. Four single-nucleotide polymorphisms (SNPs of the CA9 gene were assessed by a real-time PCR with the TaqMan assay. After adjusting for other co-variants, the individuals carrying at least one A allele at CA9 rs1048638 had a 2.303-fold risk of developing UCC than did wild-type (CC carriers. Furthermore, UCC patients who carried at least one A allele at rs1048638 had a higher invasive stage risk (p< 0.05 than did patients carrying the wild-type allele. Moreover, among the UCC patients with smoker, people with at least one A allele of CA9 polymorphisms (rs1048638 had a 4.75-fold (95% CI = 1.204-18.746 increased risk of invasive cancer. CONCLUSION: The rs1048638 polymorphic genotypes of CA9 might contribute to the prediction of susceptibility to and pathological development of UCC. This is the first study to provide insight into risk factors associated with CA9 variants in carcinogenesis of UCC in Taiwan.

  3. Jurisdicción episcopal y violencia en el clero diocesano burgalés durante el siglo XV

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    Díaz Ibáñez, Jorge

    2015-06-01

    Full Text Available In this work are analyzed, in a selective way, the different kinds of violence in the diocesan clergy of Burgos during fifteen century: violence from clergymen against laymen, between the clergymen and from laymen against clergymen. All these situations were reported to the episcopal justice of Burgos. The different cases of violence were blows, slaps and attacks with knifes and swords, taking place homicides sometimes. Definitely, the aforementioned cases show strong social tensions, internal and external, affecting in a local level the rural clergy in the diocese of Burgos.En este trabajo se realiza un análisis selectivo de las diferentes formas de presencia de la violencia en el clero diocesano burgalés durante el siglo XV. Violencia de los clérigos hacia los laicos, entre los propios clérigos y de los laicos contra los clérigos, situaciones todas ellas que fueron denunciadas ante la justicia episcopal burgalesa. Las manifestaciones de violencia fueron desde simples golpes, bofetadas y pedradas hasta ataques con cuchillos y espadas, no faltando algún caso de homicidio, todo lo cual, en definitiva, viene a ser una clara muestra de las fuertes tensiones sociales, tanto internas como externas, que a nivel local afectaban al clero rural en la diócesis de Burgos.

  4. Capilaridad de la manufactura textil en la Plana de Castelló. El caso de Onda en el siglo XV

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    Aparici Martí, Joaquín

    2010-06-01

    Full Text Available Onda, a locality with an oscillating population between 300 and 600 dwellings in the 15th century and with Moslems and Jews in the local work, becomes a new piece of the puzzle that lets us see the capillarity of the wool textile manufacture in “La Plana de Castelló”. This capillarity can be seen in the production of clothes, just like in the raw material trade or in the movement of craftsmen. To approach this situation we have basically used the series of documents of the judge of the village kept in the “Archivo del Reino de Valencia”.

    Onda, localidad con un volumen demográfico oscilante entre 300-600 fuegos en el transcurso del siglo XV, con presencia de mudéjares y judíos en el tejido productivo local, es una nueva pieza del puzzle que permite ver la capilaridad de la manufactura textil lanera a nivel comarcal (Plana de Castelló, tanto en la producción de paños, como en el comercio de materias primas o tránsito de artesanos. Para aproximarnos a esta situación hemos utilizado fundamentalmente las series del justicia de la villa conservadas en el Archivo del Reino de Valencia.

  5. X-ray fluorescence analysis of yellow pigments in altarpieces by Valencian artists of the XV and XVI centuries

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    Ferrero, J. L.; Roldán, C.; Ardid, M.; Navarro, E.

    1999-02-01

    XRF analysis has allowed a quick and precise detection and identification of the inorganic elements that compose the yellow pigments in altarpieces of the XV and XVI centuries painted by the Valencian artists Miguel Alcañiz, Vicente Macip, Juan de Juanes, Hernando Yáñez de la Almedina and Hernando Llanos. The analyses have been carried out with an XRF portable system that consists of a tube of X-rays and detectors of Si(Li) and cadmium zinc telluride. This system has enabled a non-aggressive and non-destructive analysis of many pieces at the Museo de Bellas Artes of Valencia (Spain). Among the yellow pigments we have identified a pigment composed by lead and tin oxides named lead-tin yellow (Pb 2SnO 4), frequently used in European paintings from the XIV century until the first half of the XVIII century. This fact demonstrates the influence of elements and pictorial techniques from Europe to the region of Valencia.

  6. The Condition of the Lyon Weavers in the Letters to Louis XV and Monseigneur Poulletier (1731 and 1732

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    Carmelina Imbroscio

    2014-04-01

    Full Text Available On 8th May, 1731, an ordinance of Louis XV, King of France, imposed separation between the production and sale activities of the weavers of ‘gold, silver and silk’ at the famous Lyon Manufactory in which hundreds of families worked. The ordinance plunged into despair the workers (maîtres ouvriers who, up till then, for centuries, had been allowed to sell their goods freely and were now in danger of being reduced to poverty by a handful of traffickers who knew nothing about their extremely sophisticated, skilful trade, but would be enabled to capitalize on their work. They therefore addressed two petitions (the first in 1731 and the second in 1732 to the King and Monseigneur Poulletier, the King’s Superintendent and the Manufactory’s Overseer, asking for the abrogation of the ordinance and a revision of the Manufactory’s regulations. The interesting aspect of these two petitions is that they show the workers’ consciousness of their rights; indeed, their denunciation of these abuses foretells, a century before, the two important revolts of the canuts (as the Lyon textile workers were known which were to break out in 1831 and 1834.

  7. Los conversos de Córdoba en el siglo XV. La familia del jurado Martín Alfonso

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    Cabrera Sánchez, Margarita

    2005-06-01

    Full Text Available This paper analyzes a converts'family that lived at Cordoba during the XVth century. It shows the outstanding role of converses at late medieval in Andalusian society. We also describe the different members of this family group and the important wealth that they managed. This study has been based on notarial documents from Archivo Histórico Provincial from Cordoba

    En este estudio se analiza una familia de conversos que vivió en Córdoba en el siglo XV. En él se pone de manifiesto el papel desempeñado por los conversos en el seno de la sociedad andaluza bajomedieval. En el trabajo se analizan, asimismo, los diferentes miembros de este grupo familiar, así como el importante patrimonio que acumularon los componentes de esta familia. Las fuentes utilizada para la realización del trabajo han sido los documentos notariales del Archivo Histórico Provincial de Córdoba

  8. Subaru XV: una estrategia de comunicación y mercadeo para la generación Y

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    Guillermo Armelini

    2013-03-01

    Full Text Available En el año 2009 las ventas en la industria automotriz disminuyeron. El año 2010 había comenzado mucho mejor. En este contexto, Subaru Chile, un actor del mercado con una cuota relativamente pequeña (anexo 1, decidió introducir un nuevo modelo: Subaru XV, un crossover que se presentaba como la gran apuesta para el creciente mercado de los SUV (anexos 6 y 7 El desafío de lanzar este modelo presentaba varias aristas. En primer lugar, el mercado de este tipo de vehículos ya estaba muy desarrollado por actores importantes como Toyota, Nissan y Renault (anexo 7. En segundo lugar, Subaru tenía que dirigir su acción comercial a un nuevo segmento de mercado (jóvenes entre 20 y 35 años que desconocía y, consecuentemente, debía estudiar sus hábitos y necesidades, y definir el sistema de comunicación más acorde para este target.

  9. Mallorca i la seva dependència financera del Principat (segles XIV-XV: Estudi dels censalistes catalans

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    Morello Baget, Jordi

    2003-06-01

    Full Text Available An analysis of a capbreu de censals (an inventory of perpetual annuities, drafted on request towards the end of Alfonso V's reign, not only allows us to gauge more accurately the real extent of the debt contracted by the Majorcan municipality in Catalonia, but it also indicates different social groups' degree of involvement in this external debt, together with the full identification of the main Catalan creditors. This source of information also enables us to appreciate the results of attempts to reduce the debt, thanks to measures adopted at the Concordia de Barcelona in 1431.

    L'estudi d'un capbreu de censals manat confeccionar a finals del regnat d'Alfons el Magnànim, no sols permet calibrar amb major precisió quin va ser el volum real del deute contret pel municipi mallorquí a Catalunya, sinó també conèixer el grau de participació dels distints grups socials en aquest deute extern i tenir identificats alhora els principals creditors catalans. La dita font també permet apreciar els resultats obtinguts de cara a l'efectiva disminució del pes d'aquest deute abans de mitjan segle XV, en compliment de les disposicions preses a la Concòrdia de Barcelona de 143.

  10. Ultrastructural changes in the membrane system of isolated chloroplasts of spinach under the influence of carbonic anhydrase inhibitors AA and EA

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    Marina V. Vodka

    2013-04-01

    Full Text Available The effects of carbonic anhydrase inhibitors (АА and EA on the membrane system of isolated chloroplasts of spinach were investigated. Under the influence of AA the considerable alterations in granal structure occurred, the thickness of the granal thylakoids increased by 36% and the interspace between thylakoids by 10% comparable with the control. As a result of EA treatment, the thickness of granal thylakoids enhanced by 31% and the interspace between thylakoids increased by 8% in comparison to the control. It was shown that structure of the granal system of the chloroplast was more sensitive to AA than EA. The data obtained can indicate a decrease in the activity of the thylakoid carbonic anhydrase, inhibition of electron transport and photosynthetic process as a whole in the presence of carbonic anhydrase inhibitors (AA and EA.

  11. A review of the pharmacology of carbonic anhydrase inhibitors for the treatment of glaucoma in dogs and cats.

    Science.gov (United States)

    Maślanka, Tomasz

    2015-03-01

    Glaucoma is a heterogeneous group of disorders usually associated with elevated intraocular pressure (IOP), leading to optic nerve damage, retinal ganglion cell death and irreversible vision loss. Therefore, medications that lower IOP are the mainstay of glaucoma therapy. Carbonic anhydrase inhibitors (CAIs) are some of the principal drugs used in the management of canine and feline glaucoma. This paper summarises current knowledge of the mechanism of action of these agents and their effect on IOP in dogs and cats. It also discusses potential harmful side effects of CAIs and presents current opinions about their role and place in the medical management of glaucoma in small animals.

  12. Molecular targeting of carbonic anhydrase IX in mice with hypoxic HT29 colorectal tumor xenografts.

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    Sean Carlin

    Full Text Available BACKGROUND: Carbonic anhydrase IX (CAIX is a membrane spanning protein involved in the enzymatic regulation of tumor acid-base balance. CAIX has been shown to be elevated in a number of hypoxic tumor types. The purpose of this study was to determine the efficiency of intact and IgG fragments of cG250 to target CAIX in vivo in a hypoxic tumor model. METHODOLOGY/PRINCIPAL FINDINGS: Conventional biodistribution studies were performed with (111In-DO3A-cG250, (111In-DO3A-F(ab'(2-cG250 and (111In-DO3A-Fab-cG250. Additional ex vivo analysis of the tumor was performed with markers for tumor hypoxia, blood perfusion and endogenous CAIX expression. All four data sets were digitally correlated to determine the optimal agent for determining hypoxia in a HT29 colon cancer xenograft. The HT29 human colorectal tumor xenografts show strong CAIX expression in hypoxic areas of poor blood perfusion. The intact IgG had an initial high focal uptake at the periphery of these hypoxic regions and penetration into the areas of highest CAIX expression over the 7-day study period. The lower molecular weight antibody fragments had a faster uptake into areas of high CAIX expression, but had a much lower absolute uptake at the optimal imaging times. CONCLUSIONS/SIGNIFICANCE: For the clinical detection of hypoxia induced CAIX using cG250 antibody based agents, imaging with the intact IgG at 7 days post injection would allow for the most sensitive and accurate detection of CAIX.

  13. Expression of carbonic anhydrase IX (CAIX) in malignant mesothelioma. An immunohistochemical and immunocytochemical study.

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    Capkova, L; Koubkova, L; Kodet, R

    2014-01-01

    Malignant mesothelioma is an aggressive tumor with a poor prognosis. Carbonic anhydrase IX (CAIX) is a membranously located metalloenzyme involved in pH homeostasis with influence on regulation of cell proliferation, oncogenesis and tumor progression. Much attention has been paid recently to carboanhydrases and their inhibitors as they offer an opportunity for both developing novel anticancer drugs, as well as diagnostic and prognostic tools. This study was designed to assess the expression of CAIX in malignant pleural and peritoneal mesotheliomas, their benign counterparts, and in pleural effusions from patients with malignant mesothelioma, metastatic carcinoma or a benign disease. Tissue blocks from 51 malignant mesotheliomas of pleura (47 cases; 41 epithelioid, 2 biphasic, 4 sarcomatoid) and peritoneum (4 cases; all epithelioid), 14 cases with normal or reactive pleural tissue, and 19 cell blocks were analyzed. CAIX expression was determined using immunohistochemistry and its membranous immunoreactivity was semiquantitatively evaluated. Specimens were divided into five subgroups according to the staining pattern and intensity.Overall, 92.2% (47/51) of mesotheliomas expressed CAIX. All epithelioid mesotheliomas showed CAIX positivity, which was predominantly strong and diffuse (73.3%, 33/45). Sarcomatoid mesotheliomas and sarcomatoid areas in biphasic mesotheliomas were negative. A strong diffuse staining was observed in all cases of normal mesothelia. In pleural effusions, CAIX expression was observed in malignant cells as well as in benign mesothelial cells. In conclusion, CAIX is expressed virtually in all mesotheliomas except for sarcomatoid subtype, and in benign mesothelia. There are probably more mechanisms of CAIX overexpression than hypoxia-induced in malignant mesothelioma, with the influence of other tissue specific transcription or growth factors depending on the type of the cell lineage. CAIX immunoreactivity is not a reliable diagnostic marker for

  14. Heterologous gene expression driven by carbonic anhydrase gene promoter in Dunaliella salina

    Institute of Scientific and Technical Information of China (English)

    CHAI Yurong; LU Yumin; WANG Tianyun; HOU Weihong; XUE Lexun

    2006-01-01

    Dunaliella salina, a halotolerant unicellular green alga without a rigid cell wall, can live in salinities ranging from 0.05 to 5 mol/L NaCl. These features of D. salina make it an ideal host for the production of antibodies, oral vaccine, and commercially valuable polypeptides. To produce high level of heterologous proteins from D. salina, highly efficientpromoters are required to drive expression of target genes under controlled condition. In the present study, we cloned a 5' franking region of 1.4 kb from the carbonic anhydrase (CAH) gene of D. salina by genomic walking and PCR. The fragment was ligated to the pMD18-T vector and characterized. Sequence analysis indicated that this region contained conserved motifs, including a TATA- like box and CAAT-box. Tandem (GT)n repeats that had a potential role of transcriptional control, were also found in this region. The transcription start site (TSS) of the CAH gene was determined by 5' RACE and nested PCR method. Transformation assays showed that the 1.4 kb fragment was able to drive expression of the selectable bar (bialaphos resistance) gene when the fusion was transformed into D. salina by biolistics.Northern blotting hybridizations showed that the bar transcript was most abundant in cells grown in 2 mol/L NaCl, and less abundant in 0.5 mol/L NaCl, indicating that expression of the bar gene was induced at high salinity. These results suggest the potential use of the CAH gene promoter to induce the expression of heterologous genes in D. salina under varied salt condition.

  15. The ctnG gene encodes carbonic anhydrase involved in mycotoxin citrinin biosynthesis from Monascus aurantiacus.

    Science.gov (United States)

    Li, Yan-Ping; Tang, Xiao; Wu, Wei; Xu, Yang; Huang, Zhi-Bing; He, Qing-Hua

    2015-01-01

    Citrinin, a fungal secondary metabolite of polyketide origin, is moderately nephrotoxic to vertebrates, including humans. Citrinin is synthesised by condensation of acetyl-CoA and malonyl-CoA. Six genes involved in the citrinin biosynthesis, including pksCT, ctnA and ctnB, have been cloned in Monascus purpureus. The pksCT gene encodes a polyketide synthase; ctnA is a regulatory factor; and ctnB encodes an oxidoreductase. When the three genes were respectively disrupted, the disruption strains drastically decreased citrinin production or barely produced citrinin. Ten new genes have been discovered in Monascus aurantiacus besides the above six genes. One of these gene displayed the highest similarity to the β-carbonic anhydrase gene from Aspergillus oryzae (74% similarity) and was designated ctnG. To learn more about the citrinin biosynthetic pathway, a ctnG-replacement vector was constructed to disrupt ctnG with the hygromycin resistance gene as the selection marker, then transformed into M. aurantiacus Li AS3.4384 by a protoplast-PEG method. The citrinin content of three disruptants was reduced to about 50%, meanwhile pigment production decreased by 23%, respectively, over those of the wild-type strains. ctnG was deduced to be involved in the formation of malonyl-CoA as a common precursor of red pigments and citrinin. Therefore, the disruption of the ctnG gene decreased citrinin and pigment production. M. aurantiacus Li AS3.4384 can produce higher concentrations of citrinin than other strains such as M. purpureus and M. ruber. Establishing the function of citrinin biosynthetic genes in M. aurantiacus is helpful in understanding the citrinin synthetic pathway and adopting some strategies to control contamination.

  16. The use of CA-IX as a diagnostic method for oral leukoplakia.

    Science.gov (United States)

    Pérez-Sayáns, M; Suárez-Peñaranda, J M; Torres-López, M; Supuran, C T; Gándara-Vila, P; Gayoso-Diz, P; Barros-Angueira, F; Gallas-Torreira, M; García-García, A

    2015-02-01

    The presence and degree of dysplasia are important diagnostic and prognostic criteria for oral leukoplakia, but evaluation of dysplasia is difficult and subjective. Carbonic anhydrase-IX (CA-IX) is expressed primarily in tumor cells and is considered a specific hypoxia marker. We investigated the role of CA-IX in oral leukoplakia. We investigated 30 specimens of oral leukoplakia and 35 dysplasia specimens adjacent to the tumor margin. We analyzed clinical variables including age, sex, degree of dysplasia, and smoking, clinical appearance of leukoplakia, number of lesions, location, size, clinical monitoring, malignant transformation and recurrence. For the immunohistochemical study, we used a noncommercial monoclonal antibody against human CA-IX MAb M75. We found greater CA-IX positivity in nonsmokers, erythroplakia and mottled leukoplakia, those located on the tongue, patients with multiple lesions, 2-4 cm leukoplakias and in recurrent cases, although differences were not statistically significant. All lesions in all samples without dysplasia were negative for CA-IX; however, for all other categories of dysplasia, the percentages of positivity and negativity varied. Regarding the diagnostic index values, we found a sensitivity of 32%, specificity of 100%, a positive predictive value of 100% and a negative predictive value of 13%. Leukoplakias appear mainly in females and potentially are malignant; more than 90% have some degree of dysplasia, and therefore require close clinical and histopathological monitoring. The CA-IX immunohistochemical marker may be useful for screening samples without dysplasia owing to its high specificity.

  17. Expression pattern and polymorphism of three microsatellite markers in the porcine CA3 gene

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    Zheng Rong

    2008-03-01

    Full Text Available Abstract Carbonic anhydrase III (CA3 is an abundant muscle protein characteristic of adult type-1, slow-twitch, muscle fibres. In order to further understand the functions of the porcine CA3 protein in muscle, the temporal and spatial distributions of its gene product were analysed and the association between the presence of specific polymorphisms and carcass traits in the pig was also examined. Real-time PCR revealed that the CA3 mRNA expression showed no differences with age in skeletal muscles from Yorkshire pigs at postnatal day-1, month-2, and month-4. We provide the first evidence that CA3 is differentially expressed in the skeletal muscle of Yorkshire and Meishan pig breeds. In addition, the whole pig genomic DNA sequence of CA3 was investigated and shown to contain seven exons and six introns. Comparative sequencing of the gene from three pig breeds revealed the existence of microsatellite SJ160 in intron 5 and microsatellite SJ158 and a novel microsatellite marker that includes a tandem repeat of (TCn in intron 4. We also determined the allele number and frequencies of the three loci in seven pig breeds and found that they are low polymorphic microsatellite markers. Statistical analysis showed that the CA3 microsatellite polymorphism was associated with dressing percentage, internal fat rate, carcass length, rib number and backfat thickness in the pig.

  18. La muerte individualizada en la vida cotidiana y en la literatura medieval castellana (siglo XI-XV

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    Félix A. Ferrer García

    2007-01-01

    Full Text Available Emprender un estudio parcial sobre el tema de la muerte obedece a un interés creciente por los problemas planteados por la historiografía de las mentalidades y a un intento de analizar una proposición tan interesante como la actitud de los hombres medievales ante un hecho que existe y se manifiesta por sí mismo, sin necesidad de formas conscientes o de reacciones instintivas, pero que, singularmente, comporta un tema lógico y utópico, un proceso de mitificación y otro de dogmatización. Las implicaciones teoréticas de una «ideología de la muerte» interesan más como instrumentos al servicio de un poder que como elementos incorporados a unos sentimientos en la Castilla medieval. Sorprende más la posibilidad de dominio sobre un pueblo a través de una estructura ideológica, teológica y, en parte, ilusoria que las probables muestras de solidaridad social alrededor de unos sentimientos de inseguridad en la vida y angustia ante la muerte. A lo largo de varios siglos, del XI al XV, las respuestas de los castellanos variaron sustancialmente ante una transición vida-muerte que a todos igualaba o conformaba no por la propia voluntad del individuo, sino por un mecanismo de defensa de la sociedad que, en ocasiones, contemplaba la vida como un lento camino hacia la muerte o como una «sub-muerte» misma, mostrándose su sentido como instrumento y signo de un orden jerárquico y una ortodoxia concreta frente a la rica y variada existencia de culturas en la sociedad medieval.To undertake a partial study on the subject of the death obeys to an increasing interest about the problems created by the historiography of the mentalities and to an attempt to analyze an interesting proposal as the attitude of the medieval men towards a fact that exists and it is expressed by itself, with no need of conscious forms or instinctive reactions, but that, singularly, deals with a logical and utopian subject, a mythical process and another of dogmatism. The

  19. Las dehesas maestrales de La Serena (siglos XV-XVI: cartografía de un paisaje social

    Directory of Open Access Journals (Sweden)

    Clemente Quijada, Luis Vicente

    2014-12-01

    Full Text Available In this article a cartography of the mastership dehesas of the military order of Alcantara in La Serena (Badajoz in the 15th and 18th centuries is presented. It has been carried out through the study of historical toponymy from several 16th and 18th-century documents and their contrast with modern cartography (MTN25 and MTN50. Together with a methodology for the development of landscape analysis based on the use of GIS, we submit an estimation of the whole dehesas surface (108,511.87 ha and their sheep stocking rate average (0.28 UGM for the analyzed period. The results retrieved question the livestock orientation of these spaces as a consequence of soil deficiencies. Instead of this, the article concludes that dehesas landscape is related to the jurisdictional model developed in the Estates of the Military Order of Alcantara during the Middle Ages.Presentamos en este artículo una cartografía del espacio ocupado por las dehesas maestrales de la Orden de Alcántara en La Serena (Badajoz durante los siglos XV-XVIII. La misma ha sido elaborada a partir del vaciado de la toponimia histórica procedente de diversas fuentes de los siglos XVI y XVIII y su posterior contraste con las series cartográficas actuales (MTN25 y MTN50. Junto a una metodología para el desarrollo de estudios del paisaje basada en el uso de SIG, ofrecemos una estimación de la superficie total de las dehesas (108.511,87 ha y del promedio de sus densidades ganaderas (0,28 UGM/ha durante la primera mitad del siglo XVI. Los resultados obtenidos permiten cuestionar la orientación ganadera de estas dehesas como consecuencia directa de la pobreza de los suelos. En su lugar proponemos que el adehesamiento guarda relación con el modelo jurisdiccional desarrollado en el maestrazgo de Alcántara durante la Edad Media. [fr] Cet article présente une cartographie de l’espace occupé par les dehesas du maître de l’Ordre d’Alcantara dans La Serena (Badajoz pendant les XV3 et XVIII

  20. Carbonic anhydrase-9 expression levels and prognosis in human breast cancer: association with treatment outcome.

    NARCIS (Netherlands)

    Span, P.N.; Bussink, J.; Manders, P.; Beex, L.V.A.M.; Sweep, C.G.J.

    2003-01-01

    Here, we set out to assess CA9 expression levels by real-time quantitative RT-PCR in breast cancer tissue samples obtained from 253 patients, and correlated those with relapse-free (RFS) survival. The median follow-up time was 75 months (range 2-168 months). CA9 expression was mainly found in high-g

  1. La presencia de valencianos y aragoneses en la documentación notarial cagliaritana del siglo XV

    Directory of Open Access Journals (Sweden)

    Villanueva Morte, Concepción

    2008-06-01

    Full Text Available The aim of this article is to study the commercial activity between the Crown of Aragon and Sardinia (Cagliari, and the geographical mobility that it was generated in the transition from Medieval to Modern Age, that serves to value the traffic currents and the balance of traced bonds. For it we present the first suggestive results of one taste which it has been carried about notary documentation of Cagliary in the 15th century in relation to the presence of Valencian and Aragonese there seated, for the sake of understanding the comparative difference of focus with regard to the derivative analysis of these historical sources of Sardinia and those other ones Iberian, that have already been explored in previous investigations.

    El objeto de este artículo es estudiar las relaciones comerciales entre la Corona de Aragón y Cerdeña (Cagliari, y la movilidad geográfica en la transición de la Edad Media a la Moderna, para valorar las corrientes de tráfico y el balance de vínculos trazados entre ambos territorios. Para ello presentamos los primeros resultados sugestivos de una cata realizada sobre la documentación notarial cagliaritana del siglo XV en relación a la presencia de valencianos y aragoneses allí asentados, en aras de comprender la diferencia comparativa de enfoque con respecto al análisis derivado de estas fuentes históricas sardas y aquellas otras ibéricas, que ya han sido exploradas en investigaciones anteriores.

  2. Nosotros, vosotros, ellos: relatos de viajeros judíos del siglo XV a la luz del concepto de alteridad

    Directory of Open Access Journals (Sweden)

    Cano Pérez, María José

    2015-12-01

    Full Text Available Travel literature could be considered as the nexus of numerous types of texts within the narrative genre. Nevertheless, the information it offers from historical, geographical or sociological, among others, points of view, converts it into a register from which are concealed the own experiences of travelers in their journeys. In this sense, these ones are specially relevant in identity studies in which it is possible to observe the alterity that the authors show in their writings describing, in a constant way, their perception of the places they visited but also different communities, Jewish and non-Jewish, they find. In these pages it is offered a study about the impressions of 15th century Medieval authors in their voyages.La literatura de viajes podría considerarse el nexo de multitud de tipos de textos dentro del genero de la narrativa. Sin embargo, los datos que ofrece desde el punto de vista histórico, geográfico o sociológico, entre otros, hacen de ella un registro del que subyacen además las experiencias propias de los viajeros en sus travesías. De este modo, resultan especialmente destacadas en estudios de identidad en los que observar la alteridad que muestran los autores en sus escritos en los que describen, de manera constante, su percepción de los lugares que visitan pero también las diferentes comunidades, judías y no judías, con las que se encuentran. En estas paginas se ofrece un estudio acerca de las impresiones de autores medievales del siglo XV en sus viajes.

  3. Est10: A Novel Alkaline Esterase Isolated from Bovine Rumen Belonging to the New Family XV of Lipolytic Enzymes

    Science.gov (United States)

    Rodríguez, María Cecilia; Loaces, Inés; Amarelle, Vanesa; Senatore, Daniella; Iriarte, Andrés; Fabiano, Elena; Noya, Francisco

    2015-01-01

    A metagenomic fosmid library from bovine rumen was used to identify clones with lipolytic activity. One positive clone was isolated. The gene responsible for the observed phenotype was identified by in vitro transposon mutagenesis and sequencing and was named est10. The 367 amino acids sequence harbors a signal peptide, the conserved secondary structure arrangement of alpha/beta hydrolases, and a GHSQG pentapeptide which is characteristic of esterases and lipases. Homology based 3D-modelling confirmed the conserved spatial orientation of the serine in a nucleophilic elbow. By sequence comparison, Est10 is related to hydrolases that are grouped into the non-specific Pfam family DUF3089 and to other characterized esterases that were recently classified into the new family XV of lipolytic enzymes. Est10 was heterologously expressed in Escherichia coli as a His-tagged fusion protein, purified and biochemically characterized. Est10 showed maximum activity towards C4 aliphatic chains and undetectable activity towards C10 and longer chains which prompted its classification as an esterase. However, it was able to efficiently catalyze the hydrolysis of aryl esters such as methyl phenylacetate and phenyl acetate. The optimum pH of this enzyme is 9.0, which is uncommon for esterases, and it exhibits an optimal temperature at 40°C. The activity of Est10 was inhibited by metal ions, detergents, chelating agents and additives. We have characterized an alkaline esterase produced by a still unidentified bacterium belonging to a recently proposed new family of esterases. PMID:25973851

  4. Carbonic anhydrase generates CO2 and H+ that drive spider silk formation via opposite effects on the terminal domains.

    Science.gov (United States)

    Andersson, Marlene; Chen, Gefei; Otikovs, Martins; Landreh, Michael; Nordling, Kerstin; Kronqvist, Nina; Westermark, Per; Jörnvall, Hans; Knight, Stefan; Ridderstråle, Yvonne; Holm, Lena; Meng, Qing; Jaudzems, Kristaps; Chesler, Mitchell; Johansson, Jan; Rising, Anna

    2014-08-01

    Spider silk fibers are produced from soluble proteins (spidroins) under ambient conditions in a complex but poorly understood process. Spidroins are highly repetitive in sequence but capped by nonrepetitive N- and C-terminal domains (NT and CT) that are suggested to regulate fiber conversion in similar manners. By using ion selective microelectrodes we found that the pH gradient in the silk gland is much broader than previously known. Surprisingly, the terminal domains respond in opposite ways when pH is decreased from 7 to 5: Urea denaturation and temperature stability assays show that NT dimers get significantly stabilized and then lock the spidroins into multimers, whereas CT on the other hand is destabilized and unfolds into ThT-positive β-sheet amyloid fibrils, which can trigger fiber formation. There is a high carbon dioxide pressure (pCO2) in distal parts of the gland, and a CO2 analogue interacts with buried regions in CT as determined by nuclear magnetic resonance (NMR) spectroscopy. Activity staining of histological sections and inhibition experiments reveal that the pH gradient is created by carbonic anhydrase. Carbonic anhydrase activity emerges in the same region of the gland as the opposite effects on NT and CT stability occur. These synchronous events suggest a novel CO2 and proton-dependent lock and trigger mechanism of spider silk formation.

  5. Carbonic anhydrase generates CO2 and H+ that drive spider silk formation via opposite effects on the terminal domains.

    Directory of Open Access Journals (Sweden)

    Marlene Andersson

    2014-08-01

    Full Text Available Spider silk fibers are produced from soluble proteins (spidroins under ambient conditions in a complex but poorly understood process. Spidroins are highly repetitive in sequence but capped by nonrepetitive N- and C-terminal domains (NT and CT that are suggested to regulate fiber conversion in similar manners. By using ion selective microelectrodes we found that the pH gradient in the silk gland is much broader than previously known. Surprisingly, the terminal domains respond in opposite ways when pH is decreased from 7 to 5: Urea denaturation and temperature stability assays show that NT dimers get significantly stabilized and then lock the spidroins into multimers, whereas CT on the other hand is destabilized and unfolds into ThT-positive β-sheet amyloid fibrils, which can trigger fiber formation. There is a high carbon dioxide pressure (pCO2 in distal parts of the gland, and a CO2 analogue interacts with buried regions in CT as determined by nuclear magnetic resonance (NMR spectroscopy. Activity staining of histological sections and inhibition experiments reveal that the pH gradient is created by carbonic anhydrase. Carbonic anhydrase activity emerges in the same region of the gland as the opposite effects on NT and CT stability occur. These synchronous events suggest a novel CO2 and proton-dependent lock and trigger mechanism of spider silk formation.

  6. Evaluation of impacted Brazilian estuaries using the native oyster Crassostrea rhizophorae: Branchial carbonic anhydrase as a biomarker.

    Science.gov (United States)

    Azevedo-Linhares, Maristela; Freire, Carolina A

    2015-12-01

    In this study, we investigated the use of branchial carbonic anhydrase activity in a sessile filter feeding species, the oyster Crassostrea rhizophorae, as a biomarker. The oysters were collected in three human impacted Brazilian estuaries, following a crescent latitudinal gradient: in Pernambuco state (Itamaracá), in Espírito Santo state (Piraquê), and in Paraná state (Paranaguá), in August/2003 (Winter in the southern hemisphere) and February/2004 (Summer). Three sites were chosen in each estuary for oyster sampling: Reference (R), Contaminated 1 (C1, close to industrial/harbor contamination), and Contaminated 2 (C2, near to sewage discharges). Comparing to values in oysters sampled in reference sites, there was apparent inhibition in carbonic anhydrase activity (CAA) in gills of oysters from C1 of Itamaracá and from C2 of Piraquê, both cases in Summer. On the other hand, increased CAA was noted in C2 oysters of Itamaracá in winter, and of Paranaguá, in both seasons. Branchial CAA in C. rhizophorae was thus very responsive to coastal contamination. Data are consistent with its usefulness as a supporting biomarker for inexpensive and rapid analysis in the assessment of estuaries using a sessile osmoconformer species, but preferably allied to other biomarkers and with knowledge on the suite of contaminants present.

  7. Evaluation of the therapeutic potential of carbonic anhydrase inhibitors in two animal models of dystrophin deficient muscular dystrophy.

    Science.gov (United States)

    Giacomotto, Jean; Pertl, Cordula; Borrel, Caroline; Walter, Maggie C; Bulst, Stefanie; Johnsen, Bob; Baillie, David L; Lochmüller, Hanns; Thirion, Christian; Ségalat, Laurent

    2009-11-01

    Duchenne Muscular Dystrophy is an inherited muscle degeneration disease for which there is still no efficient treatment. However, compounds active on the disease may already exist among approved drugs but are difficult to identify in the absence of cellular models. We used the Caenorhabditis elegans animal model to screen a collection of 1000 already approved compounds. Two of the most active hits obtained were methazolamide and dichlorphenamide, carbonic anhydrase inhibitors widely used in human therapy. In C. elegans, these drugs were shown to interact with CAH-4, a putative carbonic anhydrase. The therapeutic efficacy of these compounds was further validated in long-term experiments on mdx mice, the mouse model of Duchenne Muscular Dystrophy. Mice were treated for 120 days with food containing methazolamide or dichlorphenamide at two doses each. Musculus tibialis anterior and diaphragm muscles were histologically analyzed and isometric muscle force was measured in M. extensor digitorum longus. Both substances increased the tetanic muscle force in the treated M. extensor digitorum longus muscle group, dichlorphenamide increased the force significantly by 30%, but both drugs failed to increase resistance of muscle fibres to eccentric contractions. Histological analysis revealed a reduction of centrally nucleated fibers in M. tibialis anterior and diaphragm in the treated groups. These studies further demonstrated that a C. elegans-based screen coupled with a mouse model validation strategy can lead to the identification of potential pharmacological agents for rare diseases.

  8. Role of carbonic anhydrase in bone resorption induced by 1,25 dihydroxyvitamin D3 in vitro

    Science.gov (United States)

    Hall, G. E.; Kenny, A. D.

    1985-01-01

    The calvaria of 5-to-6-day-old mice treated with 1 x 10 to the -8th M of 1,25(OH)2D3 in vitro for 48 hours are examined in order to study the function of carbonic anhydrase in bone resorption. Calcium concentrations in the culture were measured to assess bone resorption. It is observed that 1,25(OH)2D3 effectively stimulates bone resorption in vitro and the resorption is dose-dependent. The effects of azetazolamide on 1,25(OH)2D3-induced bone resorption are investigated. The data reveal that 1,25(OH)2D3-induced calcium release is associated with an increase in the carbonic anhydrase activity of bone, and bone alkaline phosphatase activity is decreased and acid phosphatase activity is increased in response to 1,25(OH)2D3. A two-fold mechanism for 1,25(OH)2D3-induced bone resorption is proposed; the first mechanism is an indirect activation of osteoclasts and the second involves an interaction between hormone and osteoclast precursors.

  9. El mayordomazgo moneda de cambio de las dificultades económicas del concejo sevillano en la segunda mitad del siglo XV.

    Directory of Open Access Journals (Sweden)

    Antonio Collantes de terán Sánchez

    2015-12-01

    Full Text Available The ordinary incomes and how to manage them in Seville council along the XV century were unable to bear the increased spending and deal with the occasional need for quick cash. These circumstances forced to resort to extraordinary taxes, credit operations and other financial measures. This paper analyses how affected the situation described before to the “mayordomo” council office during the second half of that century: on the one hand, it was the subject of completely illegal manoeuvres, such as its lease, office delivery for money, etc. and, on the other, the situation forced the council to adopt contradictory resolutions frequently and to breach contracts.

  10. Vilar Maior : evolução de um castelo e povoado raiano de Riba-Côa (séc. XI a XV)

    OpenAIRE

    Magro, Maria Virgínia Antão Pêga

    2011-01-01

    Este trabalho ambiciona apresentar uma vila ribacudana, Vilar Maior, e focar os aspectos relacionados com a Arqueologia Medieval: a evolução da arquitectura militar; e o desenvolvimento urbano do povoado ao longo dos séculos XI e XV. Balizado o tema e a cronologia em que nos movimentamos expusemos diversos temas relacionados com a história de Portugal em tempos de Reconquista. A abordagem à castelologia permitiu-nos delinear variados aspectos relacionados com a estrutura militar de Vilar Maio...

  11. La tecnología sedera en Valencia a la luz de unas ordenanzas inéditas del siglo XV

    OpenAIRE

    Navarro Espinach, Germán

    2011-01-01

    Study of an unpublished book of ordinances of the 15th to 17th centuries pertaining to the silk velvets weavers of Valencia, conserved in The Hispanic Society of America in New York. Its comparison with the Valencian silk ordinances that we already know provides new information on 15th century textile technology.

    Estudio de un libro inédito de ordenanzas de los siglos XV-XVII perteneciente a los tejedores de terciopelos de seda ...

  12. Proceedings of the fifteenth meeting of the international collaboration on advanced neutron sources (ICANS-XV). Advanced neutron sources towards the next century

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Jun-ichi [Center for Neutron Science, Tokai Research Establishment, Japan Atomic Energy Research Institute, Tokai, Ibaraki (Japan); Itoh, Shinichi [Neutron Science Laboratory, High Energy Accelerator Research Organization, Tsukuba, Ibaraki (JP)] (eds.)

    2001-03-01

    The fifteenth meeting of the International Collaboration on Advanced Neutron Sources (ICANS-XV) was held at Epocal Tsukuba, International Congress Center on 6-9 November 2000. It was hosted by Japan Atomic Energy Research Institute (JAERI) and High Energy Accelerator Research Organization (KEK). This meeting focused on 'Neutron Sources toward the 21st Century' and research activities related to targets and moderators, neutron scattering instruments and accelerators were presented. The 151 of the presented papers are indexed individually. (J.P.N.)

  13. Effect of tyrosine kinase inhibitor treatment of renal cell carcinoma on the accumulation of carbonic anhydrase IX-specific chimeric monoclonal antibody cG250

    NARCIS (Netherlands)

    Oosterwijk-Wakka, J.C.; Kats-Ugurlu, G.; Leenders, W.P.J.; Kiemeney, L.A.L.M.; Old, L.J.; Mulders, P.F.A.; Oosterwijk, E.

    2011-01-01

    OBJECTIVE: To investigate the effect of three different tyrosine kinase inhibitors (TKIs) on the biodistribution of chimeric monoclonal antibody (mAb) cG250, which identifies carbonic anhydrase IX (CAIX), in nude mice bearing human renal cell carcinoma (RCC) xenografts. TKIs represent the best, but

  14. Carbonic Anhydrase II: A Model System for Artificial Copper Center Design, Protein-guided Cycloadditions, Tethering Screenings and Fragment-based Lead Discovery

    OpenAIRE

    Schulze Wischeler, Johannes

    2010-01-01

    In this thesis a variety of quite different fragment-based lead discovery approaches have been applied to the target protein carbonic anhydrase II. The different projects were strongly supported and methodologically tailored towards protein crystallography; a method which is currently emerging as a routine analytical tool. This maturation mainly results from improved radiation sources and enhanced computing power. About 200-250 da...

  15. Imágenes de Dido y Eneas en los Castigos del rey don Sancho IV (ms. 3 995 BNE, siglo XV

    Directory of Open Access Journals (Sweden)

    Charo MORENO

    2007-07-01

    Full Text Available El único manuscrito iluminado de los Castigos y documentos de Sancho IV, el ms. 3995 conservado en la Biblioteca Nacional de España y datado en el primer tercio del siglo XV, aporta dos imágenes ilustradoras de la historia de Dido y Eneas, representando de una parte a Eneas con una función amplificadora del concepto de traición que el personaje ejemplifica a nivel textual, y de otra parte a Dido, cuya ilustración responde al modelo de la muerte de la dama al caer desde la torre que se documenta en otros textos clásicos y medievales. En este artículo mostramos las similitudes iconográficas con otro modelo diferente: el de la caída de Ocozías, que, como Dido, representa la caída de la persona, del monarca y el fin de una dinastía.Le seul manuscrit enluminé des Castigos y documentos de Sancho IV, ms. 3995 conservé à la Bibliothèque Nationale d’Espagne, daté du premier tiers du XVe siècle, offre deux images illustrant l’histoire de Didon et Énée. D’une part, la représentation d’Énée présente une fonction amplificatrice du concept de trahison que le personnage véhicule au niveau textuel et, d’autre part, l’illustration de Didon répond au modèle de la mort de la dame qui tombe de la tour, modèle présent dans d’autres textes classiques et médiévaux. Il s’agira de montrer les similitudes iconographiques avec un autre modèle : celui de la chute d’Ochozias, qui, comme Didon, représente la chute de la personne, du monarque et la fin d’une dynastie.

  16. The Experience Of The Meteorological Support By The National Institute Of Meteorology During The XV Pan-american Games

    Science.gov (United States)

    Seabra, M.; Gonçalves, P.; Braga, A.; Raposo, R.; Ito, E.; Gadelha, A.; Dallantonia, A.

    2008-05-01

    The XV Pan-American Games were organized in Rio de Janeiro city during 13 to 29 July, 2007 with a participation of 5.662 athletes of 42 countries . The Ministry of Sports requested INMET to provide meteorological support to the games, with the exception of the water sports only, which fell under the responsibility of the Brazilian Navy. The meteorological activities should follow the same pattern experienced during the Olympic Games of Sydney in Australia in the year of 2000, and of Athens in Greece in 2004, with a forecast center entirely dedicated to the event. NMET developed a website with detailed information oriented to the athletes and organizing committee and to the general public. The homepage had 3 different option of idioms (Portuguese, English and Spanish). After choosing the idiom, the user could consult the meteorological data, to each competition place, and to the Pan- American Village, every 15 minutes, containing weather forecast bulletin, daily synoptic analysis, the last 10 satellite image and meteograms. Besides observed data verified "in situ" INMET supplied forecast generated by High Resolution Model (MBAR) with 7km grid resolution especially set up for the games. INMET installed 7 automatic meteorological stations near the competition places, which supplied temperature , relative humidity , atmospheric pressure, wind (direction and intensity), radiation and precipitation every 15 minutes. Those information were relayed by satellite to INMET headquarters located in Brasília and soon after they were published in the website. To help the Brazilian Olympic Committee - COB, the athletes, their technical commission and the public in general, meteorological bulletins were emitted daily. The forecast was done together with the Navy and also with INMET's 6th District located in Rio de Janeiro, and responsible for the forecast statewide. This forecast was then placed at the INMET's website. Both the 3 days weather forecast and Meteorological Alert were

  17. Bayer Facts of Science Education XV: A View from the Gatekeepers--STEM Department Chairs at America's Top 200 Research Universities on Female and Underrepresented Minority Undergraduate STEM Students

    Science.gov (United States)

    Journal of Science Education and Technology, 2012

    2012-01-01

    Diversity and the underrepresentation of women, African-Americans, Hispanics and American Indians in the nation's science, technology, engineering and mathematics (STEM) fields are the subjects of the XV: A View from the Gatekeepers--STEM Department Chairs at America's Top 200 Research Universities on Female and Underrepresented Minority…

  18. Carpintero y maestro constructor en la arquitectura gótica valenciana (siglos XIV–XV) = Carpenters and building mason in the Gothic architecture in Valencia (14th–15th centuries)

    OpenAIRE

    Izquierdo Aranda, Teresa

    2013-01-01

    Desde finales del siglo XIII hasta el último cuarto del siglo XV, la corporación de oficio de carpinteros de Valencia englobaba todas aquellas especialidades vinculadas con el trabajo en madera, por ello incluso los albañiles estaban agrupados en est

  19. Book review / reseña: PALLARÉS JIMÉNEZ, M. Á., La imprenta de los incunables de Zaragoza y el comercio internacional del libro a finales del siglo XV.

    OpenAIRE

    Sergio García Sierra

    2010-01-01

    Reseña del libro: PALLARÉS JIMÉNEZ, M. Á., La imprenta de los incunables de Zaragoza y el comercio internacional del libro a finales del siglo XV, Zaragoza, Institución «Fernando el Católico», 2008. 992 pp. ISBN: 978-84-7820-854-8.

  20. Book review / reseña: PALLARÉS JIMÉNEZ, M. Á., La imprenta de los incunables de Zaragoza y el comercio internacional del libro a finales del siglo XV.

    Directory of Open Access Journals (Sweden)

    Sergio García Sierra

    2010-01-01

    Full Text Available Reseña del libro: PALLARÉS JIMÉNEZ, M. Á., La imprenta de los incunables de Zaragoza y el comercio internacional del libro a finales del siglo XV, Zaragoza, Institución «Fernando el Católico», 2008. 992 pp. ISBN: 978-84-7820-854-8.

  1. Size and surface chemistry of nanoparticles lead to a variant behavior in the unfolding dynamics of human carbonic anhydrase

    Science.gov (United States)

    Nasir, Irem; Lundqvist, Martin; Cabaleiro-Lago, Celia

    2015-10-01

    The adsorption induced conformational changes of human carbonic anhydrase I (HCAi) and pseudo wild type human carbonic anhydrase II truncated at the 17th residue at the N-terminus (trHCAii) were studied in presence of nanoparticles of different sizes and polarities. Isothermal titration calorimetry (ITC) studies showed that the binding to apolar surfaces is affected by the nanoparticle size in combination with the inherent protein stability. 8-Anilino-1-naphthalenesulfonic acid (ANS) fluorescence revealed that HCAs adsorb to both hydrophilic and hydrophobic surfaces, however the dynamics of the unfolding at the nanoparticle surfaces drastically vary with the polarity. The size of the nanoparticles has opposite effects depending on the polarity of the nanoparticle surface. The apolar nanoparticles induce seconds timescale structural rearrangements whereas polar nanoparticles induce hours timescale structural rearrangements on the same charged HCA variant. Here, a simple model is proposed where the difference in the timescales of adsorption is correlated with the energy barriers for initial docking and structural rearrangements which are firmly regulated by the surface polarity. Near-UV circular dichorism (CD) further supports that both protein variants undergo structural rearrangements at the nanoparticle surfaces regardless of being ``hard'' or ``soft''. However, the conformational changes induced by the apolar surfaces differ for each HCA isoform and diverge from the previously reported effect of silica nanoparticles.The adsorption induced conformational changes of human carbonic anhydrase I (HCAi) and pseudo wild type human carbonic anhydrase II truncated at the 17th residue at the N-terminus (trHCAii) were studied in presence of nanoparticles of different sizes and polarities. Isothermal titration calorimetry (ITC) studies showed that the binding to apolar surfaces is affected by the nanoparticle size in combination with the inherent protein stability. 8-Anilino

  2. Carbon anhydrase IX specific immune responses in patients with metastatic renal cell carcinoma potentially cured by interleukin-2 based immunotherapy

    DEFF Research Database (Denmark)

    Rasmussen, Susanne; Donskov, Frede; Pedersen, Johannes W

    2013-01-01

    Abstract The majority of clear-cell renal cell carcinomas (ccRCC) show high and homogeneous expression levels of the tumor associated antigen (TAA) carbonic anhydrase IX (CAIX), and treatment with interleukin-2 (IL-2) based immunotherapy can lead to cure in patients with metastatic renal cell...... of disease (NED) following treatment with IL-2 based immunotherapy, and thus potentially cured. Immune reactivity in these patients was compared with samples from patients with dramatic tumor response obtained immediately at the cessation of therapy, samples from patients that experienced progressive disease...... interest in future cancer vaccines, but more studies are needed to elucidate the immunological mechanisms of action in potentially cured patients treated with an immunotherapeutic agent....

  3. Comparative analysis of 10 small molecules binding to carbonic anhydrase II by different investigators using Biacore technology.

    Science.gov (United States)

    Papalia, Giuseppe A; Leavitt, Stephanie; Bynum, Maggie A; Katsamba, Phinikoula S; Wilton, Rosemarie; Qiu, Huawei; Steukers, Mieke; Wang, Siming; Bindu, Lakshman; Phogat, Sanjay; Giannetti, Anthony M; Ryan, Thomas E; Pudlak, Victoria A; Matusiewicz, Katarzyna; Michelson, Klaus M; Nowakowski, Agnes; Pham-Baginski, Anh; Brooks, Jonathan; Tieman, Bryan C; Bruce, Barry D; Vaughn, Michael; Baksh, Michael; Cho, Yun Hee; Wit, Mieke De; Smets, Alexandra; Vandersmissen, Johan; Michiels, Lieve; Myszka, David G

    2006-12-01

    In this benchmark study, 26 investigators were asked to characterize the kinetics and affinities of 10 sulfonamide inhibitors binding to the enzyme carbonic anhydrase II using Biacore optical biosensors. A majority of the participants collected data that could be fit to a 1:1 interaction model, but a subset of the data sets obtained from some instruments were of poor quality. The experimental errors in the k(a), k(d), and K(D) parameters determined for each of the compounds averaged 34, 24, and 37%, respectively. As expected, the greatest variation in the reported constants was observed for compounds with exceptionally weak affinity and/or fast association rates. The binding constants determined using the biosensor correlated well with solution-based titration calorimetry measurements. The results of this study provide insight into the challenges, as well as the level of experimental variation, that one would expect to observe when using Biacore technology for small molecule analyses.

  4. Effect the some heavy metals on carbonic anhydrase enzymes activities from non-tumour and tumour human stomach

    OpenAIRE

    2015-01-01

    In this study, in vitro effects of certain heavy metals on the human carbonic anhydrase enzyme were examined. Inhibitory effects of metal ions ( Pb2+, Cu2+, Fe2+,Cr2+, Al3+, Ni2+, Mn2+, Cd2+, Zn2+, and Mg2+) were observed in tumour and non-tumour tissue. IC50 values were calculated for metals. The Cu2+, Zn2+, Ni2+, Cd2+ and Mg2+ IC50 values of tumour tissue were calculated as 0.034mM, 0.426mM, 0.597mM, 0.878mM and 2.52mM respectively. The Cu2+, Zn2+, Ni2+, Cd2+ and Mg2+  IC50 values of non-tu...

  5. Identifying potential selective fluorescent probes for cancer-associated protein carbonic anhydrase IX using a computational approach.

    Science.gov (United States)

    Kamstra, Rhiannon L; Floriano, Wely B

    2014-11-01

    Carbonic anhydrase IX (CAIX) is a biomarker for tumor hypoxia. Fluorescent inhibitors of CAIX have been used to study hypoxic tumor cell lines. However, these inhibitor-based fluorescent probes may have a therapeutic effect that is not appropriate for monitoring treatment efficacy. In the search for novel fluorescent probes that are not based on known inhibitors, a database of 20,860 fluorescent compounds was virtually screened against CAIX using hierarchical virtual ligand screening (HierVLS). The screening database contained 14,862 compounds tagged with the ATTO680 fluorophore plus an additional 5998 intrinsically fluorescent compounds. Overall ranking of compounds to identify hit molecular probe candidates utilized a principal component analysis (PCA) approach. Four potential binding sites, including the catalytic site, were identified within the structure of the protein and targeted for virtual screening. Available sequence information for 23 carbonic anhydrase isoforms was used to prioritize the four sites based on the estimated "uniqueness" of each site in CAIX relative to the other isoforms. A database of 32 known inhibitors and 478 decoy compounds was used to validate the methodology. A receiver-operating characteristic (ROC) analysis using the first principal component (PC1) as predictive score for the validation database yielded an area under the curve (AUC) of 0.92. AUC is interpreted as the probability that a binder will have a better score than a non-binder. The use of first component analysis of binding energies for multiple sites is a novel approach for hit selection. The very high prediction power for this approach increases confidence in the outcome from the fluorescent library screening. Ten of the top scoring candidates for isoform-selective putative binding sites are suggested for future testing as fluorescent molecular probe candidates.

  6. Topiramate Protects Pericytes from Glucotoxicity: Role for Mitochondrial CA VA in Cerebromicrovascular Disease in Diabetes.

    Science.gov (United States)

    Patrick, Ping; Price, Tulin O; Diogo, Ana L; Sheibani, Nader; Banks, William A; Shah, Gul N

    Hyperglycemia in diabetes mellitus causes oxidative stress and pericyte depletion from the microvasculature of the brain thus leading to the Blood-Brain Barrier (BBB) disruption. The compromised BBB exposes the brain to circulating substances, resulting in neurotoxicity and neuronal cell death. The decline in pericyte numbers in diabetic mouse brain and pericyte apoptosis in high glucose cultures are caused by excess superoxide produced during enhanced respiration (mitochondrial oxidative metabolism of glucose). Superoxide is precursor to all Reactive Oxygen Species (ROS) which, in turn, cause oxidative stress. The rate of respiration and thus the ROS production is regulated by mitochondrial carbonic anhydrases (mCA) VA and VB, the two isoforms expressed in the mitochondria. Inhibition of both mCA: decreases the oxidative stress and restores the pericyte numbers in diabetic brain; and reduces high glucose-induced respiration, ROS, oxidative stress, and apoptosis in cultured brain pericytes. However, the individual role of the two isoforms has not been established. To investigate the contribution of mCA VA in ROS production and apoptosis, a mCA VA overexpressing brain pericyte cell line was engineered. These cells were exposed to high glucose and analyzed for the changes in ROS and apoptosis. Overexpression of mCA VA significantly increased pericyte ROS and apoptosis. Inhibition of mCA VA with topiramate prevented increases both in glucose-induced ROS and pericyte death. These results demonstrate, for the first time, that mCA VA regulates the rate of pericyte respiration. These findings identify mCA VA as a novel and specific therapeutic target to protect the cerebromicrovascular bed in diabetes.

  7. Synthesis of 4-(2-substituted hydrazinyl)benzenesulfonamides and their carbonic anhydrase inhibitory effects.

    Science.gov (United States)

    Gul, Halise Inci; Kucukoglu, Kaan; Yamali, Cem; Bilginer, Sinan; Yuca, Hafize; Ozturk, Iknur; Taslimi, Parham; Gulcin, Ilhami; Supuran, Claudiu T

    2016-08-01

    In this study, 4-(2-substituted hydrazinyl)benzenesulfonamides were synthesized by microwave irradiation and their chemical structures were confirmed by (1)H NMR, (13)CNMR, and HRMS. Ketones used were: Acetophenone (S1), 4-methylacetophenone (S2), 4-chloroacetophenone (S3), 4-fluoroacetophenone (S4), 4-bromoacetophenone (S5), 4-methoxyacetophenone (S6), 4-nitroacetophenone (S7), 2-acetylthiophene (S8), 2-acetylfuran (S9), 1-indanone (S10), 2-indanone (S11). The compounds S9, S10 and S11 were reported for the first time, while S1-S8 was synthesized by different method than literature reported using microwave irradiation method instead of conventional heating in this study. The inhibitory effects of 4-(2-substituted hydrazinyl)benzenesulfonamide derivatives (S1-S11) against hCA I and II were studied. Cytosolic hCA I and II isoenzymes were potently inhibited by new synthesized sulphonamide derivatives with Kis in the range of 1.79 ± 0.22-2.73 ± 0.08 nM against hCA I and in the range of 1.72 ± 0.58-11.64 ± 5.21 nM against hCA II, respectively.

  8. XV ESLAB Symposium

    CERN Document Server

    1981-01-01

    The 15th ESLAB symposium was held at the end of June 1981 in Amsterdam with the topic being X-ray astronomy. The aim of this symposium was to bring together the international astrophysical community in order to 1. review the present state of X-ray astronomy in the light of new observations gathered in recent missions and to review data on interesting objects in correlated wavelen8th regions; 2. discuss theoretical models describing the phenomena observed; 3. present ESA's European X-ray Observatory Satellite (EXOSAT) and to discuss future X-ray missions and their associated instrumenta­ tion. These topics seemed to be so interesting for the scientific community that more than 120 contributions were submitted. Of these, 94 were finally accepted and approximately 200 participants attended the 5-day meeting. The symposium was organised in nine sessions covering the whole field. Every main topic was introduced by a review lecture covering the state­ of-the-art. The aim of the meeting was to assess the impact of...

  9. Xv conferencia : tuberculosis

    OpenAIRE

    Varón Rico, José A.; Cobos, Luis Francisco

    2012-01-01

    La tuberculosis se puede evitar en el niño en varias formas: en primer lugar se puede hacer una profilaxis que se llama de disposición, o sea, como la consideran los autores alemanes, mediante las prácticas de una puericultura bien realizada, ojalá en todas las clases sociales, su nutrición, sus hábitos higiénicos y dietéticos correctos, se va levantando por medio de ello resistencia no sólo a la tuberculosis sino a todas las enfermedades.

  10. Introduction: Invertebrate Neuropeptides XV

    Science.gov (United States)

    This publication represents an introduction to the fifteenth in a series of special issues of the Peptides journal dedicated to invertebrate neuropeptides. The issue addresses a number of aspects of invertebrate neuropeptide research including identification of novel invertebrate neuropeptide seque...

  11. The L-arginine/NO pathway, homoarginine, and nitrite-dependent renal carbonic anhydrase activity in young people with type 1 diabetes mellitus.

    Science.gov (United States)

    Carmann, Christina; Lilienthal, Eggert; Weigt-Usinger, Katharina; Schmidt-Choudhury, Anjona; Hörster, Irina; Kayacelebi, Arslan Arinc; Beckmann, Bibiana; Chobanyan-Jürgens, Kristine; Tsikas, Dimitrios; Lücke, Thomas

    2015-09-01

    High circulating levels of asymmetric dimethylarginine (ADMA) and low circulating levels of homoarginine (hArg) are known cardiovascular risk factors in adults. While in adults with type 1 diabetes mellitus (T1DM) circulating ADMA is significantly elevated, in children and adolescents the reported ADMA data are contradictory. In 102 children with T1DM and 95 healthy controls (HC) serving as controls, we investigated the L-arginine (Arg)/nitric oxide (NO) pathway. Children with T1DM were divided into two groups, i.e., in children with newly diagnosed diabetes mellitus [T1DM-ND; n = 10; age, 8.8 (4.4-11.2) years; HbA1c, 13 (8.9-13.9) %] and in those with long-term treatment [T1DM-T; n = 92; age, 12.5 (10.5-15.4) years; HbA1c, 8.0 (7.2-8.6) %]. The age of the HC was 11.3 (8-13.3) years. Amino acids and NO metabolites of the Arg/NO pathway, creatinine and the oxidative stress biomarker malondialdehyde (MDA) were measured by GC-MS or GC-MS/MS. Plasma hArg, ADMA and the hArg/ADMA molar ratio did not differ between the T1DM and HC groups. There was a significant difference between T1DM-T and HC with regard to plasma nitrite [0.53 (0.48-0.61) vs 2.05 (0.86-2.36) µM, P 86-2.36) µM, P < 0.0001]. Plasma MDA did not differ between the groups. The urinary nitrate-to-nitrite molar ratio (UNOXR), a measure of nitrite-dependent renal carbonic anhydrase (CA) activity, was higher in T1DM-T [1173 (738-1481), P < 0.0001] and T1DM-ND [1341 (1117-1615), P = 0.0007] compared to HC [540 (324-962)], but did not differ between T1DM-T and T1DM-ND (P = 0.272). The lower nitrite excretion in the children with T1DM may indicate enhanced renal CA-dependent nitrite reabsorption compared with healthy children. Yet, lower plasma nitrite concentration in the T1DM patients may have also contributed to the higher UNOXR. Patients' age correlated positively with plasma hArg and hArg/ADMA and urinary DMA/ADMA. Plasma ADMA and urinary ADMA, DMA, nitrite and nitrate correlated negatively with age of the

  12. The changes in the chloroplast membranes of pea leaves under the influence of carbonic anhydrase inhibitors (ions of copper and zinc

    Directory of Open Access Journals (Sweden)

    M.V. Vodka

    2014-04-01

    Full Text Available Тhe effects of carbonic anhydrase inhibitors, such as ions Cu2+ and Zn2+, on the membrane system of chloroplasts in pea leaves were investigated. After treatment of pea leaves with 250 mM Cu2+ or 400 mM Zn2+ we observed changes in the granal structure and compactness of the thylakoids in granae. It was shown that the thickness of granal thylakoids and the interspace between thylakoids increased comparing to control. Changes of the size and structure of thylakoids and granae in treated leaves may be associated with the enhanced accumulation of CO2 in the membrane. It is suggested that the carbonic anhydrase may also play a structural role in chloroplast granae.

  13. Hepatoprotective effects of Poly-[hemoglobin-superoxide dismutase-catalase-carbonic anhydrase] on alcohol-damaged primary rat hepatocyte culture in vitro.

    Science.gov (United States)

    Jiang, Wenhua; Bian, Yuzhu; Wang, Zhenghui; Chang, Thomas Ming Swi

    2017-02-01

    We have prepared a novel nanobiotherapeutic, Poly-[hemoglobin-superoxide dismutase-catalase-carbonic anhydrase], which not only transports both oxygen and carbon dioxide but also a therapeutic antioxidant. Our previous study in a severe sustained 90 min hemorrhagic shock rat model shows that it has a hepatoprotective effect. We investigate its hepatoprotective effect further in this present report using an alcohol-damaged primary hepatocyte culture model. Results show that it significantly reduced ethanol-induced AST release, lipid peroxidation, and ROS production in rat primary hepatocytes culture. It also significantly enhanced the viability of ethanol-treated hepatocytes. Thus, the result shows that Poly-[hemoglobin-superoxide dismutase-catalase-carbonic anhydrase] also has some hepatoprotective effects against alcohol-induced injury in in vitro rat primary hepatocytes cell culture. This collaborate our previous observation of its hepatoprotective effect in a severe sustained 90-min hemorrhagic shock rat model.

  14. Las capillas y capellanías reales castellano-leonesas en la Baja Edad Media (siglos XIII-XV: algunas precisiones institucionales

    Directory of Open Access Journals (Sweden)

    Nogales Rincón, David

    2005-12-01

    Full Text Available The study of royal chapels and royal chaplaincies is focus on the analysis of the relationships between de Palace Chapel and the cathedral/monastic royal chapels from a institucional, ideologic and functional criterions, on making a systematization of them and on presenting some general notes about their characteristics, ideal patterns and development in the late Middle Ages in Castille (13th-15th centuries.

    El estudio de las capillas y capellanías reales se centra en el análisis de las relaciones entre la Capilla Palacio y las capillas reales catedralicias/monásticas desde un punto de vista institucional, ideológico y funcional, en llevar a cabo una sistematización de éstas y ofrecer algunas notas generales sobre sus características, modelos ideales y evolución en la Castilla bajomedieval (siglos XIII-XV.

  15. Uso y transformación en espacio agrario del monte y del estrato arbóreo en la Ribeira Sacra durante los siglos XIV y XV.

    Directory of Open Access Journals (Sweden)

    López Sabatel, José Antonio

    2009-12-01

    Full Text Available This article wants to show the importance that the mountain played in a rural economy orientated as much to the utilization of its natural resources as to its transformation in agrarian space. As in case of the mountain, the exploitation of the wooded stratum, will allow an approximation to the agrarian landscape of the Ribeira Sacra during the XIVth and XVth centuries.

    Este artículo quiere mostrar la importancia que desempeñó el monte en una economía campesina orientada tanto al aprovechamiento de sus recursos naturales como a su transformación en espacio agrario. Al igual que en el caso del monte, la explotación del estrato arbóreo, permitirá un acercamiento al paisaje agrario de la Ribeira Sacra durante los siglos XIV y XV.

  16. Pratos e bacias de latão dos séculos XV-XVI de temática relogiosa da Casa Museu Guerra Junqueiro

    OpenAIRE

    Martins, Joana Preciosa Branco

    2010-01-01

    Este trabalho traduz-se no estudo da colecção dos pratos e bacias de latão dos séculos XV-XVI de temática religiosa da Casa Museu Guerra Junqueiro. Os pratos e bacias de latão tiveram diversas funções, de carácter religioso, como pratos de oferta, destinados ao baptismo ou à extrema-unção; e, civil, como peças ornamentais, das casas da burguesia ou dos castelos da aristocracia. Relativamente à sua origem, são mencionados numerosos locais, nomeadamente, Dinant, Nuremberga, Espanha, Itália, ent...

  17. Coscienze e città: la predicazione a Firenze tra la fine del XIII e gli inizi del XV. Considerazioni introduttive

    Directory of Open Access Journals (Sweden)

    Isabella Gagliardi

    2014-04-01

    Full Text Available Il contributo s’incentra sulla predicazione dei Frati Minori, dei Frati Predicatori e degli Eremitani di Sant’Agostino a Firenze nel periodo compreso tra gli anni Trenta del XIII secolo e gli inizi del XV secolo, in altre parole dalla lotta al catarismo fino all’affermazione delle Osservanze. In particolare nella predicazione mendicante si ricercano le tracce della visione politica dei frati che si sono avvicendati sui vari pulpiti urbani, cercando di rilevare se esista una peculiarità delle Regole e quali siano le analogie e le differenze tra le prediche di ambiente minoritico, domenicano e agostiniano a riguardo. Si rileva, quindi, una sorta di ‘eccellenza’ politica dei Frati Predicatori che dettero prova di nutrire una ben precisa consapevolezza relativa alla costruzione di una società migliore che muoveva dalla centralità del concetto e della pratica dell’equitas.

  18. Reforma religiosa, sociedad y política en la Baja Edad Media: el ejemplo de San Francisco de Palencia en el siglo XV

    Directory of Open Access Journals (Sweden)

    Rojo Alique, Francisco Javier

    2007-12-01

    Full Text Available This article focuses upon the issue of the reform of the Franciscan friary at Palencia, Spain, in the 15th century. It can provide a good example of the relationship between religious reforms and society in Medieval and Early Modern times. It also shows the role that political powers played in those reforms.El presente artículo describe cómo se produjo la implantación de la observancia en el convento de San Francisco de Palencia en el siglo XV. Se trata de un caso en el que se aprecia con bastante claridad la dimensión social que tuvieron las reformas religiosas bajomedievales, así como el papel que desempeñaron en las mismas los poderes políticos.

  19. Glass beads as identity element of the African in the cultural past of Lisbon from the mid XV century until the 1755 earthquake

    Directory of Open Access Journals (Sweden)

    M. Conceição RODRIGUES

    2009-12-01

    Full Text Available ABSTRACT: This paper is centred in the study of long glass beads, which can be considered as an identity element of some African communities. They were brought to Lisbon by slaves through the commercial routes developed between Portugal and the South Western African Coast, since the middle of the XV century. The studied specimens came from the archaeological interventions carried out in the Lisbon downtown, of the period prior to the 1755 earthquake, in the end of the 1990’s. Among them are some “Nueva Cadiz” beads, as well as “Chevron” beads and the former deserved special mention, since they are a Mediterranean manufacture. The author did similar studies of other beads, which were used as comparative elements in this paper. These beads mirror some of the events and socio-cultural aspects of the life of Africans in Lisbon since the XV century until the 1755 earthquake. Beads were used as a distinguishing element and a social valorisation. Through technical-morphological and mineralogical studies a connection between them and historical data is attempted.RESUMO: Este nosso trabalho centra-se no estudo de contas longas de vidro que consideramos ser um elemento identitário de algumas das comunidades africanas que foram trazidas como escravos, através das rotas comerciais desenvolvidas entre Portugal e a costa Ocidental da África Austral, desde meados do século XV. Os exemplares aqui em estudo são um dos elementos materiais fornecidos como resultado das intervenções arqueológicas na Lisboa anterior a 1755, e que tiveram lugar nos finais da década de 90 do século XX. Vamos procurar efectuar o estudo de um núcleo de contas de vidro, entre as quais se encontram as de cor azul tipo “Nueva Cadiz” e as contas “Chevron ou em Estrela” que apresentam várias tonalidades. As primeiras mereceram uma atenção particular por se enquadrarem num tipo de contas de fabrico mediterrânico, cujo estudo vimos desenvolvendo desde os in

  20. A conquista do paraíso inexistente: os transtornos da imaginação nos relatos de viagem dos séculos XV e XVI

    OpenAIRE

    Coelho, Rogério Mendes

    2007-01-01

    O presente trabalho propõe estudar as configurações discursivas que descreveram as realidades americanas durante o período colonial dos séculos XV e XVI. Partindo de textos produzidos por alguns navegantes do século XVI como Cristóbal Colón, Américo Vespúcio e Pero Magalhães Gândavo, o que se realizou como pesquisa foi a problematização dos textos escritos não tão-somente como discursos de fundação do espaço americano, onde nuances como história e ficção; imitação e desvio se confundem, estab...

  1. Economic analysis of Xv-Ting Case'legal Responsibility Attributing%许霆案归责的法经济学分析

    Institute of Scientific and Technical Information of China (English)

    翁孙哲

    2011-01-01

    The attribution of legal responsibility complies with the four cardinal principles,which are the principle of statutory responsibility、principle of responsibility commensurate、principle of bearing responsibility solely for one's own crime、principle of causality,these basic principles are unification of the organic.These principles could be used economics principles such as individualism、costs of transactions、public choose、externalities to analyze.Through the using of these theoretical tools,this article think the judicial decision of Xv-Ting Case,does not conform with the four principles,Therefore from the perspective of economic analysis,the judicial decision of Xv-Ting Case is no efficient.%法律责任的归责要遵循四个基本的原则,分别是责任法定原则、责任相称原则、责任自负原则、因果关系原则,这些基本原则是有机统一的。这些原则可以运用个人主义、交易成本、公共选择、外部性等经济学原理进行分析。通过这些理论工具的运用,本文认为,许霆案的司法判决违反这四个原则,因此从经济分析的角度来看,许霆案的判决是无效率的。

  2. Fluoroalkyl and Alkyl Chains Have Similar Hydrophobicities in Binding to the “Hydrophobic Wall” of Carbonic Anhydrase

    Energy Technology Data Exchange (ETDEWEB)

    J Mecinovic; P Snyder; K Mirica; S Bai; E Mack; R Kwant; D Moustakas; A Heroux; G Whitesides

    2011-12-31

    The hydrophobic effect, the free-energetically favorable association of nonpolar solutes in water, makes a dominant contribution to binding of many systems of ligands and proteins. The objective of this study was to examine the hydrophobic effect in biomolecular recognition using two chemically different but structurally similar hydrophobic groups, aliphatic hydrocarbons and aliphatic fluorocarbons, and to determine whether the hydrophobicity of the two groups could be distinguished by thermodynamic and biostructural analysis. This paper uses isothermal titration calorimetry (ITC) to examine the thermodynamics of binding of benzenesulfonamides substituted in the para position with alkyl and fluoroalkyl chains (H{sub 2}NSO{sub 2}C{sub 6}H{sub 4}-CONHCH{sub 2}(CX{sub 2}){sub n}CX{sub 3}, n = 0-4, X = H, F) to human carbonic anhydrase II (HCA II). Both alkyl and fluoroalkyl substituents contribute favorably to the enthalpy and the entropy of binding; these contributions increase as the length of chain of the hydrophobic substituent increases. Crystallography of the protein-ligand complexes indicates that the benzenesulfonamide groups of all ligands examined bind with similar geometry, that the tail groups associate with the hydrophobic wall of HCA II (which is made up of the side chains of residues Phe131, Val135, Pro202, and Leu204), and that the structure of the protein is indistinguishable for all but one of the complexes (the longest member of the fluoroalkyl series). Analysis of the thermodynamics of binding as a function of structure is compatible with the hypothesis that hydrophobic binding of both alkyl and fluoroalkyl chains to hydrophobic surface of carbonic anhydrase is due primarily to the release of nonoptimally hydrogen-bonded water molecules that hydrate the binding cavity (including the hydrophobic wall) of HCA II and to the release of water molecules that surround the hydrophobic chain of the ligands. This study defines the balance of enthalpic and

  3. Over-expression of the β-carboxysomal CcmM protein in Synechococcus PCC7942 reveals a tight co-regulation of carboxysomal carbonic anhydrase (CcaA) and M58 content.

    Science.gov (United States)

    Long, Benedict M; Rae, Benjamin D; Badger, Murray R; Price, G Dean

    2011-09-01

    Carboxysomes, containing the cell's complement of RuBisCO surrounded by a specialized protein shell, are a central component of the cyanobacterial CO(2)-concentrating mechanism. The ratio of two forms of the β-carboxysomal protein CcmM (M58 and M35) may affect the carboxysomal carbonic anhydrase (CcaA) content. We have over-expressed both M35 and M58 in the β-cyanobacterium Synechococcus PCC7942. Over-expression of M58 resulted in a marked increase in the amount of this protein in carboxysomes at the expense of M35, with a concomitant increase in the observed CcaA content of carboxysomes. Conversely, M35 over-expression diminished M58 content of carboxysomes and led to a decrease in CcaA content. Carboxysomes of air-grown wild-type cells contained slightly elevated CcaA and M58 content and slightly lower M35 content compared to their 2% CO(2)-grown counterparts. Over a range of CcmM expression levels, there was a strong correlation between M58 and CcaA content, indicating a constant carboxysomal M58:CcaA stoichiometry. These results also confirm a role for M58 in the recruitment of CcaA into the carboxysome and suggest a tight regulation of M35 and M58 translation is required to produce carboxysomes with an appropriate CA content. Analysis of carboxysomal protein ratios, resulting from the afore-mentioned over-expression studies, revealed that β-carboxysomal protein stoichiometries are relatively flexible. Determination of absolute protein quantities supports the hypothesis that M35 is distributed throughout the β-carboxysome. A modified β-carboxysome packing model is presented.

  4. The Ca(2+)/Calmodulin/CaMKK2 Axis: Nature's Metabolic CaMshaft.

    Science.gov (United States)

    Marcelo, Kathrina L; Means, Anthony R; York, Brian

    2016-10-01

    Calcium (Ca(2+)) is an essential ligand that binds its primary intracellular receptor calmodulin (CaM) to trigger a variety of downstream processes and pathways. Central to the actions of Ca(2+)/CaM is the activation of a highly conserved Ca(2+)/CaM kinase (CaMK) cascade that amplifies Ca(2+) signals through a series of subsequent phosphorylation events. Proper regulation of Ca(2+) flux is necessary for whole-body metabolism and disruption of Ca(2+) homeostasis has been linked to various metabolic diseases. Here we provide a synthesis of recent advances that highlight the roles of the Ca(2+)/CaMK axis in key metabolic tissues. An appreciation of this information is critical to understanding the mechanisms by which Ca(2+)/CaM-dependent signaling contributes to metabolic homeostasis and disease.

  5. 1. alpha. ,25-dihydroxyvitamin D sub 3 regulates the expression of carbonic anhydrase II in nonerythroid avian bone marrow cells

    Energy Technology Data Exchange (ETDEWEB)

    Billecocq, A.; Emanuel, J.R.; Levenson, R.; Baron, R. (Yale Univ. School of Medicine, New Haven, CT (USA))

    1990-08-01

    1{alpha},25-Dihydroxyvitamin D{sub 3} (1,25(OH){sub 2}D{sub 3}), the active metabolite of the steroid hormone vitamin D, is a potent regulator of macrophage and osteoclast differentiation. The mature osteoclast, unlike the circulating monocyte or the tissue macrophage, expresses high levels of carbonic anhydrase II (CAII). This enzyme generates protons and bicarbonate from water and carbon dioxide and is involved in bone resorption and acid-base regulation. To test whether 1,25(OH){sub 2}D{sub 3} could induce the differentiation of myelomonocytic precursors toward osteoclasts rather than macrophages, analyzed its effects on the expression of CAII in bone marrow cultures containing precursors common to both cell types. The expression of CAII was markedly increased by 1,25(OH){sub 2}D{sub 3} in a dose-and time-dependent manner. In bone marrow, this increase occurred at the mRNA and protein levels and was detectable as early as 24 hr after stimulation. 1,25(OH){sub 2}D{sub 3} was also found to induce CAII expression in a transformed myelomonocytic avian cell line. These results suggest that 1,25(OH){sub 2}D{sub 3} regulates the level at which myelomonocytic precursors express CAII, an enzyme that is involved in the function of the mature osteoclast.

  6. Degradation of carbonyl sulfide by Actinomycetes and detection of clade D of β-class carbonic anhydrase.

    Science.gov (United States)

    Ogawa, Takahiro; Kato, Hiromi; Higashide, Mitsuru; Nishimiya, Mami; Katayama, Yoko

    2016-09-25

    Carbonyl sulfide (COS) is an atmospheric trace gas and one of the sources of stratospheric aerosol contributing to climate change. Although one of the major sinks of COS is soil, the distribution of COS degradation ability among bacteria remains unclear. Seventeen out of 20 named bacteria belonging to Actinomycetales had COS degradation activity at mole fractions of 30 parts per million by volume (ppmv) COS. Dietzia maris NBRC 15801(T) and Mycobacterium sp. THI405 had the activity comparable to a chemolithoautotroph Thiobacillus thioparus THI115 that degrade COS by COS hydrolase for energy production. Among 12 bacteria manifesting rapid degradation at 30 ppmv COS, Dietzia maris NBRC 15801(T) and Streptomyces ambofaciens NBRC 12836(T) degraded ambient COS (∼500 parts per trillion by volume). Geodermatophilus obscurus NBRC 13315(T) and Amycolatopsis orientalis NBRC 12806(T) increased COS concentrations. Moreover, six of eight COS degrading bacteria isolated from soils had partial nucleotide sequences similar to that of the gene encoding clade D of β-class carbonic anhydrase, which included COS hydrolase. These results indicate the potential importance of Actinomycetes in the role of soils as sinks of atmospheric COS.

  7. A valorização total do espaço: capitalismo e geografia em Civilisation Matérielle, Économie et capitalisme - XV-XVIII

    Directory of Open Access Journals (Sweden)

    Guilherme Ribeiro

    2011-06-01

    Full Text Available O objetivo deste artigo é analisar a relação entre espaço e economia em Civilisation Matérielle, Économie et Capitalisme - XV-XVIII (1979 do historiador francês Fernand Braudel (1902-1985. A partir do conceito de economia-mundo, podemos observar o papel crucial do espaço em sua original interpretação sobre o desenvolvimento do capitalismo.

  8. La explotación económica del Campo Arañuelo y la economía rural de la Tierra de Plasencia a mediados del siglo XV

    Directory of Open Access Journals (Sweden)

    Clemente Ramos, Julián

    2009-06-01

    Full Text Available The ‘Campo Arañuelo’, district of the Plasencia's land, until final of the century XV bill with a scarce population and abundant grasses. Neighbors of La Vera, the area Almonte-Tajo or of other districts of the term they move with their livestocks or they establish a second vicinity in her. The concession of Plasencia to Pedro of Stúñiga in 1442, the existence of numerous seignorials estates in the term of Plasencia and a joint of demographic and agrarian growth will originate very important disputes on its use and exploitation by the middle of the XV century. This conflict will allow to have very important information on the trade of the cereal, the cattle cabins or the seasonal displacements in the term of Plasencia.

    El Campo Arañuelo, comarca de la tierra de Plasencia, contaba hasta finales del siglo XV con una escasa población y abundantes pastos. Vecinos de La Vera, la zona Almonte-Tajo o de otras comarcas del término se desplazan con sus ganados o establecen una segunda vecindad en ella. La concesión de Plasencia a Pedro de Estúñiga en 1442, la existencia de numerosos señoríos en el término placentino y una coyuntura de crecimiento demográfico y agrario van a originar disputas muy importantes sobre su aprovechamiento y explotación a mediados del siglo XV. Esta conflictividad nos permitirá disponer de información muy importante sobre el comercio del cereal, las cabañas ganaderas o los desplazamientos estacionales en el término de Plasencia.

  9. Análise epidemiológica de lesões no futebol de salão durante o XV Campeonato Brasileiro de Seleções Sub 20 Análisis epidemiológico de las lesiones en el fútbol de salón durante el XV Campeonato Brasileño de Selecciones Sub 20 Epidemiologic analysis of injuries occurred during the 15th Brazilian Indoor Soccer (Futsal) Sub20 Team Selection Championship

    OpenAIRE

    Rodrigo Nogueira Ribeiro; Leonardo Oliveira Pena Costa

    2006-01-01

    INTRODUÇÃO: Vários autores têm investigado a incidência de lesões no futebol. Entretanto, poucos trabalhos têm analisado as lesões no Futebol de Salão. O objetivo deste estudo foi analisar a incidência, circunstâncias e características das lesões registradas no Futebol de Salão durante o XV Campeonato Brasileiro de Futebol de Salão Sub 20. MÉTODOS: Fisioterapeutas ou médicos de todas as seleções participantes do XV Campeonato Brasileiro de Futebol de Salão Sub 20 responderam a um questionário...

  10. Temperature stability of Poly-[hemoglobin-superoxide dismutase-catalase-carbonic anhydrase] in the form of a solution or in the lyophilized form during storage at -80 °C, 4 °C, 25 °C and 37 °C or pasteurization at 70 °C.

    Science.gov (United States)

    Bian, Y Z; Guo, C; Chang, T M S

    2016-01-01

    Polyhemoglobin-superoxide dismutase-catalase-carbonic anhydrase (Poly-[Hb-SOD-CAT-CA]) contains all three major functions of red blood cells (RBCs) at an enhanced level. It transports oxygen, removes oxygen radicals and transports carbon dioxide. Our previous studies in a 90-min 30 mm Hg Mean Arterial Pressure (MAP) sustained hemorrhagic shock rat model shows that it is more effective than blood in the lowering of elevated intracellular pCO2, recovery of ST-elevation and histology of the heart and intestine. This paper is to analyze the storage and temperature stability. Allowable storage time for RBC is about 1 d at room temperature and 42 d at 4 °C. Also, RBC cannot be pasteurized to remove infective agents like HIV and Ebola. PolyHb can be heat sterilized and can be stored for 1 year even at room temperature. However, Poly-[Hb-SOD-CAT-CA] contains both Hb and enzymes and enzymes are particularly sensitive to storage and heat. We thus carried out studies to analyze its storage stability at different temperatures and heat pasteurization stability. Results of storage stability show that lyophilization extends the storage time to 1 year at 4 °C and 40 d at room temperature (compared to respectively, 42 d and 1 d for RBC). After the freeze-dry process, the enzyme activities of Poly-[SFHb-SOD-CAT-CA] was 100 ± 2% for CA, 100 ± 2% for SOD and 93 ± 3.5% for CAT. After heat pasteurization at 70 °C for 2 h, lyophilized Poly-[Hb-SOD-CAT-CA] retained good enzyme activities of CA 97 ± 4%, SOD 100 ± 2.5% and CAT 63.8 ± 4%. More CAT can be added during the crosslinking process to maintain the same enzyme ratio after heat pasteurization. Heat pasteurization is possible only for the lyophilized form of Poly-[Hb-SOD-CAT-CA] and not for the solution. It can be easily reconstituted by dissolving in suitable solutions that continues to have good storage stability though less than that for the lyophilized form. According to the P50 value, Poly-[SFHb-SOD-CAT-CA] retains its

  11. 呋塞米对碳酸酐酶的抑制效应再研究%Inhibitory effect of furosemide on carbonic anhydrase

    Institute of Scientific and Technical Information of China (English)

    袁美华; 蒋彦; 杨毅

    2013-01-01

    The inhibitory effect of a high efficient diuretic ,furosemide ,on carbonic anhydrase was investigated in this study .Compared with acetazolamide ,furosemide can quickly make BCAⅡ inactive when its concentration is close to the enzyme concentration . The results show that furosemide is a non-competitive inhibitor of carbonic anhydrase ,the vaules of its IC50 and KI are 0 .759 μM ,0 .51 μM . Acetazolamide is a competitive inhibitor of carbonic anhydrase ,the vaules of its IC5 0 and KI are 0.199μM ,0 .099 μM .%呋塞米是一种高效利尿剂,本实验主要探究其对碳酸酐酶的抑制效应.相比较乙酰唑胺而言,呋塞米在其浓度接近碳酸酐酶浓度时能使该酶基本失活.研究发现,呋塞米对碳酸酐酶的抑制效应表现为非竞争性抑制,其 IC50为0.759μM ,KI 为0.61μM ,乙酰唑胺的 IC50为0.199μM , KI 为0.099μM ,表现为竞争性抑制.

  12. El linaje de Cristo a la luz del “giro genealógico” del siglo XV. La respuesta de Juana de la Cruz (1481-1534

    Directory of Open Access Journals (Sweden)

    Muñoz Fernández, Ángela

    2014-06-01

    Full Text Available This research revolves around the sermon on Saint Anne in El Conhorte by Juana de la Cruz, focusing on imagery in the text about life and generation that supports the importance of maternal genealogies. Using this evidence as point of departure, this sermon is used as an example of shifting currents of opinion in female convents related to the Querelle des Femmes, currents of opinion that interacted with the main social and cultural debates of the period. These debates were closely related to the socalled “genealogical turn” which Iberian societies underwent in the 15th century.Este trabajo se articula en torno al sermón de Santa Ana de El Conhorte de Juana de la Cruz. Su temática incide en imágenes de vida y generación y defiende el peso de las genealogías maternas. A partir de esta evidencia, se plantea su estudio como exponente del desarrollo en el mundo de los conventos femeninos de corrientes de opinión relacionadas con la Querella de las Mujeres que interactuaron con los principales focos del debate social y cultural de su época, debates que guardaron relación con el llamado “giro genealógico” que experimentaron las sociedades ibéricas en el siglo XV.

  13. Catalina de Bedia: una fembra ante la justicia criminal. El individuo y su colectividad en una villa cantábrica a fines del siglo XV (Bilbao

    Directory of Open Access Journals (Sweden)

    Eduardo Muñoz Saavedra

    2016-08-01

    Full Text Available Este artículo tiene como objetivo analizar, desde diversas perspectivas, la presencia de una mujer en la documentación criminal regia castellana a fines del siglo XV. Así se atiende y reflexiona en torno a diversos elementos que explican la relación entre Catalina de Bedia, una mujer de la villa de Bilbao identificada como criminal, y los diversos espacios y niveles de socialización en el cual ella se inserta. De este modo, en primer lugar, se analizan las fuerzas históricas que confluyen para la existencia de la documentación criminal real; por otra parte, se reconstruye el accionar criminal de Catalina, considerando su movimiento, el sentido del espacio, la asociación delictiva y el accionar de los tribunales. Todo ello con el fin de acercarnos, no sólo al ámbito del crimen femenino, sino a la cotidianidad de la vida villana y sus dinámicas, estructuras y puntos de inflexión local y global.

  14. La formación de compañías para el tintado de paños. El caso de Cocentaina en el siglo XV

    Directory of Open Access Journals (Sweden)

    Llibrer Escrig, J. Antoni

    2011-06-01

    Full Text Available This article studies the woollen industry in Cocentaina, one of the most important textile center of kingdom of Valencia during the XVth century. The creation of companies for dyeing cloth was one of the most prominent aspects of this industry in Cocentaina. These companies were formed not only by dyers but also by artisans and cloth merchants who wanted to control the process of regional production and trade of wool fabrics.

    El presente trabajo pretende destacar la importancia del tintado de paños en uno de las más activos centros textiles del antiguo reino de Valencia, Cocentaina. Su amplio desarrollo artesanal durante el siglo XV se manifiesta a través de la formación de compañías para el tintado de paños. Compañías que eran suscritas no sólo por tintoreros sino también por pelaires y drapers que con ello querían garantizarse una posición de privilegio en el ámbito de la producción y el comercio regional de paños.

  15. Gene Cloning and Characterization of the Geobacillus thermoleovorans CCR11 Carboxylesterase CaesCCR11, a New Member of Family XV.

    Science.gov (United States)

    Espinosa-Luna, Graciela; Sánchez-Otero, María Guadalupe; Quintana-Castro, Rodolfo; Matus-Toledo, Rodrigo Eloir; Oliart-Ros, Rosa María

    2016-01-01

    A gene encoding a carboxylesterase produced by Geobacillus thermoleovoras CCR11 was cloned in the pET-3b cloning vector, sequenced and expressed in Escherichia coli BL21(DE3). Gene sequence analysis revealed an open reading frame of 750 bp that encodes a polypeptide of 250 amino acid residues (27.3 kDa) named CaesCCR11. The enzyme showed its maximum activity at 50 °C and pH 5-8, with preference for C4 substrates, confirming its esterase nature. It displayed good resistance to temperature, pH, and the presence of organic solvents and detergents, that makes this enzyme biotechnologically applicable in the industries such as fine and oleo-chemicals, cosmetics, pharmaceuticals, organic synthesis, biodiesel production, detergents, and food industries. A 3D model of CaesCCR11 was predicted using the Bacillus sp. monoacyl glycerol lipase bMGL H-257 structure as template (PBD code 3RM3, 99 % residue identity with CaesCCR11). Based on its canonical α/β hydrolase fold composed of 7 β-strands and 6 α-helices, the α/β architecture of the cap domain, the GLSTG pentapeptide, and the formation of distinctive salt bridges, we are proposing CaesCCR11 as a new member of family XV of lipolytic enzymes.

  16. Novel cathode materials LixNa2-xV2O6 (x = 2, 1.4, 1, 0) for high-performance lithium-ion batteries

    Science.gov (United States)

    Li, Kaiqi; Cao, Liufei; Huang, Zheng; Chen, Liang; Chen, Zhongxue; Fu, Chaopeng

    2017-03-01

    In this work, sodium doped LiVO3 cathode is proposed to achieve enhanced cycling performance for lithium ion battery (LIB) application. LixNa2-xV2O6 (x = 2, 1.4, 1, 0) compounds have been prepared and characterized, and X-ray diffraction patterns confirmed the successful Na doping with various amounts in the LiVO3. The electrochemical performances of the various Na doped compounds LiVO3, Li1.4Na0.6V2O6, LiNaV2O6, and NaVO3 are evaluated by cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectroscopy. The results reveal that Na-doping amount strongly affects the electrochemical performance, and LiNaV2O6 (x = 1) is considered as the optimized Na doped compound for LIB cathodes. The LiNaV2O6 cathode displays enhanced cycling and rate performances as a specific capacity of 193 mAh g-1 at 0.5 C after 100 cycles is delivered. The enhanced performance is explained that the doping of Na can provide good channels and increase Li+ diffusion coefficient for lithium ion intercalation/deintercalation.

  17. El ejercicio físico en el siglo xv a través de la crónica del condestable Iranzo

    Directory of Open Access Journals (Sweden)

    Gonzalo Ramírez Macías

    2016-04-01

    Full Text Available Durante mucho tiempo se ha comentado, que la Edad Media era ese periodo oscuro en el que las actividades físicas que no fueran exclusivamente de índole militar no tenían cabida, por el desprecio hacia todo aquello que no fuera formación del cuerpo para ponerlo a disposición de los ideales caballerescos y religiosos. Sin embargo, en nuestro estudio investigamos una crónica del siglo xv, Relación de los hechos del muy magnífico e más virtuoso señor, el señor don Miguel Lucas, muy digno condestable de Castilla, en la que se refieren, de manera detallada, fiestas y celebraciones de carácter no solamente cortesano sino también popular; de ahí su importancia y relevancia histórica, ya que la mayoría de textos de la época se circunscriben al ámbito nobiliario habiendo escasas referencias a las actividades lúdicas del tercer estado.

  18. Basic functional analysis of six unknown open reading frames from Saccharomyces cerevisiae: four from chromosome VII and two from chromosome XV.

    Science.gov (United States)

    Pearson, Bruce M; Schweizer, Michael

    2002-01-30

    Six open reading frames (ORFs) of unknown function from Saccharomyces cerevisiae from the left arms of chromosomes VII and XV were disrupted by the short-flanking homology method in the diploid strains FY1679 and CENPK2. In each case, the entire ORF, with the exception of the first nucleotide of the start codon, was eliminated and replaced by the kanMX4 cassette. Correct integration of the disrupting marker was checked by colony PCR of the geneticin (G418)-resistant transformants. Sporulation followed by tetrad dissection of the diploids revealed that none of the ORFs encoded a product essential for the viability of either yeast strain. The neutral effect of these disruptions extended to mating and sporulation, since it was possible to create homozygous diploid disruptants that were capable of sporulation. Basic phenotypic analysis was carried out on all strains by growing them on three different media at three different temperatures and revealed no significant differences between disruptants and the parental strains. A cognate clone and a kanMX4 disruption cassette were created for five of the six ORFs by gap repair with specific long-flanking homology cassettes. For experimental reasons, the cognate clone and disruption cassette corresponding to the sixth ORF (YGL161w) had to be created by PCR.

  19. Arrendar el dinero del rey. Fraude y estrategias financieras en el Estrado de las Rentas en la Castilla del siglo XV

    Directory of Open Access Journals (Sweden)

    Ortega Cera, Ágata

    2010-06-01

    Full Text Available This article explores the royal income from leasing of Castile in the second half of the fifteenth century, from the standpoint of the business tax. The complex administrative process involving the hiring of income can not be understood solely as a mechanism of tax collection, but must be related to other fields of economic and political action related to fiscal and financial business. This paper mainly emphasizes on analyzing some of the mechanisms developed in the auctions of the income that allowed business people to become landlords of certain tributes.

    El presente artículo profundiza en el arrendamiento de rentas regias de la Castilla de la segunda mitad del siglo XV, desde la óptica del negocio fiscal. El complejo proceso administrativo que suponen los arrendamientos de rentas no puede entenderse, únicamente, como un medio de percepción fiscal, sino que hay que conectarlo con otro tipo de campos de actuación política y económica relacionados con el negocio fiscal y financiero. Este trabajo analiza algunos de los mecanismos desarrollados en las subastas de las rentas, que permitían a los hombres de negocios convertirse en arrendadores de determinados tributos.

  20. VizieR Online Data Catalog: MBPT calculations for Ne-like ions (CrXV to KrXXVII) (Wang+, 2016)

    Science.gov (United States)

    Wang, K.; Chen, Z. B.; Si, R.; Jonsson, P.; Ekman, J.; Guo, X. L.; Li, S.; Long, F. Y.; Dang, W.; Zhao, X. H.; Hutton, R.; Chen, C. Y.; Yan, J.; Yang, X.

    2016-11-01

    Level energies, wavelengths, electric dipole, magnetic dipole, electric quadrupole, and magnetic quadrupole transition rates, oscillator strengths, and line strengths from combined relativistic configuration interaction and many-body perturbation (MBPT) calculations are reported for the 201 fine-structure states of the 2s22p6, 2s22p53l, 2s2p63l, 2s22p54l, 2s2p64l, 2s22p55l, and 2s22p56l configurations in all Ne-like ions between CrXV and KrXXVII. Calculated level energies and transition data are compared with experiments from the National Institute of Standards and Technology (NIST) and CHIANTI databases, and other recent benchmark calculations. The mean energy difference with the NIST experiments is only 0.05%. The present calculations significantly increase the amount of accurate spectroscopic data for the n>3 states in a number of Ne-like ions of astrophysical interest. A complete data set should be helpful for analyzing new observations from solar and other astrophysical sources, and is also likely to be useful for modeling and diagnosing a variety of plasmas, including astronomical and fusion plasma. (5 data files).

  1. 有关CA

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@ 什么是CA? CA(Certificaton Authority)是认证机构的国际通称,是指对数字证书的申请者发放、管理、取消数字证书的机构.CA的作用是检查证书持有者身份的合法性,并签发证书(在证书上签字),以防证书被伪造或篡改.

  2. Relationship among salivary carbonic anhydrase VI activity and flow rate, biofilm pH and caries in primary dentition.

    Science.gov (United States)

    Frasseto, F; Parisotto, T M; Peres, R C R; Marques, M R; Line, S R P; Nobre Dos Santos, M

    2012-01-01

    This study aimed to determine the activity of carbonic anhydrase isoenzyme VI (CAVI) in the saliva of preschool children with caries and to investigate the relationship between caries and salivary CAVI activity, salivary flow rate and biofilm pH before and after a 20% sucrose rinse. Thirty preschool children aged 45.3-80.3 months were divided into two groups: a caries-free group and a caries group. Clinical examinations were conducted by one examiner (κ = 0.95) according to WHO criteria (dmfs) and early caries lesions. From each subject, CAVI activity, salivary flow rate and plaque pH were determined before and after a sucrose rinse. The results were submitted to Wilcoxon, Mann-Whitney and Spearman correlation tests (α = 0.05). The results showed that prerinse CAVI activity and its variation were higher in the saliva from caries children than from caries-free children. No difference was found between the two groups in postrinse salivary CAVI activity. After rinsing, biofilm pH differences were lower in both groups (p = 0.0012 and p = 0.0037 for the caries and caries-free groups, respectively). Also, after the sucrose rinse, salivary flow rate significantly increased in caries and caries-free groups (p = 0.0003, p = 0.0037). The variation of salivary CAVI activity was negatively correlated with caries (r = -0.501, p = 0.005). Child's age showed a positive correlation with caries (r = 0.456, p = 0.011). These results suggest that variation of salivary CAVI activity and child's age are associated with dental caries in preschool children.

  3. 盐碱胁迫对尼罗罗非鱼鳃Na+/3HCO共转运子、碳酸酐酶基因表达的影响%Effects of salinity and alkalinity on mRNA expression of Na+/3HCO cotransporter and carbonic anhydrase genes fromOreochromis niloticus

    Institute of Scientific and Technical Information of China (English)

    梁从飞; 赵金良; 甘远迪; 王飞; Thammaratsuntorn Jeerawat; 伍勇; 李传阳; 罗明坤

    2016-01-01

    To understand fish osmotic adjustment mechanisms in saline and alkaline water, the partial cDNA se-quence was obtained from gills ofOreochromis niloticus. Physiological changes in serum osmolality, ion concen-tration (Na+, K+, Cl– and Ca2+), and gill carbonic anhydrase (CA) activities were determined, andCAandNBCe1 mRNA gene expressions under saline (10 g/L, 15 g/L NaCl), alkaline (1.5 g/L and 3 g/L NaHCO3), and sa-line-alkaline (salinity 10, 15 g/L NaCl; salinity 1.5, 3 g/L NaHCO3) conditions at different times (0 h, 6 h, 12 h, 24 h, 48 h, 72 h and 96 h) were compared. The results showed that serum osmolality, ion concentration, gill CA activity, CA andNBCe1 mRNA gene expression correlated positively with the strength of saline, alkaline and sa-line-alkaline stress. Over time, serum osmolality and ion concentration trends increased and then decreased. Os-motic pressure insaline and saline-alkaline water was higher than that in alkaline water. Gill CA activity in alkaline and saline-alkaline water was higher than that in saline water. Under low concentrations of stressors, CA activity reached its highest level at a later time. Slightly higherNBCe1 gene mRNA expression was detected in gills under high concentrations of stressors (P>0.05). GillCA mRNA expression in saline, alkaline and saline-alkaline water was increased, but the increase was more evident in alkaline and saline-alkaline water (P0.05)。单碱组和盐碱混合组鳃CA活性较单盐组高,低盐碱胁迫(盐度10,碱度1.5 g/L)下CA活性较晚达最高值;不同胁迫条件下, CA基因mRNA表达均表现上调,单碱、盐碱混合组更为显著(P<0.05),推测CA较NBCe1对体内3HCO-转运作用更为显著。研究结果为尼罗罗非鱼盐碱适应生理调节提供了基础资料。

  4. Topological organization of CA3-to-CA1 excitation.

    Science.gov (United States)

    Hongo, Yoshie; Ogawa, Koichi; Takahara, Yuji; Takasu, Keiko; Royer, Sebastien; Hasegawa, Minoru; Sakaguchi, Gaku; Ikegaya, Yuji

    2015-09-01

    The CA1-projecting axons of CA3 pyramidal cells, called Schaffer collaterals, constitute one of the major information flow routes in the hippocampal formation. Recent anatomical studies have revealed the non-random structural connectivity between CA3 and CA1, but little is known regarding the functional connectivity (i.e. how CA3 network activity is functionally transmitted downstream to the CA1 network). Using functional multi-neuron calcium imaging of rat hippocampal slices, we monitored the spatiotemporal patterns of spontaneous CA3 and CA1 burst activity under pharmacological GABAergic blockade. We found that spatially clustered CA3 activity patterns were transformed into layered CA1 activity sequences. Specifically, synchronized bursts initiated from multiple hot spots in CA3 ensembles, and CA1 neurons located deeper in the pyramidal cell layer were recruited during earlier phases of the burst events. The order of these sequential activations was maintained across the bursts, but the sequence velocity varied depending on the inter-burst intervals. Thus, CA3 axons innervate CA1 neurons in a highly topographical fashion.

  5. Electrodeposition of Ca Metal in CaCl2-CaO Molten Salt

    Institute of Scientific and Technical Information of China (English)

    GUO; Jun-kang; WANG; Chang-shui; CAO; Long-hao; OUYANG; Ying-gen

    2013-01-01

    To realize the continuouscalciothermic reduction in molten salts,the electrodeposition behavior of Ca metal in CaCl2-CaO molten salt was investigated by cylic voltammetry.The cyclic voltammograms at the scan rate of 100 mV/s are shown in Fig.1.As is shown,the electrodeposition potential of Ca deviated from-1.66 V to-0.97 V after CaO was added to molten CaCl2 and the decomposition of CaO

  6. Effects of sodium bicarbonate concentration on growth, photosynthesis, and carbonic anhydrase activity of macroalgae Gracilariopsis lemaneiformis, Gracilaria vermiculophylla, and Gracilaria chouae (Gracilariales, Rhodophyta).

    Science.gov (United States)

    Zhou, Wei; Sui, Zhenghong; Wang, Jinguo; Hu, Yiyi; Kang, Kyoung Ho; Hong, Hye Ran; Niaz, Zeeshan; Wei, Huihui; Du, Qingwei; Peng, Chong; Mi, Ping; Que, Zhou

    2016-06-01

    There is potential for bicarbonate to improve crop yields and economic efficiency of marine algae. However, few studies have focused on the effect of bicarbonate on the growth, photosynthesis, and enzyme activity associated with carbon utilization, especially in commercial macroalgae. Here, the addition of bicarbonate (up to 420 mg L(-1)) to macroalgal cultures has been evaluated for Gracilariopsis lemaneiformis, Gracilaria vermiculophylla, and Gracilaria chouae with respect to growth rate, photosynthetic activity, carbonic anhydrase activity, and biochemical composition. The results showed that the effects of NaHCO3 on growth, chlorophyll a, phycoerythrin, photosynthetic oxygen evolution, photochemical parameters of PSI and PSII, carbonic anhydrase activity, and nitrogen content were significant (P 336 mg L(-1) for Gp. lemaneiformis and >420 mg L(-1) for the other two species). Moreover, species-specific differences induced by supplementation with bicarbonate were discovered during culture. Optimal concentrations of NaHCO3 used in this study were 252 mg L(-1) for Gp. lemaneiformis and 336 mg L(-1) for G. vermiculophylla and G. chouae. These results suggest that an adequate supplementation of sodium bicarbonate is a viable strategy for promoting growth and photosynthetic activity in some macroalgae as well as for improving biochemical composition. The study will help to accelerate the growth rate of algae and improve the quality of thalli, and will also be useful for enhancing the understanding of carbon utilization in macroalgae.

  7. Fluorescence Lifetime Imaging of Physiological Free Cu(II) Levels in Live Cells with a Cu(II)-Selective Carbonic Anhydrase-Based Biosensor

    Science.gov (United States)

    McCranor, Bryan J.; Szmacinski, Henryk; Zeng, Hui Hui; Stoddard, A.K.; Hurst, Tamiika; Fierke, Carol A.; Lakowicz, J.R.

    2014-01-01

    Copper is a required trace element that plays key roles in a number of human enzymes, such that copper deficiency or genetic defects in copper transport lead to serious or fatal disease. Rae, et al., had famously predicted that free copper ion levels in the cell cytoplasm were extremely low, typically too low to be observable. We recently developed a variant of human apocarbonic anhydrase II for sensing metal ions that exhibits 25-fold better selectivity for Cu(II) over Zn(II) than the wild type protein, enabling us to accurately measure Cu(II) in the presence of ordinary cellular (picomolar) concentrations of free zinc. We inserted a fluorescent labeled Cu(II)-specific variant of human apocarbonic anhydrase into PC-12 cells and found that the levels are indeed extremely low (in the femtomolar range). We imaged the free Cu(II) levels in living cells by means of frequency-domain fluorescence lifetime microscopy. Implications of this finding are discussed. PMID:24671220

  8. Regulation of high glucose-induced apoptosis of brain pericytes by mitochondrial CA VA: A specific target for prevention of diabetic cerebrovascular pathology.

    Science.gov (United States)

    Price, Tulin O; Sheibani, Nader; Shah, Gul N

    2017-04-01

    Events responsible for cerebrovascular disease in diabetes are not fully understood. Pericyte loss is an early event that leads to endothelial cell death, microaneurysms, and cognitive impairment. A biochemical mechanism underlying pericyte loss is rapid respiration (oxidative metabolism of glucose). This escalation in respiration results from free influx of glucose into insulin-insensitive tissues in the face of high glucose levels in the blood. Rapid respiration generates superoxide, the precursor to all reactive oxygen species (ROS), and results in pericyte death. Respiration is regulated by carbonic anhydrases (CAs) VA and VB, the two isozymes expressed in mitochondria, and their pharmacologic inhibition with topiramate reduces respiration, ROS, and pericyte death. Topiramate inhibits both isozymes; therefore, in the earlier studies, their individual roles were not discerned. In a recent genetic study, we showed that mitochondrial CA VA plays a significant role in regulation of reactive oxygen species and pericyte death. The role of CA VB was not addressed. In this report, genetic knockdown and overexpression studies confirm that mitochondrial CA VA regulates respiration in pericytes, whereas mitochondrial CA VB does not contribute significantly. Identification of mitochondrial CA VA as a sole regulator of respiration provides a specific target to develop new drugs with fewer side effects that may be better tolerated and can protect the brain from diabetic injury. Since similar events occur in the capillary beds of other insulin-insensitive tissues such as the eye and kidney, these drugs may also slow the onset and progression of diabetic disease in these tissues.

  9. Imagem e territórios das elites burguesas galegas: a escultura funerária (séculos XIV-XV

    Directory of Open Access Journals (Sweden)

    García Rodríguez, Matías

    2012-12-01

    Full Text Available As well as a clear rising of the sumptuous tombs is asserted during the 14th and 15th centuries within the sphere of nobility, also an increase in the decoration of graves took place in that of the bourgeois elites. In fact, this phenomenon of emulation with regard to the urbanized fidalguia will be the most characteristic one of this enriched bourgeoisie, which is an essential part of the municipal oligarchies. We will analyse some aspects of this class representation, especially concerning funerary sculpture, and from a perspective of critique of ideology and lacanian theory, especially in what refers to a paradigmatic example, the tomb of Joám do Campo in São Domingos de Bonaval.

    De la misma manera en que en el ámbito de la nobleza se asiste a un claro aumento del número de sepulcros exentos y bajo arcosolio durante los siglos XIV y XV, también en el de las élites burguesas corroboramos un incremento en la decoración de sus enterramientos. De hecho, este fenómeno de emulación y/o homologación a respecto de la hidalguía urbanizada será el más característico en el seno de esta burguesía enriquecida, parte esencial de las oligarquías municipales. Analizaremos algunos aspectos de esta representación de clase, especialmente en relación a la escultura funeraria, y desde un enfoque de crítica de la ideología y teoría lacaniana, en especial por lo que respecta a un caso paradigmático como es el del sepulcro de Joám do Campo en São Domingos de Bonaval. [gl] Do mesmo jeito que no âmbito da nobreza se assiste a um claro aumento do número de sepulcros isentos e baixo arcossólio durante os séculos XIV e XV, também no das elites burguesas corroboramos um incremento na decoração dos seus enterramentos. De feito, este fenômeno de emulação e/ou homologação perante a fi dalguia urbanizada será o mais característico no seio desta burguesia enriquecida, parte essencial das oligarquias

  10. Sulfide capacities of CaO-CaF2-CaCl2 melts

    Science.gov (United States)

    Simeonov, Simeon; Sakai, Toshihiko; Maeda, Masafumi

    1992-06-01

    The sulfide capacityC_{s^{2 - } } = ({text{pct S}}^{{text{2 - }}} )(p_{{text{O}}_{text{2}} } /p_{{text{S}}_{text{2}} } )^{1/2} ) of CaO-CaF2-CaCl2 slag was determined at temperatures from 1000 °C to 1300 °C by equilibrating molten slag, molten silver, and CO-CO2-Ar gas mixture. The sulfide capacity increases with replacing CaCl2 by CaF2 in slags of constant CaO contents. The sulfide capacity also increases with increasing temperature as well as with increasing CaO content at a constant ratio of CaF2/CaCl2 of unity. A linear relationship between the sulfide capacity and carbonate capacity in literature was observed on a logarithmic scale.

  11. El acceso al gobierno de las ciudades castellanas con voto en Cortes a través del patronazgo regio durante el siglo XV

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    Diago Hernando, Máximo

    2002-12-01

    Full Text Available The author proves that the most influential group in the government of the Castilian towns during the fifteenth century, and most of all in the seventeen towns that had the right to send deputies to Parliament (Cortes, was constituted by individuals that worked at the service of the king in the main organs of central and territorial government and administration of the kingdom. He gives account of the institutional mechanism that propitiated this situation, and he stresses the significance of the creation by the king of new offices of "regidores" (aldermen. He also proves that the most influential families of this group of king's servants accumulated posts of "regidores" (aldermen in several towns, and contributed in this way to reinforce the political links that these towns established with each other and with the monarchy.

    Se demuestra que en Castilla durante el siglo XV el grupo más influyente en el gobierno de las principales ciudades, y en concreto de las diecisiete que tenían voto en Cortes, estuvo constituido por individuos que estaban al servicio de los reyes en los órganos de gobierno y administración central y territorial del reino. Se da cuenta de los mecanismos institucionales que propiciaron esta situación, y se destaca la importancia que tuvo la creación de nuevos oficios de regidor por los reyes. Se demuestra además que las familias más influyentes de este grupo de servidores del rey consiguieron acumular oficios de regidores en varias de estas ciudades, contribuyendo así a reforzar los vínculos políticos de éstas entre sí y con la propia monarquía.

  12. Las artes de la paz. Técnicas de perfumería y cosmética en recetarios castellanos de los siglos XV y XVI

    Directory of Open Access Journals (Sweden)

    Criado Vega, Teresa

    2011-12-01

    Full Text Available This paper examines the techniques for preparing perfumes and cosmetics contained in Castilian recipe books belonging to 15th and 16th centuries. These recipe books are kept in the National Library of Spain, the Royal Palace Library in Madrid and the Palatine Library in Parma. Only the text kept in this Italian library has been studied and edited. These recipe books contain about fifty recipes that specify the purpose of the perfumes and cosmetics mentioned, the ingredients used in making them and the technical processes developed for preparation of substances and the application of the compounds. All this highlights a littlestudied aspect of daily life in the Middle Ages, related to medicine and health, aesthetics and beauty, and body care.

    El presente trabajo analiza las técnicas de elaboración de perfumes y cosméticos contenidas en recetarios castellanos de los siglos XV y XVI. Dichos recetarios se conservan en la Biblioteca Nacional de España, la Biblioteca del Palacio Real de Madrid y la Biblioteca Palatina de Parma; de ellos, sólo el conservado en esta biblioteca italiana ha sido estudiado y editado. En dichos recetarios aparecen medio centenar de recetas que especifi can la finalidad de los perfumes y cosméticos citados, los ingredientes utilizados en su elaboración y los procesos técnicos seguidos para la preparación de las sustancias y la aplicación de los compuestos. Todo ello pone de relieve una faceta poco estudiada de la vida cotidiana en la Edad Media, relacionada con la medicina y la salud, con la estética y la belleza, y con el cuidado del cuerpo.

  13. Escándalos, ruydos, injurias e cochilladas: prácticas de violencia en el clero catedralicio burgalés durante el siglo XV

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    Díaz Ibáñez, Jorge

    2013-12-01

    Full Text Available The aim of this work, based mainly on manuscripts and unpublished documents from Burgos Cathedral Archive, is the study and analysis of violence, physical and verbal, among the cathedral clergy of Burgos, emphasizing the individual and collective scale of the conflicts and the variety of their causes. The cathedral chapter of Burgos exercised its jurisdiction by punishing the culprits, favouring reconciliation processes and trying to stop, often unsuccessfully, the conflicts between clergymen that increased during the last decades of the fifteenth century, and that have a close connection with the conflicts which took place between different families and lineages of the urban oligarchy of Burgos during the same period.El objetivo de este trabajo, basado fundamentalmente en fuentes manuscritas e inéditas procedentes del Archivo Catedralicio de Burgos, es el estudio y análisis de la violencia, tanto física como verbal, en el seno del clero catedralicio burgalés, poniendo de relieve la dimensión tanto individual como colectiva de los enfrentamientos y su variada casuística. El cabildo catedralicio burgalés ejerció su jurisdicción imponiendo castigos a los culpables, fomentando fórmulas de reconciliación y tratando de frenar, a menudo sin éxito, unos enfrentamientos entre clérigos que aumentaron durante las últimas décadas del siglo XV, y que guardan un estrecho paralelismo y relación con los conflictos que en la misma época se produjeron entre diferentes familias y linajes de la oligarquía urbana burgalesa.

  14. Implicaciones intelectuales y metodológicas en la selección de los autores y la terminología traductora castellana del siglo XV

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    Allés Torrent, Susanna

    2015-06-01

    Full Text Available Translations were a crucial channel for the reception of Italian Humanism in the Iberian Peninsula. This intellectual activity not only led to the recuperation of a significant part of the classical Greco-Roman legacy, but also fomented engagement with the works and ideas of contemporary Italian authors. On the one hand, this article underscores the critical role of translation in cultural transfers between both peninsulas and shows the change in authors selected to translate over the course of fifteenth century. On the other hand, it analyzes the implications of these author selections, arguing that they reveal at once an ideological transformation, a change in the conception of the very act of translation, and the adoption of new terminology.Las traducciones constituyeron uno de los canales prioritarios en la recepción del humanismo italiano en la Península Ibérica. A través de esta actividad intelectual, no sólo se recuperó una parte considerable del legado clásico grecolatino, sino que propició un acercamiento a la obra y a las ideas de los autores italianos contemporáneos. Por un lado, el presente trabajo insiste en el papel central de la traducción en el marco de la transferencia cultural entre ambas penínsulas y evidencia el cambio en la selección de los autores traducidos a lo largo del siglo XV; por otro lado, se analizan las implicaciones de dichas elecciones que, además de constituir una transformación a nivel ideológico, supusieron un cambio en la concepción de la actividad de la traducción y en la adopción de una nueva terminología.

  15. Paisaje agrario y prácticas agrícolas en la Ribeira Sacra (Galicia durante los siglos XIV y XV

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    López Sabatel, José Antonio

    2008-06-01

    Full Text Available The aim of this article is to approach what appears to be the physical contour and extent of the land recovered for agricultural use at the heart of the area falling under the influence of five monasteries situated on both banks of the River Sil in the stretch immediately preceding its flowing into the mouth of the Miño during the 14th and 15th centuries. It will also focus on the various agrarian practices used in chestnut and vine cultivation as well as work on the lands growing cereal crops. These are practices which in the relative system of cultivation will have an effect on the physiognomy of the agrarian lands throughout this period.

    Este artículo pretende un acercamiento a lo que debió ser el semblante físico y extensión de los terrenos ganados en beneficio de la actividad agrícola en el seno del área de influencia de cinco cenobios situados a ambos márgenes del río Sil en el tramo precedente a su desembocadura en el Miño durante los siglos XIV y XV. También se centrará en las diversas prácticas agrícolas destinadas al cuidado de la castaña y la vid así como al trabajo en las tierras de cereal. Prácticas éstas que en lo relativo al sistema de cultivos tendrán incidencia en la fisonomía del espacio agrario a lo largo de este periodo.

  16. Matrimonios en régimen de germania y relaciones intrafamiliares en Alicante durante el siglo XV = Germania Marriages and Domestic Relations in Alicante during the Fifteenth Century

    Directory of Open Access Journals (Sweden)

    Jaime Piqueras Juan

    2016-06-01

    Full Text Available Se presenta en este artículo la investigación realizada sobre las formas en que se aplicó el régimen económico matrimonial de comunidad de bienes o germania en diversas comunidades del norte alicantino durante la Edad Media. A través de la consulta de documentación notarial y particularmente de testamentos y contratos matrimoniales del siglo XV, se propone la existencia de una variante de dicho régimen consistente en la comunicación parcial de bienes en el matrimonio. Los documentos manifiestan la existencia de relaciones entre este sistema matrimonial y las estrategias de las familias para evitar divisiones de las propiedades agrarias con motivo de las transmisiones mediante herencia. Esta situación se produjo en un contexto de crecimiento y expansión de la manufactura textil local, considerada un agente transformador de las relaciones en el interior de las familias.In this article, we present research conducted on the ways in which the system of matrimonial community of property or germania was applied in various communities in northern Alicante during the Middle Ages. With the use of notary records and particularly wills and marriage contracts of the fifteenth century, we propose the existence of a variant of this scheme consisting of a partial community of property in marriage. The documents demonstrate the existence of a relation between this system of marriage and family strategies to prevent parceling of agricultural property due to inheritance. This took place in the context of growth and expansion of local textile manufacturing and should be regarded as an agent of transformation of relationships within families.

  17. A cultura organizacional do restaurante chalé da praça XV em Porto Alegre: espaços e tempos sendo revelados

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    Letícia Dias Fantinel

    2010-02-01

    Full Text Available Este estudo busca desvendar aspectos da cultura organizacional de um restaurante, ponto turístico da cidade de Porto Alegre, compreendendo sua dimensão simbólica por meio das representações sociais que circulam em seu ambiente, notadamente no que tange às categorias espaço e tempo. Em virtude da complexidade do tema, foram utilizados conceitos e quadros de referência teóricos da antropologia e de outras ciências humanas. O Chalé da Praça XV é um patrimônio que se localiza no centro histórico da cidade, espaço antigo, valorizado no passado pela população e hoje considerado uma vítima da degradação urbana. O método etnográfico foi utilizado na identificação das representações que circulam nesse espaço. O trabalho de campo etnográfico foi conduzido no restaurante entre fevereiro e maio de 2008. Identificaram-se as representações de tempo e espaço elaboradas por clientes e funcionários do restaurante, e desvendaram-se as homogeneidades e as heterogeneidades de sua cultura organizacional. As categorias de análise estabelecidas evidenciam as heterogeneidades presentes em seu espaço como lugar antropológico. Por fim, apresentam-se algumas alternativas para que se pense a gestão do estabelecimento, considerando, entre outros aspectos, seu potencial turístico insuficientemente explorado.

  18. Tradução comentada: experiências com textos teatrais espanhóis dos séculos XV e XVII

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    Leticia Rebollo Couto Rebollo Couto

    2015-12-01

    Full Text Available A tradução comentada é aqui aplicada ao processo de aprendizagem com tradução de textos do teatro espanhol, “Peribañez y el gobernador de Ocaña” de Lope de Veja (século XVII e “La Celestina” de Fernando de Rojas (século XV. A partir da sua constituição como texto dialogado, comentamos nas propostas de tradução feitas por aprendizes a relação de maior ou menor distanciamento, a partir da análise das formas de tratamento e da fala coloquial. As duas propostas de tradução apresentadas orientam-se por diferentes finalidades, mas têm em comum alguns problemas relacionados à especificidade temporal destes textos, e ao seu gênero, texto dramático para leitura. Trata-se de propostas de tradução para trabalhar a relação texto-texto e não texto-espetáculo, encenação. A tradução comentada é introduzida por uma revisão bibliográfica que assinala o papel do teatro espanhol na formação da dramaturgia brasileira e em particular na tensão oralidade vs escrita, latente na construção do padrão de escrita literário, como projeto do século XIX. Esta tensão entre fala e escrita é particularmente relevante para a tradução do teatro em português do Brasil, e juntamente com as formas de tratamento e as seleções mais ou menos coloquializadoras constitui um elemento chave para a fluência do texto dramático.

  19. MODELLING THE INHIBITORY ACTIVITY ON CARBONIC ANHYDRASE IV OF SUBSTITUTED THIADIAZOLE - AND THIADIAZOLINE - DISULFONAMIDES: INTEGRATION OF STRUCTURE INFORMATION

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    Sorana Daniela Bolboaca

    2006-07-01

    Full Text Available ABSTRACT:Purpose: To analyze the relationships between inhibitory activities on carbonic anhydrase IV and structures of substituted 1,3,4-thiadiazole and 1,3,4-thiadiazoline disulfonamide through integration of compounds complex structure information by the use of Molecular Descriptors Family.Method: A number of forty compounds were used to generate and compute the molecular descriptors family and to build structure-activity relationships models. The obtained multi-varied models (the models with two, respectively with four descriptors were validated by computing the cross-validation leave-one-out score (r2cv-loo, and analyzed through assessment of the squared correlation coefficients (r2, and the models stability (r2 - r2cv-loo. The estimation abilities of the multi-varied MDF-SAR model with four descriptors were analyzed in training and test sets.Results: Analysis of the obtained models shows that the best results was obtained by the multi-varied model with four molecular descriptors (r2 = 0.920. The prediction abilities of this model is sustained by the cross validation leave-one-out score (r2cv-loo = 0.903, the model stability (r2 - r2cv-loo = 0.017, and the results on training versus test analysis (no significant differences between correlation coefficients in training and test sets, p > 0.05. The multi-varied model which used four descriptors proved to render higher value of correlation coefficient comparing with previous reported models (p 0.05. El modelo multivariante que utilizó cuatro descriptores mostró un valor más alto del coeficiente de correlación en comparación con los modelos divulgados anteriormente (p < 0.01.Conclusión: El modelo multivariante con cuatro descriptores es sólido y fiable e indica que la actividad de la inhibición en la carboanhidrasa IV producida por las sufonamidas sustituidas del 1,3,4-tiadiazol- y de la 1,3,4-tiadiazolina- dependen de la naturaleza de la geometría y de la topología del compuesto

  20. ASCETIC VIEWS OF BASIL THE GREAT AND THEIR ROLE IN THE FORMATION AND DEVELOPMENT OF RELIGIOUS CONSCIOUSNESS AND SOCIAL THOUGHT IN RUSSIA IN THE SECOND HALF OF XIV - EARLY XV CENTURIES

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    A. Yu. DAVYDOV

    2015-01-01

    Full Text Available The formation and development of religious consciousness and social thought in Russia at the second half of XIV - early XV centuries was conditioned by the main facts of history and spiritual life of Russia. All the spiritual forces of Russia at the second half of XIV - early XV centuries were directed to solve practical problems of creating the united state. The development of religious-social thought in Russia was greatly influenced by the entry into the culture of Russia of numerous translations of the classics of patristic literature from Byzantium. An appeal to the creations of Byzantine thinkers had internal reasons, where the main problems were the issues of morality and strengthening of spirituality. One of the main themes of the ancient Russian scribes at the second half of XIV - early XV centuries was asceticism. The aim of the article is to analyze the moral and ascetic views of the Byzantine theologian, philosopher and church leader of the 4th century Basil the Great and reflection of his views in the ancient Russian authors‟ works. Investigation of the works of St. Basil the Great allows to reveal the specific sources that determined the growth of personal principles, moral and ascetic orientation of religious and social thought in Russia. Active asceticism became one of the main sources of additional spiritual strength needed to solve the practical problems in creating a united state.

  1. Análisis de pinturas murales góticas en Eslovenia del maestro Bolfgang y su discípulo maestro de Mače (siglo XV)

    OpenAIRE

    Križnar, Anabelle; Ruíz-Conde, Antonio; Sánchez-Soto, Pedro José

    2014-01-01

    [ES] Dentro del arte gótico Europeo, este estudio trata de explicar la técnica de pintura mural del Maestro Bolfgang y su discípulo Maestro de Mače. Se trata de dos de los más importantes pintores en el territorio de Eslovenia en la segunda mitad del siglo XV. Siguiendo una metodología basada en el examen de materiales pictóricos, se realizó una caracterización de pigmentos y morteros de soporte empleados en una serie de pinturas murales hechas por ambos artistas, en concreto en las que se en...

  2. Sequence analysis of a 9873 bp fragment of the left arm of yeast chromosome XV that contains the ARG8 and CDC33 genes, a putative riboflavin synthase beta chain gene, and four new open reading frames.

    Science.gov (United States)

    Casas, C; Aldea, M; Casamayor, A; Lafuente, M J; Gamo, F J; Gancedo, C; Ariño, J; Herrero, E

    1995-09-15

    The DNA sequence of a 9873 bp fragment located near the left telomere of chromosome XV has been determined. Sequence analysis reveals seven open reading frames. One is the ARG8 gene coding for N-acetylornithine aminotransferase. Another corresponds to CDC33, which codes for the initiation factor 4E or cap binding protein. The open reading frame AOE169 can be considered as the putative gene for the Saccharomyces cerevisiae riboflavin synthase beta chain, since its translation product shows strong homology with four prokaryotic riboflavin synthase beta chains.

  3. 血清抗碳酸酐酶Ⅲ抗体ELISA检测方法的建立与初步应用%Establishment and preliminary application of the ELISA method for anti-carbonic anhydrase III antibody detection

    Institute of Scientific and Technical Information of China (English)

    刘辰庚; 王培昌

    2011-01-01

    目的 建立人血清抗碳酸酐酶(CA)Ⅲ抗体的ELISA检测方法,并对系统性红斑狼疮、皮肌炎、糖尿病肾病、高血压肾病患者和健康人群的血清抗CAⅢ抗体水平进行初步调查.方法 使用抗CAⅢ抗体标准品、CAⅢ及相应酶标抗体建立血清抗CAⅢ抗体ELISA检测方法,验证试剂稳定性、标本保存稳定性,并进行精密度、灵敏度、回收率、抗干扰性等方法学评价;各项技术指标均合格后对系统性红斑狼疮、皮肌炎、糖尿病肾病和高血压肾病患者的血清进行抗CAⅢ抗体水平检测.结果 成功建立ELISA检测人血清抗CAⅢ抗体的方法,其批内精密度为6.2%,批间精密度为8.2%,灵敏度为0.025,回收率为106%,且具有较好的抗干扰性、试剂稳定性和标本保存稳定性.系统性红斑狼疮和糖尿病肾病患者的血清抗CAⅢ抗体水平高于健康对照相(P<0.05),阳性率分别为43%和18%.皮肌炎和高血压肾病患者的血清抗CAⅢ抗体水平与健康对照组比较无统计学差异(P>0.05),且未出现阳性结果.结论 使用现有市售试剂进行人血清抗CAⅢ抗体的ELISA检测是可行的,抗CAⅢ抗体可能参与了系统性红斑狼疮和糖尿病肾病的发生发展.%Objective To establish an ELISA method for anti-carbonic anhydrase III (CA III ) antibody detection, and to evaluate the serum level of anti-CA III antibody in normal control group and patients with systemic lupus erythemato-sus, dermatomyositis, 2-type diabetic nephropathy and hypertensive nephropathy respectively. Methods To establish the ELISA method using CA III, anti-CA III antibody and enzyme labeled secondary antibody. To evaluate the stability of the regent and sample, and the sensitivity, stability and anti-interference performance of the ELISA method. To investigate the anti-CA III antibody level in serum of normal control group and patients with systemic lupus erythematosus, dermatomyositis, 2-type

  4. Entre a Necessidade de Lembrar e a Recomendação de Condutas às Mulheres em Castela no Século XV * Entre la Necesidad de Acordarse y la Recomendación de Conductas a las Mujeres en Castilla en el Siglo XV

    Directory of Open Access Journals (Sweden)

    DANIELLE OLIVEIRA MÉRCURI

    2014-02-01

    Full Text Available Resumo: Tendo em vista que, a partir do século XV, é notável o aumento de escritos apresentando uma imagem virtuosa da mulher e de escritos em que o mote é regular e orientar a postura das nobres senhoras, indagamos o porquê de a mulher começar a ser representada de forma mais destacada e positiva nos escritos produzidos em Castela no final da Idade Média. No entanto, antes de tentarmos analisar os paralelos e distanciamentos entre esses textos que tiveram como mote defender e instruir as nobres castelhanas, devemos nos questionar sobre os motivos do interesse pela defesa das mulheres e do fomento dado aos textos que se destinavam a esse propósito, esboçado pela corte de Juan II. Em uma só palavra, devemos indagar sobre quais foram as condições de formulação dos discursos sobre e para as mulheres.Palavras- chave: Mulheres – Castela – Prescrições. Resumen: Teniendo en cuenta que, a partir del siglo XV, es notable el aumento de escritos presentando una imagen virtuosa de la mujer y de escritos en los cuales el fundamento es guiar la postura de las nobles señoras, para que ellas alcanzasen la ejemplaridad, indagamos el motivo por el que la mujer empezar a ser presentada de manera  más destacada y positiva en los escritos producidos en Castilla en fines de la Edad Media. Sin embargo, antes de intentarnos analizar los parangones entre eses textos que tuvieran  como objetivo defender y enseñar las nobles castellanas, debemos cuestionarnos sobre los motivos del interese por la defensa de las mujeres y el fomento ofrecido a los textos que se destinaban a ese propósito, esbozado  por la corte de Juan II. En una palabra, debemos indagar sobre cuales fueran las condiciones de formulación de los discursos sobre y hacia a las mujeres.   Palabras clave: Mujeres – Castilla – Recomendaciones.

  5. Carborane-Based Carbonic Anhydrase Inhibitors: Insight into CAII/CAIX Specificity from a High-Resolution Crystal Structure, Modeling, and Quantum Chemical Calculations

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    Pavel Mader

    2014-01-01

    Full Text Available Carborane-based compounds are promising lead structures for development of inhibitors of carbonic anhydrases (CAs. Here, we report structural and computational analysis applicable to structure-based design of carborane compounds with selectivity toward the cancer-specific CAIX isoenzyme. We determined the crystal structure of CAII in complex with 1-methylenesulfamide-1,2-dicarba-closo-dodecaborane at 1.0 Å resolution and used this structure to model the 1-methylenesulfamide-1,2-dicarba-closo-dodecaborane interactions with CAIX. A virtual glycine scan revealed the contributions of individual residues to the energy of binding of 1-methylenesulfamide-1,2-dicarba-closo-dodecaborane to CAII and CAIX, respectively.

  6. Effect of high concentration of inert cosolutes on the refolding of an enzyme: carbonic anhydrase B in sucrose and ficoll 70.

    Science.gov (United States)

    Monterroso, Begoña; Minton, Allen P

    2007-11-16

    The kinetics of refolding of carbonic anhydrase II following transfer from a buffer containing 5 m guanidinium chloride to a buffer containing 0.5 m guanidinium chloride were studied by measuring the time-dependent recovery of enzymatic activity. Experiments were carried out in buffer containing concentrations of two "inert" cosolutes, sucrose and Ficoll 70, a sucrose polymer, at concentrations up to 150 g/liter. Data analysis indicates that both cosolutes significantly accelerate the rate of refolding to native or compact near-native conformations, but decrease the fraction of catalytically active enzyme recovered in the limit of long time. According to the simplest model that fits the data, both cosolutes accelerate a competing side reaction yielding inactive compact species. Acceleration of the side reaction by Ficoll is significantly greater than that of sucrose at equal w/v concentrations.

  7. Metalloprotein-inhibitor binding: human carbonic anhydrase II as a model for probing metal-ligand interactions in a metalloprotein active site.

    Science.gov (United States)

    Martin, David P; Hann, Zachary S; Cohen, Seth M

    2013-11-01

    An ever-increasing number of metalloproteins are being discovered that play essential roles in physiological processes. Inhibitors of these proteins have significant potential for the treatment of human disease, but clinical success of these compounds has been limited. Herein, zinc(II)-dependent metalloprotein inhibitors in clinical use are reviewed, and the potential for using novel metal-binding groups (MBGs) in the design of these inhibitors is discussed. By using human carbonic anhydrase II as a model system, the nuances of MBG-metal interactions in the context of a protein environment can be probed. Understanding how metal coordination influences inhibitor binding may help in the design of new therapeutics targeting metalloproteins.

  8. Research and application progress of carbonic anhydrase-immobilized technology%碳酸酐酶固定化技术研究与应用进展

    Institute of Scientific and Technical Information of China (English)

    潘富军; 周作明

    2014-01-01

    Currently,the main drawbacks of the most available amine-based processes for post-combustion CO2 are amine degradation and parasitic power loss.A novel Integrated Vacuum Carbonate Absorption Process (IVCAP)was proposed to reduce the energy usage by employing a potassium carbonate aqueous solution as a solvent for CO2 absorption.However,K2 CO3 -based system has a much slower CO2 absorption rate than amine-based system does.Carbonic anhydrase is the most effective known enzyme by far that catalyzes the hydration of CO2 into bicarbonate and a proton.The research and applications of immobilized carbonic anhydrase were reviewed,and the application prospect of IVCAP process improvement for carbon dioxide capture by selecting magnetic carrier material was presented.%目前以有机胺为吸收剂脱除 CO2的化学吸收法多存在氨基易分解、再生能耗高等不足。新型的 IVCAP 工艺采用碳酸钾水溶液吸收 CO2,可大幅节能降耗,但吸收速率较有机胺慢。碳酸酐酶是至今发现的最有效的 CO2水合酶催化剂,将该酶添加至 IVCAP 工艺中,可显著提高 CO2吸收速率。文中综述了固定化碳酸酐酶在碳捕集与封存技术中的研究和应用进展,并对其选用磁性载体材料强化 IVCAP 工艺对 CO2的捕集应用前景进行了展望。

  9. Occurrence of ascaridoid nematodes in selected edible fish from the Persian Gulf and description of Hysterothylacium larval type XV and Hysterothylacium persicum n. sp. (Nematoda: Raphidascarididae).

    Science.gov (United States)

    Shamsi, Shokoofeh; Ghadam, Masoumeh; Suthar, Jaydipbhai; Ebrahimzadeh Mousavi, Hoseinali; Soltani, Mehdi; Mirzargar, Saeed

    2016-11-01

    Despite several reports on the presence of the potentially zoonotic nematodes among edible fishes in the Persian Gulf, there is still no study on the specific identification of these parasites or their genetic characterisation. In the present study, a total of 600 fish belonging to five popular species of fish in the region, including Otolithes ruber, Psettodes erumei, Saurida tumbil, Scomberomorus commerson and Sphyraena jello were examined for infection with nematode parasites. Detailed microscopy of nematodes found in the present study followed by characterisation of the first and second internal transcribed spacers (ITS-1 and ITS-2, respectively) showed that they belong to five distinct taxa that could be potentially zoonotic. Anisakis type I was found in four species of fish, had identical ITS sequences as Anisakis typica previously reported in Australian waters and was different from those reported in the Nearctic. Hysterothylacium type VI in the present study was morphologically similar to those previously described from Australasian waters and ITS sequences were identical among Australian specimens and those found in the present study. Another Hysterothylacium larval type was also found in the present study which had identical ITS sequences and similar morphology to those previously reported and identified as H. amoyense in China Sea. Since no ITS sequence data from a well identified adult H. amoyense with an identifiable museum voucher number is yet available and due to some other issues discussed in the article we suggest assignment of this larval type from the China Sea and the Persian Gulf to H. amoyense is doubtful until future studies on a well identified male specimen of H. amoyense or other species reveals the specific identity of this larval type. We propose to refer to this larval type as Hysterothylacium larval type XV. In the present study we also describe a new species, Hysterothylacium persicum and discuss how to differentiate it from closely

  10. La ropa del quintero (jammās según una fetua de al-Qawrī (s. XV

    Directory of Open Access Journals (Sweden)

    Camarero Castellano, Inmaculada

    2009-12-01

    Full Text Available This article focuses on a fatwā— written by the fifteenth-century Muslim jurist al-Qarawī, which is included in al-Wansharīsī’s al- Mi‘yar. In this fatwā— al-Qarawī responds to various questions regarding the making of a contract for labour upon unirrigated land (muzāra‘a between the landowner and his tenant. Among the questions received on this matter, a request is made for an impoverished landowner to have the right to demand from his tenant the jallābiyya and the salhām/ silhām. Hitherto the term k-bb-sh had not been documented anywhere else under this form. This article suggests that this fatwā contains not one, but rather two distinct fatwā-s. It also takes issue with the differences between the editions of al-Mi‘yar made in Rabat and Fez. Finally, it highlights the various translations and interpretations of the fatwā— and the many divergences between them.

    Una fetua de al-Qawrī (s. xv recogida en al-Miʻyār de al-Wanšarīsī responde a varias cuestiones relacionadas con el contrato de aparcería en tierra de secano (muzāraʻa esttablecida entre el dueño de la tierra y el quintero (jammās. En una de ellas se pide la legalidad para que este aparcero sin reccursos exija una prenda de ropa (k-bb-š a su «socio», tal y como en otras ocasiones se le ha permitido solicitar la ŷallābiyya y el salhām/silhām. Hasta la fecha, el término k-bb-š no se haya registrado bajo esta forma en otro lugar. En este trabajo se plantea la posibilidad de que se trate de dos fetuas diferentes y se pone en cuestión la edición moderna de Rabat, que no se ajusta a la de Fez. Para terminar, se marcan las diferenccias con respecto a la interpretación y tradducción que de esta fetua ha realizado V. Lagardère.

  11. Cultura visual y genealogía en la corte regia de Castilla durante la segunda mitad del siglo XV

    Directory of Open Access Journals (Sweden)

    David NOGALES RINCÓN

    2011-07-01

    Full Text Available Durante la segunda mitad del siglo XV la corte castellana asistió a una consolidación del gusto por la materia genealógica, paralela al despliegue de una intensa retórica que tenía por objeto la familia y los matrimonios regios. Estos procesos serían el resultado, en última instancia, de ciertos cambios culturales e históricos y de necesidades específicas de legitimación, en el contexto de una agitada vida política. El presente trabajo tiene por objeto estudiar los recursos visuales, de dimensión figurativa, verbal o emblemática, empleados en la exaltación genealógica de la realeza castellano-leonesa durante los reinados de Enrique IV (1454-1474 e Isabel I (1474-1504, en torno a obras y empresas artísticas significativas de la cultura cortesana de fines de la Edad Media, como la Genealogía de los Reyes de Alonso de Cartagena o la galería de la Sala de los Reyes del Alcázar de Segovia.Au cours de la deuxième moitié du XVe siècle, la cour castillane assista à une consolidation du goût pour la matière généalogique parallèle au déploiement d’une intense rhétorique qui avait pour objet la famille et les mariages royaux. Ces processus seraient le résultat, en dernier ressort, de certains changements culturels et historiques, et de besoins spécifiques de légitimation, dans un contexte de vie politique agitée. Le présent travail a pour objet l’étude des moyens visuels, de dimension figurative, verbale, ou emblématique, employés dans l’exaltation généalogique de la royauté castillano-léonaise durant les règnes d’Henri IV (1454-1474 et d’Isabelle I (1474-1504, au travers d’œuvres et d’entreprises artistiques significatives de la culture de cour de cette fin du moyen âge, telles que la Généalogie des rois d’Alonso de Cartagena ou la galerie de la Salle des Rois de l’Alcazar de Ségovie.

  12. Physiological function, diversity of carbonic anhydrase and its application%碳酸酐酶的生理功能、多样性及其在CO2捕集中的应用

    Institute of Scientific and Technical Information of China (English)

    李春秀; 姜笑辰; 邱勇隽; 许建和

    2013-01-01

    碳酸酐酶(carbonic anhydrase)作为一种活性中心含有锌离子的金属酶,能够可逆催化CO2生成碳酸氢盐的水合反应,该反应在生物体内承担着多样的生理学功能,具有高度的生物学意义.除广泛存在于真核生物以外,该酶在淡水、海水、嗜常温、嗜热、厌氧、好氧、致病、产酸、自养、异养等多种原核微生物中也有广泛的分布,并参与光合作用、呼吸作用和以CO2作为底物的反应,维持生理pH以及离子转运等生理过程.近年来,随着温室效应的日益加剧,生物固定CO2作为该酶的一种全新应用引起了研究者的广泛关注.回顾了碳酸酐酶作为催化剂参与CO2固定过程的历史、现状和最新发现,同时展望了未来应用的趋势.%As a metalloenzyme combining a Zn2+ at its active centers,carbonic anhydrase catalyze reaction between CO2 and H2O reversibly, the reaction can undertakes various physiological functions in organisms. Carbonic anhydrase can exist in the eukaryote, and in diversity of prokaryotes. Evidence for the presence of carbonic anhydrase is obtained for freshwater, marine, mesophilic, thermophilic, aerobic, anaerobic, pathogenic, symbiotic, acetogenic, autotrophic, heterotrophic, and photosynthetic species. In prokaryotes, carbonic anhydrases are involved in various biochemical and physiological processes, including photosynthesis, respiration, ion transport, and CO2 and bicarbonate balance. While anthropogenic CO2 emission has led to adverse impact on climate and has been implicated in global warming, this enzyme has found a new dimension in the field of biomimetic CO2 sequestration. This paper reviews the research advances on carbonic anhydrase-driven processes for CO2 sequestration research and engineering and, suggests the possible future directions in application.

  13. De la pacificación al desarrollo sostenible. Discurso del Señor Presidente de Costa Rica, Ingeniero José María Figueres, en la Apertura de la XV reunión de presidentes centroamericanos.

    OpenAIRE

    Figueres, José María

    2016-01-01

    De la pacificación al desarrollo sostenible. Discurso del Señor Presidente de Costa Rica, Ingeniero José María Figueres, en la Apertura de la XV reunión de presidentes centroamericanos. Guácimo, Costa Rica, 20 de agosto de 1994

  14. Accessing the nuclear symmetry energy in Ca+Ca collisions

    Directory of Open Access Journals (Sweden)

    Chbihi A.

    2012-07-01

    Full Text Available The status of the analysis of the INDRA-VAMOS experiement performed at GANIL, using the reactions 40,48Ca+40,48Ca reactions at 35AMeV, are presented. Isotopic distributions of fragments produced in multifragmentation events provide information on the importance of the surface term contribution in the symmetry energy by comparison to AMD predictions.

  15. Extra and intracelular activities of carbonic anhydrase of the marine microalga Tetraselmis gracilis (Chlorophyta Atividade extra e intracelular da Anidrase Carbônica na microalga marinha Tetraselmis gracilis (Chlorophyta

    Directory of Open Access Journals (Sweden)

    Marilda Rigobello-Masini

    2003-07-01

    Full Text Available The activities of extra and intracellular carbonic anhydrases (CA were studied in the microalgae Tetraselmis gracilis (Kylin Butcher (Chlorophyta, Prasinophyceae growing in laboratory cultivation. During ten days of batch cultivation, daily determinations of pH, cell number, enzymatic activity, and total dissolved inorganic carbon (DIC, as well as its main species, CO2 and HCO3-, were performed. Enzymatic activity increased as the growing cell population depleted inorganic carbon from the medium. Carbon dioxide concentration decreased quickly, especially in the third day of cultivation, when a significant increase of the intracellular enzymatic activity was observed. Bicarbonate concentration had its largest decrease in the cultivation medium in the fourth day, when the activity of the extracellular enzyme had its largest increase, suggesting its use by the alga through CA activity. After the fourth cultivation day, half of the cultures were aerated with CO2-free atmospheric air, which caused an increase in the total and external activity of the enzyme, although, in this condition, the stationary growth phase began earlier than in cultures aerated with atmospheric air. The pH of the media was measured daily, increasing from the first to the fourth day, and remaining almost constant until the end of the cultivation. Algal material transferred to the dark lost all enzymatic activity.As atividades da Anidrase Carbônica (AC extra e intracelular foram estudadas na microalga marinha Tetraselmis gracilis (Kylin Butcher (Chlorophyta, Prasinophyceae crescendo em cultivos laboratoriais. Durante dez dias de cultivo, determinações diárias do pH, número de células, atividades enzimáticas, carbono inorgânico total dissolvido (CID e suas principais espécies CO2 e HCO3- foram feitas. A atividade enzimática aumentou na medida em que a população celular em crescimento retirava carbono inorgânico do meio de cultivo. A concentração de dióxido de

  16. The enzyme-inhibitor approach to cell-selective labelling. Pt. 1; Sulphonamide inhibitors of carbonic anhydrase as carriers for red cell labelling: in vitro uptake of pIBS by human red blood cells

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Jaspal; Wyeth, P. (Southampton Univ. (UK))

    1991-01-01

    Red cell carbonic anhydrase is identified as an ideal target in an enzyme-inhibitor approach to radiolabel localisation. Current problems in blood pool labelling could be overcome by using selective sulphonamide inhibitors as carriers. p-Iodobenzenesulphonamide (pIBS) was selected as the choice reagent for red blood cell labelling. Rapid uptake of ({sup 125}I)-pIBS was found in vitro, consistent with passive diffusion across the cell membrane. The intracellular binding could be attributed to interaction with two specific acceptor sites, with dissociation constants of 4.9 +- 1.0 and 0.10+- 0.05 {mu}mol dm{sup -3}, and maximum binding capacities of 166 +- 5 and 19.9 +- 1.0 {mu}mol dm{sup -3}, respectively under the experimental conditions. These data correlate with the two major carbonic anhydrase isozymes; acceptor assignments were confirmed by gel chromatography of the red cell lysate. (author).

  17. Gene fusions with human carbonic anhydrase II for efficient expression and rapid single-step recovery of recombinant proteins: expression of the Escherichia coli F1-ATPase epsilon subunit.

    Science.gov (United States)

    Van Heeke, G; Shaw, R; Schnizer, R; Couton, J M; Schuster, S M; Wagner, F W

    1993-08-01

    A new expression vector was constructed which allows the overproduction in Escherichia coli of tripartite proteins consisting of human carbonic anhydrase isozyme II (hCAII), a peptide linker containing an enterokinase cleavage site, and a target protein of interest. Carbonic anhydrase is soluble and stable in E. coli and serves as a highly specific purification tag in the recovery of the fusion protein by a single affinity chromatography step. The enterokinase cleavage site was engineered into the construct to allow accurate and efficient release of the target protein. To demonstrate the practical value of this vector, the E. coli F1-ATPase epsilon subunit was expressed as a fusion with hCAII. After a single purification step, biologically active recombinant E. coli F1-ATPase epsilon subunit was recovered following proteolytic removal of the hCAII moiety.

  18. CERCETĂRI ŞTIINŢIFICE PRIVIND SUBIECTUL INFRACŢIUNILOR PREVĂZUTE ÎN CAPITOLELE XV ŞI XVI DIN PARTEA SPECIALĂ A CODULUI PENAL

    Directory of Open Access Journals (Sweden)

    Ruslan POPOV

    2015-11-01

    Full Text Available Printre oamenii de ştiinţă care au contribuit la elaborarea concepţiei teoretice de soluţionare a problemei privind subiectul infracţiunilor prevăzute în Capitolele XV şi XVI din Partea Specială a Codului penal se numără: S.Brînza, V.Cuşnir, D.-L. Melinte, V.Moraru, I.Nastas, V.Stati, C.Timofei, I.Ţurcan (Republica Moldova; I.Brad, C.Duvac, A.O. Sabău-Pop (România; N.V. Bugaevskaia, V.A. Volkolupova, V.A Lobârev, M.N. Haciaturian, S.S. Cerebedov (Federaţia Rusă; V.P. Kovalenko, R.L. Maximovici, T.Sluţka (Ucraina. Lucrările acestor autori constituie baza teoretică a investigaţiei noastre. Studiul de faţă are scopul să întregească cercetările efectuate anterior în domeniu, în el fiind evidenţiate unele tendinţe şi aspecte noi, specifice etapei actuale de dezvoltare a relaţiilor sociale.THE SCIENTIFIC RESEARCH ON THE SUBJECT OF THE OFFENCES REFFERED TO AT CHAPTERS XV AND XVI OF THE SPECIAL PART OF THE PENAL CODEAmong the scientists who helped develop the theoretical concept with regard to solving the problem concerning the subject of the offences set out at Chapters XV and XVI of the Special Part of the Penal Code are the following names: S.Brinza, V.Cusnir, D.-L. Melinte, V.Moraru, I.Nastas, V.Stati, C.Timofei, I.Turcan (Republic of Moldova; I.Brad, C.Duvac, A.O. Sabau-Pop (Romania; N.V. Bugaevskaia, V.A. Volkolupova, V.A Lobarev, M.N. Haciaturian, S.S. Cerebedov (Russian Federation; V.P. Kovalenko, R.L. Maximovici, T.Slutka (Ukraine. The works of these authors form the theoretical basis of our investigation. This study aims to complement previous research conducted in the field, highlighting some of the trends and new issues specific to the current stage of development of social relationships.

  19. Expression of von Hippel-Lindau tumor suppressor and tumor-associated carbonic anhydrases Ⅸ and Ⅻ in normal and neoplastic colorectal mucosa

    Institute of Scientific and Technical Information of China (English)

    Antti J. Kivela; Abdul Waheed; William S. Sly; Hannu Rajaniemi; Silvia Pastorekova; Jaromir Pastorek; Seppo Parkkila; Juha Saarnio; Tuomo J. Karttunen; Jyrki Kivela; Anna-Kaisa Parkkila; Maria Bartosova; Vojtech Mucha; Michal Novak

    2005-01-01

    AIM: To analyze possible relationships between CA Ⅸ/ CA Ⅻ and pVHL expression in normal and neoplastic colorectal mucosa.METHODS: Immunohistochemical staining of 42 tissue specimens obtained from 17 cancer patients was performed to evaluate the distribution and semi-quantitatively assess the levels of CA Ⅸ, CA Ⅻ and pVHL. VHL mRNAs from 14fresh-frozen tumors was amplified by RT-PCR and subjected to sequencing. CA9 and CA12 mRNA levels were analyzed by semi-quantitative RT-PCR in comparison with VEGF as an indicator of hypoxia that uncouples the pVHL control.RESULTS: Tumor tissues were associated with a borderline increase of CA Ⅸ staining signal and slight but significant decrease of CA Ⅻ immunoreactivity, whereas no association was found for pVHL. Sequence analysis of RT-PCR-amplified VHL mRNAs revealed no deletions/ mutations, suggesting that they were VHL-competent. We did not observe any correlation between pVHL andCA Ⅸ/CA Ⅻ proteins as well as between VEGF and CA9mRNAs, but the tumor-associated changes in mRNA levels of VEGF and CA12showed a significant inverse relationship. CONCLUSION: Our results indicate that CA9 and CA12 are regulated by different intratumoral factors and that lack of apparent relationship between the levels of CA Ⅸ/CA Ⅻ and pVHL cannot be fully assigned to uncoupling of negative regulatory function of pVHL by tumor hypoxia signified by induced VEGF transcription. The interplay between the functional pVHL and CA Ⅸ/CA Ⅻ in colorectal tumors seems rather complex and is not evident merely at the expression levels.

  20. Reconfiguración de alianzas políticas en contextos críticos: los caciques de San Andrés de Machaca (Pacajes, Audiencia de Charcas, siglos XV-XVII

    Directory of Open Access Journals (Sweden)

    Ariel Jorge Morrone

    2015-02-01

    Full Text Available Este trabajo explora las estrategias de reconfiguración política articuladas por los líderes étnicos de San Andrés de Machaca (actual provincia Ingavi, departamento de La Paz, Bolivia, en tres contextos críticos: la invasión incaica (a mediados del siglo xv, la sistematización del orden colonial hispánico (fines del siglo xvi y el desarrollo posterior de este sistema (primera mitad del siglo xvii. Cada situación definió nuevas reglas del juego político, ante las cuales las autoridades étnicas apelaron a una variedad de prácticas: la reorganización territorial, la asignación de recursos (de consumo y de prestigio, los rituales de negociación, la memoria genealógica y el tramado de redes personales.

  1. Salustiano de Dios y Eugenia Torijano (coords., Cultura, política y práctica del Derecho. Juristas de Salamanca, Siglos XV-XX, Ediciones Universidad de Salamanca, Salamanca, 2012, 567 págs.

    Directory of Open Access Journals (Sweden)

    Guillermo Hierrezuelo Conde

    2013-03-01

    Full Text Available En esta obra se recogen hasta siete estudios relativos a juristas de Salamanca en el período que comprende desde el s. XV hasta el pasado siglo XX. El primero de ellos está dedicado a distintos juristas salmantinos que vivieron durante el s. XV, destacando la figura de Pedro de Luna, conocido como papa Benedicto XIII; el segundo de los artículos pone de relieve la importancia de los colegios mayores salmantinos, institución en la que se tramitaron numerosos expedientes a los colegiales para la averiguación de la limpieza de sangre, así como otros aspectos, como la honorabilidad de la línea familiar; la tercera de las colaboraciones gira en torno a la figura del oficial de la administración española en el s. XVIII, y a las referencias que sobre ella se recogen en la obra de Jean Pierre Dedieu titulada La muerte del letrado; el cuarto estudia la personalidad del catedrático Vicente Fernández de Ocampo, que vivió entre 1743 y 1815; el quinto al informe realizado al proyecto de Código Civil de 1851 por la Facultad de jurisprudencia de la Universidad de Salamanca, que aunque no llegó a entrar en vigor adquirió gran trascendencia en el ámbito civil; el sexto, a la importancia de las audiencias de lo criminal de Salamanca y Ciudad Rodrigo, hasta la supresión de esta última; y el último de ellos, a aquellos profesores de la Universidad de Salamanca que vivieron los primeros años de la Dictadura franquista, entre los que podemos citar a Teodoro Andrés Marcos y Nicolás Rodríguez Aniceto, entre otros.

  2. Sonoma County, CA, 2013 Lidar

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Sonoma County Vegetation Mapping and LiDAR Consortium retained WSI to provide lidar and Orthophoto data and derived products in Sonoma County, CA. A classified LAS...

  3. CA125 in ovarian cancer

    DEFF Research Database (Denmark)

    Duffy, M J; Bonfrer, J M; Kulpa, J

    2005-01-01

    value in the detection of early ovarian cancer. At present, therefore, CA125, either alone or in combination with other modalities, cannot be recommended for screening for ovarian cancer in asymptomatic women outside the context of a randomized controlled trial. Preoperative levels in postmenopausal...... women, however, may aid the differentiation of benign and malignant pelvic masses. Serial levels during chemotherapy for ovarian cancer are useful for assessing response to treatment. Although serial monitoring following initial chemotherapy can lead to the early detection of recurrent disease......CA125 is currently the most widely used tumor marker for ovarian epithelial cancer. The aim of this article is to provide guidelines for the routine clinical use of CA125 in patients with ovarian cancer. Due to lack of sensitivity for stage I disease and lack of specificity, CA125 is of little...

  4. Cathodic behavior of molten CaCl2-CaO and CaCl2-NaCl-CaO

    Science.gov (United States)

    Wang, Shu-Lan; Wang, Wei; Li, Shi-Chao; Cao, Shan-Hui

    2010-12-01

    The cathodic behavior of molten CaCl2, CaCl2-CaO and equimolar CaCl2-NaCl-CaO was studied by cyclic voltammograms and constant potential polarization at temperatures of 1123 to 1173 K on molybdenum and titanium electrodes. The diffusion coefficient of Ca2+ (CaO) in molten CaCl2-CaO was calculated from the linear relationship between the square root of scan rate and the peak current density. The deposition potentials and the potential temperature coefficient of CaO in molten CaCl2-0.5mol%CaO and CaCl2-NaCl-0.5mol%CaO were also obtained from their cyclic voltammograms. The result shows that CaO is more easily reduced than CaCl2. The addition of NaCl in molten CaCl2-CaO induces the underpotential electrodeposition of CaO.

  5. Análise epidemiológica de lesões no futebol de salão durante o XV Campeonato Brasileiro de Seleções Sub 20 Análisis epidemiológico de las lesiones en el fútbol de salón durante el XV Campeonato Brasileño de Selecciones Sub 20 Epidemiologic analysis of injuries occurred during the 15th Brazilian Indoor Soccer (Futsal Sub20 Team Selection Championship

    Directory of Open Access Journals (Sweden)

    Rodrigo Nogueira Ribeiro

    2006-02-01

    Full Text Available INTRODUÇÃO: Vários autores têm investigado a incidência de lesões no futebol. Entretanto, poucos trabalhos têm analisado as lesões no Futebol de Salão. O objetivo deste estudo foi analisar a incidência, circunstâncias e características das lesões registradas no Futebol de Salão durante o XV Campeonato Brasileiro de Futebol de Salão Sub 20. MÉTODOS: Fisioterapeutas ou médicos de todas as seleções participantes do XV Campeonato Brasileiro de Futebol de Salão Sub 20 responderam a um questionário para investigar a ocorrência de lesões durante as partidas. A taxa de resposta foi de 100%. RESULTADOS: Um total de 32 lesões foi registrado durante as 23 partidas, com incidência de 1,39 lesão por partida ou 208,6 lesões por 1.000 horas/jogo. Aproximadamente 1 a 3 lesões por partida resultaram em afastamento de jogadores em partidas ou treinamentos. As lesões de contato eram predominantes em 65,62% (21 das 32 lesões e a maioria dessas lesões não resultou no afastamento dos jogadores. CONCLUSÕES: O presente estudo observou que a incidência das lesões durante o XV Campeonato Brasileiro de Futebol de Salão Sub 20 foi semelhante à registrada em torneios de Futebol de Salão, mas superior aos achados em torneios de futebol, caracterizando a especificidade do esporte. Entretanto, circunstâncias e características são similares entre eles devido à semelhança de demanda do esporte.INTRODUCCIÓN: Varios autores han estado investigando la incidencia de lesiones en el fútbol. Sin embargo, pocos trabajos han estado analizando las lesiones en el fútbol de salón. El objetivo de este estudio fue el de analizar la incidencia, y las circunstancias, y características de las lesiones registradas en el fútbol de salón durante el XV Campeonato Brasileño de Fútbol de salón Sub 20. MÉTODOS: Médicos y/o fisioterapeutas del todos los participantes del XV Campeonato Brasileño de Fútbol de salón Sub 20 contestaron una encuesta

  6. The Role of Hypoxia-Inducible Factor-1α, Glucose Transporter-1, (GLUT-1 and Carbon Anhydrase IX in Endometrial Cancer Patients

    Directory of Open Access Journals (Sweden)

    Pawel Sadlecki

    2014-01-01

    Full Text Available Hypoxia-inducible factor-1α (HIF-1α, glucose transporter-1 (GLUT-1, and carbon anhydrase IX (CAIX are important molecules that allow adaptation to hypoxic environments. The aim of our study was to investigate the correlation between HIF-1α, GLUT-1, and CAIX protein level with the clinicopathological features of endometrial cancer patients. Materials and Methods. 92 endometrial cancer patients, aged 37–84, were enrolled to our study. In all patients clinical stage, histologic grade, myometrial invasion, lymph node, and distant metastases were determined. Moreover, the survival time was assessed. Immunohistochemical analyses were performed on archive formalin fixed paraffin embedded tissue sections. Results. High significant differences (P=0.0115 were reported between HIF-1α expression and the histologic subtype of cancer. Higher HIF-1α expression was associated with the higher risk of recurrence (P=0.0434. The results of GLUT-1 and CAIX expression did not reveal any significant differences between the proteins expression in the primary tumor and the clinicopathological features. Conclusion. The important role of HIF-1α in the group of patients with the high risk of recurrence and the negative histologic subtype of the tumor suggest that the expression of this factor might be useful in the panel of accessory pathomorphological tests and could be helpful in establishing more accurate prognosis in endometrial cancer patients.

  7. Effect of CO2 concentrations on the activity of photosynthetic CO2 fixation and extracelluar carbonic anhydrase in the marine diatom Skeletonema costatum

    Institute of Scientific and Technical Information of China (English)

    CHEN Xiongwen; GAO Kunshan

    2003-01-01

    The growth and activity of photosynthetic CO2 uptake and extracellular carbonic anhydrase (Caext) of the marine diatom Skeletonema costatum were investigated while cultured at different levels of CO2 in order to see its physiological response to different CO2 concentrations under either a low (30 μmol·m-2·s-1) or high (210 μmol·m-2·s-1) irradiance. The changes in CO2 concentrations (4-31 μmol/L) affected the growth and net photosynthesis to a greater extent under the low than under the high light regime. Caext was detected in the cells grown at 4 μmol/L CO2 but not at 31 and 12 μmol/L CO2, with its activity being about 2.5-fold higher at the high than at the low irradiance. Photo- synthetic CO2 affinity (1/ K1/2(CO2)) of the cells decreased with increased CO2 concentrations in culture. The cells cultured under the high-light show significantly higher photosynthetic CO2 affinity than those grown at the low-light level. It is concluded that the regulations of Caext activity and photosynthetic CO2 affinity are dependent not only on CO2 concentration but also on light availability, and that the development of higher Caext activity and CO2 affinity under higher light level could sufficiently support the photosynthetic demand for CO2 even at low level of CO2.

  8. Major contribution of the type II beta carbonic anhydrase CanB (Cj0237) to the capnophilic growth phenotype of Campylobacter jejuni.

    Science.gov (United States)

    Al-Haideri, Halah; White, Michael A; Kelly, David J

    2016-02-01

    Campylobacter jejuni, the leading cause of human bacterial gastroenteritis, requires low environmental oxygen and high carbon dioxide for optimum growth, but the molecular basis for the carbon dioxide requirement is unclear. One factor may be inefficient conversion of gaseous CO2 to bicarbonate, the required substrate of various carboxylases. Two putative carbonic anhydrases (CAs) are encoded in the genome of C. jejuni strain NCTC 11168 (Cj0229 and Cj0237). Here, we show that the deletion of the cj0237 (canB) gene alone prevents growth in complex media at low (1% v/v) CO2 and significantly reduces the growth rate at high (5% v/v) CO2. In minimal media incubated under high CO2, the canB mutant grew on L-aspartate but not on the key C3 compounds L-serine, pyruvate and L-lactate, showing that CanB is crucial in bicarbonate provision for pyruvate carboxylase-mediated oxaloacetate synthesis. Nevertheless, purified CanB (a dimeric, anion and acetazolamide sensitive, zinc-containing type II beta-class enzyme) hydrates CO2 actively only above pH 8 and with a high Km (∼ 34 mM). At typical cytoplasmic pH values and low CO2, these kinetic properties might limit intracellular bicarbonate availability. Taken together, our data suggest CanB is a major contributor to the capnophilic growth phenotype of C. jejuni.

  9. Association between dental-oral health in young adults and salivary glutathione, lipid peroxidation and sialic acid levels and carbonic anhydrase activity

    Directory of Open Access Journals (Sweden)

    L.K. Öztürk

    2008-11-01

    Full Text Available The aim of the present study was to evaluate the relationship between salivary oxidative stress and dental-oral health. Healthy young adults, matched for gender and age, with (N = 21, 10 men, mean age: 20.3 ± 1 years and without (N = 16, 8 men, mean age: 21.2 ± 1.8 years caries were included in this study. The World Health Organization (WHO caries diagnostic criteria were used for determining the decayed, missing, filled teeth (DMFT index. The oral hygiene and gingival status were assessed using the simplified oral hygiene index and gingival index, respectively. Unstimulated salivary total protein, glutathione (GSH, lipid peroxidation and total sialic acid levels, carbonic anhydrase activity, and salivary buffering capacity were determined by standard methods. Furthermore, salivary pH was measured with pH paper and salivary flow rate was calculated. Simplified oral hygiene index and gingival index were not significantly different between groups but DMFT scores were significant (P < 0.01. Only, GSH values were significantly different (P < 0.05 between groups (2.2 and 1.6 mg/g protein in young adults without caries and with caries, respectively. There was a significant negative correlation between DMFT and GSH (r = -0.391; P < 0.05; Pearson's correlation coefficient. Our results suggest that there is an association between caries history and salivary GSH levels.

  10. In Vivo Loss of Function Screening Reveals Carbonic Anhydrase IX as a Key Modulator of Tumor Initiating Potential in Primary Pancreatic Tumors

    Directory of Open Access Journals (Sweden)

    Nabendu Pore

    2015-06-01

    Full Text Available Reprogramming of energy metabolism is one of the emerging hallmarks of cancer. Up-regulation of energy metabolism pathways fuels cell growth and division, a key characteristic of neoplastic disease, and can lead to dependency on specific metabolic pathways. Thus, targeting energy metabolism pathways might offer the opportunity for novel therapeutics. Here, we describe the application of a novel in vivo screening approach for the identification of genes involved in cancer metabolism using a patient-derived pancreatic xenograft model. Lentiviruses expressing short hairpin RNAs (shRNAs targeting 12 different cell surface protein transporters were separately transduced into the primary pancreatic tumor cells. Transduced cells were pooled and implanted into mice. Tumors were harvested at different times, and the frequency of each shRNA was determined as a measure of which ones prevented tumor growth. Several targets including carbonic anhydrase IX (CAIX, monocarboxylate transporter 4, and anionic amino acid transporter light chain, xc- system (xCT were identified in these studies and shown to be required for tumor initiation and growth. Interestingly, CAIX was overexpressed in the tumor initiating cell population. CAIX expression alone correlated with a highly tumorigenic subpopulation of cells. Furthermore, CAIX expression was essential for tumor initiation because shRNA knockdown eliminated the ability of cells to grow in vivo. To the best of our knowledge, this is the first parallel in vivo assessment of multiple novel oncology target genes using a patient-derived pancreatic tumor model.

  11. Absence of OsβCA1 causes CO2 deficit and affects leaf photosynthesis and stomatal response to CO2 in rice.

    Science.gov (United States)

    Chen, Taiyu; Wu, Huan; Wu, Jiemin; Fan, Xiaolei; Li, Xianghua; Lin, Yongjun

    2017-01-31

    Plants always adjust the opening of stomatal pores to adapt to the environments, such as [CO2 ], humidity and temperature. Low [CO2 ] will trigger the opening of stomatal pores to absorb extra CO2 . However, little is known about how CO2 supply affects the carbon fixation and opening of stomatal pores in rice. Here, a chloroplast-located β-carbonic anhydrase (β-CA) coding gene was found to be involved in carbon assimilation and CO2 -mediated stomatal pore response in rice. OsβCA1 was constitutively expressed in all tissues and its transcripts were induced by high [CO2 ] in leaves. Both T-DNA mutant and RNAi lines showed phenotypes of lower biomass and CA activities. The knock-out of OsβCA1 obviously decreased the photosynthesis capacity, as demonstrated by the increased CO2 compensation point and decreased light saturation point in the mutant; while the knock-out increased the opening ratio of stomatal pores and water loss rate. Moreover, the mutant showed a delayed response to low [CO2 ], and they could not be closed to the degree of wild plants even though the stomatal pores could rapidly respond to high [CO2 ]. Genome-wide gene expression analysis via RNA-seq demonstrated that the transcript abundance of the genes related to RuBisCO, photosystem compounds and opening of stomatal pores were globally up-regulated in the mutant. Taken together, the inadequate CO2 supply caused by the absence of OsβCA1 reduces photosynthesis efficiency, triggers the opening of stomatal pores and finally decreases their sensitivity to CO2 fluctuation. This article is protected by copyright. All rights reserved.

  12. 小新月菱形藻碳酸酐酶活性和光合作用对高盐度胁迫的响应%Response of carbonic anhydrase activity and photosynthesis to high salinity stress in Nitzschia closterium f.minutissima

    Institute of Scientific and Technical Information of China (English)

    余锦兰; 夏建荣; 邹永东

    2011-01-01

    Salinity is an important ecological factor in the algal growth.Water loss would lead to the increase of salinity in mass culture of fish food diatom, which could affect the algal photosynthesis and inorganic carbon utilization.In this paper, impacts of salinity on the growth, carbonic anhydrase activity, photosynthesis (P-I curve )and chlorophyll a fluorescence parameters in Nitzschia closterium f.minutissima were investigated to explore the photosynthetic mechanism of the diatom under the high salinity.The results showed that the specific growth rate when Nitzschia closterium f.minutissima was grown in high salinity (70)was decreased by 59.2% compared with the normal seawater, but it can maintain the growth to a certain degree in salinity up to 60 - 70, which suggested that Nitzschia closterium f.minutissima had a stronger tolerance to high salinity.The extracellular carbonic anhydrase activity which was measured by an electrometric method was reduced by 66.3%, and Chl.a and Chl.c contents which was determined spectrophotometrically were also decreased by 50.0% and 45.7% in high salinity (70).The extracellular CA activity was inhibited in high salinity environment which showed that capacity of HCO3- catalyzed by extracellular CA into CO2 declined, and high salinity stress can damage the Chl.a/b light harvesting complex (LHCII) and reaction-center complex and affect pigment synthesis.The chlorophyll a fluorescence parameters were measured by saturation pulse, and the maximal efficiency of PS Ⅱ photochemistry ( Fv/Fm ),actual photochemical efficiency of PS Ⅱ (Yield), photochemical quenching co-efficient (qP)decreased,whereas non-photochemical quenching co-efficient (qN)increased when the algae were grown in high salinity.These results showed that the high salinity stress would damage the PS Ⅱ reaction center, inhibit primary reaction of photosynthesis as well as the process of photosynthetic electron transport.The photosynthetic rate in the varied

  13. CA on CD评析

    Institute of Scientific and Technical Information of China (English)

    周秀会

    2007-01-01

    结合作者使用 CA On CD 的经验和体会,全面而具体地分析了 CA on CD 的使用功能,明确了其优点及不足之处,同时,针对这些不足之处进行了探索和尝试,提出了利用检索技巧解决这些不足之处的方法。并结合实例详细说明。

  14. The site of net absorption of Ca from the intestinal tract of growing pigs and effect of phytic acid, Ca level and Ca source on Ca digestibility.

    Science.gov (United States)

    González-Vega, J Caroline; Walk, Carrie L; Liu, Yanhong; Stein, Hans H

    2014-01-01

    An experiment was conducted to test the hypothesis that the standardised digestibility of Ca in calcium carbonate and Lithothamnium calcareum Ca is not different regardless of the level of dietary Ca, and that phytic acid affects the digestibility of Ca in these two ingredients to the same degree. The objectives were to determine where in the intestinal tract Ca absorption takes place and if there are measurable quantities of basal endogenous Ca fluxes in the stomach, small intestine or large intestine. Diets contained calcium carbonate or L. calcareum Ca as the sole source of Ca, 0% or 1% phytic acid and 0.4% or 0.8% Ca. A Ca-free diet was also formulated and used to measure endogenous fluxes and losses of Ca. Nine growing pigs (initial body weight 23.8 ± 1.3 kg) were cannulated in the duodenum and in the distal ileum, and faecal, ileal and duodenal samples were collected. Duodenal endogenous fluxes of Ca were greater (p phytic acid, but decreased (p phytic acid, but may be affected by dietary Ca level depending on the Ca source. Calcium from calcium carbonate is mostly absorbed before the duodenum, but Ca from L. calcareum Ca is mostly absorbed in the jejunum and ileum.

  15. The diagnostic value of joint detection of serum CA19-9, CA125 and CA242 for cholangiocarcinoma

    Institute of Scientific and Technical Information of China (English)

    Cui Da-Peng; Han Lei; Liu Zhen-Xian; Yang He; Zhang Ying-Chun

    2016-01-01

    Objective:To study the diagnostic value of joint detection of serum CA19-9, CA125 and CA242 for cholangiocarcinoma.Methods:A total of 35 patients with cholangiocarcinoma who received surgical resection in our hospital were selected as malignant group, 30 patients with cholelithiasis who received surgical resection in our hospital during the same period were selected as benign group, serum samples were collected before surgery to determine CA19-9, CA125 and CA242 content, and cholangiocarcinoma tissue and normal bile duct tissue were collected after surgery to determine the content of proliferation and invasion molecules. Results:Serum CA19-9, CA125 and CA242 levels of malignant group were significantly higher than those of control group; PROX-1, Ki-67, Bcl-2, Bad, Gab1, LOXL2, TRPM7 and CXCL12 levels in cholangiocarcinoma tissue were higher than those in benign bile duct tissue, and E-cadherin level was lower than that in benign bile duct tissue; serum CA19-9, CA125 and CA242 levels were positively correlated with PROX-1, Ki-67, Bcl-2, Bad, Gab1, LOXL2, TRPM7 and CXCL12 levels, and negatively correlated with E-cadherin level.Conclusion:Joint detection of serum CA19-9, CA125 and CA242 can not only provide reference for the diagnosis of cholangiocarcinoma, but can also provide basis for the evaluation of proliferation, invasion and other malignant biological behaviors.

  16. The Effect of Nitrogen Sources and Its Additional Strategies on L-valine Fermentation by Brevibacterium flavum XV0505%氮源及其补加策略对L-缬氨酸发酵的影响

    Institute of Scientific and Technical Information of China (English)

    冯宁; 白亚磊; 徐庆阳; 谢希贤; 陈宁

    2011-01-01

    通过分析黄色短杆菌xv0505发酵生产L-缬氨酸的过程,得知在菌体生长期和快速产酸期氮源对L-缬氨酸发酵的影响不同.以黄色短杆菌XV0505为供试菌株,研究了不同氮源种类及不同氮源浓度对L-缬氨酸发酵过程的影响,选定了以豆饼水解液和硫酸铵为氮源,并确定了合适的初始氮源浓度.在初始氮源浓度相同的情况下,考察了间歇流加补氮策略、恒氮源浓度补氮策略和幂函数流加补氮策略对L-缬氨酸发酵的影响,研究发现,幂指数补氮策略可减少频繁的取样及铵浓度检测,在缺乏在线监测系统和反馈自控系统的情况下,将发酵体系中氮源浓度维持在合适值,既可适度促进菌体生长,又可使L-缬氨酸的产量得到进一步提高.在最优的氮源添加策略下,在30 L发酵罐发酵60 h,发酵液中L-缬氨酸可达63.17 g/L,糖酸转化率24.69%.%By analyzing the L-valine fermentation process by Brevibacterium flavum XV0505, one of important factors influenced on the bacterial productivity and L-valine yield is nitrogen source and its additional strategies. The effect of nitrogen sources on the fermentation of L-valine was studied by adding different nitrogen sources with different concentrations. Therefore, soybean hydrolysates and ammonium sulfate were selected as the appropriate nitrogen source, and the best L-valine yield was obtained with the medium supplemented low initial concentration of 225 mmol/L. In the case of the same initial nitrogen concentration, the effects of three nitrogen feeding strategies (intermittent nitrogen feeding,constant concentration feeding and power function feeding) on biomass, yield of L-valine,concentration of byproduct and conversion rate were studied in the 30L fermentor. The result showed that the concentration and the feed rate of nitrogen source were effectively and timely manipulated by power function feeding, while lacking of online monitoring and feedback

  17. 水化层影响酸酐酶内CO2扩散行为的分子动力学模拟%Molecular dynamics simulation for hydration effect on CO2 diffusion in carbonic anhydrase

    Institute of Scientific and Technical Information of China (English)

    陈功; 卢滇楠; 吴建中; 刘铮

    2015-01-01

    The hydration layer of the enzyme in the bulk gas phase has great effects on its catalytic performance. Molecular dynamics (MD) simulations at all-atom level was applied to investigate the effects of the hydration layer thickness on the diffusion of carbon dioxide molecules into the active site of a carbonic anhydrase enzyme from a bulk gas phase. Based on the distribution of water molecules surrounding the carbonic anhydrase enzyme, the effects of the hydration layer thickness on the protein structure and CO2 transport from the bulk gas phase to the protein active site was studied. The simulation results suggested an optimal hydration layer thickness of 0.7 nm for CO2 diffusion. The CO2 adsorption sites were identified, which compose of the diffusion channel inside the carbonic anhydrase. The MD simulation revealed the open states of these adsorption sites, which may be useful to identify the bottleneck position of the diffusion channel. The molecular insight is helpful for design and optimization of carbonic anhydrase, enabling more efficient CO2 adsorption and conversion.%气相中酶分子表面的水化层对其催化行为具有显著的影响。本文采用全原子分子动力学模拟方法考察了气相体系碳酸酐酶表面的水化层对酶结构以及CO2在酶分子中扩散行为的影响。首先展现了水分子在酶分子及其活性中心周围的分布,研究了水化层厚度对于酶结构以及CO2扩散速率的影响;发现最有利于CO2扩散进入酶分子的水化层厚度为0.7 nm。确认了碳酸酐酶内CO2的吸附位点,通过对其开合状态统计,显示出碳酸酐酶中CO2扩散通道中的瓶颈位置。上述结果对设计和优化碳酸酐酶催化气相体系中CO2的吸附和转化提供了依据和启示。

  18. Isotopic Effects on Stereodynamics for Ca+HCI, Ca+DCI, and Ca+TClReactions

    Institute of Scientific and Technical Information of China (English)

    Li-zhi Wang; Chuan-lu Yang; Jing-juan Liang; Jing Xiao; Qing-gang Zhang

    2011-01-01

    The vector correlations in Ca+HC1,Ca+DCI,and Ca+TCI reactions have been investigated by means of the quasi-classical trajectory calculations on PES constructed by means of multireference configuration interaction.The distributions of P(θr),P(Φr) and the PDDCSs of (2π/σ)(dσ00/dωt),(2π/σ)(dσ20/dωt),(2π/σ)(dσ22+/dωt),(2π/σ)(dσ21-/dωt) have been calculated based on the surface.The remarkable isotopic effects in the reactions are observed,and the mechanism which may be ascribed to different mass factors is discussed.

  19. Solar Ca II K Observations

    Science.gov (United States)

    Bertello, Luca; Pevtsov, Alexei A.; Tlatov, Andrey; Singh, Jagdev

    2016-07-01

    Some of the most important archives of past and current long-term solar synoptic observations in the resonance line of Ca II K are described here. These observations are very important for understanding the state of the solar magnetism on time scales up to several decades. The first observations of this kind began in 1904 at the Kodaikanal Observatory (India), followed by similar programs at different other locations. Regular full-disk Ca II K monitoring programs started in 1915 at the Mount Wilson Observatory (USA) and in 1917 at the National Solar Observatory of Japan. Beginning in 1919 and in 1926 regular observations were taken also at the Paris-Meudon Observatory (France) and at the "Donati solar tower telescope of the Arcetri Astrophysical Observatory in Italy, respectively. In 1926 the the Astronomical Observatory of the Coimbra University in Portugal started its own program of Ca II K observations. Although some of these programs have been terminated over the years, their data archives constitute a unique resource for studies of solar variability. In the early 1970s, the National Solar Observatory (NSO) at Sacramento Peak (USA) started a new program of daily Sun-as-a-star observations in the Ca II K line. Today the NSO is continuing these observations through its Synoptic Optical Long-term Investigations of the Sun (SOLIS) facility.

  20. Typologia sygnetów drukarskich (na przykładzie znaków stosowanych przez polskich impresorów od XV do połowy XVII wieku

    Directory of Open Access Journals (Sweden)

    Katarzyna Krzak-Weiss

    2009-01-01

    Full Text Available Celem niniejszego artykułu jest przedstawienie typologii sygnetów drukarskich stosowanych przez impresorów działających na ziemiach polskich od XV do połowy XVII stulecia, a zatem od momentu, gdy ów element wytłoczony został w polskim druku po raz pierwszy, do chwili, gdy polska typografia (a wraz z nią i sygnet przeżywać zaczęły wyraźny kryzys. Wydzielony tymi ramami chronologicznymi zbiór liczy ponad 100 znaków impresorskich, a zatem na tyle dużo, by potrzebne, a wręcz konieczne, było jego uporządkowanie. Metodą, która pozwala uczynić to możliwie najprzejrzyściej, jest wyodrębnienie w ramach przedmiotu badań poszczególnych typów, co odbywa się na podstawie odpowiednio dobranych kryteriów. Odpowiednio, czyli tak, by uwzględniały każdy aspekt badanej materii i pozwalały na ukazanie jej w sposób jak najpełniejszy. W przypadku sygnetów drukarskich kryteria te muszą mieć nade wszystko na względzie fakt, że godła impresorskie są nie tylko elementami typograficznymi, ale i graficznymi, co powoduje, że rozpatrywać je należy w świetle zarówno typografii (czy szerzej bibliologii, jak i sztuki graficznej. Wziąwszy to pod uwagę, bogaty i wielce zróżnicowany zespół, jaki tworzą polskie sygnety używane od XV do połowy XVII wieku, uporządkować można na podstawie trzech kryteriów: chronologicznego, ikonograficznego i związanego z morfologią książki.

  1. EMRE Is a Matrix Ca(2+) Sensor that Governs Gatekeeping of the Mitochondrial Ca(2+) Uniporter.

    Science.gov (United States)

    Vais, Horia; Mallilankaraman, Karthik; Mak, Don-On Daniel; Hoff, Henry; Payne, Riley; Tanis, Jessica E; Foskett, J Kevin

    2016-01-26

    The mitochondrial uniporter (MCU) is an ion channel that mediates Ca(2+) uptake into the matrix to regulate metabolism, cell death, and cytoplasmic Ca(2+) signaling. Matrix Ca(2+) concentration is similar to that in cytoplasm, despite an enormous driving force for entry, but the mechanisms that prevent mitochondrial Ca(2+) overload are unclear. Here, we show that MCU channel activity is governed by matrix Ca(2+) concentration through EMRE. Deletion or charge neutralization of its matrix-localized acidic C terminus abolishes matrix Ca(2+) inhibition of MCU Ca(2+) currents, resulting in MCU channel activation, enhanced mitochondrial Ca(2+) uptake, and constitutively elevated matrix Ca(2+) concentration. EMRE-dependent regulation of MCU channel activity requires intermembrane space-localized MICU1, MICU2, and cytoplasmic Ca(2+). Thus, mitochondria are protected from Ca(2+) depletion and Ca(2+) overload by a unique molecular complex that involves Ca(2+) sensors on both sides of the inner mitochondrial membrane, coupled through EMRE.

  2. Feedforward non-Michaelis-Menten mechanism for CO(2) uptake by Rubisco: contribution of carbonic anhydrases and photorespiration to optimization of photosynthetic carbon assimilation.

    Science.gov (United States)

    Igamberdiev, Abir U; Roussel, Marc R

    2012-03-01

    Rubisco, the most abundant protein serving as the primary engine generating organic biomass on Earth, is characterized by a low catalytic constant (in higher plants approx. 3s(-1)) and low specificity for CO(2) leading to photorespiration. We analyze here why this enzyme evolved as the main carbon fixation engine. The high concentration of Rubisco exceeding the concentration of its substrate CO(2) by 2-3 orders of magnitude makes application of Michaelis-Menten kinetics invalid and requires alternative kinetic approaches to describe photosynthetic CO(2) assimilation. Efficient operation of Rubisco is supported by a strong flux of CO(2) to the chloroplast stroma provided by fast equilibration of bicarbonate and CO(2) and forwarding the latter to Rubisco reaction centers. The main part of this feedforward mechanism is a thylakoidal carbonic anhydrase associated with photosystem II and pumping CO(2) from the thylakoid lumen in coordination with the rate of electron transport, water splitting and proton gradient across the thylakoid membrane. This steady flux of CO(2) limits photosynthesis at saturating CO(2) concentrations. At low ambient CO(2) and correspondingly limited capacity of the bicarbonate pool in the stroma, its depletion at the sites of Rubisco is relieved by utilizing O(2) instead of CO(2), i.e. by photorespiration, a process which supplies CO(2) back to Rubisco and buffers the redox state and energy level in the chloroplast. Thus, the regulation of Rubisco function aims to keep steady non-equilibrium levels of CO(2), NADPH/NADP and ATP/ADP in the chloroplast stroma and to optimize the condition of homeostatic photosynthetic flux of matter and energy.

  3. Label-free characterization of carbonic anhydrase-novel inhibitor interactions using surface plasmon resonance, isothermal titration calorimetry and fluorescence-based thermal shift assays.

    Science.gov (United States)

    Rogez-Florent, Tiphaine; Duhamel, Laetitia; Goossens, Laurence; Six, Perrine; Drucbert, Anne-Sophie; Depreux, Patrick; Danzé, Pierre-Marie; Landy, David; Goossens, Jean-François; Foulon, Catherine

    2014-01-01

    This work describes the development of biophysical unbiased methods to study the interactions between new designed compounds and carbonic anhydrase II (CAII) enzyme. These methods have to permit both a screening of a series of sulfonamide derivatives and the identification of a lead compound after a thorough study of the most promising molecules. Interactions data were collected using surface plasmon resonance (SPR) and thermal shift assay (TSA). In the first step, experiments were performed with bovine CAII isoform and were extended to human CAII. Isothermal titration calorimetry (ITC) experiments were also conducted to obtain thermodynamics parameters necessary for the processing of the TSA data. Results obtained with this reference methodology demonstrate the effectiveness of SPR and TSA. KD values obtained from SPR data were in perfect accordance with ITC. For TSA, despite the fact that the absolute values of KD were quite different, the same affinity scale was obtained for all compounds. The binding affinities of the analytes studied vary by more than 50 orders of magnitude; for example, the KD value determined by SPR were 6 ± 4 and 299 ± 25 nM for compounds 1 and 3, respectively. This paper discusses some of the theoretical and experimental aspects of the affinity-based methods and evaluates the protein consumption to develop methods for the screening of further new compounds. The double interest of SPR, that is, for screening and for the quick thorough study of the interactions parameters (ka , kd , and KD ), leads us to choose this methodology for the study of new potential inhibitors.

  4. Identification of putative unfolding intermediates of the mutant His-107-tyr of human carbonic anhydrase II in a multidimensional property space.

    Science.gov (United States)

    Halder, Puspita; Taraphder, Srabani

    2016-06-01

    In this article, we develop an extensive search procedure of the multi-dimensional folding energy landscape of a protein. Our aim is to identify different classes of structures that have different aggregation propensities and catalytic activity. Following earlier studies by Daggett et al. [Jong, D. D.; Riley, R.: Alonso, D.O.: Dagett, V. J. Mol. Biol. 2002, 319, 229], a series of high temperature all-atom classical molecular simulation studies has been carried out to derive a multi-dimensional property space. Dynamical changes in these properties are then monitored by projecting them along a one-dimensional reaction coordinate, dmean . We have focused on the application of this method to partition a wide array of conformations of wild type human carbonic anhydrase II (HCA II) and its unstable mutant His-107-Tyr along dmean by sampling a 35-dimensional property space. The resultant partitioning not only reveals the distribution of conformations corresponding to stable structures of HCA II and its mutant, but also allows the monitoring of several partially unfolded and less stable conformations of the mutant. We have investigated the population of these conformations at different stages of unfolding and collected separate sets of structures that are widely separated in the property space. The dynamical diversity of these sets are examined in terms of the loading of their respective first principal component. The partially unfolded structures thus collected are qualitatively mapped on to the experimentally postulated light molten globule (MGL) and molten globule (MG) intermediates with distinct aggregation propensities and catalytic activities. Proteins 2016; 84:726-743. © 2016 Wiley Periodicals, Inc.

  5. KWU-werkersklasdramas in Afrikaans (ca. 1930 - ca. 1950

    Directory of Open Access Journals (Sweden)

    J. L. Coetser

    1999-05-01

    Full Text Available GWU working class theatre in Afrikaans (ca. 1930 - ca. 1950In 1984 Elsabé Brink drew attention to plays, prose and poetry written between 1930 and 1950 in Afrikaans by members of the Garment Workers’ Union (GWU. Scholars such as Stander and Willemse (1992, Van Niekerk (1996 and Van Wyk (1995, 1997 have also referred to GWU plays. Apart from these overviews, GWU plays as such have not yet received the attention they deserve. This article presents a revaluation, initially by providing an overview of their contents, followed by an examination of cultural, economic and political influences. It is argued that - retrospectively - the GWU plays reflected a unique cultural specificity from the framework established by Sitas (1986 for more contemporary working class theatre.

  6. Ca2+ dynamics in zebrafish morphogenesis

    Directory of Open Access Journals (Sweden)

    Yusuke Tsuruwaka

    2017-01-01

    Full Text Available Intracellular calcium ion (Ca2+ signaling is heavily involved in development, as illustrated by the use of a number of Ca2+ indicators. However, continuous Ca2+ patterns during morphogenesis have not yet been studied using fluorescence resonance energy transfer to track the Ca2+ sensor. In the present study, we monitored Ca2+ levels during zebrafish morphogenesis and differentiation with yellow cameleon, YC2.12. Our results show not only clear changes in Ca2+ levels but also continuous Ca2+ patterns at 24 hpf and later periods for the first time. Serial Ca2+dynamics during early pharyngula period (Prim-5-20; 24–33 hpf was successfully observed with cameleon, which have not reported anywhere yet. In fact, high Ca2+ level occurred concurrently with hindbrain development in segmentation and pharyngula periods. Ca2+ patterns in the late gastrula through segmentation periods which were obtained with cameleon, were similar to those obtained previously with other Ca2+sensor. Our results suggested that the use of various Ca2+ sensors may lead to novel findings in studies of Ca2+ dynamics. We hope that these results will prove valuable for further research in Ca2+ signaling.

  7. Extended Relativistic Configuration Interaction and Many-body Perturbation Calculations of Spectroscopic Data for the N ≤ 6 Configurations in Ne-like Ions between Cr xv and Kr xxvii

    Science.gov (United States)

    Wang, K.; Chen, Z. B.; Si, R.; Jönsson, P.; Ekman, J.; Guo, X. L.; Li, S.; Long, F. Y.; Dang, W.; Zhao, X. H.; Hutton, R.; Chen, C. Y.; Yan, J.; Yang, X.

    2016-10-01

    Level energies, wavelengths, electric dipole, magnetic dipole, electric quadrupole, and magnetic quadrupole transition rates, oscillator strengths, and line strengths from combined relativistic configuration interaction and many-body perturbation calculations are reported for the 201 fine-structure states of the 2{s}22{p}6, 2{s}22{p}53l, 2s2{p}63l, 2{s}22{p}54l, 2s2{p}64l, 2{s}22{p}55l, and 2{s}22{p}56l configurations in all Ne-like ions between Cr xv and Kr xxvii. Calculated level energies and transition data are compared with experiments from the National Institute of Standards and Technology (NIST) and CHIANTI databases, and other recent benchmark calculations. The mean energy difference with the NIST experiments is only 0.05%. The present calculations significantly increase the amount of accurate spectroscopic data for the n > 3 states in a number of Ne-like ions of astrophysical interest. A complete data set should be helpful for analyzing new observations from solar and other astrophysical sources, and is also likely to be useful for modeling and diagnosing a variety of plasmas, including astronomical and fusion plasma.

  8. El barrio de Arriasa y tres elementos de la aljama judía de Toledo en el siglo XV: la carnicería, la «sinagoga vieja» y el «castillo viejo»

    Directory of Open Access Journals (Sweden)

    Passini, Jean

    2008-06-01

    Full Text Available Already mentioned in 13th century written sources, the Arriasa neighborhood was an area within the Toledan Jewish quarter that still remained to be identified and demarcated. Documentary evidence –tenancy agreement charters dated back from the 13th until the 18th centuries–, as well as information on the vicissitudes experienced by the Jewish common properties from the late 15th century on, have been used to locate the butcher’s stalls, the “old synagogue” and the “old castle” on a street plan. Thus, the Arriasa neighborhood has been clearly delimited.

    Mencionado ya en el siglo XIII, el barrio de Arriasa había sido uno de los sectores de la Judería de Toledo más difíciles de localizar. Menciones en contratos conservados de arrendamiento de casas desde fines del siglo XIII y hasta la segunda mitad del siglo XVIII, y las vicisitudes sufridas por las propiedades inmuebles de la aljama judía desde fines del siglo xv han permitido situar la carnicería, la «sinagoga vieja» y el «castillo viejo». De esta manera se delimita claramente el barrio de Arriasa, que se distingue del barrio del Degolladero, aclarando además las referencias a la «sinagoga vieja» y al «castillo viejo».

  9. Sequence analysis of a 13.4 kbp fragment from the left arm of chromosome XV reveals a malate dehydrogenase gene, a putative Ser/Thr protein kinase, the ribosomal L25 gene and four new open reading frames.

    Science.gov (United States)

    Casamayor, A; Khalid, H; Balcells, L; Aldea, M; Casas, C; Herrero, E; Ariño, J

    1996-09-01

    A 13421 bp fragment located near the left telomere of chromosome XV (cosmid pEOA461) has been sequenced. Seven non-overlapping open reading frames (ORFs) encoding polypeptides longer than 100 residues have been found (AOB859, AOC184, AOE375, AOX142i, AOE423, AOA476 and AOE433). An additional ORF (AOE131) is found within AOA476. Three of them (AOC184, AOA476 and AOE433) show no remarkable identity with proteins deposited in the data banks. ORF AOB859 is quite similar to a hypothetical yeast protein of similar size located in chromosome VI, particularly within the C-terminal half. AOE375 encodes a new member of the glycogen synthase kinase-3 subfamily of Ser/Thr protein kinases. AOX142i is the gene encoding the previously described ribosomal protein L25. AOE423 codes for a protein virtually identical to the MDH2 malate dehydrogenase isozyme. However, our DNA sequence shows a single one-base insertion upstream of the reported initiating codon. This would produce a larger ORF by extending 46 residues the N-terminus of the protein. The existence of this insertion has been confirmed in three different yeast strains, including FY1679.

  10. Extended relativistic configuration interaction and many-body perturbation calculations of spectroscopic data for the $n \\leq 6$ configurationsin ne-like ions between Cr XV and Kr XXVII

    CERN Document Server

    Wang, Kai; Si, Ran; Jönsson, Per; Ekman, Jörgen; Guo, Xue Lin; Li, Shuang; Long, Fei Yun; Dang, Wei; Zhao, Xiao Hui; Hutton, Roger; Chen, Chong Yang; Yan, Jan; Yang, Xu

    2016-01-01

    Level energies, wavelengths, electric dipole, magnetic dipole, electric quadrupole, and magnetic quadrupole transition rates, oscillator strengths, and line strengths from combined relativistic configuration interaction and many-body perturbation calculations are reported for the 201 fine-structure states of the $2s^2 2p^6$, $2s^2 2p^5 3l$, $2s 2p^6 3l$, $2s^2 2p^5 4l$, $2s 2p^6 4l$, $2s^2 2p^5 5l$, and $2s^2 2p^5 6l$ configurations in all Ne-like ions between Cr XV and Kr XXVII. Calculated level energies and transition data are compared with experiments from the NIST and CHIANTI databases, and other recent benchmark calculations. The mean energy difference with the NIST experiments is only 0.05%. The present calculations significantly increase the amount of accurate spectroscopic data for the $n >3$ states in a number of Ne-like ions of astrophysics interest. A complete dataset should be helpful in analyzing new observations from the solar and other astrophysical sources, and is also likely to be useful for ...

  11. Lattice Dynamics of fcc Ca

    DEFF Research Database (Denmark)

    Stassis, C.; Zaretsky, J.; Misemer, D. K.;;

    1983-01-01

    to the propagation of elastic waves. The frequencies of the T1[ξξ0] branch for ξ between approximately 0.5 and 0.8 are slightly above the velocity-of-sound line determined from the low-frequency measurements. Since a similar effect has been observed in FCC Yb, it is natural to assume that the anomalous dispersion......A large single crystal of FCC Ca was grown and was used to study the lattice dynamics of this divalent metal by coherent inelastic neutron scattering. The phonon dispersion curves were measured, at room temperature, along the [ξ00], [ξξ0], [ξξξ], and [0ξ1] symmetry directions. The dispersion curves...... bear a striking resemblance to those of FCC Yb, which is also a divalent metal with an electronic band structure similar to that of Ca. In particular, the shear moduli c44 and (c11-c 12)/2 differ by a factor of 3.4, which implies that FCC Ca (like FCC Yb) is very anisotropic with regard...

  12. Fine tuning of cytosolic Ca 2+ oscillations

    Science.gov (United States)

    Dupont, Geneviève; Combettes, Laurent

    2016-01-01

    Ca 2+ oscillations, a widespread mode of cell signaling, were reported in non-excitable cells for the first time more than 25 years ago. Their fundamental mechanism, based on the periodic Ca 2+ exchange between the endoplasmic reticulum and the cytoplasm, has been well characterized. However, how the kinetics of cytosolic Ca 2+ changes are related to the extent of a physiological response remains poorly understood. Here, we review data suggesting that the downstream targets of Ca 2+ are controlled not only by the frequency of Ca 2+ oscillations but also by the detailed characteristics of the oscillations, such as their duration, shape, or baseline level. Involvement of non-endoplasmic reticulum Ca 2+ stores, mainly mitochondria and the extracellular medium, participates in this fine tuning of Ca 2+ oscillations. The main characteristics of the Ca 2+ exchange fluxes with these compartments are also reviewed. PMID:27630768

  13. [Effect of polycarbophil Ca on IBS].

    Science.gov (United States)

    Mine, Tetsuya

    2006-08-01

    In this chapter, I mentioned the effect of polycarbophil Ca on IBS. IBS is classified into 3 types; diarrhea type, constipation type and combined type. Polycarbophil Ca is effective for all types of IBS.

  14. Barnacle muscle: Ca2+, activation and mechanics.

    Science.gov (United States)

    Ashley, C C; Griffiths, P J; Lea, T J; Mulligan, I P; Palmer, R E; Simnett, S J

    1993-01-01

    In this review, aspects of the ways in which Ca2+ is transported and regulated within muscle cells have been considered, with particular reference to crustacean muscle fibres. The large size of these fibres permits easy access to the internal environment of the cell, allowing it to be altered by microinjection or microperfusion. At rest, Ca2+ is not in equilibrium across the cell membrane, it enters the cell down a steep electrochemical gradient. The free [Ca2+] at rest is maintained at a value close to 200 nM by a combination of internal buffering systems, mainly the SR, mitochondria, and the fixed and diffusible Ca(2+)-binding proteins, as well as by an energy-dependent extrusion system operating across the external cell membrane. This system relies upon the inward movement of Na+ down its own electrochemical gradient to provide the energy for the extrusion of Ca2+ ions. As a result of electrical excitation, voltage-sensitive channels for Ca2+ are activated and permit Ca2+ to enter the cell more rapidly than at rest. It has been possible to determine both the amount of Ca2+ entering by this step, and what part this externally derived Ca2+ plays in the development of force as well as in the free Ca2+ change. The latter can be determined directly by Ca(2+)-sensitive indicators introduced into the cell sarcoplasm. A combination of techniques, allowing both the total and free Ca2+ changes to be assessed during electrical excitation, has provided valuable information as to how muscle cells buffer their Ca2+ in order to regulate the extent of the change in the free Ca2+ concentration. The data indicate that the entering Ca2+ can only make a small direct contribution to the force developed by the cell. The implication here is that the major source of Ca2+ for contraction must be derived from the internal Ca2+ storage sites within the SR system, a view reinforced by caged Ca2+ methods. The ability to measure the free Ca2+ concentration changes within a single cell during

  15. CA-CA互操作研究%Research of CA-CA Interoperability

    Institute of Scientific and Technical Information of China (English)

    沈士根; 叶培松; 陈宝明

    2005-01-01

    文章介绍了国际上CA-CA之间实现互操作的信任模式,然后根据中国目前的PKI实际情况,提出了以桥CA为全局模式,局部可采用严格层次信任模式来实现各CA之间的互操作.

  16. Altered network timing in the CA3-CA1 circuit of hippocampal slices from aged mice.

    Directory of Open Access Journals (Sweden)

    Daniel J Kanak

    Full Text Available Network patterns are believed to provide unique temporal contexts for coordinating neuronal activity within and across different regions of the brain. Some of the characteristics of network patterns modeled in vitro are altered in the CA3 or CA1 subregions of hippocampal slices from aged mice. CA3-CA1 network interactions have not been examined previously. We used slices from aged and adult mice to model spontaneous sharp wave ripples and carbachol-induced gamma oscillations, and compared measures of CA3-CA1 network timing between age groups. Coherent sharp wave ripples and gamma oscillations were evident in the CA3-CA1 circuit in both age groups, but the relative timing of activity in CA1 stratum pyramidale was delayed in the aged. In another sample of aged slices, evoked Schaffer collateral responses were attenuated in CA3 (antidromic spike amplitude and CA1 (orthodromic field EPSP slope. However, the amplitude and timing of spontaneous sharp waves recorded in CA1 stratum radiatum were similar to adults. In both age groups unit activity recorded juxtacellularly from unidentified neurons in CA1 stratum pyramidale and stratum oriens was temporally modulated by CA3 ripples. However, aged neurons exhibited reduced spike probability during the early cycles of the CA3 ripple oscillation. These findings suggest that aging disrupts the coordination of patterned activity in the CA3-CA1 circuit.

  17. An inhibitory effect of extracellular Ca2+ on Ca2+-dependent exocytosis.

    Directory of Open Access Journals (Sweden)

    Wei Xiong

    Full Text Available AIM: Neurotransmitter release is elicited by an elevation of intracellular Ca(2+ concentration ([Ca(2+](i. The action potential triggers Ca(2+ influx through Ca(2+ channels which causes local changes of [Ca(2+](i for vesicle release. However, any direct role of extracellular Ca(2+ (besides Ca(2+ influx on Ca(2+-dependent exocytosis remains elusive. Here we set out to investigate this possibility on rat dorsal root ganglion (DRG neurons and chromaffin cells, widely used models for studying vesicle exocytosis. RESULTS: Using photolysis of caged Ca(2+ and caffeine-induced release of stored Ca(2+, we found that extracellular Ca(2+ inhibited exocytosis following moderate [Ca(2+](i rises (2-3 µM. The IC(50 for extracellular Ca(2+ inhibition of exocytosis (ECIE was 1.38 mM and a physiological reduction (∼30% of extracellular Ca(2+ concentration ([Ca(2+](o significantly increased the evoked exocytosis. At the single vesicle level, quantal size and release frequency were also altered by physiological [Ca(2+](o. The calcimimetics Mg(2+, Cd(2+, G418, and neomycin all inhibited exocytosis. The extracellular Ca(2+-sensing receptor (CaSR was not involved because specific drugs and knockdown of CaSR in DRG neurons did not affect ECIE. CONCLUSION/SIGNIFICANCE: As an extension of the classic Ca(2+ hypothesis of synaptic release, physiological levels of extracellular Ca(2+ play dual roles in evoked exocytosis by providing a source of Ca(2+ influx, and by directly regulating quantal size and release probability in neuronal cells.

  18. Beatas y comunidad cívica. Algunas claves interpretativas de la espiritualidad femenina urbana bajomedieval (Córdoba, siglos XIV-XV

    Directory of Open Access Journals (Sweden)

    Graña Cid, María del Mar

    2012-12-01

    Full Text Available In the light of the usual historical image presenting the late medieval female religious movement as lacking coherence and being determined by the phenomenon of a socio-economic female surplus, these pages raise the importance of the analysis of its characteristic connection with the cities in order to evaluate their features, associative forms and intentions and, consequently, the political dimension of urban women’s spirituality. The focus is on one sector of the movement, namely the non-regulated religious life, considered within an Andalusian framework that was particularly conspicuous in female religious expression: the city of Córdoba, reformist epicenter during the last two centuries of the Middle Ages.

    Frente a la habitual imagen historiográfi ca que presenta al movimiento religioso femenino bajomedieval como falto de coherencia y determinado por fenómenos de excedencia socioeconómica de mujeres, estas páginas plantean la importancia del análisis de su característica conexión con las ciudades para valorar sus fisonomías, formas asociativas e intencionalidades y, consiguientemente, la dimensión política de la espiritualidad femenina urbana. Se centran sobre un sector del movimiento, la vida beata no reglada y, dentro de un marco andaluz especialmente potente en manifestaciones religiosas femeninas, en la ciudad de Córdoba, epicentro reformista durante los dos últimos siglos medievales.

  19. 46 CFR 7.130 - Point Conception, CA to Point Sur, CA.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Point Conception, CA to Point Sur, CA. 7.130 Section 7.130 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY PROCEDURES APPLICABLE TO THE PUBLIC BOUNDARY LINES Pacific Coast § 7.130 Point Conception, CA to Point Sur, CA. (a) A line drawn from...

  20. Testing coral paleothermometers (B/Ca, Mg/Ca, Sr/Ca, U/Ca andδ18O) under impacts of large riverine runoff

    Institute of Scientific and Technical Information of China (English)

    CHEN Tianran; YU Kefu; ZHAO Jianxin; YAN Hongqiang; SONG Yinxian; FENG Yuexing; CHEN Tegu

    2015-01-01

    Sea surface temperature (SST) proxies including B/Ca, Mg/Ca, Sr/Ca, U/Ca andδ18O were analyzed in the skeleton of aPorites coral collected from the Zhujiang River (Pearl River) Estuary (ZRE). These geochemical proxies are influenced by river runoff and this area of the northern South China Sea is strongly affected by seasonal freshwater floods. We assessed the robustness of each SST proxy through comparison with the local instrumental SST. Coral Sr/Ca shows the highest correlation with SST variations (r2=0.59), suggesting Sr/Ca is the most robust SST proxy. In contrast, coralδ18O (r2=0.46), B/Ca (r2=0.43) and U/Ca (r2=0.41) ratios were only moderately correlated with SST variations, suggesting that they are disturbed by some other factors in addition to SST. The poor correlation (r2=0.27) between SST and Mg/Ca indicates that Mg/Ca in coral skeletons is not a simple function of SST variations. This may ultimately limit the use of Mg/Ca as a coral paleothermometer.

  1. Multiple Ca2+ sensors in secretion

    DEFF Research Database (Denmark)

    Walter, Alexander M; Groffen, Alexander J; Sørensen, Jakob Balslev;

    2011-01-01

    Regulated neurotransmitter secretion depends on Ca(2+) sensors, C2 domain proteins that associate with phospholipids and soluble N-ethylmaleimide-sensitive fusion attachment protein receptor (SNARE) complexes to trigger release upon Ca(2+) binding. Ca(2+) sensors are thought to prevent spontaneous...... fusion at rest (clamping) and to promote fusion upon Ca(2+) activation. At least eight, often coexpressed, Ca(2+) sensors have been identified in mammals. Accumulating evidence suggests that multiple Ca(2+) sensors interact, rather than work autonomously, to produce the complex secretory response...... observed in neurons and secretory cells. In this review, we present several working models to describe how different sensors might be arranged to mediate synchronous, asynchronous and spontaneous neurotransmitter release. We discuss the scenario that different Ca(2+) sensors typically act on one shared...

  2. Autonomous CaMKII requires further stimulation by Ca2+/calmodulin for enhancing synaptic strength.

    Science.gov (United States)

    Barcomb, Kelsey; Buard, Isabelle; Coultrap, Steven J; Kulbe, Jacqueline R; O'Leary, Heather; Benke, Timothy A; Bayer, K Ulrich

    2014-08-01

    A hallmark feature of Ca(2+)/calmodulin (CaM)-dependent protein kinase II (CaMKII) is generation of autonomous (Ca(2+)-independent) activity by T286 autophosphorylation. Biochemical studies have shown that "autonomous" CaMKII is ∼5-fold further stimulated by Ca(2+)/CaM, but demonstration of a physiological function for such regulation within cells has remained elusive. In this study, CaMKII-induced enhancement of synaptic strength in rat hippocampal neurons required both autonomous activity and further stimulation. Synaptic strength was decreased by CaMKIIα knockdown and rescued by reexpression, but not by mutants impaired for autonomy (T286A) or binding to NMDA-type glutamate receptor subunit 2B (GluN2B; formerly NR2B; I205K). Full rescue was seen with constitutively autonomous mutants (T286D), but only if they could be further stimulated (additional T305/306A mutation), and not with two other mutations that additionally impair Ca(2+)/CaM binding. Compared to rescue with wild-type CaMKII, the CaM-binding-impaired mutants even had reduced synaptic strength. One of these mutants (T305/306D) mimicked an inhibitory autophosphorylation of CaMKII, whereas the other one (Δstim) abolished CaM binding without introducing charged residues. Inhibitory T305/306 autophosphorylation also reduced GluN2B binding, but this effect was independent of reduced Ca(2+)/CaM binding and was not mimicked by T305/306D mutation. Thus, even autonomous CaMKII activity must be further stimulated by Ca(2+)/CaM for enhancement of synaptic strength.

  3. Análise quali-quantitativa da arborização na praça XV de novembro em Ribeirão Preto - SP, Brasil

    Directory of Open Access Journals (Sweden)

    Gustavo de Nobrega Romani

    2012-06-01

    Full Text Available A Praça XV de Novembro, implantada em meados do século XIX, tem grande valor histórico-cultural, além de se constituir em uma das principais áreas verdes do centro da cidade de Ribeirão Preto. Visando ao conhecimento detalhado da vegetação para fins de orientação do manejo e conservação dessa área, foi feito um levantamento quali-quantitativo e fitossociológico das árvores e palmeiras da praça. Foram medidas altura e Diâmetro à Altura do Peito (DAP e identificados todos os indivíduos de porte arbóreo (árvores e palmeiras presentes na Praça, em nível de espécie. A praça ocupa uma área de 15.456,00 m², onde foram amostradas 42 espécies distribuídas por 19 famílias, num total de 161 indivíduos. Apesar de o local apresentar arborização com alto índice de diversidade de espécies (Shannon-Weaver de 3,14, os exemplares necessitam de maior atenção quanto a problemas ligados à fitossanidade e podas adequadas, fazendo que resulte em espaço seguro para os frequentadores e em boa qualidade paisagística.

  4. ‘Una myga ymatge en paper, de ploma, de mà de Johannes‘. La fugitiva sombra de Van Eyck en la Corona de Aragón a mediados del siglo XV

    Directory of Open Access Journals (Sweden)

    Montero Tortajada, Encarna

    2016-03-01

    Full Text Available This paper analyses the mention of a quill drawing attributed to Van Eyck in a Valencian postmortem inventory, dated 1452. The properties belonged to Andreu Garcia, a priest well known in the historical record because of his connections with the most notable artists working in Valencia during the first half of the 15th century. This reference compels a new examination of the ever more improbable presence of Van Eyck in Aragonese territories. It also offers a new insight into the early imprint of his paintings in these lands, given that the first owner of the drawing was the painter Berenguer Mateu (Jaume Mateu’s brother, likewise a prominent Valencian painter.El artículo analiza la mención de un dibujo a pluma atribuido a Van Eyck en un inventario post-mortem fechado en 1452, y realizado en Valencia. Los bienes del elenco pertenecieron a Andreu Garcia, presbítero beneficiado en la catedral de la ciudad bien conocido por la historiografía en virtud de sus importantes vínculos con los artistas más señalados que trabajaron en la urbe durante la primera mitad del siglo XV. La noticia da pie a una nueva revisión del cada vez más improbable paso de Van Eyck por los territorios de la Corona de Aragón, así como de la huella temprana de su pintura en estos lugares, habida cuenta de que, como revela el documento, el primer propietario del dibujo fue Berenguer Mateu, pintor hermano de Jaume Mateu, uno de los mejores representantes de la segunda generación de pintores del Gótico Internacional en la capital del Reino.

  5. Influence of NaCl-CaCl2 on Decomposing REPO4 with CaO

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The influence of NaCl-CaCl2 on thermal decomposition of REPO4 (RE: Ce, La, Nd, Th) with CaO was studied.The heat decomposing process of REPO4 was tested with TG-DTA experiments.The results showed that the decomposition temperature of REPO4 with CaO was reduced because of adding NaCl-CaCl2 mixture (NaCl:CaCl2=1:1).The influence of the addition of NaCl-CaCl2, roasting temperature and roasting time on decomposition ratio of REPO4 with CaO was studied.The results showed that the decomposition ratio of REPO4with CaO was 79% when the addition percentage of NaCl-CaCl2 was 10%, the roasting temperature was 750℃, and the roasting time was 1 h.

  6. Involvement of Ca2+/CaM in the signal transduction of acetylcholine regulating stomatal movement

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    It has been known that the neurotransmitter acetylcholine (ACh) also exists in plants and is able to regulate the movement of stomata. In another aspect, Ca2+/CaM as the second messengers have a critical role of signal transduction in stomatal guard-cell. Here we showed that Ca2+/CaM were also involved in theACh regulated stomatal movement. In the medium containing Ca2+, the Ca2+ channel blockers (NIF and Ver) and CaM inhibitors (TFP and W7) could neutralize the ACh induced stomatal opening, however, they are ineffective in the medium containing K+. Those results indicated that Ca2+/CaM were involved in the signal transduction pathway of ACh regulating stomatal movement.

  7. Ca2+ cycling in heart cells from ground squirrels: adaptive strategies for intracellular Ca2+ homeostasis.

    Directory of Open Access Journals (Sweden)

    Xiao-Chen Li

    Full Text Available Heart tissues from hibernating mammals, such as ground squirrels, are able to endure hypothermia, hypoxia and other extreme insulting factors that are fatal for human and nonhibernating mammals. This study was designed to understand adaptive mechanisms involved in intracellular Ca(2+ homeostasis in cardiomyocytes from the mammalian hibernator, ground squirrel, compared to rat. Electrophysiological and confocal imaging experiments showed that the voltage-dependence of L-type Ca(2+ current (I(Ca was shifted to higher potentials in ventricular myocytes from ground squirrels vs. rats. The elevated threshold of I(Ca did not compromise the Ca(2+-induced Ca(2+ release, because a higher depolarization rate and a longer duration of action potential compensated the voltage shift of I(Ca. Both the caffeine-sensitive and caffeine-resistant components of cytosolic Ca(2+ removal were more rapid in ground squirrels. Ca(2+ sparks in ground squirrels exhibited larger amplitude/size and much lower frequency than in rats. Due to the high I(Ca threshold, low SR Ca(2+ leak and rapid cytosolic Ca(2+ clearance, heart cells from ground squirrels exhibited better capability in maintaining intracellular Ca(2+ homeostasis than those from rats and other nonhibernating mammals. These findings not only reveal adaptive mechanisms of hibernation, but also provide novel strategies against Ca(2+ overload-related heart diseases.

  8. Comparison of QSAR models based on combinations of genetic algorithm, stepwise multiple linear regression, and artificial neural network methods to predict Kd of some derivatives of aromatic sulfonamides as carbonic anhydrase II inhibitors.

    Science.gov (United States)

    Maleki, Afshin; Daraei, Hiua; Alaei, Loghman; Faraji, Aram

    2014-01-01

    Four stepwise multiple linear regressions (SMLR) and a genetic algorithm (GA) based multiple linear regressions (MLR), together with artificial neural network (ANN) models, were applied for quantitative structure-activity relationship (QSAR) modeling of dissociation constants (Kd) of 62 arylsulfonamide (ArSA) derivatives as human carbonic anhydrase II (HCA II) inhibitors. The best subsets of molecular descriptors were selected by SMLR and GA-MLR methods. These selected variables were used to generate MLR and ANN models. The predictability power of models was examined by an external test set and cross validation. In addition, some tests were done to examine other aspects of the models. The results show that for certain purposes GA-MLR is better than SMLR and for others, ANN overcomes MLR models.

  9. Degradation products of the artificial azo dye, Allura red, inhibit esterase activity of carbonic anhydrase II: A basic in vitro study on the food safety of the colorant in terms of enzyme inhibition.

    Science.gov (United States)

    Esmaeili, Sajjad; Ashrafi-Kooshk, Mohammad Reza; Khaledian, Koestan; Adibi, Hadi; Rouhani, Shohre; Khodarahmi, Reza

    2016-12-15

    Allura red is a widely used food colorant, but there is debate on its potential security risk. In the present study, we found that degradation products of the dye were more potent agents with higher carbonic anhydrase inhibitory action than the parent dye. The mechanism by which the compounds inhibit the enzyme activity has been determined as competitive mode. In addition, the enzyme binding properties of the compounds were investigated employing different spectroscopic techniques and molecular docking. The analyses of fluorescence quenching data revealed the existence of the same binding site for the compounds on the enzyme molecule. The thermodynamic parameters of ligand binding were not similar, which indicates that different interactions are responsible in binding of the parent dye and degradation products to the enzyme. It appears that enzyme inhibition should be considered, more seriously, as a new opened dimension in food safety.

  10. Characterization of one Novel Flavone and four New Source Compounds from the Bark of Millettia ovalifolia and In-Vitro Inhibition of Carbonic Anhydrase-II by the Novel Flavonoid

    Directory of Open Access Journals (Sweden)

    Taj Ur Rahman

    2015-06-01

    Full Text Available The phytochemical examination of the extract of bark of Millettia ovalifolia yielded chemical constituents, which included one novel flavonoid 7-(4-methoxyphenyl-9H-furo [2, 3-f] chromen-9-one and four new source compounds characterized as 3,7-Dihydroxy-2-phenyl-4H-chromen-4-one, (E-Ethyl-13-(3,4-dimethoxyphenylacrylate, (E-Methyl-3-(3,4-dimethoxyphenylacrylate and N-Ethylacetamide. These compounds were characterized by using advance modern spectroscopic analytical techniques such as UV, IR, 1D, 2D NMR and mass spectrometry. The novel flavonoid (1 displayed significant inhibition of cytosolic form of bovine carbonic anhydrase-II with IC 50 value of 17.86 ± 0.07 µM. This flavonoid may be used as a new pharmacophore to treat cystic fibrosis, glaucoma, epilepsy, leaukomia and other disorders such as neurology etc.

  11. γCaMKII shuttles Ca²⁺/CaM to the nucleus to trigger CREB phosphorylation and gene expression.

    Science.gov (United States)

    Ma, Huan; Groth, Rachel D; Cohen, Samuel M; Emery, John F; Li, Boxing; Hoedt, Esthelle; Zhang, Guoan; Neubert, Thomas A; Tsien, Richard W

    2014-10-09

    Activity-dependent CREB phosphorylation and gene expression are critical for long-term neuronal plasticity. Local signaling at CaV1 channels triggers these events, but how information is relayed onward to the nucleus remains unclear. Here, we report a mechanism that mediates long-distance communication within cells: a shuttle that transports Ca(2+)/calmodulin from the surface membrane to the nucleus. We show that the shuttle protein is γCaMKII, its phosphorylation at Thr287 by βCaMKII protects the Ca(2+)/CaM signal, and CaN triggers its nuclear translocation. Both βCaMKII and CaN act in close proximity to CaV1 channels, supporting their dominance, whereas γCaMKII operates as a carrier, not as a kinase. Upon arrival within the nucleus, Ca(2+)/CaM activates CaMKK and its substrate CaMKIV, the CREB kinase. This mechanism resolves long-standing puzzles about CaM/CaMK-dependent signaling to the nucleus. The significance of the mechanism is emphasized by dysregulation of CaV1, γCaMKII, βCaMKII, and CaN in multiple neuropsychiatric disorders.

  12. Dissection of local Ca(2+) signals inside cytosol by ER-targeted Ca(2+) indicator.

    Science.gov (United States)

    Niwa, Fumihiro; Sakuragi, Shigeo; Kobayashi, Ayana; Takagi, Shin; Oda, Yoichi; Bannai, Hiroko; Mikoshiba, Katsuhiko

    2016-10-07

    Calcium (Ca(2+)) is a versatile intracellular second messenger that operates in various signaling pathways leading to multiple biological outputs. The diversity of spatiotemporal patterns of Ca(2+) signals, generated by the coordination of Ca(2+) influx from the extracellular space and Ca(2+) release from the intracellular Ca(2+) store the endoplasmic reticulum (ER), is considered to underlie the diversity of biological outputs caused by a single signaling molecule. However, such Ca(2+) signaling diversity has not been well described because of technical limitations. Here, we describe a new method to report Ca(2+) signals at subcellular resolution. We report that OER-GCaMP6f, a genetically encoded Ca(2+) indicator (GECI) targeted to the outer ER membrane, can monitor Ca(2+) release from the ER at higher spatiotemporal resolution than conventional GCaMP6f. OER-GCaMP6f was used for in vivo Ca(2+) imaging of C. elegans. We also found that the spontaneous Ca(2+) elevation in cultured astrocytes reported by OER-GCaMP6f showed a distinct spatiotemporal pattern from that monitored by plasma membrane-targeted GCaMP6f (Lck-GCaMP6f); less frequent Ca(2+) signal was detected by OER-GCaMP6f, in spite of the fact that Ca(2+) release from the ER plays important roles in astrocytes. These findings suggest that targeting of GECIs to the ER outer membrane enables sensitive detection of Ca(2+) release from the ER at subcellular resolution, avoiding the diffusion of GECI and Ca(2+). Our results indicate that Ca(2+) imaging with OER-GCaMP6f in combination with Lck-GCaMP6f can contribute to describing the diversity of Ca(2+) signals, by enabling dissection of Ca(2+) signals at subcellular resolution.

  13. Biotic Control of Surface pH and Evidence of Light-Induced H+ Pumping and Ca2+-H+ Exchange in a Tropical Crustose Coralline Alga.

    Science.gov (United States)

    Hofmann, Laurie C; Koch, Marguerite; de Beer, Dirk

    2016-01-01

    Presently, an incomplete mechanistic understanding of tropical reef macroalgae photosynthesis and calcification restricts predictions of how these important autotrophs will respond to global change. Therefore, we investigated the mechanistic link between inorganic carbon uptake pathways, photosynthesis and calcification in a tropical crustose coralline alga (CCA) using microsensors. We measured pH, oxygen (O2), and calcium (Ca2+) dynamics and fluxes at the thallus surface under ambient (8.1) and low (7.8) seawater pH (pHSW) and across a range of irradiances. Acetazolamide (AZ) was used to inhibit extracellular carbonic anhydrase (CAext), which mediates hydrolysis of HCO3-, and 4,4' diisothiocyanatostilbene-2,2'-disulphonate (DIDS) that blocks direct HCO3- uptake by anion exchange transport. Both inhibited photosynthesis, suggesting both diffusive uptake of CO2 via HCO3- hydrolysis to CO2 and direct HCO3- ion transport are important in this CCA. Surface pH was raised approximately 0.3 units at saturating irradiance, but less when CAext was inhibited. Surface pH was lower at pHSW 7.8 than pHSW 8.1 in the dark, but not in the light. The Ca2+ fluxes were large, complex and temporally variable, but revealed net Ca2+ uptake under all conditions. The temporal variability in Ca2+ dynamics was potentially related to localized dissolution during epithallial cell sloughing, a strategy of CCA to remove epiphytes. Simultaneous Ca2+ and pH dynamics suggest the presence of Ca2+/H+ exchange. Rapid light-induced H+ surface dynamics that continued after inhibition of photosynthesis revealed the presence of a light-mediated, but photosynthesis-independent, proton pump. Thus, the study indicates metabolic control of surface pH can occur in CCA through photosynthesis and light-inducible H+ pumps. Our results suggest that complex light-induced ion pumps play an important role in biological processes related to inorganic carbon uptake and calcification in CCA.

  14. Biotic Control of Surface pH and Evidence of Light-Induced H+ Pumping and Ca2+-H+ Exchange in a Tropical Crustose Coralline Alga.

    Directory of Open Access Journals (Sweden)

    Laurie C Hofmann

    Full Text Available Presently, an incomplete mechanistic understanding of tropical reef macroalgae photosynthesis and calcification restricts predictions of how these important autotrophs will respond to global change. Therefore, we investigated the mechanistic link between inorganic carbon uptake pathways, photosynthesis and calcification in a tropical crustose coralline alga (CCA using microsensors. We measured pH, oxygen (O2, and calcium (Ca2+ dynamics and fluxes at the thallus surface under ambient (8.1 and low (7.8 seawater pH (pHSW and across a range of irradiances. Acetazolamide (AZ was used to inhibit extracellular carbonic anhydrase (CAext, which mediates hydrolysis of HCO3-, and 4,4' diisothiocyanatostilbene-2,2'-disulphonate (DIDS that blocks direct HCO3- uptake by anion exchange transport. Both inhibited photosynthesis, suggesting both diffusive uptake of CO2 via HCO3- hydrolysis to CO2 and direct HCO3- ion transport are important in this CCA. Surface pH was raised approximately 0.3 units at saturating irradiance, but less when CAext was inhibited. Surface pH was lower at pHSW 7.8 than pHSW 8.1 in the dark, but not in the light. The Ca2+ fluxes were large, complex and temporally variable, but revealed net Ca2+ uptake under all conditions. The temporal variability in Ca2+ dynamics was potentially related to localized dissolution during epithallial cell sloughing, a strategy of CCA to remove epiphytes. Simultaneous Ca2+ and pH dynamics suggest the presence of Ca2+/H+ exchange. Rapid light-induced H+ surface dynamics that continued after inhibition of photosynthesis revealed the presence of a light-mediated, but photosynthesis-independent, proton pump. Thus, the study indicates metabolic control of surface pH can occur in CCA through photosynthesis and light-inducible H+ pumps. Our results suggest that complex light-induced ion pumps play an important role in biological processes related to inorganic carbon uptake and calcification in CCA.

  15. Interlamellar CA1 network in the hippocampus

    OpenAIRE

    Yang, Sunggu; Yang, Sungchil; Moreira, Thais; Hoffman, Gloria; Carlson, Greg C.; Bender, Kevin J.; Alger, Bradley E.; Tang, Cha-Min

    2014-01-01

    It has generally been thought that CA1 cells form only negligible connections with each other along the longitudinal axis of the hippocampus. But if CA1 cells were interconnected in an effective autoassociational network, this information would add a critical new dimension to our understanding of cellular processing within this structure. Here, we report the existence of a well-organized, longitudinally projecting synaptic network among CA1 pyramidal neurons. We further show that synapses of ...

  16. Localized Calcineurin Confers Ca2+-Dependent Inactivation Upon Neuronal L-Type Ca2+ Channels

    OpenAIRE

    2012-01-01

    Excitation-driven entry of Ca2+ through L-type voltage-gated Ca2+ channels controls gene expression in neurons and a variety of fundamental activities in other kinds of excitable cells. The probability of opening of CaV1.2 L-type channels is subject to pronounced enhancement by cAMP-dependent protein kinase (PKA), which is scaffolded to CaV1.2 channels by A-kinase anchoring proteins (AKAPs). CaV1.2 channels also undergo negative autoregulation via Ca2+-dependent inactivation (CDI), which stro...

  17. Glutamate excitotoxicity and Ca2+-regulation of respiration: Role of the Ca2+ activated mitochondrial transporters (CaMCs).

    Science.gov (United States)

    Rueda, Carlos B; Llorente-Folch, Irene; Traba, Javier; Amigo, Ignacio; Gonzalez-Sanchez, Paloma; Contreras, Laura; Juaristi, Inés; Martinez-Valero, Paula; Pardo, Beatriz; Del Arco, Araceli; Satrustegui, Jorgina

    2016-08-01

    Glutamate elicits Ca(2+) signals and workloads that regulate neuronal fate both in physiological and pathological circumstances. Oxidative phosphorylation is required in order to respond to the metabolic challenge caused by glutamate. In response to physiological glutamate signals, cytosolic Ca(2+) activates respiration by stimulation of the NADH malate-aspartate shuttle through Ca(2+)-binding to the mitochondrial aspartate/glutamate carrier (Aralar/AGC1/Slc25a12), and by stimulation of adenine nucleotide uptake through Ca(2+) binding to the mitochondrial ATP-Mg/Pi carrier (SCaMC-3/Slc25a23). In addition, after Ca(2+) entry into the matrix through the mitochondrial Ca(2+) uniporter (MCU), it activates mitochondrial dehydrogenases. In response to pathological glutamate stimulation during excitotoxicity, Ca(2+) overload, reactive oxygen species (ROS), mitochondrial dysfunction and delayed Ca(2+) deregulation (DCD) lead to neuronal death. Glutamate-induced respiratory stimulation is rapidly inactivated through a mechanism involving Poly (ADP-ribose) Polymerase-1 (PARP-1) activation, consumption of cytosolic NAD(+), a decrease in matrix ATP and restricted substrate supply. Glutamate-induced Ca(2+)-activation of SCaMC-3 imports adenine nucleotides into mitochondria, counteracting the depletion of matrix ATP and the impaired respiration, while Aralar-dependent lactate metabolism prevents substrate exhaustion. A second mechanism induced by excitotoxic glutamate is permeability transition pore (PTP) opening, which critically depends on ROS production and matrix Ca(2+) entry through the MCU. By increasing matrix content of adenine nucleotides, SCaMC-3 activity protects against glutamate-induced PTP opening and lowers matrix free Ca(2+), resulting in protracted appearance of DCD and protection against excitotoxicity in vitro and in vivo, while the lack of lactate protection during in vivo excitotoxicity explains increased vulnerability to kainite-induced toxicity in Aralar

  18. The initial 41Ca/40Ca ratios in two type A Ca-Al-rich inclusions: Implications for the origin of short-lived 41Ca

    Science.gov (United States)

    Liu, Ming-Chang

    2017-03-01

    This paper reports new 41Ca-41K isotopic data for two Type A CAIs, NWA 3118 #1Nb (Compact Type A) and Vigarano 3138 F8 (Fluffy Type A), from reduced CV3 chondrites. The NWA CAI is found to have carried live 41Ca at the level of (4.6 ± 1.9) ×10-9 , consistent with the proposed Solar System initial 41Ca /40Ca = 4.2 ×10-9 by Liu et al. (2012a). On the other hand, the Vigarano CAI does not have resolvable radiogenic 41K excesses that can be attributed to the decay of 41Ca. Combined with the 26Al data that have been reported for these two CAIs, we infer that the 41Ca distribution was not homogeneous when 26Al was widespread at the canonical level of 26Al /27Al = 5.2 ×10-5 . Such a 41Ca heterogeneity can be understood under two astrophysical contexts: in situ charged particle irradiation by the protoSun in the solar nebula that had inherited some baseline 10Be abundance from the molecular cloud, and Solar System formation in a molecular cloud enriched in 26Al and 41Ca contaminated by massive star winds. That said, more high quality 41Ca data are still needed to better understand the origin of this radionuclide.

  19. Supralinear dendritic Ca(2+) signalling in young developing CA1 pyramidal cells.

    Science.gov (United States)

    Pohle, Jörg; Bischofberger, Josef

    2014-11-15

    Although Ca(2+) is critically important in activity-dependent neuronal development, not much is known about the regulation of dendritic Ca(2+) signals in developing neurons. Here, we used ratiometric Ca(2+) imaging to investigate dendritic Ca(2+) signalling in rat hippocampal pyramidal cells during the first 1-4 weeks of postnatal development. We show that active dendritic backpropagation of Nav channel-dependent action potentials (APs) evoked already large dendritic Ca(2+) transients in animals aged 1 week with amplitudes of ∼150 nm, similar to the amplitudes of ∼160 nM seen in animals aged 4 weeks. Although the AP-evoked dendritic Ca(2+) load increased about four times during the first 4 weeks, the peak amplitude of free Ca(2+) concentration was balanced by a four-fold increase in Ca(2+) buffer capacity κs (∼70 vs. ∼280). Furthermore, Ca(2+) extrusion rates increased with postnatal development, leading to a slower decay time course (∼0.2 s vs. ∼0.1 s) and more effective temporal summation of Ca(2+) signals in young cells. Most importantly, during prolonged theta-burst stimulation dendritic Ca(2+) signals were up to three times larger in cells at 1 week than at 4 weeks of age and much larger than predicted by linear summation, which is attributable to an activity-dependent slow-down of Ca(2+) extrusion. As Ca(2+) influx is four-fold smaller in young cells, the larger Ca(2+) signals are generated using four times less ATP consumption. Taken together, the data suggest that active backpropagations regulate dendritic Ca(2+) signals during early postnatal development. Remarkably, during prolonged AP firing, Ca(2+) signals are several times larger in young than in mature cells as a result of activity-dependent regulation of Ca(2+) extrusion rates.

  20. EMRE Is a Matrix Ca2+ Sensor that Governs Gatekeeping of the Mitochondrial Ca2+ Uniporter

    Directory of Open Access Journals (Sweden)

    Horia Vais

    2016-01-01

    Full Text Available The mitochondrial uniporter (MCU is an ion channel that mediates Ca2+ uptake into the matrix to regulate metabolism, cell death, and cytoplasmic Ca2+ signaling. Matrix Ca2+ concentration is similar to that in cytoplasm, despite an enormous driving force for entry, but the mechanisms that prevent mitochondrial Ca2+ overload are unclear. Here, we show that MCU channel activity is governed by matrix Ca2+ concentration through EMRE. Deletion or charge neutralization of its matrix-localized acidic C terminus abolishes matrix Ca2+ inhibition of MCU Ca2+ currents, resulting in MCU channel activation, enhanced mitochondrial Ca2+ uptake, and constitutively elevated matrix Ca2+ concentration. EMRE-dependent regulation of MCU channel activity requires intermembrane space-localized MICU1, MICU2, and cytoplasmic Ca2+. Thus, mitochondria are protected from Ca2+ depletion and Ca2+ overload by a unique molecular complex that involves Ca2+ sensors on both sides of the inner mitochondrial membrane, coupled through EMRE.

  1. Biphasic decay of the Ca transient results from increased sarcoplasmic reticulum Ca leak

    Science.gov (United States)

    Sankaranarayanan, Rajiv; Li, Yatong; Greensmith, David J.; Eisner, David A.

    2016-01-01

    Key points Ca leak from the sarcoplasmic reticulum through the ryanodine receptor (RyR) reduces the amplitude of the Ca transient and slows its rate of decay.In the presence of β‐adrenergic stimulation, RyR‐mediated Ca leak produces a biphasic decay of the Ca transient with a fast early phase and a slow late phase.Two forms of Ca leak have been studied, Ca‐sensitising (induced by caffeine) and non‐sensitising (induced by ryanodine) and both induce biphasic decay of the Ca transient.Only Ca‐sensitising leak can be reversed by traditional RyR inhibitors such as tetracaine.Ca leak can also induce Ca waves. At low levels of leak, waves occur. As leak is increased, first biphasic decay and then slowed monophasic decay is seen. The level of leak has major effects on the shape of the Ca transient. Abstract In heart failure, a reduction in Ca transient amplitude and contractile dysfunction can by caused by Ca leak through the sarcoplasmic reticulum (SR) Ca channel (ryanodine receptor, RyR) and/or decreased activity of the SR Ca ATPase (SERCA). We have characterised the effects of two forms of Ca leak (Ca‐sensitising and non‐sensitising) on calcium cycling and compared with those of SERCA inhibition. We measured [Ca2+]i with fluo‐3 in voltage‐clamped rat ventricular myocytes. Increasing SR leak with either caffeine (to sensitise the RyR to Ca activation) or ryanodine (non‐sensitising) had similar effects to SERCA inhibition: decreased systolic [Ca2+]i, increased diastolic [Ca2+]i and slowed decay. However, in the presence of isoproterenol, leak produced a biphasic decay of the Ca transient in the majority of cells while SERCA inhibition produced monophasic decay. Tetracaine reversed the effects of caffeine but not of ryanodine. When caffeine (1 mmol l−1) was added to a cell which displayed Ca waves, the wave frequency initially increased before waves disappeared and biphasic decay developed. Eventually (at higher caffeine concentrations), the

  2. Ischemic damage in hippocampal CA1 is dependent on glutamate release and intact innervation from CA3

    DEFF Research Database (Denmark)

    Benveniste, H; Jørgensen, M B; Sandberg, M;

    1989-01-01

    The removal of glutamatergic afferents to CA1 by destruction of the CA3 region is known to protect CA1 pyramidal cells against 10 min of transient global ischemia. To investigate further the pathogenetic significance of glutamate, we measured the release of glutamate in intact and CA3-lesioned CA...... is dependent on glutamate release and intact innervation from CA3....

  3. Carbonic anhydrase IX and response to postmastectomy radiotherapy in high-risk breast cancer: a subgroup analysis of the DBCG82 b and c trials

    DEFF Research Database (Denmark)

    Kyndi, M.; Sorensen, F.B.; Alsner, J.;

    2008-01-01

    -points were loco-regional recurrence, distant metastases, disease-specific survival and overall survival. Statistical analyses included kappa statistics, chi(2) or exact tests, Kaplan-Meier probability plots, Log-rank test and Cox regression analyses. Results CA IX was assessable in 945 cores. The percentage...

  4. Carbonic anhydrase IX and response to postmastectomy radiotherapy in high-risk breast cancer: a subgroup analysis of the DBCG82 b and c trials

    DEFF Research Database (Denmark)

    Kyndi, Marianne; Sørensen, Flemming Brandt; Knudsen, Helle;

    2008-01-01

    -points were loco-regional recurrence, distant metastases, disease-specific survival and overall survival. Statistical analyses included kappa statistics, chi2 or exact tests, Kaplan-Meier probability plots, Log-rank test and Cox regression analyses. RESULTS: CA IX was assessable in 945 cores. The percentage...

  5. Localized calcineurin confers Ca2+-dependent inactivation on neuronal L-type Ca2+ channels.

    Science.gov (United States)

    Oliveria, Seth F; Dittmer, Philip J; Youn, Dong-ho; Dell'Acqua, Mark L; Sather, William A

    2012-10-31

    Excitation-driven entry of Ca(2+) through L-type voltage-gated Ca(2+) channels controls gene expression in neurons and a variety of fundamental activities in other kinds of excitable cells. The probability of opening of Ca(V)1.2 L-type channels is subject to pronounced enhancement by cAMP-dependent protein kinase (PKA), which is scaffolded to Ca(V)1.2 channels by A-kinase anchoring proteins (AKAPs). Ca(V)1.2 channels also undergo negative autoregulation via Ca(2+)-dependent inactivation (CDI), which strongly limits Ca(2+) entry. An abundance of evidence indicates that CDI relies upon binding of Ca(2+)/calmodulin (CaM) to an isoleucine-glutamine motif in the carboxy tail of Ca(V)1.2 L-type channels, a molecular mechanism seemingly unrelated to phosphorylation-mediated channel enhancement. But our work reveals, in cultured hippocampal neurons and a heterologous expression system, that the Ca(2+)/CaM-activated phosphatase calcineurin (CaN) is scaffolded to Ca(V)1.2 channels by the neuronal anchoring protein AKAP79/150, and that overexpression of an AKAP79/150 mutant incapable of binding CaN (ΔPIX; CaN-binding PXIXIT motif deleted) impedes CDI. Interventions that suppress CaN activity-mutation in its catalytic site, antagonism with cyclosporine A or FK506, or intracellular perfusion with a peptide mimicking the sequence of the phosphatase's autoinhibitory domain-interfere with normal CDI. In cultured hippocampal neurons from a ΔPIX knock-in mouse, CDI is absent. Results of experiments with the adenylyl cyclase stimulator forskolin and with the PKA inhibitor PKI suggest that Ca(2+)/CaM-activated CaN promotes CDI by reversing channel enhancement effectuated by kinases such as PKA. Hence, our investigation of AKAP79/150-anchored CaN reconciles the CaM-based model of CDI with an earlier, seemingly contradictory model based on dephosphorylation signaling.

  6. Isolation and characterization of higher metallofullerenes Ca@C92 and Ca@C94

    Indian Academy of Sciences (India)

    Yuliang Che; Hua Yang; Hongxiao Jin; Chunxin Lu; Ziyang Liu

    2009-05-01

    We report for the first time isolation of Ca@C92 and Ca@C94 by multi-stage highperformance liquid chromatography technique without recycling equipment. It is notable that higher metallofullerenes containing alkaline earth metal ions could be isolated although their relative yields are extremely low. Ca@C92 and Ca@C94 are also confirmed by LD-TOF mass spectrometry and characterrized by UV-Vis-NIR absorption measurements.

  7. Ca(V)1 and Ca(V)2 channels engage distinct modes of Ca(2+) signaling to control CREB-dependent gene expression.

    Science.gov (United States)

    Wheeler, Damian G; Groth, Rachel D; Ma, Huan; Barrett, Curtis F; Owen, Scott F; Safa, Parsa; Tsien, Richard W

    2012-05-25

    Activity-dependent gene expression triggered by Ca(2+) entry into neurons is critical for learning and memory, but whether specific sources of Ca(2+) act distinctly or merely supply Ca(2+) to a common pool remains uncertain. Here, we report that both signaling modes coexist and pertain to Ca(V)1 and Ca(V)2 channels, respectively, coupling membrane depolarization to CREB phosphorylation and gene expression. Ca(V)1 channels are advantaged in their voltage-dependent gating and use nanodomain Ca(2+) to drive local CaMKII aggregation and trigger communication with the nucleus. In contrast, Ca(V)2 channels must elevate [Ca(2+)](i) microns away and promote CaMKII aggregation at Ca(V)1 channels. Consequently, Ca(V)2 channels are ~10-fold less effective in signaling to the nucleus than are Ca(V)1 channels for the same bulk [Ca(2+)](i) increase. Furthermore, Ca(V)2-mediated Ca(2+) rises are preferentially curbed by uptake into the endoplasmic reticulum and mitochondria. This source-biased buffering limits the spatial spread of Ca(2+), further attenuating Ca(V)2-mediated gene expression.

  8. Ca(2+) signalling in the Golgi apparatus.

    Science.gov (United States)

    Pizzo, Paola; Lissandron, Valentina; Capitanio, Paola; Pozzan, Tullio

    2011-08-01

    The Golgi apparatus plays a central role in lipid and protein post-translational modification and sorting. Morphologically the organelle is heterogeneous and it is possible to distinguish stacks of flat cysternae (cis- and medial Golgi), tubular-reticular networks and vesicles (trans-Golgi). These morphological differences parallel a distinct functionality with a selective distribution and complementary roles of the enzymes found in the different compartments. The Golgi apparatus has been also shown to be involved in Ca(2+) signalling: it is indeed endowed with Ca(2+) pumps, Ca(2+) release channels and Ca(2+) binding proteins and is thought to participate in determining the spatio-temporal complexity of the Ca(2+) signal within the cell, though this role is still poorly understood. Recently, it has been demonstrated that the organelle is heterogeneous in terms of Ca(2+) handling and selective reduction of Ca(2+) concentration, both in vitro and in a genetic human disease, within one of its sub-compartment results in alterations of protein trafficking within the secretory pathway and of the entire Golgi morphology. In this paper we review the available information on the Ca(2+) toolkit within the Golgi, its heterogeneous distribution in the organelle sub-compartments and discuss the implications of these characteristics for the physiopathology of the Golgi apparatus.

  9. LATS refining ladle slag modifying with CaO-CaF2

    Institute of Scientific and Technical Information of China (English)

    Hongming Wang; Guirong Li; Zhongming Ren; Bo Li; Xuejun Zhang; Guomin Shi

    2007-01-01

    To reduce the slag sticking onto the snorkel of the ladle during the ladle alloying treatment station (LATS) process, CaO-CaF2 (the mass ratio of CaO/CaF2 is 1:1) was employed as the modifier of the LATS refining ladle slag. The effect of CaO-CaF2 on the melting point, viscosity, and desulfurizing capability of the ladle slag was investigated. The melting point of the unmodified ladle slag is 1439°C. When adding 20wt% CaO-CaF2, the melting point is decreased to 1327°C. At 1500°C, the viscosity of the unmodified ladle slag is 6.5 Pa·s, which can be decreased lower than 2 Pa·s by adding more than 10wt% CaO-CaF2. The experimental results of desulfurization of the melts show that the desulfurizing power of the ladle slag can be enhanced by adding CaO-CaF2.

  10. By Regulating Mitochondrial Ca2+-Uptake UCP2 Modulates Intracellular Ca2+.

    Directory of Open Access Journals (Sweden)

    Lukas Jaroslaw Motloch

    Full Text Available The possible role of UCP2 in modulating mitochondrial Ca2+-uptake (mCa2+-uptake via the mitochondrial calcium uniporter (MCU is highly controversial.Thus, we analyzed mCa2+-uptake in isolated cardiac mitochondria, MCU single-channel activity in cardiac mitoplasts, dual Ca2+-transients from mitochondrial ((Ca2+m and intracellular compartment ((Ca2+c in the whole-cell configuration in cardiomyocytes of wild-type (WT and UCP2-/- mice.Isolated mitochondria showed a Ru360 sensitive mCa2+-uptake, which was significantly decreased in UCP2-/- (229.4±30.8 FU vs. 146.3±23.4 FU, P0.05 and transsarcolemmal Ca2+-influx was inhibited suggesting a possible compensatory mechanism. Additionally, we observed an inhibitory effect of ATP on mCa2+-uptake in WT mitoplasts and (Ca2+m of cardiomyocytes leading to an increase of (Ca2+c while no ATP dependent effect was observed in UCP2-/-.Our results indicate regulatory effects of UCP2 on mCa2+-uptake. Furthermore, we propose, that previously described inhibitory effects on MCU by ATP may be mediated via UCP2 resulting in changes of excitation contraction coupling.

  11. Ca-Dependent Folding of Human Calumenin

    Science.gov (United States)

    Mazzorana, Marco; Hussain, Rohanah; Sorensen, Thomas

    2016-01-01

    Human calumenin (hCALU) is a six EF-hand protein belonging to the CREC family. As other members of the family, it is localized in the secretory pathway and regulates the activity of SERCA2a and of the ryanodine receptor in the endoplasmic reticulum (ER). We have studied the effects of Ca2+ binding to the protein and found it to attain a more compact structure upon ion binding. Circular Dichroism (CD) measurements suggest a major rearrangement of the protein secondary structure, which reversibly switches from disordered at low Ca2+ concentrations to predominantly alpha-helical when Ca2+ is added. SAXS experiments confirm the transition from an unfolded to a compact structure, which matches the structural prediction of a trilobal fold. Overall our experiments suggest that calumenin is a Ca2+ sensor, which folds into a compact structure, capable of interacting with its molecular partners, when Ca2+ concentration within the ER reaches the millimolar range. PMID:26991433

  12. El brocado de estaño en relieve aplicado. Evolución histórica y material en la Europa medieval con atención al arte español (siglos XV-XVI

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    Rodríguez López, Ainhoa

    2014-12-01

    Full Text Available The term applied tin-relief brocade (commonly called applied brocade refers to painted decoration that simulates the velvet and silk brocades made of gold and silver threads commonly used in Europe in the fifteenth and sixteenth centuries. This technique uses a mould, tin leaf, and filling mass to reproduce in a mechanical way the relief motifs of textile brocades. Once cut, they are applied to artwork, and then sometimes gilded or painted. The discovery of many examples of this type of decoration in northern Spain has led us to the study of the documentary sources, especially Spanish ones, with the purpose of improving our understanding of the technique, its historic and material development, and the typology of standardized patterns. Furthermore, this study has provided us with an important glossary of the relief painting additive techniques that culminated in applied tinrelief brocade.El término brocado de estaño en relieve aplicado (comúnmente conocido como brocado aplicado se refiere a una decoración polícroma que imita los brocados de terciopelo y seda hechos con hilos de oro y plata, los cuales dominan el mundo de la moda de Europa en los siglos XV y XVI. Esta técnica reproduce mecánicamente a través de una matriz, lámina de estaño y masa de relleno motivos en relieve de brocados textiles, que, una vez recortados, son aplicados sobre la obra, pudiendo estar en ocasiones dorados y pintados. El hallazgo de más ejemplos de esta decoración en el Norte de España nos ha conducido a analizar las fuentes documentales, especialmente las españolas, con el objetivo de ampliar nuestro conocimiento sobre la técnica en cuestión, su evolución histórica y material y sus diferentes tipologías. Asimismo, dicho estudio nos ha proporcionado un importante glosario de técnicas pictóricas en relieve por adición precursoras del brocado de estaño en relieve aplicado.

  13. Judíos y redes personales en Tierra de Campos durante la segunda mitad del siglo XV: un Cuaderno de Minutas de Avecindamientos de Villalón

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    Castaño, Javier

    2009-12-01

    Full Text Available In the middle decades of the fifteenth century Jews were registered as local citizens in the municipal council records of individual Castilian towns. Traditionally, a citizen was recorded as belonging to a parish or parochial neighborhood within the local political community; this would exclude Jews by definition as they were designated separately as a religious caste. The study of unpublished documents related to the Castilian locale of Villalón –characterized by the economic importance of its fairs promoted by the 4th count of Benavente– in the region of Tierra de Campos during a period of general political disorder, records that the municipal council assigned citizenship to Jews in relation to their community (aljama through which specific aspects of their lives were regulated, and by which the local council rather than other political instances assumed control of that community. With the help of other primary sources, these documents reveal the suggestion of personal networks in which Jewish physicians play a key role.

    En las décadas centrales del siglo XV algunos judíos fueron inscritos por las autoridades concejiles como vecinos en distintas localidades castellanas. Tradicionalmente, la vec