Enzyme Carbonic Anhydrase Research Articles

Relationship between zinc content and carbonic anhydrase activity in blood of anemic pregnant women in Turkey.

Carbonic anhydrase (CA) in pregnancy plays an important part in gaseous exchange across the placenta. The aim of our study was to determine the relationship between zinc content and the CA activity in blood of anemic and normal pregnant women in their third trimester, in Turkey. The patients with hemoglobin values below 11 g/dL were accepted as anemic. CA enzyme activity and zinc levels in erythrocyte of anemic and non-anemic pregnant women were carried out in 27 non-anemic pregnant women and 31 anemic pregnant women. Mean corpuscular volume (MCV) levels of the participants were also tested. Zinc levels were lower in the anemic group compared to the non-anemic group (P = 0.049). Total CA enzyme activity was also lower in the anemic group (P = 0.044). MCV levels were found to be lower in the anemic group (P = 0.007). The decrease in these values was statistically significant (P < 0.05). This is the first study to evaluate the zinc content in red blood cells of anemic pregnant women in the third trimester and its relationship with carbonic anhydrase activity. CA isoenzymes to work healthily, providing iron and zinc supports is important for fetal development.

Uncovering the Cyclic AMP Signaling Pathway of the Protozoan Parasite Entamoeba histolytica and Understanding Its Role in Phagocytosis.

Second messenger signaling controls a surprisingly diverse range of processes in several eukaryotic pathogens. Molecular machinery and pathways involving these messengers thus hold tremendous opportunities for therapeutic interventions. Relative to Ca2+ signaling, the knowledge of a crucial second messenger cyclic AMP (cAMP) and its signaling pathway is very scant in the intestinal parasite Entamoeba histolytica. In the current study, mining the available genomic resources, we have for the first time identified the cAMP signal transduction pathway of E. histolytica. Three heptahelical proteins with variable G-protein-coupled receptor domains, heterotrimeric G-proteins (Gα, Gβ, and Gγ subunits), soluble adenylyl cyclase, cyclase-associated protein, and enzyme carbonic anhydrase were identified in its genome. We could also identify several putative candidate genes for cAMP downstream effectors such as protein kinase A, A-kinase anchoring proteins, and exchange protein directly activated by the cAMP pathway. Using specific inhibitors against key identified targets, we could observe changes in the intracellular cAMP levels as well as defect in the rate of phagocytosis of red blood cells by the parasite E. histolytica. We thus strongly believe that characterization of some of these unexplored crucial signaling determinants will provide a paradigm shift in understanding the pathogenicity of this organism.

Role of water on deep eutectic solvents (DES) properties and gas transport performance in biocatalytic supported DES membranes

The development of efficient and clean CO2 capture technologies is a topic of utmost importance in the global environmental agenda. In this work, a wide range of analytical procedures (1H and 13C NMR, TGA, DSC, FT-IR, viscosity, density, refractive index, fluorescence anisotropy, UV–Vis) was used to investigate the properties of deep eutectic solvent (DES) composed of choline chloride and levulinic acid (ChCl:LA), conditioned to four different water activity (aw) values. Also, the impact of using the enzyme carbonic anhydrase (CA), known for its ability to reversibly convert CO2 into bicarbonate, was assessed on DES properties. The ChCl:LA-water mixtures showed to be present as a cohesive cluster up to aw = 0.753 and, above that, in a hydrated form with a free water layer that could crystalize at negative temperatures (-40 to −45 °C), suggesting anti-freezing properties of the solvent. DES were then supported in polymeric hydrophilic membranes. Based on CO2 and N2 permeabilities through these membranes, the one that contained ChCl:LA at aw = 0.216 was further studied regarding its long-term stability. This supported liquid membrane showed a consistent behavior for up to 30 repeated cycles and a stable operating behavior for transmembrane pressure differences in the range of 0.50–1.25 bar. These findings evidence the stability of supported DES membranes and the potential for CO2 capture.

Phthalocyanine complexes with (4-isopropylbenzyl)oxy substituents: preparation and evaluation of anti-carbonic anhydrase, anticholinesterase enzymes and molecular docking studies

In this study, the preparation, aggregation behavior and investigation of carbonic anhydrase and cholinesterase enzyme inhibition features of non-peripherally (4-isopropylbenzyl)oxy-substituted phthalocyanines (4–6) are reported for the first time. The chemical structures of these new phthalocyanines were elucidated by UV-Vis (ultraviolet-visible), FT-IR (Fourier transform infrared spectrometry), NMR (nuclear magnetic resonance) and MALDI-TOF (matrix-assisted laser desorption/ionization time-of-flight) mass spectrometry. The substitution of 4-isopropylbenzyl)oxy groups benefits a remarkable solubility and redshift of the phthalocyanines Q-band. Also, these complexes were tested against some enzymes such as butyrylcholinesterase enzyme, human carbonic anhydrase I and II isoforms and acetylcholinesterase enzyme. The phthalocyanine complexes showed Ki values of in the range of 478.13 ± 57.25–887.25 ± 101.20 µM against hCA I, 525.16 ± 45.87–921.14 ± 81.25 µM against hCA II, 68.33 ± 9.13–201.15 ± 35.86 µM against AChE and 86.25 ± 13.65–237.54 ± 24.7 µM against BChE. Molecular docking studies were performed to investigate the binding modes and interaction energies of the (2–6) complexes with the hCA I (PDB ID:1BMZ), hCA II (PDB ID:2ABE), AChE (PDB ID:4EY6) and BChE (PDB ID:2PM8).

The Evaluation of Inhibition Effects of Antibiotics on the Sheep Stomach Carbonic Anhydrase I and II Isozymes

Carbonic anhydrases are vital class of enzymes that participate in so many essential physiological events in the organism and associated with many diseases. Inhibitors of carbonic anhydrase enzymes are used in pharmacological applications in many areas such as antiobesity, antiglaucoma, anticancer agents and anticonvulsants. So, this study focuses on the characterization of CA-I and CA-II isoenzymes purified from sheep stomach and investigating the inhibition effects of antibiotics on these enzymes. The findings show that the antibiotics studied strongly inhibit CA-I and CA-II isozymes. In our presented study, using Sepharose 4B-L-Tyrosine sulfanilamide affinity gel chromatography, carbonic anhydrase I and carbonic anhydrase II isoenzymes were purified from sheep stomach with a yield of 51.9%, 78%, respectively and specific activity of CA I and CA II are 4864.8 EU/mg and 5652.02 EU/mg, respectively. The overall purifications from sheep stomach CA I and CA II were approximately 529.4 and 615.2 fold respectively. To check the purify of the enzymes, it was conducted an electrophoretic method so-called Sodium Dodecyl Sulphate-Polyacrylamide Gel Electrophoresis (SDS-PAGE) and single bands were detected for both enzymes. Additionally, the effects of antibiotics on sheep stomach CA I and CA II isozymes activities, using both hydratase and esterase activity methods, were researched. IC50 values of enrofloxacin, tylosin and ampicillin antibiotics that inhibit CA I enzyme with hydratase activity were found as 1.41, 0.033 and 1.56 mM, respectively. IC50 values for CA II enzyme with hydratase activity of the same antibiotics were found as 2.47, 0.039 and 1.63 mM, respectively. Kanamycin and amikacin antibiotics inhibited both CA I and CA II enzymes with esterase activity. IC50 values for CA I and CA II enzymes with esterase activity of kanamycin antibiotic were determined as 0.0488 and 0.118 mM, respectively. IC50 values of amikacin for CA I and CA II enzymes with esterase activity were determined as 0.0163 and 0.036 mM, respectively.

Design, synthesis, characterization, biological evaluation, and molecular docking studies of novel 1,2-aminopropanthiols substituted derivatives as selective carbonic anhydrase, acetylcholinesterase and α-glycosidase enzymes inhibitors

In the article, various substituted derivatives of 1,2-aminopropanthiol (1a–g) have been prepared by a general and efficient method, in one-steps, starting from available thiirane and aromatic amines (aniline, o-toluidine) as a convenient source of sulfur and nitrogen. The synthesized compounds were fully characterized by spectral and analytical data. Seven novel compounds are synthesized. The biochemical properties indicating their potential for constituting an anti-Alzheimer’s disease substance were also recorded revealing strong carbonic anhydrase I, and II, α-glycosidase, and acetylcholinesterase inhibitory effects. These synthesized novel 1,2-aminopropanthiols substituted derivatives (1a–g) were found to be effective inhibitors for the α-glycosidase, human carbonic anhydrase I and II, and acetylcholinesterase enzymes, with Ki values in the range of 11.47 ± 0.87–24.09 ± 6.37 µM for α-glycosidase, 29.30 ± 4.67-79.01 ± 4.49 µM for hCA I, 14.27 ± 2.82-30.85 ± 12.24 µM for hCA II and 5.76 ± 1.55–55.39 ± 2.27 µM for AChE, respectively. In the last step of this study, molecular docking calculations were obtained in order to compare the biological activities of indicated molecules against the enzymes of acetylcholinesterase, butyrylcholinesterase and α-glycosidase. Communicated by Ramaswamy H. Sarma

The control of acidity in tumor cells: a biophysical model

Acidosis of the tumor microenvironment leads to cancer invasion, progression and resistance to therapies. We present a biophysical model that describes how tumor cells regulate intracellular and extracellular acidity while they grow in a microenvironment characterized by increasing acidity and hypoxia. The model takes into account the dynamic interplay between glucose and hbox {O}_2 consumption with lactate and hbox {CO}_2 production and connects these processes to hbox {H}^+ and hbox {HCO}_3^- fluxes inside and outside cells. We have validated the model with independent experimental data and used it to investigate how and to which extent tumor cells can survive in adverse micro-environments characterized by acidity and hypoxia. The simulations show a dominance of the hbox {H}^+ exchanges in well-oxygenated regions, and of hbox {HCO}_3^- exchanges in the inner hypoxic regions where tumor cells are known to acquire malignant phenotypes. The model also includes the activity of the enzyme Carbonic Anhydrase 9 (CA9), a known marker of tumor aggressiveness, and the simulations demonstrate that CA9 acts as a nonlinear hbox {pH}_i equalizer at any hbox {O}_2 level in cells that grow in acidic extracellular environments.

Carbonic anhydrase enzyme inhibition and biological activities of Satureja hortensis L. essential oil

Recently, there is a great need to discover new natural carbonic anhydrase (CA) inhibitor sources to be used as diuretic, antiglaucoma, anti-obesity, anticancer, and anti-infective drugs. Therefore, evaluation of CA inhibition activity and possible inhibition mechanism of the essential oil of Satureja hortensis L. (SHEO) were investigated for the first time by this study. Additionally, total phenolic content known effective for CA inhibition and the other biological activities was determined for the first time. Since the volatile compound and total phenolic content of essential oil of S. hortensis grown in Bingöl exhibited great differences than those in the literature, the antioxidant and antimicrobial activities of SHEO were also investigated. Carbonic anhydrase inhibition of SHEO was determined as IC50: 0.1 ± 0.002 μg/mL. Further, molecular docking studies between the main volatile compounds and CA have been conducted to better understand the CA inhibition mechanism of SHEO. The main compounds were as β-decalol (19.10%), perillaldehyde (17.11%), perillyl alcohol (16.87%), carvacrol (13.47%), and thymol (12.32%) by GC-MS. β-decalol was detected in an essential oil for the first time. Based on the molecular docking studies, thymol and β-decalol showed great potential for CA inhibition. Besides, total phenolic content was determined as 623 ± 2.88 μg/mL gallic acid equivalent (GAE) and 736 ± 3.46 μg/mL catechin equivalent (CE). The essential oil showed high antioxidant capacity [(SC50: 0.069 ± 0.283 μg/mL for 2,2-diphenyl-1-picrylhydrazyl (DPPH•) and 1031 ± 5.03 μM trolox equivalent antioxidant capacity (TEAC) for ferric reducing power (FRAP)]. The essential oil also showed significant antimicrobial activity against six Gram-positive and six Gram-negative bacteria, and a fungus. Minimal inhibitory concentrations (MICs) were 15.6 μg/mL and 31.2 μg/mL for MRSA ATCC 67101 and C. albicans, respectively. The rest of eleven bacteria exhibited MICs between 3.9-7.8 μg/mL. Consequently, SHEO could be used as antioxidant and antimicrobial agent at very low concentrations. In addition, SHEO significantly inhibited CA, thus, SHEO was a promising source for CA inhibitors and it might have potential to be used for treatment of CA related diseases.

Synthesis, in vitro inhibition effect of novel phthalocyanine complexes as carbonic anhydrase and paraoxonase enzyme inhibitors

The preparation and assessment of carbonic anhydrase and paraoxonase enzyme inhibition properties of 3-(2-(5-amino-4-(4-bromophenyl)-3-methyl-1H-pyrazol-1-yl)ethoxy)phthalonitrile (2) and its nitrogen-containing non-peripheral phthalocyanine derivatives (3 and 4) are reported for the first time. The new phthalonitrile and its phthalocyanine derivatives have been elucidated by FT-IR spectroscopy, 1H-NMR, [Formula: see text]C-NMR, mass and UV-vis spectroscopy. The results demonstrated that all synthesized compounds moderately inhibited carbonic anhydrase and paraoxonase enzymes. Among the compounds, the most active ones were found to be compound 4 for PON (Ki : 0.14 [Formula: see text]M), compound 3 for hCA I (Ki : 22.52 [Formula: see text]M) and compound 1 for hCA II (Ki : 13.62 [Formula: see text]M).

Chemical kinetics of the development of coronaviral infection in the human body: Critical conditions, toxicity mechanisms, “thermoheliox”, and “thermovaccination”

Kinetic modeling of the behavior of complex chemical and biochemical systems is an effective approach to study of the mechanisms of the process. A kinetic model of coronaviral infection development with a description of the dynamic behavior of the main variables, including the concentration of viral particles, affected cells, and pathogenic microflora, is proposed. Changes in the concentration of hydrogen ions in the lungs and the pH -dependence of carbonic anhydrase activity (a key breathing enzyme) are critical. A significant result is the demonstration of an acute bifurcation transition that determines life or system collapse. This transition is connected with exponential growth of concentrations of the process participants and with functioning of the key enzyme carbonic anhydrase in development of toxic effects. Physical and chemical interpretations of the therapeutic effects of the body temperature rise and the potential therapeutic effect of “thermoheliox” (respiration with a thermolized mixture of helium and oxygen) are given. The phenomenon of “thermovaccination” is predicted, which involves stimulation of the immune response by “thermoheliox”.

Correlation of fluorescence microscopy, electron microscopy, and NanoSIMS stable isotope imaging on a single tissue section

Correlative light and electron microscopy allows localization of specific molecules at the ultrastructural level in biological tissue but does not provide information about metabolic turnover or the distribution of labile molecules, such as micronutrients. We present a method to directly correlate (immuno)fluorescent microscopy, (immuno)TEM imaging and NanoSIMS isotopic mapping of the same tissue section, with nanometer-scale spatial precision. The process involves chemical fixation of the tissue, cryo sectioning, thawing, and air-drying under a thin film of polyvinyl alcohol. It permits to effectively retain labile compounds and strongly increases NanoSIMS sensitivity for 13C-enrichment. The method is illustrated here with correlated distribution maps of a carbonic anhydrase enzyme isotype, β-tubulin proteins, and 13C- and 15N-labeled labile micronutrients (and their anabolic derivates) within the tissue of a reef-building symbiotic coral. This broadly applicable workflow expands the wealth of information that can be obtained from multi-modal, sub-cellular observation of biological tissue.

Carbonic anhydrase influences asymmetric sodium and acetate transport across omasum of sheep.

ObjectiveOmasum is an important site for the absorption of short chain fatty acids. The major route for the transport of acetate is via sodium hydrogen exchanger (NHE). However, a discrepancy in the symmetry of sodium and acetate transport has been previously reported, the mechanism of which is unclear. In this study, we investigated the possible role of carbonic anhydrase (CA) for this asymmetry.MethodsOmasal tissues were isolated from healthy sheep (N = 3) and divided into four groups; pH 7.4 and 6.4 alone and in combination with Ethoxzolamide. Electrophysiological measurements were made using Ussing chamber and the electrical measurements were made using computer controlled voltage clamp apparatus. Effect(s) of CA inhibitor on acetate and sodium transport flux rate of Na22 and 14C-acetate was measured in three different flux time periods. Data were presented as mean±standard deviation and level of significance was ascertained at p≤0.05.ResultsMucosal to serosal flux of Na (JmsNa) was greater than mucosal to serosal flux of acetate (JmsAc) when the pH was decreased from 7.4 to 6.4. However, the addition of CA inhibitor almost completely abolished this discrepancy (JmsNa ≈ JmsAc).ConclusionThe results of the present study suggest that the additional protons required to drive the NHE were provided by the CA enzyme in the isolated omasal epithelium. The findings of this study also suggest that the functions of CA may be exploited for better absorption in omasum.

One-pot synthesis of efficient carbonic anhydrase-zeolitic imidazolate framework-8 composite for enhancing CO2 absorption

Carbonic anhydrase (CA) enzyme-based absorption process is under development for CO2 capture. How to maintain the activity and stability of CA enzyme is the important issue related to this emerging process. The immobilization technologies are regarding as the promising method to stabilize CA in harsh environments. This work encapsulated CA into zeolitic imidazolate framework-8 (ZIF-8) with different particle sizes according to several preparation protocols and investigated their activity and stability. The experimental results revealed that the preliminary crystallization time, enzyme dosing amount, and particle sizes of ZIF-8 had a significant influence on the catalytic performance of immobilized CA. The remaining activity of the CA after immobilization ranged from 52 to 93 % depending on the employed preparation protocol. In addition, the immobilized CA with particle size of ∼400 nm exhibited better activity compared to those with particle sizes of ∼100 nm and 1000 nm. Moreover, with the increase of the preliminary crystallization time, the stability of immobilized CA descended.

Effects of nitrogen additions on mesophyll and stomatal conductance in Manchurian ash and Mongolian oak

The response of plant CO2 diffusion conductances (mesophyll and stomatal conductances, gm and gsc) to soil drought has been widely studied, but few studies have investigated the effects of soil nitrogen addition levels on gm and gsc. In this study, we investigated the responses of gm and gsc of Manchurian ash and Mongolian oak to four soil nitrogen addition levels (control, low nitrogen, medium nitrogen and high nitrogen) and the changes in leaf anatomy and associated enzyme activities (aquaporin (AQP) and carbonic anhydrase (CA)). Both gm and gsc increased with the soil nitrogen addition levels for both species, but then decreased under the high nitrogen addition level, which primarily resulted from the enlargements in leaf and mesophyll cell thicknesses, mesophyll surface area exposed to intercellular space per unit leaf area and stomatal opening status with soil nitrogen addition. Additionally, the improvements in leaf N content and AQP and CA activities also significantly promoted gm and gsc increases. The addition of moderate levels of soil nitrogen had notably positive effects on CO2 diffusion conductance in leaf anatomy and physiology in Manchurian ash and Mongolian oak, but these positive effects were weakened with the addition of high levels of soil nitrogen.

Comparison of reactions with different calcium sources for CaCO3 production using carbonic anhydrase

AbstractIn this study, we investigated the effect of calcium sources with different solubilities and the carbonic anhydrase (CA) enzyme on carbonate mineralization reaction, and analyzed the reaction rate, the morphology of the formed precipitate, and the surface. The CO2 mineralization rate was affected by the rate of CO2 hydration and the rate of Ca ionization. For all of the calcium sources tested, CA improved the overall carbonate mineralization rate, but depending on the solubility of each calcium source, the reaction rates were in the order of CaCl2 &gt; Ca(OH)2 &gt; CaO. From CaCl2, calcium carbonate was generated rapidly. This was due to the high concentration of calcium ions in the solution because it was easily dissolved. But because of its high surface energy, calcite and vaterite coexisted. On the other hand, Ca(OH)2 and CaO had relatively low solubility and the rate of calcium carbonate production was slow, but after the reaction, CaCO3 with a calcite structure was formed. © 2020 Society of Chemical Industry and John Wiley &amp; Sons, Ltd.

Quantum mechanical study of human carbonic anhydrase II in complex with polyamines as novel inhibitors: Kinetic and thermodynamic investigation

Spermine and spermidine polyamines are investigated as a new class inhibitors of different carbonic anhydrase (CA) isoforms using DFT calculations. Our results indicate these two polyamines, inhibited the human carbonic anhydrase with very different inhibition profiles compared to other inhibitors. According to calculated results, studied polyamines are anchored to the non-protein zinc ligand (hydroxyl ion) by means of a hydrogen bond of 2.6 Å involving one of terminal ammonium group and an intermediate complex is formed, [(his)3Zn(II)(OH)/polyamine], which is in good agreement with experimental data. By transferring a proton from the terminal ammonium group of polyamine inhibitor to the oxygen atom of the hydroxyl group, the active form of the CA enzyme converted to the inactive form. Finally, the HOMO-LUMO and AIM analysis have been done to understand the details of interaction between studied polyamines and CA active center in intermediate complex in water phase.

Elucidating the Role of Thermal Flexibility of Hydrogels in Protein Refolding.

Synthetic chaperones are stimuli-responsive materials that facilitate the refolding of denatured proteins in their native form and release refolded proteins in solution in the presence of external stimuli. Thermoresponsive hydrogels are a class of synthetic chaperones that require heat as an external stimulus to refold the denatured proteins into their biologically active conformations; however, the mechanism by which these hydrogels participate in protein refolding mechanism remains unclear. In this study, we explore the role of physical and structural changes in the hydrogel matrix that may participate in protein refolding efficacies of thermally responsive poly(vitamin B5 analogous methacrylamide) poly(B5AMA) hydrogels. Poly(B5AMA) hydrogels of different net charges, hydrophobicity, and cross-linking densities are synthesized by radical polymerization method and are evaluated for the restoration of enzymatic activity of thermally denatured enzymes (lysozyme and carbonic anhydrase) as a function of temperature and time and for the presence of residual water in the hydrogel architecture. The hydrogels with promising protein renaturation efficacies are further evaluated for their interactions with denatured proteins, and the role of thermal flexibility of the hydrogel matrix in protein refolding capabilities is elucidated.

Trace Metal Substitution in Marine Phytoplankton

The sinking of organic matter to the deep ocean leaves extremely low concentrations of major and trace nutrients for photosynthetic organisms at the sunlit surface. As a result, marine phytoplankton make use of alternative sources of essential elements and have evolved to substitute some elements by others in various biochemical processes. A particularly intriguing example is that of Zn, which is used in many biochemical functions but is often depleted down to picomolar concentrations in surface seawater. Laboratory data show that many phytoplankton species are able to achieve high growth rates by replacing Zn with Cd or Co in cultures. One documented biochemical replacement occurs in some carbonic anhydrases that are used in the acquisition of inorganic carbon for photosynthesis. Field data show the existence of such enzymes in surface seawater and indicate a replacement of Zn by Cd and Co in the surface waters of the eastern tropical South Pacific. Those results point at interesting opportunities for future research. ▪ The dearth of essential elements in surface seawater has caused marine phytoplankton to substitute some trace metals by others in various biochemical processes. ▪ Many species can substitute Cd and/or Co for Zn as a metal center in carbonic anhydrase enzymes that are used in the acquisition of inorganic carbon for photosynthesis. ▪ Field data show the presence of such enzymes in the sea and indicate a replacement of Zn by Cd and Co in the surface upwelling waters of the eastern tropical South Pacific. ▪ New analytical and molecular tools provide opportunities to elucidate the unusual biochemistry of marine phytoplankton.

Expanding the anticancer potential of 1,2,3-triazoles via simultaneously targeting Cyclooxygenase-2, 15-lipoxygenase and tumor-associated carbonic anhydrases

Cancer is a multifactorial disorder involving multiplicity of interrelated signaling pathways and molecular targets. To that end, a multi-target design strategy was adopted to develop some 1,2,3-triazoles hybridized with some pharmacophoric anticancer fragments, as first-in-class simultaneous inhibitors of COX-2, 15-LOX and tumor associated carbonic anhydrase enzymes. Results revealed that compounds 5a, 5d, 8b and 8c were potent inhibitors of COX-2 and 15-LOX enzymes. COX-2 inhibitory activity was further demonstrated by the inhibition of the accumulation of 6-keto-PGF1α, a metabolite of COX-2 products in two cancer cell lines. The sulfonamide bearing derivatives 5d and 8c were effective nanomolar and submicromolar inhibitors of tumor associated hCA XII isoform, respectively. Strong to moderate inhibitory activities were observed in the in vitro antiproliferative assay on lung (A549), liver (HepG2) and breast (MCF7) cancer cell lines (IC50 2.37–28.5 μM) with high safety margins on WI-38 cells. A cytotoxic advantage of CA inhibition was observed as an increased activity against tumor cell lines expressing CA IX/XII. Further mechanistic clues for the anticancer activities of compound 5a and its sulfonamide analog 5d were derived from induction of cell cycle arrest at G2/M phase. They also triggered apoptosis via increasing expression levels of caspase-9 and Bax together with suppressing that of Bcl-2. The in vitro anti-tumor activity was reflected as reduced tumor size upon treatment with 8c in an in vivo cancer xenograft model. Docking experiments on the target enzymes supported their in vitro data and served as further molecular evidence. In silico calculations and ligand efficiency indices were promising. In light of these data, such series could offer new structural insights into the understanding and development of multi-target COX-2/15-LOX/hCA inhibitors for anticancer outcomes.

Determination of carbonic anhydrase enzyme activity in halophilic/halotolerant bacteria

In the present study, esterase and hydratase activities of carbonic anhydrase (CA) enzyme of twenty-one halophilic/halotolerant bacterial isolates were investigated. According to the obtained data, ten isolates possess both esterase and hydratase activity, whereas six isolates possess only hydratase activity. The highest esterase activity was obtained from Halomonas neptunia (EM23), Bacillus pumilus (EM3) and Bacillus sp. (EM21), whereas the highest hydratase activity was obtained from Bacillus sp. (EM21), Bacillus sp. (EM13) and Halobacillus sp. (EM7), respectively. Two amino acids (l-cysteine and l-glutamic acid) and an herbicide (Simazine) were tested on CA of two bacterial isolates (EM21 and EM23). According to the obtained results in amino acids and herbicide applications, l-cysteine and simazine activated CA, whereas l-glutamic acid inhibited the CA activities of two bacterial isolates. In this paper, we have reported the CA activities in Gram positive bacteria for the first time. As CAs are important in all organisms including microorganisms, the determination of the presence of CAs and illustrating their functions in microorganisms is of vital importance in protecting the health of human being and nature.