Carbonic Anhydrase Enzyme Activities Research Articles

Changes in Paraoxonase, β-Glucosidase, and Carbonic Anhydrase Enzymes Related to Age and Scopolamine-Induced Memory Impairment in Rats

This study aimed to investigate the changes in Paraoxonase (PON), Carbonic Anhydrase (CA), and β-glucosidase levels of different aged rats and scopolamine-induced memory impairment rats. This study used young, adult, and middle-aged male Wistar Albino rats. Scopolamine was administered as a single dose/multiple doses and a Morris water maze (MWM) was used for spatial learning testing in rats. Enzyme-linked immunosorbent assays (ELISAs) were used to determine serum and liver PON and β-glucosidase levels. The CA enzyme activity was assayed following the hydration of CO2. As a result of the comparison of age-related and scopolamine-related changes in PON and β-glucosidase levels in liver and serum samples, no significant age-related and scopolamine-effective changes were observed in serum, while liver PON and liver β-glucosidase levels were found to change significantly. CA activity studies, on the other hand, showed that adults have the lowest CA activity compared to young and middle-aged groups and scopolamine inhibited CA activity in vivo. We found that adult rats modeled with memory impairment had statistically lower levels of liver PON and liver β-glucosidase. CA activity was also found to be significantly reduced. β-glucosidase and CA should be further investigated in terms of neurodegenerative disease risk factors, just like PON, whose importance has been determined by numerous studies in the literature.

Oligomers of restructured-carrageenan impart resilience towards nickel-triggered pernicious outcomes in Mentha arvensis L.

Radiation degradation occurs through ionizing radiations, an eco-friendly, effective, simple and single-step degradation process in which the degraded products are structurally modified (chemical modification). Nickel (Ni) manifests beneficial effects at minimal concentrations and becomes toxic at higher concentrations, thereby affecting the yield, growth and development of plants. Therefore, the present study was conducted to explore the role of structurally-modified carrageenan in imparting resilience towards nickel-triggered phytotoxicity in Mentha arvensis L. and to prove the structure-function relationship of irradiated carrageenan (ICA). The various treatments applied through foliage to the Mentha arvensis L. plant were Control, ICA (80 mg L−1), ICA (100 mg L−1), ICA (120 mg L−1), Ni (80 mg kg−1), Ni (80 mg kg−1) + ICA (80 mg L−1), Ni (80 mg kg−1) + ICA (100 mg L−1) and Ni (80 mg kg−1) + ICA (120 mg L−1). The characterization techniques employed for analysis of carrageenan samples include scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR) and Ultraviolet-visible spectroscopy (UV-Vis). The present study was based on growth, photosynthesis, antioxidant enzymatic activities, oxidative stress biomarkers, SEM, confocal analysis of leaves and roots, and quality and yield parameters. A significant reduction of 16.45%, 22.01%, 15.38%, and 10.15% was noticed in the values of maximum quantum yield of PSII (Fv/Fm), carbonic anhydrase (CA) enzyme activity, essential oil (EO) content, and menthol content under Ni stress (80 mg kg−1). However, the foliar supplementation of 100 mg L−1 ICA enriched the values of the said parameters by 15.15%, 22.82%, 23.63%, and 4.25%, respectively. The oxidative stress biomarkers were escalated by 47.92%, 50.95%, and 35.35% for electrolyte leakage (EL), hydrogen peroxide (H2O2) content and thiobarbituric acid reactive substances (TBARS) content in Ni-stressed plants. Although, a significant down-regulation of 46.62%, 66.97%, and 32.50% was recorded in plants grown in Ni-contaminated soil and supplemented with ICA best dose.

The Effect of Pomegranate-Black Carrot Juice on Serum and Erythrocytes of Sedentary Subjects Exposed to Exhausting Exercise

Background. In this study, the effects of pomegranate-black carrot juice mixture on serum and erythrocytes of sedentary individuals who had exhaustion test were investigated. Methods. A total of 20 men voluntarily participated in the study. Blood samples were obtained from participants on three conditions. First, before the study, blood samples of participants were collected (baseline). Second, the same participants performed in the 20-meter shuttle run test for 1 week each day and were subjected to oxidative stress. Lastly, the same participants were given a mixture of pomegranate-black carrot juices (100 ml/100 ml) for a week, 45 minutes prior to the 20-meter shuttle run test, and the stress + supplement was performed. Blood samples were taken at the end of each process. Results. In the erythrocytes, while the oxidative stress condition malondialdehyde (MDA) level and carbonic anhydrase (CA) enzyme activity levels increased compared to the baseline, reduced glutathione (GSH) level, glutathione reductase (GR), and glutathione S-transferase (GST) enzyme activity levels decreased. In stress + supplement conditions, while GSH and GR levels increased according to oxidative stress conditions, CA and MDA levels decreased. While the lactate dehydrogenase (LDH) level of the oxidative stress condition increased compared to the baseline, the LDH level of the stress + supplement decreased compared to the oxidative stress condition. Conclusions. Our results showed that the level of oxidative stress in subjects exposed to the exhaustion test decreased with the mixture of pomegranate-black carrot juices.

Piperazin incorporated Schiff Base derivatives: Assessment of in vitro biological activities, metabolic enzyme inhibition properties, and molecular docking calculations.

The cytotoxic activities of the compounds were determined by the 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide (MTT) method in human breast cancer (MCF-7), human cervical cancer (HeLa), and mouse fibroblast (L929) cell lines. The compounds MAAS-5 and four modified the supercoiled tertiary structure of pBR322 plasmid DNA. MAAS-5 showed the highest cytotoxic activity in HeLa, MCF-7, and L929 cells with IC50 values of 16.76 ± 3.22, 28.83 ± 5.61, and 2.18 ± 1.22 µM, respectively. MAAS-3 was found to have almost the lowest cytotoxic activities with the IC50 values of 93.17 ± 9.28, 181.07 ± 11.54, and 16.86 ± 6.42 µM in HeLa, MCF-7, and L929 cells respectively at 24 h. Moreover, the antiepileptic potentials of these compounds were investigated in this study. To this end, the effect of newly synthesized Schiff base derivatives on the enzyme activities of carbonic anhydrase I and II isozymes (human carbonic anhydrase [hCA] I and hCA II) was evaluated spectrophotometrically. The target compounds demonstrated high inhibitory activities compared with standard inhibitors with Ki values in the range of 4.54 ± 0.86-15.46 ± 8.65 nM for hCA I (Ki value for standard inhibitor = 12.08 ± 2.00 nM), 1.09 ± 0.32-29.94 ± 0.82 nM for hCA II (Ki value for standard inhibitor = 18.22 ± 4.90 nM). Finally, the activities of the compounds were compared with the Gaussian programme in the B3lyp, HF, M062X base sets with 6-31++G (d,p) levels. In addition, the activities of five compounds against various breast cancer proteins and hCA I and II were compared with molecular docking calculations. Also, absorption, distribution, metabolism, excretion, and toxicity analysis was performed to investigate the possibility of using five compounds as drug candidates.

Enzyme-based CO2/N2 separation nano-membrane via optimization of carbonic anhydrase-functionalized graphene oxide

Protein-based biomass materials are resource-saving and environment-friendly. Especially, carbonic anhydrase (CA) is an enzyme that catalyzes the conversion of carbon dioxide (CO2) into bicarbonate (HCO3−). Recent studies focused on utilizing CA for a CO2 capture application; however, its application is limited due to its low stability and requirement of water molecules for hydration of CA. In this study, CA was immobilized onto a graphene oxide (GO) sheet by two kinds of adsorption mechanism—physisorption and chemisorption to investigate what interaction is more effective for separation. Depending on the adsorption mechanism, CA position on GO and enzymatic activity of CA can be regulated. Physically interacted or chemically reacted GO-CA was used to prepare a nanoscale multilayer structure with layer-by-layer (LbL) assembly. The physically interacted GO-CA (Ph-GO-CA) nano-membrane has CO2 capture properties (N2/CO2 selectivity 4.19) that can be attributed to the enlarged interlayer spacing and catalytic conversion of CA molecules. However, Ch-GO-CA nano-membranes rarely capture CO2 gas and have a low N2/CO2 selectivity. Therefore, Ph-GO-CA is more effective than Ch-GO-CA for capturing CO2 gas.

Composition characterization and biological activity study of Achillea vermicularis extract and extract-loaded nanoparticles.

Antiproliferative activity of Achillea vermicularis extracts was calculated on glial (C6) and keratinocyte (HaCaT) cell lines using XTT assay. It was observed that all extracts of A. vermicularis at the determined concentration were not cytotoxic in HaCaT cell lines. The nanoparticles (NPs) of the extract with the best cytotoxic activity was prepared, and necessary characterization studies were performed. Results showed that NP containing the extract has a lower IC50 value and more cytotoxic activity in C6 cells compared to the only extract. Furthermore, the antiepileptic potentials of these substances were explored in this study. The effect of A. vermicularis extracts on the enzyme activities of carbonic anhydrase I and II isoenzymes (hCA I and hCA II) was measured using spectrophotometry to achieve this goal. A. vermicularis extracts demonstrated high inhibitory activities compared to standard inhibitor (acetazolamide, AAZ), with IC50 values in the range of 5.04-10.8μg/ml for hCA I, and 5.40-9.22μg/ml for hCA II. High-performance liquid chromatography diode array detector (HPLC-DAD) was used in this investigation to assess the main chemicals found in the extract and NPs. The results showed that the ethanol extract (157.636μg/mg extract) and NPs (4.631μg/mg extract) had a significant amount of the 8-hydroxy salvigenin component.

The roles of plasma accessible and cytosolic carbonic anhydrases in bicarbonate (HCO3-) excretion in Pacific hagfish (Eptatretus stoutii).

Pacific hagfish (Eptatretus stoutii) are marine scavengers and feed on decaying animal carrion by burrowing their bodies inside rotten carcasses where they are exposed to several threatening environmental stressors, including hypercapnia (high partial pressures of CO2). Hagfish possess a remarkable capacity to tolerate hypercapnia, and their ability to recover from acid-base disturbances is well known. To deal with the metabolic acidosis resulting from exposure to high CO2, hagfish can mount a rapid elevation of plasma HCO3- concentration (hypercarbia). Once PCO2 is restored, hagfish quickly excrete their HCO3- load, a process that likely involves the enzyme carbonic anhydrase (CA), which catalyzes HCO3- dehydration into CO2 at the hagfish gills. We aimed to characterize the role of branchial CA in CO2/HCO3- clearance from the plasma at the gills of E. stoutii, under control and high PCO2 (hypercapnic) exposure conditions. We assessed the relative contributions of plasma accessible versus intracellular (cytosolic) CA to gill HCO3- excretion by measuring in situ [14C]-HCO3- fluxes. To accomplish this, we employed a novel surgical technique of individual gill pouch arterial perfusion combined with perifusion of the gill afferent to efferent water ducts. [14C]-HCO3- efflux was measured at the gills of fish exposed to control, hypercapnic (48h) and recovery from hypercapnia conditions (6h), in the presence of two well-known pharmacological inhibitors of CA, the membrane impermeant C18 (targets membrane bound, plasma accessible CA) and membrane-permeant acetazolamide, which targets all forms of CA, including extracellular and intracellular cytosolic CAs. C18 did not affect HCO3- flux in control fish, whereas acetazolamide resulted in a significant reduction of 72%. In hypercapnic fish, HCO3- fluxes were much higher and perfusion with acetazolamide caused a reduction of HCO3- flux by 38%. The same pattern was observed for fish in recovery, where in all three experimental conditions, there was no significant inhibition of plasma-accessible CA. We also observed no change in CA enzyme activity (measured in vitro) in any of the experimental PCO2 conditions. In summary, our data suggests that there are additional pathways for HCO3- excretion at the gills of hagfish that are independent of plasma-accessible CA.

Metal Chelators Ethylenediaminetetraacetic acid (EDTA) and N,N,N′,N′‐tetrakis(2‐pyridinylmethyl)‐1,2‐ethanediamine (TPEN) Interfere with Carbonic Anhydrase (CA) Activity in Wilbur‐Anderson Assay (WAa)

In our effort to set up a laboratory for undergraduate students with the tentative title ”Studying enzymatic activity of Carbonic Anhydrase”, we successfully determined carbonic anhydrase activity and demonstrated its inhibition by Acetazolamide, a potent CA inhibitor, using the Wilbur‐Anderson assay (WAa) using 6 experimental set‐ups with a class of 24 students.WAa hinges upon determining the time T (in seconds) required for 4 mL of saturated with carbon dioxide (CO2) water to lower pH from 8.3 to 6.3 of the mixture when added to 6 mL of 0.02M Tris buffer at 0°C without (T0) and with enzyme (TE). Activity (A) is defined as A = 2*(T0/TE‐1) assay units (AU). In n = 16 blank trials, T0 = 75.0±10.7s (Mean±Standard deviation), and with 0.001mg of CA in n = 12 trials, TE = 50.2±8.1s, A = 0.99±0.66 AU (p < 0.001). When for a test we used EDTA, a carboxylic high‐affinity metal ion chelator, to inactivate this Zn2+‐containing enzyme, we unexpectedly encountered that in the presence of the sodium salt of EDTA (Na2EDTA): 1) T was significantly slowed in a concentration‐dependent manner: for 5µM, 50µM, and 500µM, T was 84.3±7.9s (n = 10, p < 0.05), 108.5±.6s (n = 7, p < 0.001), and 130.8±22.7s (n = 10, p < 0.001), respectively; and 2) unexpectedly, in the context of the previous finding, Na2EDTA significantly enhanced CA activity (TE = 38.5±4.0s, A = 1.84 AU, n = 10, p < 0.001) in the presence of 5µM Na2EDTA that was abrogated by 10µM Acetazolamide, a potent CA inhibitor (T = 138.3±10.4s, n = 7, p < 0.001). TPEN, a pyridinic non‐carboxylic metal ion chelator that is more potent in metal ion chelation that EDTA, significantly slowed T0 (99.5±15.9s, n = 4) similar to Na2EDTA, and significantly enhance CA activity (TE = 41.1±3.8, n = 4, p < 0.05) with equal potency.This indicates that principally chemically different metal ion chelators EDTA and TPEN interfere with the determination of CA activity in the context of WAa. Studies to explain these phenomena are underway with the hypotheses that the contaminating metal ions that catalyze CO2 hydration/dehydration without CA are responsible for the observed phenomena.

The Effects of Ciglitazone on Enzyme Activities of Carbonic Anhydrase II and Glucose-6- Phosphate Dehydrogenase

Ciglitazone is a compound belonging to the thiazolidinedione (TZD) class and has hypoglycemic effects. Although ciglitazone is not used as a drug, it has been used as a template for the development of other TZD group drugs. Like many TZD group drugs, ciglitazone causes anemia. In this study, the effects of ciglitazone on the enzyme activities of Glucose-6- Phosphate Dehydrogenase (G6PD) and Carbonic Anhydrase II (CA II), which have important functions in maintaining erythrocyte functions and integrity, were investigated in vitro. Pure human erythrocyte CA II and G6PD enzymes were used for activity measurements. Both esterase and hydratase activities were measured for CA II. The result of activity measurements, it was observed that ciglitazone inhibited CA II (IC50 =0.0063 mM for hydratase activity, and IC50 =0.047 mM for esterase activity) and G6PD (IC50 = 0.067 mM) activities. As a result, it was concluded that these enzyme inhibitions may be important in the anemia-causing mechanisms of cigitazone.

Squalene–polyethyleneimine–dynamic constitutional frameworks enhancing the enzymatic activity of carbonic anhydrase

Carbonic anhydrase is an essential enzyme that catalyzes the hydration/dehydration of carbon dioxide, which is highly relevant to carbon capture processes. It's encapsulation in dynameric capsules enhance its activity, durability and stability.

Fortifying nursery soil-less media with cyanobacteria for enhancing the growth of tomato

Priming nursery media to develop robust nurseries is a major objective of horticulturists for improving yields and quality of produce, and use of cyanobacteria, with both plant growth promoting and biofertilizing properties, can be valuable for generating robust nurseries of tomato. The potential of cyanobacteria as supplements to different soilless media combinations involving perlite, cocopeat and vermiculite (P,C,V) in different combinations was evaluated in terms of their ability to enhance the growth of tomato, from seed to fruiting stage. Agriculturally beneficial cyanobacterial cultures - Anabaena laxa, Calothrix elenkinii, and biofilm- Anabaena torulosa-Trichoderma viride (An-Tr) were used to augment these media and evaluated in Pro-Trays, pot and polyhouse beds respectively. Significant differences were recorded in terms of plant and media parameters. A positive correlation (r = 0.55, 0.78) between PEP carboxylase and Carbonic anhydrase enzyme activities was observed in Pro-Tray and polyhouse experiments. The performance of C:V + C. elenkinii, P:C:V + An-Tr, PM (Potting mix; C:V:P, 3:1:1) + A. laxa in terms of leaf, soil and nutrient data suggested their superiority among all other treatments. An enhancement of 14.70% and 36.55% in fruit and flower count was observed in PM + A. laxa over control. Among all the media evaluated, PM was most responsive to augmentation using any of the cultures, highlighting it as an effective nursery medium. A. laxa proved most superior among the cultures evaluated. Future research is focused on the upscaling the use of A. laxa as a nursery medium supplement for enhancing growth and productivity of tomato.

Transcriptomic Responses of Rhizobium phaseoli to Root Exudates Reflect Its Capacity to Colonize Maize and Common Bean in an Intercropping System.

Corn and common bean have been cultivated together in Mesoamerica for thousands of years in an intercropping system called “milpa,” where the roots are intermingled, favoring the exchange of their microbiota, including symbionts such as rhizobia. In this work, we studied the genomic expression of Rhizobium phaseoli Ch24-10 (by RNA-seq) after a 2-h treatment in the presence of root exudates of maize and bean grown in monoculture and milpa system under hydroponic conditions. In bean exudates, rhizobial genes for nodulation and degradation of aromatic compounds were induced; while in maize, a response of genes for degradation of mucilage and ferulic acid was observed, as well as those for the transport of sugars, dicarboxylic acids and iron. Ch24-10 transcriptomes in milpa resembled those of beans because they both showed high expression of nodulation genes; some genes that were expressed in corn exudates were also induced by the intercropping system, especially those for the degradation of ferulic acid and pectin. Beans grown in milpa system formed nitrogen-fixing nodules similar to monocultured beans; therefore, the presence of maize did not interfere with Rhizobium–bean symbiosis. Genes for the metabolism of sugars and amino acids, flavonoid and phytoalexin tolerance, and a T3SS were expressed in both monocultures and milpa system, which reveals the adaptive capacity of rhizobia to colonize both legumes and cereals. Transcriptional fusions of the putA gene, which participates in proline metabolism, and of a gene encoding a polygalacturonase were used to validate their participation in plant–microbe interactions. We determined the enzymatic activity of carbonic anhydrase whose gene was also overexpressed in response to root exudates.

Предикторы перекисного окисления липидов как критерий диагностики первичной открытоугольной глаукомы

This review of modern literature presents the issue of early diagnosis of primary open-angle glaucoma (POAG) which is one of the most important problems in ophthalmology. According to the World Health Organization (WHO), the number of glaucoma patients all over the world ranges from 60.5 to 105 million people, and in the next 10 years it will increase by another 10 million. The subtle onset of the disease usually leads to late diagnosis, since visual field defects are often first detectable by visual field testing when 25–35% of retinal ganglion cells have already been lost. In modern studies, it has been established that the cell death in POAG is accompanied by oxidative stress. It is considered a key factor indicating the pathological process of a fairly large number of chronic diseases of the whole body, including complicated eye pathologies and inflammatory processes. The resulting free radicals oxidize lipids and phospholipids which leads to their peroxidation and triggers damage to cell membranes. The lipid peroxidation is one of obligatory processes occurring in neurodegenerative conditions including POAG. Modern technologies analyzing lipid peroxidation may accelerate the diagnosis, to identify glaucoma biomarkers at an earlier stage, and as a result to maintain quality of vision more efficiently. These studies were carried out in different countries and using different methods such as serological proteomic analysis, chromatography and mass spectrometry, and new technological approaches such as MultiOmics. The study of the protein profile, lipase activity, nitric oxide concentration, activity of carbonic anhydrase enzyme, malondialdehyde (MDA) and other compounds are also very informative. Various fluids were taken as a basis for the study: tears, aqueous humor of the anterior chamber, blood and its components. Together these technologies enable to evaluate the oxidative process in different ways. Earlier diagnosis of glaucoma is very important as it will enable to maintain the quality of vision for a longer time and reduce the rate of the disease progression. Keywords: primary open-angle glaucoma, lipid peroxidation, lacrimal fluid, serum.

TOXICOLOGICAL EFFECTS OF METAL IONS AND SOME PESTICIDES ON CARBONIC ANHYDRASE ACTIVITY PURIFIED FROM BIGHEAD CARP (HYPOPHTHALMICHTHYS NOBILIS) GILL TISSUE

In this work, the total carbonic anhydrase (CA) enzymes were obtained from bighead carp (Hypophthalmichthys nobilis) gill tissue with a purification fold of 239.62, specific activity of 26128.18 EU mg-1 and a yield of 44.04 % using Sepharose affinity column chromatography. For recording the CA purity, gel electrophoresis was performed in this part. The molecular weight (MW) of total CA enzyme was found 31 kDa. Additionally, the inhibitory effects of diverse pesticide compounds (carbaryl, carbofuran, permethrin, dimethoate, cypermethrin and λ-cyhalothrin) and heavy metals (Cu2+, Fe2+, Pb2+, Co2+) on CA bighead carp gill tissue CA enzyme activities were investigated and also the results calculated, and then plotted. The some pesticide compounds had IC50 amounts in the range of 0.36 - 253.35 μM. Also, the metal ions used had IC50 values ranging from 7.84 to 95.28 mm. As a result of these studies, a stable pH is set as pH: 8.0. CA inhibitors are target molecules in drug design studies.

Alterations in Enzyme Activity of Carbonic Anhydrase, 6-phosphogluconate Dehydrogenase and Thioredoxin Reductase in Rats Exposed to Doxorubicin and Morin

Objective: Carbonic anhydrase (CA), 6-phosphogluconate dehydrogenase (6PGD) and thioredoxin reductase (TrxR) enzymes are the essential biological molecules needed for metabolic processes in all living cells. This study was designed to investigate the activities of CA, 6PGD and TrxR enzymes in the brain, kidney, liver, heart and testis tissues of the rats exposed to Dox and morin. Methods: Male Wistar albino rats were randomly divided into three groups as control, morin and DOX, each of them containing 7 rats. At the end of the experimental procedure, CA, 6PGD and TrxR enzyme activities in tissues of rats were determined spectrophotometrically. Results: In our study, we observed that DOX activated CA enzyme in liver and kidney tissues while inhibiting CA enzyme in the other tissues, activated 6PGD enzyme in the kidney, liver and heart tissues, and inhibited the TrxR enzyme in all the tissues. In addition, morin activated CA enzyme in the liver tissue while inhibiting CA enzyme in the brain, heart and testis tissues. Morin activated 6PGD enzyme activity while it inhibited TrxR enzyme in all the tissues. Conclusion: The findings showed that doxorubicin and morin had similar properties in the tissues as to their effect on enzyme activities.

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.

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.

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.

Sanger's Reagent Sensitized Photocleavage of Amide Bond for Constructing Photocages and Regulation of Biological Functions.

Photolabile groups offer promising tools to study biological processes with high spatial and temporal control. In the investigation, we designed and prepared several new glycine amide derivatives of Sanger's reagent and demonstrated that they serve as a new class of photocages for Zn2+ and an acetylcholinesterase (AChE) inhibitor. We showed that the mechanism for photocleavage of these substances involves initial light-driven cyclization between the 2,4-dinitrophenyl and glycine methylene groups to form acyl benzimidazole N-oxides, which undergo secondary photoinduced decarboxylation in association with rupture of an amide bond. The cleavage reactions proceed with modest to high quantum yields. We demonstrated that these derivatives can be used in targeted intracellular delivery of Zn2+, fluorescent imaging by light-triggered Zn2+ release, and regulation of biological processes including the enzymatic activity of carbonic anhydrase (CA), negative regulation of N-methyl-d-aspartate receptors (NMDARs), and pulse rate of cardiomyocytes. The successful proof-of-concept examples described above open a new avenue for using Sanger's reagent-based glycine amides as photocages for the exploration of complex cellular functions and signaling pathways.

Enzyme activities suggest that the NAD-ME C4 type CCM exist in Ulva sp.

Ulva sp. is a large intertidal species of green algae that has been a causative species in green tide in the Qingdao sea area of China since 2008. To explore the physiological basis of outbreaks, we investigated the photosynthetic carbon sequestration mechanism of Ulva sp. Growth and breeding capacity, chlorophyll fluorescence parameters, chlorophyll content, and enzyme activities of carbonic anhydrase and other important enzymes in the C4 pathway were measured when different inorganic carbon sources were provided (0, 400, 1500, 20,000 μL·L−1 of CO2 or HCO3−). When CO2 was absent (0 μL·L−1 CO2), chlorophyll fluorescence parameters [Fv/Fm, Y (II), Y(I)] and chlorophyll content decreased significantly, but NPQ parameters and MDH and PEPC enzyme activities increased significantly and PEPCK enzyme activity was not affected significantly. When HCO3− was added, chlorophyll content and NAD-ME enzyme activity decreased significantly. These results indicated that lack of CO2 could stimulate photoprotection of Ulva sp. containing decreasing the synthesis of chlorophyll and reducing the PSII reaction center of the open state. Ulva sp. may not have the PEPCK C4 type CCM and might use the NAD-ME C4 type CCM to tolerate the stress caused by the lack of CO2.