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Sample records for anhydrase ix expression

  1. Efficient Expression and Crystallization System of Cancer-Associated Carbonic Anhydrase Isoform IX.

    PubMed

    Leitans, Janis; Kazaks, Andris; Balode, Agnese; Ivanova, Jekaterina; Zalubovskis, Raivis; Supuran, Claudiu T; Tars, Kaspars

    2015-11-25

    Human carbonic anhydrase IX (CA IX) is overexpressed in a number of solid tumors and is considered to be a marker for cellular hypoxia that it is not produced in most normal tissues. CA IX contributes to the acidification of the extracellular matrix, which, in turn, favors tumor growth and metastasis. Therefore, CA IX is considered to be a promising anti-cancer drug target. However, the ability to specifically target CA IX is challenging due to the fact that the human genome encodes 15 different carbonic anhydrase isoforms that have a high degree of homology. Furthermore, structure-based drug design of CA IX inhibitors so far has been largely unsuccessful due to technical difficulties regarding the expression and crystallization of the enzyme. Currently, only one baculovirus-produced CA IX structure in complex with a nonspecific CA inhibitor, acetazolamide, is available in Protein Data Bank. We have developed an efficient system for the production of the catalytic domain of CA IX in methylotrophic yeast Pichia pastoris. The produced protein can be easily crystallized in the presence of inhibitors, as we have demonstrated for several 2-thiophene-sulfonamide compounds. We have also observed significant differences in the binding mode of chemically identical compounds to CA IX and CA II, which can be further exploited in the design of CA IX-specific inhibitors. PMID:26522624

  2. Assessment of carbonic anhydrase IX expression and extracellular pH in B-cell lymphoma cell line models.

    PubMed

    Chen, Liu Qi; Howison, Christine M; Spier, Catherine; Stopeck, Alison T; Malm, Scott W; Pagel, Mark D; Baker, Amanda F

    2015-05-01

    The expression of carbonic anhydrase IX (CA IX) and its relationship to acidosis in lymphomas has not been widely studied. We investigated the protein expression of CA IX in a human B-cell lymphoma tissue microarray, and in Raji, Ramos and Granta 519 lymphoma cell lines and tumor models, while also investigating the relationship with hypoxia. An imaging method, acidoCEST magnetic resonance imaging (MRI), was used to estimate lymphoma xenograft extracellular pH (pHe). Our results showed that clinical lymphoma tissues and cell line models in vitro and in vivo had moderate CA IX expression. Although in vitro studies showed that CA IX expression was induced by hypoxia, in vivo studies did not show this correlation. Untreated lymphoma xenograft tumor pHe had acidic fractions, and an acidity score was qualitatively correlated with CA IX expression. Therefore, CA IX is expressed in B-cell lymphomas and is qualitatively correlated with extracellular acidosis in xenograft tumor models. PMID:25130478

  3. Assessment of carbonic anhydrase IX expression and extracellular pH in B-cell lymphoma cell line models

    PubMed Central

    Chen, Liu Qi; Howison, Christine M.; Spier, Catherine; Stopeck, Alison T.; Malm, Scott W.; Pagel, Mark D.; Baker, Amanda F.

    2015-01-01

    The expression of carbonic anhydrase (CA IX) and it’s relation to acidosis in lymphomas has not been widely studied. We investigated the protein expression of CA IX in a human B-cell lymphoma tissue microarray, and in Raji, Ramos, and Granta 519 lymphoma cell lines and tumor models, while also investigating the relation with hypoxia. An imaging method, acidoCEST MRI, was used to estimate lymphoma xenograft extracellular pH (pHe). Our results showed that clinical lymphoma tissues and cell line models in vitro and in vivo had moderate CA IX expression. Although in vitro studies showed that CA IX expression was induced by hypoxia, in vivo studies did not show this correlation. Untreated lymphoma xenograft tumor pHe had acidic fractions, and an Acidity Score was qualitatively correlated with CA IX expression. Therefore, CA IX is expressed in B-cell lymphomas and is qualitatively correlated with extracellular acidosis in xenograft tumor models. PMID:25130478

  4. PEGylated Bis-Sulfonamide Carbonic Anhydrase Inhibitors Can Efficiently Control the Growth of Several Carbonic Anhydrase IX-Expressing Carcinomas.

    PubMed

    Akocak, Suleyman; Alam, M Raqibul; Shabana, Ahmed M; Sanku, Rajesh Kishore Kumar; Vullo, Daniela; Thompson, Harry; Swenson, Erik R; Supuran, Claudiu T; Ilies, Marc A

    2016-05-26

    A series of aromatic/heterocyclic bis-sulfonamides were synthesized from three established aminosulfonamide carbonic anhydrase (CA, EC 4.2.1.1) inhibitor pharmacophores, coupled with either ethylene glycol oligomeric or polymeric diamines to yield bis-sulfonamides with short or long (polymeric) linkers. Testing of novel inhibitors and their precursors against a panel of membrane-bound CA isoforms, including tumor-overexpressed CA IX and XII and cytosolic isozymes, identified nanomolar-potent inhibitors against both classes and several compounds with medium isoform selectivity in a detailed structure-activity relationship study. The ability of CA inhibitors to kill tumor cells overexpressing CA IX and XII was tested under normoxic and hypoxic conditions, using 2D and 3D in vitro cellular models. The study identified a nanomolar potent PEGylated bis-sulfonamide CA inhibitor (25) able to significantly reduce the viability of colon HT-29, breast MDA-MB231, and ovarian SKOV-3 cancer cell lines, thus revealing the potential of polymer conjugates in CA inhibition and cancer treatment. PMID:27144971

  5. Prognostic Significance of Carbonic Anhydrase IX Expression in Cancer Patients: A Meta-Analysis

    PubMed Central

    van Kuijk, Simon J. A.; Yaromina, Ala; Houben, Ruud; Niemans, Raymon; Lambin, Philippe; Dubois, Ludwig J.

    2016-01-01

    Hypoxia is a characteristic of many solid tumors and an adverse prognostic factor for treatment outcome. Hypoxia increases the expression of carbonic anhydrase IX (CAIX), an enzyme that is predominantly found on tumor cells and is involved in maintaining the cellular pH balance. Many clinical studies investigated the prognostic value of CAIX expression, but most have been inconclusive, partly due to small numbers of patients included. The present meta-analysis was therefore performed utilizing the results of all clinical studies to determine the prognostic value of CAIX expression in solid tumors. Renal cell carcinoma was excluded from this meta-analysis due to an alternative mechanism of upregulation. 958 papers were identified from a literature search performed in PubMed and Embase. These papers were independently evaluated by two reviewers and 147 studies were included in the analysis. The meta-analysis revealed strong significant associations between CAIX expression and all endpoints: overall survival [hazard ratio (HR) = 1.76, 95% confidence interval (95%CI) 1.58–1.98], disease-free survival (HR = 1.87, 95%CI 1.62–2.16), locoregional control (HR = 1.54, 95%CI 1.22–1.93), disease-specific survival (HR = 1.78, 95%CI 1.41–2.25), metastasis-free survival (HR = 1.82, 95%CI 1.33–2.50), and progression-free survival (HR = 1.58, 95%CI 1.27–1.96). Subgroup analyses revealed similar associations in the majority of tumor sites and types. In conclusion, these results show that patients having tumors with high CAIX expression have higher risk of locoregional failure, disease progression, and higher risk to develop metastases, independent of tumor type or site. The results of this meta-analysis further support the development of a clinical test to determine patient prognosis based on CAIX expression and may have important implications for the development of new treatment strategies. PMID:27066453

  6. Evaluation of Nonpeptidic Ligand Conjugates for SPECT Imaging of Hypoxic and Carbonic Anhydrase IX-Expressing Cancers.

    PubMed

    Lv, Peng-Cheng; Putt, Karson S; Low, Philip S

    2016-07-20

    As tumors grow, vasculature is often deficient or malformed, resulting in many localized areas of hypoxia. Cells located in these hypoxic regions exhibit an altered gene expression pattern that can significantly alter resistance to conventional anticancer treatments such as ionizing radiation and chemotherapeutic drugs. A priori knowledge of the level of hypoxia within a tumor may better guide clinical care. In an effort to create a hypoxia specific imaging agent, a ligand for the tissue hypoxia marker, carbonic anhydrase IX (CA IX), was synthesized and used as a targeting ligand to deliver an attached (99m)Tc-chelating agent. Binding of the resulting conjugates to hypoxic cancer cells was first characterized in vitro. Whole animal imaging and biodistribution studies then were performed to determine tumor specificity in vivo. Several conjugates were found to bind selectively to CA IX expressing tumors in a receptor-dependent manner. We suggest that such conjugates could prove useful in identifying hypoxic cancers and/or quantitating the level of hypoxia within a tumor. PMID:27362480

  7. High Stromal Carbonic Anhydrase IX Expression Is Associated With Decreased Survival in p16-Negative Head-and-Neck Tumors

    SciTech Connect

    Brockton, Nigel; Dort, Joseph; Lau, Harold; Hao, Desiree; Brar, Sony; Klimowicz, Alexander; Petrillo, Stephanie; Diaz, Roman; Doll, Corinne; Magliocco, Anthony

    2011-05-01

    Purpose: Head-and-neck squamous cell carcinoma (HNSCC) is the fifth most common malignancy worldwide. Alcohol use and tobacco use are the most established risk factors; however, human papilloma virus (HPV) infection is a major risk factor for a subset of HNSCCs. Although HPV-positive tumors typically present at a more advanced stage at diagnosis, they are associated with a better prognosis. Tumor hypoxia confers poor prognosis and treatment failure, but direct tumor oxygen measurement is challenging. Endogenous markers of hypoxia (EMHs) have been proposed but have not replicated the prognostic utility of direct oxygen measurement. The expression of endogenous markers of hypoxia may be influenced by oxygen-independent factors, such as the HPV status of the tumor. Methods and Materials: Consecutive cases of locally advanced HNSCC, treated with a uniform regimen of combined radiotherapy and chemotherapy, were identified. Tissue microarrays were assembled from triplicate 0.6-mm cores of archived tumor tissue. HPV status was inferred from semiquantitative p16 immunostaining and directly measured by use of HPV-specific chromogenic in situ hybridization and polymerase chain reaction. Automated quantitative fluorescent immunohistochemistry was conducted to measure epithelial and stromal expression of carbonic anhydrase IX (CAIX) and glucose transporter 1 (GLUT1). Results: High stromal CAIX expression was associated with significantly reduced overall survival (p = 0.03) in patients with p16-negative tumors. Conclusions: This is the first study to use quantitative immunohistochemistry to examine endogenous markers of hypoxia stratified by tumor p16/HPV status. Assessment of CAIX expression in p16-negative HNSCC could identify patients with the least favorable prognosis and inform therapeutic strategies.

  8. Inhibition of carbonic anhydrase IX as a novel anticancer mechanism

    PubMed Central

    Supuran, Claudiu T

    2012-01-01

    Carbonic anhydrases (CA, EC 4.2.1.1) catalyze the interconversion bewteen carbon dioxide and bicarbonate with generation of protons. The carbonic anhydrase isozyme IX (CA IX) is highly overexpresed in hypoxic tumors and shows very restricted expression in normal tissues. CA IX is a dimeric protein possessing very high catalytic activity for the hydration of carbon dioxide to protons and bicarbonate. Its quaternary structure is unique among members of this family of enzymes, allowing for structure-based drug design campaigns of selective inhibitors. Inhibition of CA IX with sulfonamide and/or coumarin inhibitors was recently shown to lead to a potent retardation for the growth of both primary tumors and metastases. Some fluorescent sulfonamides were shown to accumulate only in hypoxic tumor cells overexpressing CA IX, and might be used as diagnostic tools for imaging of hypoxic cancers. Sulfonamide inhibitors were also more effective in inhibiting the growth of the primary tumors when associated with irrdiation. CA IX is thus both a diagnostic and therapeutic validated target for the management of hypoxic tumors normally non-responsive to classical chemio- and radiotherapy. PMID:22787577

  9. Catalytic activity of human carbonic anhydrase isoform IX is displayed both extra- and intracellularly.

    PubMed

    Klier, Michael; Jamali, Somayeh; Ames, Samantha; Schneider, Hans-Peter; Becker, Holger M; Deitmer, Joachim W

    2016-01-01

    Most carbonic anhydrases catalyse the reversible conversion of carbon dioxide to protons and bicarbonate, either as soluble cytosolic enzymes, in or at intracellular organelles, or at the extracellular face of the cell membrane as membrane-anchored proteins. Carbonic anhydrase isoform IX (CA IX), a membrane-bound enzyme with catalytic activity at the extracellular membrane surface, has come to prominence in recent years because of its association with hypoxic tissue, particularly tumours, often indicating poor prognosis. We have evaluated the catalytic activity of CA IX heterologously expressed in Xenopus laevis oocytes by measuring the amplitude and rate of cytosolic pH changes as well as pH changes at the outer membrane surface (pHs ) during addition and removal of 5% CO2 /25 mm HCO3-, and by mass spectrometry. Our results indicate both extracellular and intracellular catalytic activity of CA IX. Reduced rates of CO2 -dependent intracellular pH changes after knockdown of CA IX confirmed these findings in two breast cancer cell lines: MCF-7 and MDA-MB-231. Our results demonstrate a new function of CA IX that may be important in the search for therapeutic cancer drugs targeting CA IX. PMID:26470855

  10. New selective carbonic anhydrase IX inhibitors: synthesis and pharmacological evaluation of diarylpyrazole-benzenesulfonamides.

    PubMed

    Rogez-Florent, Tiphaine; Meignan, Samuel; Foulon, Catherine; Six, Perrine; Gros, Abigaëlle; Bal-Mahieu, Christine; Supuran, Claudiu T; Scozzafava, Andrea; Frédérick, Raphaël; Masereel, Bernard; Depreux, Patrick; Lansiaux, Amélie; Goossens, Jean-François; Gluszok, Sébastien; Goossens, Laurence

    2013-03-15

    Carbonic anhydrase (CA) IX expression is increased upon hypoxia and has been proposed as a therapeutic target since it has been associated with poor prognosis, tumor progression and pH regulation. We report the synthesis and the pharmacological evaluation of a new class of human carbonic anhydrase (hCA) inhibitors, 4-(5-aryl-2-hydroxymethyl-pyrazol-1-yl)-benzenesulfonamides. A molecular modeling study was conducted in order to simulate the binding mode of this new family of enzyme inhibitors within the active site of hCA IX. Pharmacological studies revealed high hCA IX inhibitory potency in the parameters nanomolar range. This study showed that the position of sulfonamide group in meta of the 1-phenylpyrazole increase a selectivity hCA IX versus hCA II of our compounds. An in vitro antiproliferative screening has been performed on the breast cancer MDA-MB-231 cell using doxorubicin as cytotoxic agent and in presence of selected CA IX inhibitor. The results shown that the cytotoxic efficiency of doxorubicin in an hypoxic environment, expressed in IC50 value, is restored at 20% level with 1μM CA IX inhibitor. PMID:23168081

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

    PubMed

    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

    2016-08-23

    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 properties that allow for low pH stability and activity. Furthermore, the unfolding process of hCA IX-c appears to be reversible, and its catalytic efficiency is thought to be correlated directly with its stability between pH 3.0 and 8.0 but not above pH 8.0. To rationalize this, we determined the X-ray crystal structure of hCA IX-c to 1.6 Å resolution. Insights from this study suggest an understanding of hCA IX-c stability and activity in low-pH tumor microenvironments and may be applicable to determining pH-related effects on enzymes. PMID:27439028

  12. Circulating Carbonic Anhydrase IX and Antiangiogenic Therapy in Breast Cancer

    PubMed Central

    Brown-Glaberman, Ursa; Marron, Marilyn; Chalasani, Pavani; Livingston, Robert; Iannone, Maria; Specht, Jennifer; Stopeck, Alison T.

    2016-01-01

    Introduction. Carbonic anhydrase IX (CAIX) is a hypoxia regulated metalloenzyme integral to maintaining cellular pH. Increased CAIX expression is associated with poor prognosis in breast cancer. To explore CAIX as a biomarker for breast cancer therapies, we measured plasma CAIX levels in healthy control subjects and in breast cancer patients. Methods. In control subjects we evaluated plasma CAIX stability via commercially available ELISA. We then similarly quantified plasma CAIX levels in (1) locally advanced breast cancer (LABC) patients treated with neoadjuvant paclitaxel + sunitinib (T + S) followed by doxorubicin and cyclophosphamide (AC); (2) metastatic breast cancer (MBC) patients treated with systemic chemotherapy. Results. Plasma CAIX levels were stable at room temperature for at least 48 hours in control subjects. Mean baseline plasma CAIX levels were lower in controls compared to patients with LABC or MBC. In LABC, CAIX levels rose significantly in response to administration of antiangiogenic therapy (T + S) (p = 0.02) but not AC (p = 0.37). In patients with MBC treated without an antiangiogenic agent CAIX levels did not change with therapy. Conclusions. Our results suggest that CAIX may be an easily obtained, stable measure of tumor associated hypoxia as well as a useful pharmacodynamic biomarker for antiangiogenic therapy. PMID:26941473

  13. Carbonic anhydrase IX is a clinically significant tissue and serum biomarker associated with renal cell carcinoma

    PubMed Central

    TAKACOVA, MARTINA; BARTOSOVA, MARIA; SKVARKOVA, LUCIA; ZATOVICOVA, MIRIAM; VIDLICKOVA, IVANA; CSADEROVA, LUCIA; BARATHOVA, MONIKA; BREZA, JAN; BUJDAK, PETER; PASTOREK, JAROMIR; BREZA, JAN; PASTOREKOVA, SILVIA

    2013-01-01

    Carbonic anhydrase IX (CA IX) is regarded as one of the most prominent markers of tumor hypoxia with potential to serve as a diagnostic biomarker, prognostic indicator as well as tumor therapeutic target. The aim of the present study was to perform an in-depth analysis of CA IX expression in blood and tissue samples and to evaluate the significance of CA IX status for different renal cell carcinomas (RCCs). The expression of CA IX was determined in blood and tissue samples from 74 kidney cancer patients using reverse transcription polymerase chain reaction (RT-PCR), enzyme-linked immunosorbent assay (ELISA), Western blotting (WB) and immunohistochemistry (IHC). The CA IX status was correlated with RCC type and tumor stage. IHC and WB provided evidence for a significantly higher expression of CA IX in clear cell RCC (CCRCC) specimens compared to other RCCs. RT-PCR assay revealed that 32.42% of all RCC patients possess CA9-positive cells in peripheral blood and three-quarters of CA9-positive patients were diagnosed with CCRCC. When the patients were subdivided according to tumor stage, decreased positivity was observed with higher tumor stage (50% in T1 vs. 17% in T3). Serum CA IX levels determined by ELISA were significantly higher in CCRCC patients than in non-CCRCC. A significant association between s-CA IX and CCRCC tumor stage was also determined (T1-87.51 vs. T3-341.98 pg/ml, p=0.046). We demonstrated that the CA IX expression profiles in blood and tissue samples from 74 kidney cancer patients are closely correlated with their histological subtypes. This is the first study reporting CA IX expression in blood and tissue samples from kidney cancer patients determined by four different methods. PMID:23255918

  14. Discovery and characterization of novel selective inhibitors of carbonic anhydrase IX.

    PubMed

    Dudutienė, Virginija; Matulienė, Jurgita; Smirnov, Alexey; Timm, David D; Zubrienė, Asta; Baranauskienė, Lina; Morkūnaite, Vaida; Smirnovienė, Joana; Michailovienė, Vilma; Juozapaitienė, Vaida; Mickevičiūtė, Aurelija; Kazokaitė, Justina; Bakšytė, Sandra; Kasiliauskaitė, Aistė; Jachno, Jelena; Revuckienė, Jurgita; Kišonaitė, Miglė; Pilipuitytė, Vilma; Ivanauskaitė, Eglė; Milinavičiūtė, Goda; Smirnovas, Vytautas; Petrikaitė, Vilma; Kairys, Visvaldas; Petrauskas, Vytautas; Norvaišas, Povilas; Lingė, Darius; Gibieža, Paulius; Capkauskaitė, Edita; Zakšauskas, Audrius; Kazlauskas, Egidijus; Manakova, Elena; Gražulis, Saulius; Ladbury, John E; Matulis, Daumantas

    2014-11-26

    Human carbonic anhydrase IX (CA IX) is highly expressed in tumor tissues, and its selective inhibition provides a potential target for the treatment of numerous cancers. Development of potent, highly selective inhibitors against this target remains an unmet need in anticancer therapeutics. A series of fluorinated benzenesulfonamides with substituents on the benzene ring was designed and synthesized. Several of these exhibited a highly potent and selective inhibition profile against CA IX. Three fluorine atoms significantly increased the affinity by withdrawing electrons and lowering the pKa of the benzenesulfonamide group. The bulky ortho substituents, such as cyclooctyl or even cyclododecyl groups, fit into the hydrophobic pocket in the active site of CA IX but not CA II, as shown by the compound's co-crystal structure with chimeric CA IX. The strongest inhibitor of recombinant human CA IX's catalytic domain in human cells achieved an affinity of 50 pM. However, the high affinity diminished the selectivity. The most selective compound for CA IX exhibited 10 nM affinity. The compound that showed the best balance between affinity and selectivity bound with 1 nM affinity. The inhibitors described in this work provide the basis for novel anticancer therapeutics targeting CA IX. PMID:25358084

  15. Discovering novel carbonic anhydrase type IX (CA IX) inhibitors from seven million compounds using virtual screening and in vitro analysis.

    PubMed

    Salmas, Ramin Ekhteiari; Senturk, Murat; Yurtsever, Mine; Durdagi, Serdar

    2016-06-01

    Carbonic anhydrase type IX (CA IX) enzyme is mostly over expressed in different cancer cell lines and tumor tissues. Potent CA IX inhibitors can be effective for adjusting the pH imbalance in tumor cells. In the present work, we represented the successful application of high throughput virtual screening (HTVS) of large dataset from ZINC database included of ∼7 million compounds to discover novel inhibitors of CA IX. HTVS and molecular docking were performed using consequence Glide/standard precision (SP), extra precision (XP) and induced fit docking (IFD) molecular docking protocols. For each compound, docking code calculates a set of low-energy poses and then exhaustively scans the binding pocket of the target with small compounds. Novel CA IX inhibitor candidates were suggested based on molecular modeling studies and a few of them were tested using in vitro analysis. These compounds were determined as good inhibitors against human CA IX target with Ki in the range of 0.85-1.58 μM. In order to predict the pharmaceutical properties of the selected compounds, ADME (absorption, distribution, metabolism and excretion) analysis was also carried out. PMID:25950196

  16. Characterization of carbonic anhydrase IX (CA IX) as an endogenous marker of chronic hypoxia in live human tumor cells

    SciTech Connect

    Vordermark, Dirk . E-mail: vordermark_d@klinik.uni-wuerzburg.de; Kaffer, Anja; Riedl, Susanne; Katzer, Astrid; Flentje, Michael

    2005-03-15

    Purpose: Published clinical studies provide conflicting data regarding the prognostic significance of carbonic anhydrase IX (CA IX) overexpression as an endogenous marker of tumor hypoxia and its comparability with other methods of hypoxia detection. We performed a systematic analysis of CA IX protein levels under various in vitro conditions of tumor hypoxia in HT 1080 human fibrosarcoma and FaDu human pharyngeal carcinoma cells. Because sorting of live CA IX positive cells from tumors provides a tool to study the radiosensitivity of chronically hypoxic cells, we modified and tested a CA IX flow cytometry protocol on mixed hypoxic/aerobic suspensions of HT 1080 and FaDu cells. Methods and materials: HT 1080 and FaDu cells were treated with up to 24 h of in vitro hypoxia and up to 96 h of reoxygenation. To test the effect of nonhypoxic stimuli, glucose and serum availability, pH and cell density were modified. CA IX protein was quantified in Western blots of whole-cell lysates. Mixed suspensions with known percentages of hypoxic cells were prepared for CA IX flow cytometry. The same mixtures were assayed for clonogenic survival after 10 Gy. Results: Hypoxia-induced CA IX protein expression was seen after >6 h at {<=}5% O{sub 2}, and protein was stable over 96 h of reoxygenation in both cell lines. Glucose deprivation abolished the hypoxic CA IX response, and high cell density caused CA IX induction under aerobic conditions. Measured percentages of CA IX-positive cells in mixtures closely reflected known percentages of hypoxic cells in HT 1080 and were associated with radioresistance of mixtures after 10 Gy. Conclusion: CA IX is a stable marker of current or previous chronic hypoxia but influenced by nonhypoxic stimuli. Except the time course of accumulation, all properties of this marker resembled our previous findings for hypoxia-inducible factor-1{alpha}. A modified flow cytometry protocol provided good separability of CA IX-negative and -positive cells in vitro

  17. Recent Developments in Targeting Carbonic Anhydrase IX for Cancer Therapeutics

    PubMed Central

    McDonald, Paul C.; Winum, Jean-Yves; Supuran, Claudiu T.; Dedhar, Shoukat

    2012-01-01

    Carbonic anhydrase IX (CAIX) is a hypoxia-inducible enzyme that is overexpressed by cancer cells from many tumor types, and is a component of the pH regulatory system invoked by these cells to combat the deleterious effects of a high rate of glycolytic metabolism. CAIX functions to help produce and maintain an intracellular pH (pHi) favorable for tumor cell growth and survival, while at the same time participating in the generation of an increasingly acidic extracellular space, facilitating tumor cell invasiveness. Pharmacologic interference of CAIX catalytic activity using monoclonal antibodies or CAIX-specific small molecule inhibitors, consequently disrupting pH regulation by cancer cells, has been shown recently to impair primary tumor growth and metastasis. Many of these agents are in preclinical or clinical development and constitute a novel, targeted strategy for cancer therapy. PMID:22289741

  18. Is carbonic anhydrase IX a validated target for molecular imaging of cancer and hypoxia?

    PubMed Central

    Li, Jianbo; Zhang, Guojian; Wang, Xuemei; Li, Xiao-Feng

    2015-01-01

    ABSTRACT  The presence of hypoxia is a general feature of most solid malignancies, and hypoxia is considered as one of major factors for anticancer therapy failure. Carbonic anhydrase IX (CAIX) has been reported to be an endogenous hypoxia marker, CAIX monoclonal antibodies, their segments and inhibitors are developed for CAIX imaging. However, growing evidence indicates that CAIX expression under hypoxia condition may be cancer cell lines or cancer-type dependent. Here we review the current literature on CAIX and discuss the advantage and limitation of CAIX as a target for tumor hypoxia imaging. Accordingly, CAIX would be unreliable as a universal target for cancer and tumor hypoxia visualization. PMID:25963430

  19. Chapter 13: Carbonic Anhydrase IX as an Imaging and Therapeutic Target for Tumors and Metastases

    PubMed Central

    Tafreshi, Narges K.; Lloyd, Mark C.; Bui, Marilyn M.; Gillies, Robert J.; Morse, David L.

    2014-01-01

    Carbonic anhydrase IX (CAIX) which is a zinc containing metalloprotein, efficiently catalyzes the reversible hydration of carbon dioxide. It is constitutively up-regulated in several cancer types and has an important role in tumor progression, acidification and metastasis. High expression of CAIX generally correlates with poor prognosis and is related to a decrease in the disease-free interval following successful therapy. Therefore, it is considered as a prognostic indicator in oncology. In this review, we describe CAIX regulation and its role in tumor hypoxia, acidification and metastasis. In addition, the molecular imaging of CAIX and its potential for use in cancer detection, diagnosis, staging, and for use in following therapy response is discussed. Both antibodies and small molecular weight compounds have been used for targeted imaging of CAIX expression. The use of CAIX expression as an attractive and promising candidate marker for systemic anticancer therapy is also discussed. PMID:24146382

  20. Carnosine inhibits carbonic anhydrase IX-mediated extracellular acidosis and suppresses growth of HeLa tumor xenografts

    PubMed Central

    2014-01-01

    Background Carbonic anhydrase IX (CA IX) is a transmembrane enzyme that is present in many types of solid tumors. Expression of CA IX is driven predominantly by the hypoxia-inducible factor (HIF) pathway and helps to maintain intracellular pH homeostasis under hypoxic conditions, resulting in acidification of the tumor microenvironment. Carnosine (β-alanyl-L-histidine) is an anti-tumorigenic agent that inhibits the proliferation of cancer cells. In this study, we investigated the role of CA IX in carnosine-mediated antitumor activity and whether the underlying mechanism involves transcriptional and translational modulation of HIF-1α and CA IX and/or altered CA IX function. Methods The effect of carnosine was studied using two-dimensional cell monolayers of several cell lines with endogenous CA IX expression as well as Madin Darby canine kidney transfectants, three-dimensional HeLa spheroids, and an in vivo model of HeLa xenografts in nude mice. mRNA and protein expression and protein localization were analyzed by real-time PCR, western blot analysis, and immunofluorescence staining, respectively. Cell viability was measured by a flow cytometric assay. Expression of HIF-1α and CA IX in tumors was assessed by immunohistochemical staining. Real-time measurement of pH was performed using a sensor dish reader. Binding of CA IX to specific antibodies and metabolon partners was investigated by competitive ELISA and proximity ligation assays, respectively. Results Carnosine increased the expression levels of HIF-1α and HIF targets and increased the extracellular pH, suggesting an inhibitory effect on CA IX-mediated acidosis. Moreover, carnosine significantly inhibited the growth of three-dimensional spheroids and tumor xenografts compared with untreated controls. Competitive ELISA showed that carnosine disrupted binding between CA IX and antibodies specific for its catalytic domain. This finding was supported by reduced formation of the functional metabolon of CA IX

  1. Saccharin: a Lead Compound for Structure-Based Drug Design of Carbonic Anhydrase IX Inhibitors

    PubMed Central

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

    2015-01-01

    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. PMID:25614109

  2. Structural Insights into Carbonic Anhydrase IX Isoform Specificity of Carbohydrate-Based Sulfamates

    PubMed Central

    2015-01-01

    Carbonic anhydrase IX (CA IX) is an extracellular transmembrane homodimeric zinc metalloenzyme that has been validated as a prognostic marker and therapeutic target for several types of aggressive cancers. CA IX shares a close homology with other CA isoforms, making the design of CA IX isoform selective inhibitors challenging. In this paper, we describe the development of a new class of CA IX inhibitors that comprise a sulfamate as the zinc binding group, a variable linker, and a carbohydrate “tail” moiety. Seven compounds inhibited CA IX with low nM Ki values of 1–2 nM and also exhibited permeability profiles to preferentially target the binding of extracellular CA IX over cytosolic CAs. The crystal structures of two of these compounds in complex with a CA IX-mimic (a variant of CA II, with active site residues that mimic CA IX) and one compound in complex with CA II have been determined to 1.7 Å resolution or better and demonstrate a selective mechanism of binding between the hydrophilic and hydrophobic pockets of CA IX versus CA II. These compounds present promising candidates for anti-CA IX drugs and the treatment for several aggressive cancer types. PMID:25254302

  3. Phosphorylation of carbonic anhydrase IX controls its ability to mediate extracellular acidification in hypoxic tumors.

    PubMed

    Ditte, Peter; Dequiedt, Franck; Svastova, Eliska; Hulikova, Alzbeta; Ohradanova-Repic, Anna; Zatovicova, Miriam; Csaderova, Lucia; Kopacek, Juraj; Supuran, Claudiu T; Pastorekova, Silvia; Pastorek, Jaromir

    2011-12-15

    In the hypoxic regions of a tumor, carbonic anhydrase IX (CA IX) is an important transmembrane component of the pH regulatory machinery that participates in bicarbonate transport. Because tumor pH has implications for growth, invasion, and therapy, determining the basis for the contributions of CA IX to the hypoxic tumor microenvironment could lead to new fundamental and practical insights. Here, we report that Thr443 phosphorylation at the intracellular domain of CA IX by protein kinase A (PKA) is critical for its activation in hypoxic cells, with the fullest activity of CA IX also requiring dephosphorylation of Ser448. PKA is activated by cAMP, which is elevated by hypoxia, and we found that attenuating PKA in cells disrupted CA IX-mediated extracellular acidification. Moreover, following hypoxia induction, CA IX colocalized with the sodium-bicarbonate cotransporter and other PKA substrates in the leading edge membranes of migrating tumor cells, in support of the concept that bicarbonate metabolism is spatially regulated at cell surface sites with high local ion transport and pH control. Using chimeric CA IX proteins containing heterologous catalytic domains derived from related CA enzymes, we showed that CA IX activity was modulated chiefly by the intracellular domain where Thr443 is located. Our findings indicate that CA IX is a pivotal mediator of the hypoxia-cAMP-PKA axis, which regulates pH in the hypoxic tumor microenvironment. PMID:22037869

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

    PubMed

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

    2014-01-01

    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

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

    PubMed Central

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

    2013-01-01

    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

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

    PubMed

    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. PMID:26457530

  7. Evaluation of a Carbonic Anhydrase IX-Targeted Near-Infrared Dye for Fluorescence-Guided Surgery of Hypoxic Tumors.

    PubMed

    Lv, Peng-Cheng; Roy, Jyoti; Putt, Karson S; Low, Philip S

    2016-05-01

    Proof-of-principle studies in ovarian, lung, and brain cancer patients have shown that fluorescence-guided surgery can enable removal of otherwise undetectable malignant lesions, decrease the number of cancer-positive margins, and permit identification of disease-containing lymph nodes that would have normally evaded resection. Unfortunately, the current arsenal of tumor-targeted fluorescent dyes does not permit identification of all cancers, raising the need to design new tumor-specific fluorescent dyes to illuminate the currently undetectable cancers. In an effort to design a more universal fluorescent cancer imaging agent, we have undertaken to synthesize a fluorophore that could label all hypoxic regions of tumors. We report here the synthesis, in vitro binding, and in vivo imaging of a near-infrared (NIR) fluorescent dye that is targeted to carbonic anhydrase IX (CA IX), i.e., a widely accepted marker of hypoxic tissues. The low molecular weight NIR probe, named Hypoxyfluor, is shown to bind CA IX with high affinity and accumulate rapidly and selectively in CA IX positive tumors. Because nearly all human cancers contain hypoxic regions that express CA IX abundantly, this NIR probe should facilitate surgical resection of a wide variety of solid tumors. PMID:27043317

  8. Application of Monoclonal Antibody G250 Recognizing Carbonic Anhydrase IX in Renal Cell Carcinoma

    PubMed Central

    Oosterwijk-Wakka, Jeannette C.; Boerman, Otto C.; Mulders, Peter F. A.; Oosterwijk, Egbert

    2013-01-01

    Monoclonal antibody G250 (mAbG250) recognizes a determinant on carbonic anhydrase IX (CAIX). CAIX is expressed by virtually all renal cell carcinomas of the clear cell type (ccRCC), but expression in normal tissues is restricted. The homogeneous CAIX expression in ccRCC and excellent targeting capability of mAbG250 in animal models led to the initiation of the clinical evaluation of mAbG250 in (metastatic) RCC (mRCC) patients. Clinical studies confirmed the outstanding targeting ability of mAbG250 and cG250 PET imaging, as diagnostic modality holds great promise for the future, both in detecting localized and advanced disease. Confirmation of the results obtained in the non-randomized clinical trials with unmodified cG250 is needed to substantiate the value of cG250 treatment in mRCC. cG250-Based radio immuno-therapy (RIT) holds promise for treatment of patients with small-volume disease, and adjuvant treatment with unmodified cG250 may be of value in selected cases. In the upcoming years, ongoing clinical trials should provide evidence for these assumptions. Lastly, whether cG250-based RIT can be combined with tyrosine kinase inhibitors, which constitutes the current standard treatment for mRCC, needs to be established. PMID:23759990

  9. Carbonic anhydrase IX correlates with survival and is a potential therapeutic target for neuroblastoma.

    PubMed

    Ameis, Helen M; Drenckhan, Astrid; Freytag, Morton; Izbicki, Jakob R; Supuran, Claudiu T; Reinshagen, Konrad; Holland-Cunz, Stefan; Gros, Stephanie J

    2016-06-01

    Carbonic anhydrase IX (CAIX) is involved in pathological processes including tumorgenicity, metastases and poor survival in solid tumors. Twenty-two neuroblastoma samples of patients who were surgically treated at the University Medical Center Hamburg-Eppendorf were evaluated immunohistochemically for expression of CAIX. Results were correlated with clinical parameters and outcome. Neuroblastoma Kelly and SH-EP-Tet-21/N cells were examined for CAIX expression and inhibited with specific inhibitors, FC5-207A and FC8-325A. 32% of neuroblastoma tumors expressed CAIX. This was significantly associated with poorer survival. Kelly and SH-EP-Tet-21/N cells showed a major increase of CAIX RNA under hypoxic conditions. Proliferation of Kelly cells was significantly decreased by CAIX inhibitors, FC5-207A and FC8-325A, while proliferation of SH-EP-Tet-21/N cells was only significantly affected by FC8-325A. CAIX is a potent biomarker that predicts survival in neuroblastoma patients. CAIX-targeted therapy in neuroblastoma cell lines is highly effective and strengthens the potential of CAIX as a clinical therapeutic target in a selected patient collective. PMID:25884234

  10. Sulfamate inhibitor S4 influences carbonic anhydrase IX ectodomain shedding in colorectal carcinoma cells.

    PubMed

    Hektoen, Helga Helseth; Ree, Anne Hansen; Redalen, Kathrine Røe; Flatmark, Kjersti

    2016-10-01

    Carbonic anhydrase IX (CAIX) is a pivotal pH regulator under hypoxia, which by its tumor-specific expression represents an attractive target for cancer therapy. Here, we report on effects of the sulfamate CAIX inhibitor S4 (4-(3'-(3″,5″-dimethylphenyl)ureido)phenyl sulfamate) in colorectal carcinoma cell lines. S4 was administered under experimental hypoxia or normoxia to HT29, KM20L2 and HCT116 cells. Effects on survival, proliferation, pH, lactate extrusion and CAIX protein expression were evaluated. S4 treatment resulted in attenuated hypoxia-induced extracellular acidification and reduced clonogenic survival under hypoxia in HT29 cells. The pH effects were present only in a [Formula: see text]-free buffer system and were accompanied by decreased lactate extrusion. The main finding of this work was that S4 treatment caused alterations in CAIX ectodomain shedding. This merits further investigation to understand how sulfamates influence CAIX activity and how such drugs may be of use in cancer treatment. PMID:26244271

  11. N-β-glycosyl sulfamides are selective inhibitors of the cancer associated carbonic anhydrase isoforms IX and XII.

    PubMed

    Rodríguez, Oscar M; Maresca, Alfonso; Témpera, Carlos A; Bravo, Rodolfo D; Colinas, Pedro A; Supuran, Claudiu T

    2011-08-01

    The transmembrane isoforms of carbonic anhydrase (CA IX and XII) have been shown to be linked to carcinogenesis and their inhibition to arrest primary tumor and metastases growth. In this Letter, we present a series of peracetylated and deprotected N-β-glycosyl sulfamides that were tested for the inhibition of 4 carbonic anhydrase isoforms: the cytosolic hCA I and hCA II and transmembrane tumor-associated IX and XII. Compounds 1-4 and 6-8 selectively target cancer-associated CAs (IX and XII) with K(I)s in the low nanomolar range. PMID:21723123

  12. Imaging of carbonic anhydrase IX with an 111In-labeled dual-motif inhibitor.

    PubMed

    Yang, Xing; Minn, Il; Rowe, Steven P; Banerjee, Sangeeta Ray; Gorin, Michael A; Brummet, Mary; Lee, Hye Soo; Koo, Soo Min; Sysa-Shah, Polina; Mease, Ronnie C; Nimmagadda, Sridhar; Allaf, Mohamad E; Pomper, Martin G

    2015-10-20

    We developed a new scaffold for radionuclide-based imaging and therapy of clear cell renal cell carcinoma (ccRCC) targeting carbonic anhydrase IX (CAIX). Compound XYIMSR-01, a DOTA-conjugated, bivalent, low-molecular-weight ligand, has two moieties that target two separate sites on CAIX, imparting high affinity. We synthesized [111In]XYIMSR-01 in 73.8-75.8% (n = 3) yield with specific radioactivities ranging from 118 - 1,021 GBq/μmol (3,200-27,600 Ci/mmol). Single photon emission computed tomography of [111In]XYIMSR-01 in immunocompromised mice bearing CAIX-expressing SK-RC-52 tumors revealed radiotracer uptake in tumor as early as 1 h post-injection. Biodistribution studies demonstrated 26% injected dose per gram of radioactivity within tumor at 1 h. Tumor-to-blood, muscle and kidney ratios were 178.1 ± 145.4, 68.4 ± 29.0 and 1.7 ± 1.2, respectively, at 24 h post-injection. Retention of radioactivity was exclusively observed in tumors by 48 h, the latest time point evaluated. The dual targeting strategy to engage CAIX enabled specific detection of ccRCC in this xenograft model, with pharmacokinetics surpassing those of previously described radionuclide-based probes against CAIX. PMID:26418876

  13. Imaging of carbonic anhydrase IX with an 111In-labeled dual-motif inhibitor

    PubMed Central

    Rowe, Steven P.; Banerjee, Sangeeta Ray; Gorin, Michael A.; Brummet, Mary; Lee, Hye Soo; Koo, Soo Min; Sysa-Shah, Polina; Mease, Ronnie C.; Nimmagadda, Sridhar; Allaf, Mohamad E.; Pomper, Martin G.

    2015-01-01

    We developed a new scaffold for radionuclide-based imaging and therapy of clear cell renal cell carcinoma (ccRCC) targeting carbonic anhydrase IX (CAIX). Compound XYIMSR-01, a DOTA-conjugated, bivalent, low-molecular-weight ligand, has two moieties that target two separate sites on CAIX, imparting high affinity. We synthesized [111In]XYIMSR-01 in 73.8–75.8% (n = 3) yield with specific radioactivities ranging from 118 – 1,021 GBq/μmol (3,200–27,600 Ci/mmol). Single photon emission computed tomography of [111In]XYIMSR-01 in immunocompromised mice bearing CAIX-expressing SK-RC-52 tumors revealed radiotracer uptake in tumor as early as 1 h post-injection. Biodistribution studies demonstrated 26% injected dose per gram of radioactivity within tumor at 1 h. Tumor-to-blood, muscle and kidney ratios were 178.1 ± 145.4, 68.4 ± 29.0 and 1.7 ± 1.2, respectively, at 24 h post-injection. Retention of radioactivity was exclusively observed in tumors by 48 h, the latest time point evaluated. The dual targeting strategy to engage CAIX enabled specific detection of ccRCC in this xenograft model, with pharmacokinetics surpassing those of previously described radionuclide-based probes against CAIX. PMID:26418876

  14. Hypoxia-induced carbonic anhydrase IX facilitates lactate flux in human breast cancer cells by non-catalytic function

    PubMed Central

    Jamali, Somayeh; Klier, Michael; Ames, Samantha; Felipe Barros, L.; McKenna, Robert; Deitmer, Joachim W.; Becker, Holger M.

    2015-01-01

    The most aggressive tumour cells, which often reside in hypoxic environments, rely on glycolysis for energy production. Thereby they release vast amounts of lactate and protons via monocarboxylate transporters (MCTs), which exacerbates extracellular acidification and supports the formation of a hostile environment. We have studied the mechanisms of regulated lactate transport in MCF-7 human breast cancer cells. Under hypoxia, expression of MCT1 and MCT4 remained unchanged, while expression of carbonic anhydrase IX (CAIX) was greatly enhanced. Our results show that CAIX augments MCT1 transport activity by a non-catalytic interaction. Mutation studies in Xenopus oocytes indicate that CAIX, via its intramolecular H+-shuttle His200, functions as a “proton-collecting/distributing antenna” to facilitate rapid lactate flux via MCT1. Knockdown of CAIX significantly reduced proliferation of cancer cells, suggesting that rapid efflux of lactate and H+, as enhanced by CAIX, contributes to cancer cell survival under hypoxic conditions. PMID:26337752

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

    PubMed

    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. PMID:26408817

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

    PubMed

    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. PMID:27322137

  17. Metallocene-based inhibitors of cancer-associated carbonic anhydrase enzymes IX and XII.

    PubMed

    Salmon, Adam J; Williams, Michael L; Wu, Quoc K; Morizzi, Julia; Gregg, Daniel; Charman, Susan A; Vullo, Daniela; Supuran, Claudiu T; Poulsen, Sally-Ann

    2012-06-14

    In this study, 20 metallocene-based compounds comprising extensive structural diversity were synthesized and evaluated as carbonic anhydrase (CA, EC 4.2.1.1) inhibitors. These compounds proved moderate to good CA inhibitors in vitro, with several compounds displaying selectivity for cancer-associated isozymes CA IX and CA XII compared to off-target CA I and CA II. Compound 6 was the most potent ferrocene-based inhibitor with K(i)s of 5.9 and 6.8 nM at CA IX and XII, respectively. A selection of key drug-like parameters comprising Log P, Log D, solubility, and in vitro metabolic stability and permeability were measured for two of the ferrocene-based compounds, regioisomers 1 and 5. Compounds 1 and 5 were found to have characteristics consistent with lipophilic compounds, however, our findings show that the lipophilicity of the ferrocene moiety is not well modeled by replacement with either a naphthyl or a phenyl moiety in software prediction tools. PMID:22540953

  18. Novel sulfonamide bearing coumarin scaffolds as selective inhibitors of tumor associated carbonic anhydrase isoforms IX and XII.

    PubMed

    Chandak, Navneet; Ceruso, Mariangela; Supuran, Claudiu T; Sharma, Pawan K

    2016-07-01

    Four novel scaffolds consisting of total 24 compounds (1a-1o, 2a-2c, 3a-3c and 4a-4c) bearing aromatic sulfonamide and coumarin moieties connected through various linkers were synthesized in order to synergize the inhibition potential of both the moieties against four selected human carbonic anhydrase isoforms (hCA I, II, IX & XII). All compounds were found to be potent inhibitors of tumor associated hCA IX & XII while at the same time required large amounts to inhibit off-targeted housekeeping hCA I & II. Selectivity was more pronounced against hCA II over I, and hCA XII over IX. Results were compared with antitumor drug acetazolamide. One derivative 2b of series 2 was found to be a better selective inhibitor of hCA IX and XII. PMID:27137360

  19. Human monoclonal antibodies targeting carbonic anhydrase IX for the molecular imaging of hypoxic regions in solid tumours

    PubMed Central

    Ahlskog, J K J; Schliemann, C; Mårlind, J; Qureshi, U; Ammar, A; Pedley, R B; Neri, D

    2009-01-01

    Background: Hypoxia, which is commonly observed in areas of primary tumours and of metastases, influences response to treatment. However, its characterisation has so far mainly been restricted to the ex vivo analysis of tumour sections using monoclonal antibodies specific to carbonic anhydrase IX (CA IX) or by pimonidazole staining, after the intravenous administration of this 2-nitroimidazole compound in experimental animal models. Methods: In this study, we describe the generation of high-affinity human monoclonal antibodies (A3 and CC7) specific to human CA IX, using phage technology. Results: These antibodies were able to stain CA IX ex vivo and to target the cognate antigen in vivo. In one of the two animal models of colorectal cancer studied (LS174T), CA IX imaging closely matched pimonidazole staining, with a preferential staining of tumour areas characterised by little vascularity and low perfusion. In contrast, in a second animal model (SW1222), distinct staining patterns were observed for pimonidazole and CA IX targeting. We observed a complementary pattern of tumour regions targeted in vivo by the clinical-stage vascular-targeting antibody L19 and the anti-CA IX antibody A3, indicating that a homogenous pattern of in vivo tumour targeting could be achieved by a combination of the two antibodies. Conclusion: The new human anti-CA IX antibodies are expected to be non-immunogenic in patients with cancer and may serve as broadly applicable reagents for the non-invasive imaging of hypoxia and for pharmacodelivery applications. PMID:19623173

  20. Sulfonamide derivative targeting carbonic anhydrase IX as a nuclear imaging probe for colorectal cancer detection in vivo

    PubMed Central

    Guan, Siao-Syun; Cheng, Chun-Chia; Ho, Ai-Sheng; Wang, Chia-Chi; Luo, Tsai-Yueh; Liao, Tse-Zung; Chang, Jungshan; Wu, Cheng-Tien; Liu, Shing-Hwa

    2015-01-01

    Hypoxic microenvironment is a common situation in solid tumors. Carbonic anhydrase IX (CA9) is one of the reliable cellular biomarkers of hypoxia. The role of CA9 in colorectal cancer (CRC) remains to be clarified. CA9 inhibitor such as sulfonamides is known to block CA9 activation and reduce tumor growth consequently. Here, we aimed to investigate the CA9 expression in serum and tumor from different stages of CRC patients and utilize sulfonamide derivative with indium-111 labeling as a probe for CRC nuclear imaging detection in vivo. The serum CA9 was correlated with the tumor CA9 levels in different stages of CRC patients. Hypoxia increased cell viability and CA9 expression in colorectal cancer HCT-15 cells. Sulfonamide derivative 5-(2-aminoethyl)thiophene-2-sulfonamide (ATS) could bind with CA9 in vitro under hypoxia. Moreover, tumor tissues in HCT-15-induced xenograft mice possessed higher hypoxic fluorescence signal as compared with other organs. We also found that the radioisotope signal of indium-111 labeled ATS, which was utilized for CRC detection in HCT-15-induced xenograft mice, was markedly enhanced in tumors as compared with non-ATS control. Taken together, these findings suggest that CA9 is a potential hypoxic CRC biomarker and measurement of serum CA9 can be as a potential tool for diagnosing CA9 expressions in CRC clinical practice. The radioisotope-labeled sulfonamide derivative (ATS) may be useful to apply in CRC patients for nuclear medicine imaging. PMID:26447758

  1. Synthesis and inhibition potency of novel ureido benzenesulfonamides incorporating GABA as tumor-associated carbonic anhydrase IX and XII inhibitors.

    PubMed

    Ceruso, Mariangela; Antel, Sabrina; Scozzafava, Andrea; Supuran, Claudiu T

    2016-01-01

    New ureido benzenesulfonamides incorporating a GABA moiety as a linker between the ureido and the sulfonamide functionalities were synthesized and their inhibition potency determined against both the predominant cytosolic (hCA I and II) and the transmembrane tumor-associated (hCA IX and XII) isoforms of the metalloenzyme carbonic anhydrase (CA, EC 4.2.1.1). The majority of these compounds were medium potency inhibitors of the cytosolic isoform hCA I and effective hCA II inhibitors, whereas they showed strong inhibition of the two transmembrane tumor-associated isoforms hCA IX and XII, with KIs in nanomolar range. Only one derivative had a good selectivity for inhibition of the tumor-associated hCA IX target isoform over the cytosolic and physiologically dominant off-target hCA I and II, being thus a potential tool to develop new anticancer agents. PMID:25792500

  2. Pyrazolylbenzo[d]imidazoles as new potent and selective inhibitors of carbonic anhydrase isoforms hCA IX and XII.

    PubMed

    Kumar, Satish; Ceruso, Mariangela; Tuccinardi, Tiziano; Supuran, Claudiu T; Sharma, Pawan K

    2016-07-01

    Novel pyrazolylbenzo[d]imidazole derivatives (2a-2f) were designed, synthesized and evaluated against four human carbonic anhydrase isoforms belonging to α family comprising of two cytosolic isoforms hCA I and II as well as two transmembrane tumor associated isoforms hCA IX and XII. Starting from these derivatives that showed high potency but low selectivity in favor of tumor associated isoforms hCA IX and XII, we investigated the impact of removing the sulfonamide group. Thus, analogs 3a-3f without sulfonamide moiety were synthesized and biological assay revealed a good activity as well as an excellent selectivity as inhibitors for tumor associated hCA IX and hCA XII and the same was analyzed by molecular docking studies. PMID:27166574

  3. Lipocalin 2 prevents oral cancer metastasis through carbonic anhydrase IX inhibition and is associated with favourable prognosis.

    PubMed

    Lin, Chiao-Wen; Yang, Wei-En; Lee, Wei-Jiunn; Hua, Kuo-Tai; Hsieh, Feng-Koo; Hsiao, Michael; Chen, Chia-Cheng; Chow, Jyh-Ming; Chen, Mu-Kuan; Yang, Shun-Fa; Chien, Ming-Hsien

    2016-07-01

    Lipocalin 2 (LCN2), a secreted glycoprotein, is up- or downregulated in different human cancers. At present, the functional role of LCN2 in the progression of oral squamous cell carcinoma (OSCC), which accounts for most head and neck cancers, remains poorly understood, particularly with respect to its involvement in invasion and metastasis. In this study, we observed that LCN2 expression decreased in patients with OSCC and lymph node metastasis compared with that in patients without metastasis. A higher LCN2 expression correlated with the survival of patients with OSCC. Furthermore, LCN2 overexpression in OSCC cells reduced in vitro migration and invasion and in vivo metastasis, whereas its silencing induced an increase in cell motility. Mechanistically, LCN2 inhibited the cell motility of OSCC cells through hypoxia-inducible factor (HIF)-1α-dependent transcriptional inhibition of the carbonic anhydrase IX (CAIX). CAIX overexpression relieved the migration inhibition imposed by LCN2 overexpression in OSCC cells. Moreover, a microRNA (miR) analysis revealed that LCN2 can suppress CAIX expression and cell migration through miR-4505 induction. Examination of tumour tissues from patients with OSCC and OSCC-transplanted mice revealed an inverse correlation between LCN2 and CAIX expression. Furthermore, patients with LCN2(strong)/CAIX(weak) revealed the lowest frequency of lymph node metastasis and the longest survival. Our findings suggest that LCN2 suppresses tumour metastasis by targeting the transcriptional and post-transcriptional regulation of CAIX in OSCC cells. LCN2 overexpression may be a novel OSCC treatment strategy and a useful biomarker for predicting OSCC progression. PMID:27207653

  4. A systematic quantitative approach to rational drug design and discovery of novel human carbonic anhydrase IX inhibitors.

    PubMed

    Sethi, Kalyan K; Verma, Saurabh M

    2014-08-01

    Drug design involves the design of small molecules that are complementary in shape and charge to the biomolecular target with which they interact and therefore will bind to it. Three-dimensional quantitative structure-activity relationship (3D-QSAR) studies were performed for a series of carbonic anhydrase IX inhibitors using comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) techniques with the help of SYBYL 7.1 software. The large set of 36 different aromatic/heterocyclic sulfamates carbonic anhydrase (CA, EC 4.2.1.1) inhibitors, such as hCA IX, was chosen for this study. The conventional ligand-based 3D-QSAR studies were performed based on the low energy conformations employing database alignment rule. The ligand-based model gave q(2) values 0.802 and 0.829 and r(2) values 1.000 and 0.994 for CoMFA and CoMSIA, respectively, and the predictive ability of the model was validated. The predicted r(2) values are 0.999 and 0.502 for CoMFA and CoMSIA, respectively. SEA (steric, electrostatic, hydrogen bond acceptor) of CoMSIA has the significant contribution for the model development. The docking of inhibitors into hCA IX active site using Glide XP (Schrödinger) software revealed the vital interactions and binding conformation of the inhibitors. The CoMFA and CoMSIA field contour maps are well in agreement with the structural characteristics of the binding pocket of hCA IX active site, which suggests that the information rendered by 3D-QSAR models and the docking interactions can provide guidelines for the development of improved hCA IX inhibitors as leads for various types of metastatic cancers including those of cervical, renal, breast and head and neck origin. PMID:24090419

  5. The Potential of Liposomes with Carbonic Anhydrase IX to Deliver Anticancer Ingredients to Cancer Cells in Vivo

    PubMed Central

    Ng, Huei Leng Helena; Lu, Aiping; Lin, Ge; Qin, Ling; Yang, Zhijun

    2014-01-01

    Drug delivery nanocarriers, especially targeted drug delivery by liposomes are emerging as a class of therapeutics for cancer. Early research results suggest that liposomal therapeutics enhanced efficacy, while simultaneously reducing side effects, owing to properties such as more targeted localization in tumors and active cellular uptake. Here, we highlight the features of immunoliposomes that distinguish them from previous anticancer therapies, and describe how these features provide the potential for therapeutic effects that are not achievable with other modalities. While a large number of studies has been published, the emphasis here is placed on the carbonic anhydrase IX (CA-IX) and the conjugated liposomes that are likely to open a new chapter on drug delivery system by using immunoliposomes to deliver anticancer ingredients to cancer cells in vivo. PMID:25547490

  6. 5-Aryl-1H-pyrazole-3-carboxylic acids as selective inhibitors of human carbonic anhydrases IX and XII.

    PubMed

    Cvijetić, Ilija N; Tanç, Muhammet; Juranić, Ivan O; Verbić, Tatjana Ž; Supuran, Claudiu T; Drakulić, Branko J

    2015-08-01

    Inhibitory activity of a congeneric set of 23 phenyl-substituted 5-phenyl-pyrazole-3-carboxylic acids toward human carbonic anhydrase (hCA, EC 4.2.1.1) isoforms I, II, IX and XII was evaluated by a stopped-flow CO2 hydrase assay. These compounds exerted a clear, selective inhibition of hCA IX and XII over hCAI and II, with Ki in two to one digit micromolar concentrations (4-50 μM). Derivatives bearing bulkier substituents in para-position of the phenyl ring inhibited hCA XII at one-digit micromolar concentrations, while derivatives having alkyl substituents in both ortho- and meta-positions inhibited hCA IX with Kis ranging between 5 and 25 μM. Results of docking experiments offered a rational explanation on the selectivity of these compounds toward CA IX and XII, as well as on the substitution patterns leading to best CA IX or CA XII inhibitors. By examining the active sites of these four isoforms with GRID generated molecular-interaction fields, striking differences between hCA XII and the other three isoforms were observed. The field of hydrophobic probe (DRY) appeared significantly different in CA XII active site, comparing to other three isoforms studied. To the best of our knowledge such an observation was not reported in literature so far. Considering the selectivity of these carboxylates towards membrane-associated over cytosolic CA isoforms, the title compounds could be useful for the development of isoform-specific non-sulfonamide CA inhibitors. PMID:26088336

  7. A novel library of saccharin and acesulfame derivatives as potent and selective inhibitors of carbonic anhydrase IX and XII isoforms.

    PubMed

    Carradori, Simone; Secci, Daniela; De Monte, Celeste; Mollica, Adriano; Ceruso, Mariangela; Akdemir, Atilla; Sobolev, Anatoly P; Codispoti, Rossella; De Cosmi, Federica; Guglielmi, Paolo; Supuran, Claudiu T

    2016-03-01

    Small libraries of N-substituted saccharin and N-/O-substituted acesulfame derivatives were synthesized and tested as atypical and selective inhibitors of four different isoforms of human carbonic anhydrase (hCA I, II, IX and XII, EC 4.2.1.1). Most of them inhibited hCA XII in the low nanomolar range, hCA IX with KIs ranging between 19 and 2482nM, whereas they were poorly active against hCA II (KIs >10μM) and hCA I (KIs ranging between 318nM and 50μM). Since hCA I and II are ubiquitous off-target isoforms, whereas the cancer-related isoforms hCA IX and XII were recently validated as drug targets, these results represent an encouraging achievement in the development of new anticancer candidates. Moreover, the lack of a classical zinc binding group in the structure of these inhibitors opens innovative, yet unexplored scenarios for different mechanisms of inhibition that could explain the high inhibitory selectivity. A computational approach has been carried out to further rationalize the biological data and to characterize the binding mode of some of these inhibitors. PMID:26810710

  8. Carbonic anhydrase IX induction defines a heterogeneous cancer cell response to hypoxia and mediates stem cell-like properties and sensitivity to HDAC inhibition.

    PubMed

    Ledaki, Ioanna; McIntyre, Alan; Wigfield, Simon; Buffa, Francesca; McGowan, Simon; Baban, Dilair; Li, Ji-Liang; Harris, Adrian L

    2015-08-14

    Carbonic anhydrase IX (CAIX) is strongly induced by hypoxia and its overexpression is associated with poor therapeutic outcome in cancer. Here, we report that hypoxia promotes tumour heterogeneity through the epigenetic regulation of CAIX. Based on hypoxic CAIX expression we identify and characterize two distinct populations of tumour cells, one that has inducible expression of CAIX and one that does not. The CAIX+ve population is enriched with cells expressing cancer stem cell markers and which have high self-renewal capacity. We show that differential CAIX expression is due to differences in chromatin structure. To further investigate the relationship between chromatin organization and hypoxic induction of CAIX expression we investigated the effect of JQ1 an inhibitor of BET bromodomain proteins and A366 a selective inhibitor of the H3K9 methyltransferase G9a/GLP. We identified that these drugs were able to modulate hypoxic CAIX expression induction. This further highlights the role of epigenetic modification in adaption to hypoxia and also in regulation of heterogeneity of cells within tumours. Interestingly, we identified that the two subpopulations show a differential sensitivity to HDAC inhibitors, NaBu or SAHA, with the CAIX positive showing greater sensitivity to treatment. We propose that drugs modulating chromatin regulation of expression may be used to reduce heterogeneity induced by hypoxia and could in combination have significant clinical consequences. PMID:26305601

  9. Carbonic anhydrase IX induction defines a heterogeneous cancer cell response to hypoxia and mediates stem cell-like properties and sensitivity to HDAC inhibition

    PubMed Central

    Wigfield, Simon; Buffa, Francesca; McGowan, Simon; Baban, Dilair; Li, Ji-liang; Harris, Adrian L.

    2015-01-01

    Carbonic anhydrase IX (CAIX) is strongly induced by hypoxia and its overexpression is associated with poor therapeutic outcome in cancer. Here, we report that hypoxia promotes tumour heterogeneity through the epigenetic regulation of CAIX. Based on hypoxic CAIX expression we identify and characterize two distinct populations of tumour cells, one that has inducible expression of CAIX and one that does not. The CAIX+ve population is enriched with cells expressing cancer stem cell markers and which have high self-renewal capacity. We show that differential CAIX expression is due to differences in chromatin structure. To further investigate the relationship between chromatin organization and hypoxic induction of CAIX expression we investigated the effect of JQ1 an inhibitor of BET bromodomain proteins and A366 a selective inhibitor of the H3K9 methyltransferase G9a/GLP. We identified that these drugs were able to modulate hypoxic CAIX expression induction. This further highlights the role of epigenetic modification in adaption to hypoxia and also in regulation of heterogeneity of cells within tumours. Interestingly, we identified that the two subpopulations show a differential sensitivity to HDAC inhibitors, NaBu or SAHA, with the CAIX positive showing greater sensitivity to treatment. We propose that drugs modulating chromatin regulation of expression may be used to reduce heterogeneity induced by hypoxia and could in combination have significant clinical consequences. PMID:26305601

  10. Synthesis and carbonic anhydrase I, II, IX and XII inhibitory activity of sulfamates incorporating piperazinyl-ureido moieties.

    PubMed

    Congiu, Cenzo; Onnis, Valentina; Deplano, Alessandro; Balboni, Gianfranco; Ceruso, Mariangela; Supuran, Claudiu T

    2015-09-01

    A series of sulfamates were synthesized using as lead compound SLC-0111, a sulfonamide carbonic anhydrase (CA, EC 4.2.1.1) inhibitor in Phase I clinical trials. The new derivatives incorporated ureido moieties as spacers between the benzene sulfamate fragment which binds the zinc ion from the active site, and the tail of the inhibitor, but the urea moieties were part of a substituted piperazine ring system. The derivatives (and some of their phenol precursors) were tested for the inhibition of the cytosolic, hCA I and II (off target isoforms) and the trans-membrane, tumor-associated hCA IX and XII enzymes (anticancer drug targets). Generally hCA I was not effectively inhibited, whereas many low nanomolar inhibitors were evidenced against hCA II (KIs in the range of 1.0-94.4 nM), IX (KIs in the range of 0.91-36.9 nM), and XII (KIs in the range of 1.0-84.5 nM). The best substitution fragments at the piperazine ring included the following moieties: 3-methylphenyl, 2,3-dimethylphenyl, 4-methoxyphenyl, 6-arylpyrimidine-2-yl. PMID:26233796

  11. Mapping Selective Inhibition of the Cancer-Related Carbonic Anhydrase IX Using Structure-Activity Relationships of Glucosyl-Based Sulfamates.

    PubMed

    Mahon, Brian P; Lomelino, Carrie L; Ladwig, Janina; Rankin, Gregory M; Driscoll, Jenna M; Salguero, Antonieta L; Pinard, Melissa A; Vullo, Daniela; Supuran, Claudiu T; Poulsen, Sally-Ann; McKenna, Robert

    2015-08-27

    Inhibition of human carbonic anhydrase IX (hCA IX) has shown to be therapeutically advantageous for treating many types of highly aggressive cancers. However, designing selective inhibitors for hCA IX has been difficult due to its high structural homology and sequence similarity with off-target hCAs. Recently, the use of glucosyl sulfamate inhibitors has shown promise as selective inhibitors for hCA IX. In this study, we present five X-ray crystal structures, determined to a resolution of 1.7 Å or better, of both hCA II (a ubiquitous CA) and an engineered hCA IX-mimic in complex with selected glucosyl sulfamates and structurally rationalize mechanisms for hCA IX selectivity. Results from this study have allowed us, for the first time, to empirically "map" key interactions of the hCA IX active site in order to establish parameters needed to design novel hCA IX selective inhibitors. PMID:26203869

  12. Evaluation of carbonic anhydrase IX as a therapeutic target for inhibition of breast cancer invasion and metastasis using a series of in vitro breast cancer models

    PubMed Central

    Ward, Carol; Meehan, James; Mullen, Peter; Supuran, Claudiu; Dixon, J. Michael; Thomas, Jeremy S.; Winum, Jean-Yves; Lambin, Philippe; Dubois, Ludwig; Pavathaneni, Nanda-Kumar; Jarman, Edward J.; Renshaw, Lorna; Um, InHwa; Kay, Charlene; Harrison, David J.; Kunkler, Ian H.; Langdon, Simon P.

    2015-01-01

    Triple negative, resistant or metastatic disease are major factors in breast cancer mortality, warranting novel approaches. Carbonic anhydrase IX (CAIX) is implicated in survival, migration and invasion of breast cancer cells and inhibition provides an innovative therapeutic strategy. The efficacy of 5 novel ureido-substituted sulfamate CAIX inhibitors were assessed in increasingly complex breast cancer models, including cell lines in normoxia and hypoxia, 3D spheroids and an ex-vivo explant model utilizing fresh biopsy tissue from different breast cancer subtypes. CAIX expression was evaluated in a tissue microarray (TMA) of 92 paired lymph node and primary breast cancers and 2 inhibitors were appraised in vivo using MDA-MB-231 xenografts. FC11409B, FC9398A, FC9403, FC9396A and S4 decreased cell proliferation and migration and inhibited 3D spheroid invasion. S4, FC9398A and FC9403A inhibited or prevented invasion into collagen. FC9403A significantly reversed established invasion whilst FC9398A and DTP348 reduced xenograft growth. TMA analysis showed increased CAIX expression in triple negative cancers. These data establish CAIX inhibition as a relevant therapeutic goal in breast cancer, targeting the migratory, invasive, and metastatic potential of this disease. The use of biopsy tissue suggests efficacy against breast cancer subtypes, and should provide a useful tool in drug testing against invasive cancers. PMID:26259239

  13. Synthesis of 4-(thiazol-2-ylamino)-benzenesulfonamides with carbonic anhydrase I, II and IX inhibitory activity and cytotoxic effects against breast cancer cell lines.

    PubMed

    Abdel Gawad, Nagwa M; Amin, Noha H; Elsaadi, Mohammed T; Mohamed, Fatma M M; Angeli, Andrea; De Luca, Viviana; Capasso, Clemente; Supuran, Claudiu T

    2016-07-01

    A series of 4-(thiazol-2-ylamino)-benzenesulfonamides was synthesized and screened for their carbonic anhydrase (CA, EC 4.2.1.1) inhibitory and cytotoxic activity on human breast cancer cell line MCF-7. Human (h) CA isoforms I, II and IX were included in the study. The new sulfonamides showed excellent inhibition of all three isoforms, with KIs in the range of 0.84-702nM against hCA I, of 0.41-288nM against hCA II and of 5.6-29.2 against the tumor-associated hCA IX, a validated anti-tumor target, with a sulfonamide (SLC-0111) in Phase I clinical trials for the treatment of hypoxic, metastatic solid tumors overexpressing CA IX. The new compounds showed micromolar inhibition of growth efficacy against breast cancer MCF-7 cell lines. PMID:27234893

  14. Carbonic anhydrase-9 expression in head and neck cancer: a meta-analysis.

    PubMed

    Peridis, Stamatios; Pilgrim, Gemma; Athanasopoulos, Ioannis; Parpounas, Konstantinos

    2011-05-01

    The purpose of the study was to compare CA-9 positivity versus CA-9 negativity in head and neck malignancies and to correlate levels of CA-9 with tumor grade, size, and nodal status. Overall and disease-free survival were also compared for CA-9 positive and negative tumors. A literature search was performed using Medline, Embase, Ovid and Cochrane databases for studies between 1990 and 2009. Carbonic anhydrase IX, CA IX, CA-9, head and neck, and survival were used as search terms. Random-effect meta-analytical techniques were conducted for outcome measures of overall survival and disease-free survival. Sixteen studies matched the selection criteria, reporting on 1,470 patients. Eight hundred and forty two specimens were reported as being CA-9 positive or negative: 512 (60.81%) were CA-9 positive and 330 (39.19%) were CA-9 negative. Nine hundred and eighty specimens had levels of CA-9 expression recorded: 547 (55.82%) had high levels of CA-9 and 433 (44.18%) had low CA-9 levels. Survival was significantly reduced if the tumor was positive for CA-9 (P < 0.0001). Disease-free survival is significantly reduced in patients with CA-9 positive (P = 0.0008) head and neck malignant tumors. The presence of CA-9 in head and neck malignant tumors is associated with reduced overall survival and disease-free survival. PMID:21246209

  15. A survey of carbonic anhydrase mRNA expression in enamel cells

    PubMed Central

    LACRUZ, Rodrigo S.; HILVO, Mika; KURTZ, Ira; PAINE, Michael L.

    2010-01-01

    Enamel formation requires rigid control of pH homeostasis during all stages of development to prevent disruptions to crystal growth. The acceleration of the generation of bicarbonate by carbonic anhydrases (CA) has been suggested as one of the pathways used by ameloblasts cells to regulate extracellular pH yet only two isozymes (CA II and CA VI) have been reported to date during enamel formation. The mammalian CA family contains 16 different isoforms of which 13 are enzymatically active. We have conducted a systematic screening by RT-PCR on the expression of all known CA isoforms in mouse enamel organ epithelium (EOE) cells dissected from new born, in secretory ameloblasts derived from 7-day old animals, and in the LS8 ameloblast cell line. Results show that all CA isoforms are expressed by EOE/ameloblast cells in vivo. The most highly expressed are the catalytic isozymes CA II, VI, IX, and XIII, and the acatalytic CA XI isoform. Only minor differences were found in CA expression levels between 1-day EOE cells and 7-day old secretory stage ameloblasts, whereas LS8 cells expressed fewer CA isoforms than both of these. The broad expression of CAs by ameloblasts reported here contributes to our understanding of pH homeostasis during enamel development and demonstrates its complexity. Our results also highlight the critical role that regulation of pH plays during the development of enamel. PMID:20175995

  16. 1,2-Benzisothiazole Derivatives Bearing 4-, 5-, or 6-Alkyl/arylcarboxamide Moieties Inhibit Carbonic Anhydrase Isoform IX (CAIX) and Cell Proliferation under Hypoxic Conditions.

    PubMed

    Coviello, Vito; Marchi, Beatrice; Sartini, Stefania; Quattrini, Luca; Marini, Anna Maria; Simorini, Francesca; Taliani, Sabrina; Salerno, Silvia; Orlandi, Paola; Fioravanti, Anna; Desidero, Teresa Di; Vullo, Daniela; Da Settimo, Federico; Supuran, Claudiu T; Bocci, Guido; La Motta, Concettina

    2016-07-14

    Three novel series of 1,2-benzisothiazole derivatives have been developed as inhibitors of carbonic anhydrase isoform IX. Compounds 5c and 5j, tested in vitro on the human colon cell line HT-29, blocked the growth of cells cultured under chemically induced hypoxic conditions, displaying a specific activity against cancer cells characterized by CAIX up-regulation. Moreover, a synergistic activity of 5c with SN-38 (the active metabolite of irinotecan) and 5-fluorouracil on cell proliferation under hypoxic conditions was demonstrated. PMID:27305384

  17. Detecting Extracellular Carbonic Anhydrase Activity Using Membrane Inlet Mass Spectrometry

    PubMed Central

    Delacruz, Joannalyn; Mikulski, Rose; Tu, Chingkuang; Li, Ying; Wang, Hai; Shiverick, Kathleen T.; Frost, Susan C.; Horenstein, Nicole A.; Silverman, David N.

    2010-01-01

    Current research into the function of carbonic anhydrases in cell physiology emphasizes the role of membrane-bound carbonic anhydrases, such as carbonic anhydrase IX that has been identified in malignant tumors and is associated with extracellular acidification as a response to hypoxia. We present here a mass spectrometric method to determine the extent to which total carbonic anhydrase activity is due to extracellular carbonic anhydrase in whole cell preparations. The method is based on the biphasic rate of depletion of 18O from CO2 measured by membrane inlet mass spectrometry. The slopes of the biphasic depletion are a sensitive measure of the presence of carbonic anhydrase outside and inside of the cells. This property is demonstrated here using suspensions of human red cells in which external carbonic anhydrase was added to the suspending solution. It is also applied to breast and prostate cancer cells which both express exofacial carbonic anhydrase IX. Inhibition of external carbonic anhydrase is achieved by use of a membrane impermeant inhibitor that was synthesized for this purpose, p-aminomethylbenzenesulfonamide attached to a polyethyleneglycol polymer. PMID:20417171

  18. Non-invasive Detection of Breast Cancer Lymph Node Metastasis using Carbonic Anhydrases IX and XII Targeted Imaging Probes

    PubMed Central

    Tafreshi, Narges K.; Bui, Marilyn M.; Bishop, Kellsey; Lloyd, Mark C.; Enkemann, Steven A.; Lopez, Alexis S.; Abrahams, Dominique; Carter, Bradford W.; Vagner, Josef; Grobmyer, Stephen R.; Gillies, Robert J.; Morse, David L.

    2014-01-01

    Purpose To develop targeted molecular imaging probes for the non-invasive detection of breast cancer lymph node metastasis. Methods Six cell surface or secreted markers were identified by expression profiling and from the literature as being highly expressed in breast cancer lymph node metastases. Two of these markers were cell surface carbonic anhydrase isozymes (CAIX and/or CAXII) and were validated for protein expression by immunohistochemistry (IHC) of patient tissue samples on a breast cancer tissue microarray containing 47 normal breast tissue samples, 42 ductal carcinoma in situ, 43 invasive ductal carcinomas without metastasis, 46 invasive ductal carcinomas with metastasis and 49 lymph node macrometastases of breast carcinoma. Targeted probes were developed by conjugation of CAIX and CAXII specific monoclonal antibodies (mAbs) to a near-infrared fluorescent dye. Results Together, these two markers were expressed in 100% of the lymph node metastases surveyed. Selectivity of the imaging probes were confirmed by intravenous injection into nude mice bearing mammary fat pad tumors of marker expressing cells, and non-expressing cells or by pre-injection of unlabeled antibody. Imaging of LN metastases showed that peritumorally-injected probes detected nodes harboring metastatic tumor cells. As few as 1,000 cells were detected, as determined by implanting, under ultrasound guidance, a range in number of CAIX and CAXII expressing cells into the axillary LNs. Conclusion These imaging probes have potential for non-invasive staging of breast cancer in the clinic and elimination of unneeded surgery, which is costly and associated with morbidities. PMID:22016510

  19. Detecting changes in tumor hypoxia with carbonic anhydrase IX and pimonidazole.

    PubMed

    Shin, Kyung Hwan; Diaz-Gonzalez, Juan A; Russell, James; Chen, Qing; Burgman, Paul; Li, Xiao-Feng; Ling, C Clifton

    2007-01-01

    We have used immunohistochemistry to examine the dynamics of tumor hypoxia.. Expression of CAIX is known to be influenced by tumor hypoxia, and this protein has been shown to be an endogenous hypoxia marker in several models. However, due to its long half-life, it could also be present in oxygenated tissue that had recently been hypoxic. To investigate this issue we have compared CAIX expression to the exogenous hypoxia marker, pimonidazole using HT29 (human colorectal cancer) xenografts. We manipulated tumor hypoxia with carbogen and hydralazine, treatments that respectively increased and decreased tumor oxygenation. (Carbogen was given 75 minutes and hydralazine 30 minutes before sacrifice). In tumors from the control group, CAIX and pimonidazole exhibited similar (though not identical) spatial distribution, and for both markers, the fraction of the section staining positively was similar (13.2% and 12.6% respectively). The mice treated with hydralazine showed a significant increase in pimonidazole accumulation (37.2%, p = 0.03), though the CAIX positive fraction was unchanged (14.2%). In contrast, in the carbogen group pimonidazole staining decreased to 3% (p = 0.01) though CAIX expression was again unaltered. These results suggest that comparison of CAIX and pimonidazole will allow for the detection of reoxygenation. PMID:17172824

  20. Carbonic anhydrase inhibitors: synthesis and inhibition of the human carbonic anhydrase isoforms I, II, VII, IX and XII with benzene sulfonamides incorporating 4,5,6,7-tetrabromophthalimide moiety.

    PubMed

    Sethi, Kalyan K; Vullo, Daniella; Verma, Saurabh M; Tanç, Muhammet; Carta, Fabrizio; Supuran, Claudiu T

    2013-10-01

    A series of 4,5,6,7-tetrabromo-1,3-dioxoisoindolin-2-yl benzenesulfonamide derivatives (compounds 1-8) was synthesized by reaction of benzene sulfonamide derivatives with 4,5,6,7-tetrabromophthalic anhydride moiety. These new sulfonamides were investigated as inhibitors of the zinc metalloenzyme carbonic anhydrase (CA, EC 4.2.1.1) and more specifically against the human (h) cytosolic isoforms hCA I, II and VII and the transmembrane tumor-associated isoform hCA IX and XII. The new compounds were good hCA I inhibitors (Kis in the range of 143 to >10,000nM), but were moderately effective, as hCA II inhibitors (Kis of 47-190nM) and poor hCA VII inhibitors (Kis in the range of 54-175nM) compared to acetazolamide. The tumor-associated hCA IX was effectively inhibited with Kis ranging between 8.5 and 234nM and hCA XII with inhibition constants in the range of 6.1-197nM with high selectivity ratio. The structure-activity relationship (SAR) with this series of sulfonamides is straightforward, with the main features leading to good activity for each isoforms being established. The high sequence hCA alignment homology and molecular docking study of compounds was performed to rationalize the SAR reported over here. PMID:23965175

  1. Cloning and expression of Brassica napus beta-carbonic anhydrase cDNA.

    PubMed

    Deng, Qiu-Hong; Li, Mao-Teng; Yu, Long-Jiang

    2009-01-01

    A new full-length beta-carbonic anhydrase cDNA was obtained from Brassica napus by homologous cloning. The cDNA has an open-reading frame of 996 nucleotides, encoding 331 amino acids with a calculated molecular weight of 35,692 Da and an estimated pI value of 5.459. The deduced amino acid sequence of beta-carbonic anhydrase from Brassica napus shared significant identity with beta-carbonic anhydrases from Brassica carinata, Arabidopsis thaliana, and Thlaspi caerulescens (97.9%, 94%, and 93.5% identity, respectively). This cDNA was expressed in Escherichia coli BL21 (DE3) using the expression vector pET-32a(+). The expression band corresponded to the calculated mass plus the N-terminal fusion protein derived from the vector. PMID:20158161

  2. Sulfonamides incorporating heteropolycyclic scaffolds show potent inhibitory action against carbonic anhydrase isoforms I, II, IX and XII.

    PubMed

    Barresi, Elisabetta; Salerno, Silvia; Marini, Anna Maria; Taliani, Sabrina; La Motta, Concettina; Simorini, Francesca; Da Settimo, Federico; Vullo, Daniela; Supuran, Claudiu T

    2016-02-15

    Three series of polycyclic compounds possessing either primary sulfonamide or carboxylic acid moieties as zinc-binding groups were investigated as inhibitors of four physiologically relevant CA isoforms, the cytosolic hCA I and II, as well as the transmembrane hCA IX and XII. Most of the new sulfonamides reported here showed excellent inhibitory effects against isoforms hCA II, IX and XII, but no highly isoform-selective inhibition profiles. On the other hand, the carboxylates selectively inhibited hCA IX (KIs ranging between 40.8 and 92.7nM) without inhibiting significantly the other isoforms. Sulfonamides/carboxylates incorporating polycyclic ring systems such as benzothiopyranopyrimidine, pyridothiopyranopyrimidine or dihydrobenzothiopyrano[4,3-c]pyrazole may be considered as interesting candidates for exploring the design of isoform-selective CAIs with various pharmacologic applications. PMID:26796953

  3. Kinetic and X-ray crystallographic investigations on carbonic anhydrase isoforms I, II, IX and XII of a thioureido analog of SLC-0111.

    PubMed

    Lomelino, Carrie L; Mahon, Brian P; McKenna, Robert; Carta, Fabrizio; Supuran, Claudiu T

    2016-03-01

    SLC-0111 (4-(4-fluorophenylureido)-benzenesulfonamide) is the first carbonic anhydrase (CA, EC 4.2.1.1) IX inhibitor to reach phase I clinical trials as an antitumor/antimetastatic agent. Here we report a kinetic and X-ray crystallographic study of a congener of SLC-0111 which incorporates a thioureido instead of ureido linker between the two aromatic rings as inhibitor of four physiologically relevant CA isoforms. Similar to SLC-0111, the thioureido derivative was a weak hCA I and II inhibitor and a potent one against hCA IX and XII. X-ray crystallography of its adduct with hCA II and comparison of the structure with that of other five hCA II-sulfonamide adducts belonging to the SLC-0111 series, afforded us to understand the particular inhibition profile of the new sulfonamide. Similar to SLC-0111, the thioureido sulfonamide primarily interacted with the hydrophobic side of the hCA II active site, with the tail participating in van der Waals interactions with Phe131 and Pro202, in addition to the coordination of the deprotonated sulfonamide to the active site metal ion. On the contrary, the tail of other sulfonamides belonging to the SLC-0111 series (2-isopropyl-phenyl; 3-nitrophenyl) were orientated towards the hydrophilic half of the active site, which was correlated with orders of magnitude better inhibitory activity against hCA II, and a loss of selectivity for the inhibition of the tumor-associated CAs. PMID:26810836

  4. The impact of hydroquinone on acetylcholine esterase and certain human carbonic anhydrase isoenzymes (hCA I, II, IX, and XII).

    PubMed

    Scozzafava, Andrea; Kalın, Pınar; Supuran, Claudiu T; Gülçin, İlhami; Alwasel, Saleh H

    2015-12-01

    Carbonic anhydrases (CAs) are widespread and the most studied members of a great family of metalloenzymes in higher vertebrates including humans. CAs were investigated for their inhibition of all of the catalytically active mammalian isozymes of the Zn(2+)-containing CA, (CA, EC 4.2.1.1). On the other hand, acetylcholinesterase (AChE. EC 3.1.1.7), a serine protease, is responsible for ACh hydrolysis and plays a fundamental role in impulse transmission by terminating the action of the neurotransmitter ACh at the cholinergic synapses and neuromuscular junction. In the present study, the inhibition effect of the hydroquinone (benzene-1,4-diol) on AChE activity was evaluated and effectively inhibited AChE with Ki of 1.22 nM. Also, hydroquinone strongly inhibited some human cytosolic CA isoenzymes (hCA I and II) and tumour-associated transmembrane isoforms (hCA IX, and XII), with Kis in the range between micromolar (415.81 μM) and nanomolar (706.79 nM). The best inhibition was observed in cytosolic CA II. PMID:25586344

  5. 9,10-Dibromo-N-aryl-9,10-dihydro-9,10-[3,4]epipyrroloanthracene-12,14-diones: Synthesis and Investigation of Their Effects on Carbonic Anhydrase Isozymes I, II, IX, and XII.

    PubMed

    Göksu, Haydar; Topal, Meryem; Keskin, Ali; Gültekin, Mehmet S; Çelik, Murat; Gülçin, İlhami; Tanc, Muhammet; Supuran, Claudiu T

    2016-06-01

    N-substituted maleimides were synthesized from maleic anhydride and primary amines. 1,4-Dibromo-dibenzo[e,h]bicyclo-[2,2,2]octane-2,3-dicarboximide derivatives (4a-f) were prepared by the [4+2] cycloaddition reaction of dibromoanthracenes with the N-substituted maleimide derivatives. The carbonic anhydrase (CA, EC 4.2.1.1) inhibitory effects of the new derivatives were assayed against the human (h) isozymes hCA I, II, IX, and XII. All tested bicyclo dicarboximide derivatives exhibited excellent inhibitory effects in the nanomolar range, with Ki values in the range of 117.73-232.87 nM against hCA I and of 69.74-111.51 nM against hCA II, whereas they were low micromolar inhibitors against hCA IX and XII. PMID:27174792

  6. Ectopic expression of mitochondrial gamma carbonic anhydrase 2 causes male sterility by anther indehiscence.

    PubMed

    Villarreal, Fernando; Martín, Victoria; Colaneri, Alejandro; González-Schain, Nahuel; Perales, Mariano; Martín, Mariana; Lombardo, Cristina; Braun, Hans-Peter; Bartoli, Carlos; Zabaleta, Eduardo

    2009-07-01

    Plant mitochondria include gamma-type carbonic anhydrases (gammaCAs) of unknown function. In Arabidopsis, the gammaCAs form a gene family of five members which all are attached to the NADH dehydrogenase complex (complex I) of the respiratory chain. Here we report a functional analysis of gamma carbonic anhydrase 2 (CA2). The gene encoding CA2 is constitutively expressed in all plant organs investigated but it is ten fold induced in flowers, particularly in tapetal tissue. Ectopic expression of CA2 in Arabidopsis causes male sterility in transgenic plants. In normal anther development, secondary thickenings of the endothecial cell wall cause anthers to open upon dehydration. Histological analyses revealed that abnormal secondary thickening prevents anther opening in 35S::CA2 transgenic plants. CA2 abundance in transgenic plants is increased 2-3 fold compared to wild-type plants as revealed by Western blotting analyses. Moreover, abundance of other members of the CA family, termed CA3 and CAL2, is increased in transgenic plants. Oxygen uptake measurements revealed that respiration in transgenic plants is mainly based on NADH reduction by the alternative NADH dehydrogenases present in plant mitochondria. Furthermore, the formation of reactive oxygen species (ROS) is very low in transgenic plants. We propose that reduction in ROS inhibits H(2)O(2) dependent lignin polymerization in CA2 over-expressing plants, thereby causing male sterility. PMID:19326245

  7. Design and synthesis of novel 4-(4-oxo-2-arylthiazolidin-3-yl)benzenesulfonamides as selective inhibitors of carbonic anhydrase IX over I and II with potential anticancer activity.

    PubMed

    Suthar, Sharad Kumar; Bansal, Sumit; Lohan, Sandeep; Modak, Vikarm; Chaudhary, Anil; Tiwari, Amit

    2013-08-01

    The novel 4-(4-oxo-2-arylthiazolidin-3-yl)benzenesulfonamide derivatives were designed and synthesized for selective carbonic anhydrase IX (CA IX) inhibitory activity with anticancer potential. In the CA inhibition assay, 3f was found to be the most potent and selective inhibitor of CA IX with inhibitory constant (K(I)) value of 2.2 nM. Among the synthesized compounds, 3f showed IC₅₀ values of 5.03 μg/ml (cisplatin: 6.56 μg/ml), 5.81 μg/ml (cisplatin: 5.85 μg/ml), and 23.93 μg/ml (cisplatin: 2.75 μg/ml) against COLO-205, MDA-MB-231, and DU-145 cell lines, respectively. At IC₅₀, 3f caused cell shrinkage, nuclear condensation, and nuclear fragmentation events characteristic to apoptosis in the Hoechst 33258 and acridine orange-ethidium bromide staining studies of COLO-205 cells. In the Dalton's lymphoma ascites (DLA) solid tumor model 3f decreased tumor volume by 64.83% (cisplatin: 71.62%), while increase in mean body weight was found to be only 4.09% (cisplatin: 3.47%). PMID:23827177

  8. Quantitative Characterization of the Interaction Space of the Mammalian Carbonic Anhydrase Isoforms I, II, VII, IX, XII, and XIV and their Inhibitors, Using the Proteochemometric Approach.

    PubMed

    Rasti, Behnam; Karimi-Jafari, Mohammad H; Ghasemi, Jahan B

    2016-09-01

    The critical role of carbonic anhydrases in different physiological processes has put this protein family at the center of attention, challenging major diseases like glaucoma, neurological disorders such as epilepsy and Alzheimer's disease, obesity, and cancers. Many QSAR/QSPR (quantitative structure-activity/property relationship) researches have been carried out to design potent carbonic anhydrase inhibitors (CAIs); however, using inhibitors with no selectivity for different isoforms can lead to major side-effects. Given that QSAR/QSPR methods are not capable of covering multiple targets in a unified model, we have applied the proteochemometric approach to model the interaction space that governs selective inhibition of different CA isoforms by some mono-/dihydroxybenzoic acid esters. Internal and external validation methods showed that all models were reliable in terms of both validity and predictivity, whereas Y-scrambling assessed the robustness of the models. To prove the applicability of our models, we showed how structural changes of a ligand can affect the selectivity. Our models provided interesting information that can be useful for designing inhibitors with selective behavior toward isoforms of carbonic anhydrases, aiding in their selective inhibition. PMID:26990115

  9. Improved muscle-derived expression of human coagulation factor IX from a skeletal actin/CMV hybrid enhancer/promoter.

    PubMed

    Hagstrom, J N; Couto, L B; Scallan, C; Burton, M; McCleland, M L; Fields, P A; Arruda, V R; Herzog, R W; High, K A

    2000-04-15

    Hemophilia B is caused by the absence of functional coagulation factor IX (F.IX) and represents an important model for treatment of genetic diseases by gene therapy. Recent studies have shown that intramuscular injection of an adeno-associated viral (AAV) vector into mice and hemophilia B dogs results in vector dose-dependent, long-term expression of biologically active F.IX at therapeutic levels. In this study, we demonstrate that levels of expression of approximately 300 ng/mL (6% of normal human F.IX levels) can be reached by intramuscular injection of mice using a 2- to 4-fold lower vector dose (1 x 10(11) vector genomes/mouse, injected into 4 intramuscular sites) than previously described. This was accomplished through the use of an improved expression cassette that uses the cytomegalovirus (CMV) immediate early enhancer/promoter in combination with a 1.2-kilobase portion of human skeletal actin promoter. These results correlated with enhanced levels of F.IX transcript and secreted F.IX protein in transduced murine C2C12 myotubes. Systemic F.IX expression from constructs containing the CMV enhancer/promoter alone was 120 to 200 ng/mL in mice injected with 1 x 10(11) vector genomes. Muscle-specific promoters performed poorly for F.IX transgene expression in vitro and in vivo. However, the incorporation of a sequence from the alpha-skeletal actin promoter containing at least 1 muscle-specific enhancer and 1 enhancer-like element further improved muscle-derived expression of F.IX from a CMV enhancer/promoter-driven expression cassette over previously published results. These findings will allow the design of a clinical protocol for therapeutic levels of F.IX expression with lower vector doses, thus enhancing efficacy and safety of the protocol. (Blood. 2000;95:2536-2542) PMID:10753832

  10. Carbonic anhydrase IV (CAR4) is expressed on IL-5 activated murine eosinophils

    PubMed Central

    Wen, Ting; Mingler, Melissa K.; Wahl, Benjamin; Khorki, M. Eyad; Pabst, Oliver; Zimmermann, Nives; Rothenberg, Marc E.

    2014-01-01

    Eosinophilia and its cellular activation are hallmark features of asthma, as well as other allergic/TH2 disorders, yet there are few, if any, reliable surface markers of eosinophil activation. We have employed a FACS-based genome-wide screening system to identify transcriptional alterations in murine lung eosinophils recruited and activated by pulmonary allergen exposure. Using a relatively stringent screen with false-positive correction, we identified 82 candidate genes that could serve as eosinophil activation markers and/or pathogenic effector markers in asthma. Carbonic anhydrase IV (Car4) was a top dysregulated gene with 36-fold induction in allergen-elicited pulmonary eosinophils, which was validated by quantitative PCR, IHC and by flow cytometry. Eosinophil CAR4 expression was kinetically regulated by IL-5 but not IL-13. IL-5 was both necessary and sufficient for induction of eosinophil CAR4. While CAR4-deficient mice did not have a defect in eosinophil recruitment to the lung nor a change in eosinophil pH-buffering capacity, allergen-challenged chimeric mice that contained Car4−/− hematopoietic cells aberrantly expressed a series of genes enriched in biological processes involved in epithelial differentiation, keratinization, and anion exchange. In conclusion, we have determined that eosinophils express CAR4 following IL-5 or allergen exposure, and that CAR4 is involved in regulating the lung transcriptome associated with allergic airway inflammation; as such, CAR4 has potential value for diagnosing and monitoring eosinophilic responses. PMID:24808371

  11. Expression Patterns and Subcellular Localization of Carbonic Anhydrases Are Developmentally Regulated during Tooth Formation

    PubMed Central

    Reibring, Claes-Göran; El Shahawy, Maha; Hallberg, Kristina; Kannius-Janson, Marie; Nilsson, Jeanette; Parkkila, Seppo; Sly, William S.; Waheed, Abdul; Linde, Anders; Gritli-Linde, Amel

    2014-01-01

    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 future single or

  12. Expression of Human Carbonic Anhydrase in the Cyanobacterium Synechococcus PCC7942 Creates a High CO2-Requiring Phenotype 1

    PubMed Central

    Price, G. D.; Badger, M. R.

    1989-01-01

    Active human carbonic anhydrase II (HCAII) protein was expressed in the cyanobacterium Synechococcus PCC7942 by means of transformation with the bidirectional expression vector, pCA. This expression was driven by the bacterial Tac promoter and was regulated by the IacIQ repressor protein, which was expressed from the same plasmid. Expression levels reached values of around 0.3% of total cell protein and this protein appeared to be entirely soluble in nature and located within the cytosol of the cell. The expression of this protein has dramatic effects on the photosynthetic physiology of the cell. Induction of expression of carbonic anhydrase (CA) activity in both high dissolved inorganic carbon (Ci) and low Ci grown cells leads the creation of a high Ci requiring phenotype causing: (a) a dramatic increase in the K0.5 (Ci) for photosynthesis, (b) a loss of the ability to accumulate internal Ci, and (c) a decrease in the lag between the initial Ci accumulation following illumination and the efflux of CO2 from the cells. In addition, the effects of the expressed CA can largely be reversed by the carbonic anhydrase inhibitor ethoxyzolamide. As a result of the above findings, it is concluded that the CO2 concentrating mechanism in Synechococcus PCC7942 is largely dependent on (a) the absence of CA activity from the cytosol, and (b) the specific localization of CA activity in the carboxysome. A theoretical model of photosynthesis and Ci accumulation is developed in which the carboxysome plays a central role as both the site of CO2 generation from HCO3− and a resistance barrier to CO2 efflux from the cell. There is good qualitative agreement between this model and the measured physiological effects of expressed cytosolic CA in Synechococcus cells. Images Figure 7 PMID:16667062

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

    NASA Astrophysics Data System (ADS)

    Chai, Yurong; Lu, Yumin; Wang, Tianyun; Hou, Weihong; Xue, Lexun

    2006-12-01

    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 efficient promoters 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.

  14. Identification and expression of a novel carbonic anhydrase isozyme in the pufferfish Takifugu vermicularis.

    PubMed

    Sumi, Kanij Rukshana; Nou, Ill-Sup; Kho, Kang Hee

    2016-08-22

    Carbonic anhydrase (CA) is a key element for maintaining acid base balance in fish. In our present experiment, novel CA isozymes were identified from the pear puffer (Takifugu vermicularis). Based on the high homology of two predicted CA sequences of the tiger puffer (Takifugu rubripes), a 1715bp novel cDNA was obtained from T. vermicularis. The open reading frame showed a complete coding sequence of 552bp with a deduced peptide sequence of 183 amino acids that exhibited highest (97%) identity with pufferfish putative CA III and CA IV-like sequences. In addition, this translated protein sequence showed 36-37% identity with zebrafish CA IV-like, CA XVa, CA XVb, and CA XVc proteins. Phylogenetic analysis revealed that the pufferfish novel protein (pCAn) was a membrane-bound CA protein. Alignment of multiple CA sequences illustrated that most of the putative active site residues of the pCAn isozyme were situated at highly conserved regions of the CA sequences. Examination of motif distribution suggested that the pCAn isozyme was very similar to the puffer predicted CA IV-like isozyme. Reverse transcription-polymerase chain reaction (PCR) analysis showed highly differential expression in the brain, gills, kidney, and muscle, whereas CA mRNA expression was almost absent in heart, liver, and intestine. Quantitative PCR expression of CA mRNA abundance suggested several-fold higher expression of pCAn isozymes in the gills compared to other tissues tested. Our results suggest that the pCAn isozyme might be related to CA IV-like isozymes. Further functional studies are needed to investigate the function of the pCAn isozyme in T. vermicularis. PMID:27188255

  15. Expression of human factor IX in rat capillary endothelial cells: Toward somatic gene therapy for hemophilia B

    SciTech Connect

    Shounan Yao; Wilson, J.M.; Nabel, E.G.; Kurachi, Sumiko; Hachiya, H.L.; Kurachi, Kotoku )

    1991-09-15

    In aiming to develop a gene therapy approach for hemophilia B, the authors expressed and characterized human factor IX in rat capillary endothelial cells (CECs). Moloney murine leukemia virus-derived retrovirus vectors that contain human factor IX cDNA linked to heterologous promoters and the neomycin-resistant gene were constructed and employed to prepare recombinant retroviruses. Rat CECs and NIH 3T3 cells infected with these viruses were selected with the neomycin analogue, G418 sulfate, and tested for expression of factor IX. A construct with the factor IX cDNA under direct control by long terminal repeat gave the highest level of expression as quantitated by immunoassays as well as clotting activity assays. A single RNA transcript of 4.4 kilobases predicted by the construct and a recombinant factor IX were found. The recombinant human factor IX produced showed full clotting activity, demonstrating that CECs have an efficient mechanism for posttranslational modifications, including {gamma}-carboxylation, essential for its biological activity. These results, in addition to other properties of the endothelium, including large number of cells, accessibility, and direct contact with the circulating blood, suggest that CECs can serve as an efficient drug delivery vehicle producing factor IX in a somatic gene therapy for hemophilia B.

  16. Normal Fertility Requires the Expression of Carbonic Anhydrases II and IV in Sperm.

    PubMed

    Wandernoth, Petra M; Mannowetz, Nadja; Szczyrba, Jaroslaw; Grannemann, Laura; Wolf, Anne; Becker, Holger M; Sly, William S; Wennemuth, Gunther

    2015-12-01

    HCO3 (-) is a key factor in the regulation of sperm motility. High concentrations of HCO3 (-) in the female genital tract induce an increase in sperm beat frequency, which speeds progress of the sperm through the female reproductive tract. Carbonic anhydrases (CA), which catalyze the reversible hydration of CO2 to HCO3 (-), represent potential candidates in the regulation of the HCO3 (-) homeostasis in sperm and the composition of the male and female genital tract fluids. We show that two CA isoforms, CAII and CAIV, are distributed along the epididymal epithelium and appear with the onset of puberty. Expression analyses reveal an up-regulation of CAII and CAIV in the different epididymal sections of the knockout lines. In sperm, we find that CAII is located in the principal piece, whereas CAIV is present in the plasma membrane of the entire sperm tail. CAII and CAIV single knockout animals display an imbalanced HCO3 (-) homeostasis, resulting in substantially reduced sperm motility, swimming speed, and HCO3 (-)-enhanced beat frequency. The CA activity remaining in the sperm of CAII- and CAIV-null mutants is 35% and 68% of that found in WT mice. Sperm of the double knockout mutant mice show responses to stimulus by HCO3 (-) or CO2 that were delayed in onset and reduced in magnitude. In comparison with sperm from CAII and CAIV double knockout animals, pharmacological loss of CAIV in sperm from CAII knockout animals, show an even lower response to HCO3 (-). These results suggest that CAII and CAIV are required for optimal fertilization. PMID:26487715

  17. Identification and expression of cotton (Gossypium hirsutum L.) plastidial carbonic anhydrase.

    PubMed

    Hoang, C V; Wessler, H G; Local, A; Turley, R B; Benjamin, R C; Chapman, K D

    1999-12-01

    Four carbonic anhydrase (CA) cDNA clones were isolated from a 48 h dark-grown cotton (Gossypium hirsutum L.) seedling cDNA library. Nucleotide sequence analysis revealed two different CA isoforms designated GhCA1 and GhCA2. The encoded polypeptides possess N-terminal serine/threonine-rich regions indicative of plastid transit peptides, and approximately 80% sequence identity to other plant plastidial beta-CAs. The GhCA1 cDNA encodes a nearly complete preprotein of 323 amino acids with a molecular mass of 34.9 kDa and a predicted mature protein of 224 amino acids with a molecular mass of 24.3 kDa. Eleven nucleotide differences within ORFs of GhCA1 and GhCA2 result in 5 conservative amino acid substitutions. The 3' GhCA2 untranslated region contains five additional substitutions and one single nucleotide addition. GhCA1 clones, nearly full-length or with 70% of the transit peptide deleted, were expressed as LacZ alpha fusion proteins in E. coli. Lysates of these strains contained 9-fold higher levels of CA activity as compared to untransformed controls and this activity was inhibited by CA-specific inhibitors. Sulfanilamide, acetazolamide, ethoxyzolamide, each at 10 mM, inhibited recombinant CA activity approximately 50%, 65%, and 75%, respectively. In plant tissue homogenates these inhibitors reduced CA activity by 50%, 70%, and 95%, respectively. Although CA activity was bighest in extracts of mature cotton leaves, probing total RNA with GhCA1 revealed CA transcript levels to be highest in the cotyledons of dark-grown cotton seedlings. Collectively, our data indicate the presence of a plastid-localized CA in cotyledons of germinated seeds, suggesting a role for CA in postgerminative growth. PMID:10682348

  18. Normal Fertility Requires the Expression of Carbonic Anhydrases II and IV in Sperm*

    PubMed Central

    Wandernoth, Petra M; Mannowetz, Nadja; Szczyrba, Jaroslaw; Grannemann, Laura; Wolf, Anne; Becker, Holger M.; Sly, William S.; Wennemuth, Gunther

    2015-01-01

    HCO3− is a key factor in the regulation of sperm motility. High concentrations of HCO3− in the female genital tract induce an increase in sperm beat frequency, which speeds progress of the sperm through the female reproductive tract. Carbonic anhydrases (CA), which catalyze the reversible hydration of CO2 to HCO3−, represent potential candidates in the regulation of the HCO3− homeostasis in sperm and the composition of the male and female genital tract fluids. We show that two CA isoforms, CAII and CAIV, are distributed along the epididymal epithelium and appear with the onset of puberty. Expression analyses reveal an up-regulation of CAII and CAIV in the different epididymal sections of the knockout lines. In sperm, we find that CAII is located in the principal piece, whereas CAIV is present in the plasma membrane of the entire sperm tail. CAII and CAIV single knockout animals display an imbalanced HCO3− homeostasis, resulting in substantially reduced sperm motility, swimming speed, and HCO3−-enhanced beat frequency. The CA activity remaining in the sperm of CAII- and CAIV-null mutants is 35% and 68% of that found in WT mice. Sperm of the double knockout mutant mice show responses to stimulus by HCO3− or CO2 that were delayed in onset and reduced in magnitude. In comparison with sperm from CAII and CAIV double knockout animals, pharmacological loss of CAIV in sperm from CAII knockout animals, show an even lower response to HCO3−. These results suggest that CAII and CAIV are required for optimal fertilization. PMID:26487715

  19. Transgenic mice over-expressing carbonic anhydrase I showed aggravated joint inflammation and tissue destruction

    PubMed Central

    2012-01-01

    Background Studies have demonstrated that carbonic anhydrase I (CA1) stimulates calcium salt precipitation and cell calcification, which is an essential step in new bone formation. Our study had reported that CA1 encoding gene has a strong association with rheumatoid arthritis (RA) and ankylosing spondylitis (AS), two rheumatic diseases with abnormal new bone formation and bone resorption in joints. This study investigated the effect of CA1 on joint inflammation and tissue destruction in transgenic mice that over-express CA1 (CA1-Tg). Methods CA1-Tg was generated with C57BL/6J mice by conventional methods. CA1-Tg was treated with collagen-II to induce arthritis (CIA). Wild-type mice, CA1-Tg treated with bovine serum albumin (BSA) and transgenic mice over-expressing PADI4 (PADI4-Tg), a gene known to be involved in rheumatoid arthritis, were used as controls. Histochemistry and X-ray radiographic assay were used to examine joint destruction. Western blotting and real time-PCR were used to examine CA1 expression. Results CIA was observed in 60% of CA1-Tg, 20% of PADI4-Tg and 20% of wild-type mice after collagen injections. No CIA was found in CA1-Tg mice that received injections of BSA. The arthritic score was 5.5 ± 0.84 in the CA1-Tgs but the score was less than 2 in the injected wild-type mice and the PADI4-Tgs. The thickness of the hind paws in the CA1-Tgs was 3.46 ± 0.11 mm, which was thicker than that of PADI4-Tgs (2.23 ± 0.08 mm), wild-type mice (2.08 ± 0.06 mm) and BSA-treated CA1-Tgs (2.04 ± 0.07 mm). Histochemistry showed obvious inflammation, synovial hyperplasia and bone destruction in the joints of CA1-Tg that was not detected in PADI4-Tgs or wild-type mice. X-ray assays showed bone fusion in the paws and spines of CA1-Tg mice. Conclusion Over-expression of CA1 may aggravate joint inflammation and tissue destruction in the transgenic mice. PMID:23256642

  20. The effects of CA IX catalysis products within tumor microenvironment.

    PubMed

    Santi, Alice; Caselli, Anna; Paoli, Paolo; Corti, Denise; Camici, Guido; Pieraccini, Giuseppe; Taddei, Maria Letizia; Serni, Sergio; Chiarugi, Paola; Cirri, Paolo

    2013-01-01

    Solid tumors are composed of both cancer cells and various types of accessory cells, mainly fibroblasts, that collectively compose the so called tumor-microenvironment. Cancer-associated fibroblasts have been described to actively participate in cancer progression by establishing a cytokine-mediated as well as metabolic crosstalk with cancer cells. In the present paper we show that activated human fibroblasts are able to boost tumor cells proliferation and that this effect is greatly dependent on stromal carbonic anhydrase IX (CA IX) activity. In fact fibroblasts show a strong upregulation of CA IX expression upon activation by cancer cells, while CA IX products, protons and bicarbonate, exert differential effects on cancer cells proliferation. While acidification of extracellular pH, a typical condition of rapidly growing solid tumors, is detrimental for tumor cells proliferation, bicarbonate, through its organication, supplies cancer cells with intermediates useful to sustain their high proliferation rate. Here we propose a new kind of fibroblasts/tumor cells crosstalk within tumor microenvironment, mediated by stromal CA IX products, aimed to favor cancer cells growth, opening new perspectives on CA IX role in tumor microenvironment. PMID:24168032

  1. A combined theoretical and spectroscopic study of 4,6-di-O-acetyl-2,3-dideoxy-D-erythro-hex-2-enopyranosyl sulfamide: a novel glycosyl carbonic anhydrase IX inhibitor.

    PubMed

    Lavecchia, Martín J; Diez, Reinaldo Pis; Colinas, Pedro A

    2011-02-15

    The novel 4,6-di-O-acetyl-2,3-dideoxy-D-erythro-hex-2-enopyranosyl sulfamide, which exhibits selectivity for inhibiting isoform IX of carbonic anhydrase as overexpressed in many tumors, has been investigated from a combined theoretical and spectroscopic point of view. The conformational study of the compound shows that the α-anomeric form is more stable than the β-anomeric form from a thermodynamic point of view after including solvent effects. This fact suggests that the synthesis reaction could take place mainly under thermodynamic control as the main experimental product is the α-anomeric form of the sulfamide. Calculated α/β ratio is about 95:5, in excellent agreement with experimental data. Optimized geometries of the α-anomeric form agree quite well with crystallographic data. The inclusion of a solvent has negligible effects on the conformations. A detailed analysis of some geometric parameters shed light into the conformational behavior of the sulfamide in terms of both exo- and endo-anomeric effects and antiperiplanar relationships. Natural bond orbital calculations confirm those findings. Several intramolecular hydrogen bonds, characterized through the Atoms-in-Molecules theory, were found in the stable conformers. They, however, seem to play no relevant role in determining the relative stability of α conformers with respect to the β ones. Calculated (1)H and (13)C NMR chemical shifts support previous findings concerning configuration and conformation assignments of the title sulfamide. The IR spectrum of the compound is recorded and reported for the first time and the assignment of some of the most important bands is accomplished with the aid of calculated harmonic vibrational frequencies. PMID:21237448

  2. The novel CA IX inhibition antibody chKM4927 shows anti-tumor efficacy in vivo.

    PubMed

    Yamaguchi, Ayami; Usami, Katsuaki; Shimabe, Munetake; Hasegawa, Kazumasa; Asada, Masao; Motoki, Kazuhiro; Tahara, Tomoyuki; Masuda, Kazuhiro

    2015-04-01

    Carbonic anhydrase IX (CA IX) is an attractive target for cancer therapy. Many anti-CA IX antibodies have been reported but few have been shown to possess inhibition activity. Furthermore, effective use of CA IX-inhibition antibodies for cancer immunotherapy has not been well-validated since data are mainly limited to in vitro assays. In this study, we established that chKM4927, an anti-CA IX chimeric antibody, recognizes CA IX and has CA IX-specific inhibition activity. ChKM4927 also retains antibody-dependent cellular cytotoxicity (ADCC) activity against CA IX-expressing cancer cells. Compared to controls, chKM4927 treatment (10 mg/kg) showed anti-tumor activity in the VMRC-RCW xenograft model in vivo. ChKM4927-attenuated ADCC activity showed equally effective anti-tumor activity. These results suggest that the CA IX-inhibition antibody chKM4927 has an anti-tumor effect in the VMRC-RCW xenograft model via an ADCC-independent mechanism. PMID:25862852

  3. Analysis, characterisation and expression of gill-expressed carbonic anhydrase genes in the freshwater crayfish Cherax quadricarinatus.

    PubMed

    Ali, Muhammad Yousuf; Pavasovic, Ana; Mather, Peter B; Prentis, Peter J

    2015-06-15

    Changes in water quality parameters such as pH and salinity can have a significant effect on productivity of aquaculture species. Similarly, relative osmotic pressure influences various physiological processes and regulates expression of a number of osmoregulatory genes. Among those, carbonic anhydrase (CA) plays a key role in systemic acid-base balance and ion regulation. Redclaw crayfish (Cherax quadricarinatus) are unique in their ability to thrive in environments with naturally varied pH levels, suggesting unique adaptation to pH stress. To date, however, no studies have focused on identification and characterisation of CA or other osmoregulatory genes in C. quadricarinatus. Here, we analysed the redclaw gill transcriptome and characterized CA genes along with a number of other key osmoregulatory genes that were identified in the transcriptome. We also examined patterns of gene expression of these CA genes when exposed to three pH treatments. In total, 72,382,710 paired end Illumina reads were assembled into 36,128 contigs with an average length of 800bp. Approximately 37% of contigs received significant BLAST hits and 22% were assigned gene ontology terms. Three full length CA isoforms; cytoplasmic CA (ChqCAc), glycosyl-phosphatidylinositol-linked CA (ChqCAg), and β-CA (ChqCA-beta) as well as two partial CA gene sequences were identified. Both partial CA genes showed high similarity to ChqCAg and appeared to be duplicated from the ChqCAg. Full length coding sequences of Na(+)/K(+)-ATPase, V-type H(+)-ATPase, sarcoplasmic Ca(+)-ATPase, arginine kinase, calreticulin and Cl(-) channel protein 2 were also identified. Only the ChqCAc gene showed significant differences in expression across the three pH treatments. These data provide valuable information on the gill expressed CA genes and their expression patterns in freshwater crayfish. Overall our data suggest an important role for the ChqCAc gene in response to changes in pH and in systemic acid-base balance in

  4. Transcriptome analysis and characterisation of gill-expressed carbonic anhydrase and other key osmoregulatory genes in freshwater crayfish Cherax quadricarinatus.

    PubMed

    Ali, Muhammad Yousuf; Pavasovic, Ana; Mather, Peter B; Prentis, Peter J

    2015-12-01

    The pH and salinity balance mechanisms of crayfish are controlled by a set of transport-related genes. We identified a set of the genes from the gill transcriptome from a freshwater crayfish Cherax quadricarinatus using the Illumina NGS-sequencing technology. We identified and characterized carbonic anhydrase (CA) genes and some other key genes involved in systematic acid-base balance and osmotic/ionic regulation. We also examined expression patterns of some of these genes across different sublethal pH levels [1]. A total of 72,382,710 paired-end Illumina reads were assembled into 36,128 contigs with an average length of 800 bp. About 37% of the contigs received significant BLAST hits and 22% were assigned gene ontology terms. These data will assist in further physiological-genomic studies in crayfish. PMID:26543880

  5. Transcriptome analysis and characterisation of gill-expressed carbonic anhydrase and other key osmoregulatory genes in freshwater crayfish Cherax quadricarinatus

    PubMed Central

    Ali, Muhammad Yousuf; Pavasovic, Ana; Mather, Peter B.; Prentis, Peter J.

    2015-01-01

    The pH and salinity balance mechanisms of crayfish are controlled by a set of transport-related genes. We identified a set of the genes from the gill transcriptome from a freshwater crayfish Cherax quadricarinatus using the Illumina NGS-sequencing technology. We identified and characterized carbonic anhydrase (CA) genes and some other key genes involved in systematic acid-base balance and osmotic/ionic regulation. We also examined expression patterns of some of these genes across different sublethal pH levels [1]. A total of 72,382,710 paired-end Illumina reads were assembled into 36,128 contigs with an average length of 800 bp. About 37% of the contigs received significant BLAST hits and 22% were assigned gene ontology terms. These data will assist in further physiological-genomic studies in crayfish. PMID:26543880

  6. Effects of novel auto-inducible medium on growth, activity and CO₂ capture capacity of Escherichia coli expressing carbonic anhydrase.

    PubMed

    Watson, Stuart K; Kan, Eunsung

    2015-10-01

    A glucose-based auto-inducible medium (glucose-AIM) has been developed to enhance both growth and expression of lac operon-linked carbonic anhydrase (CA) expression in a recombinant strain of Escherichia coli. When the E. coli expressing CA was grown on various media, the glucose-based auto-inducible medium (glucose AIM) resulted in a CA activity of 1022 mU OD(600 nm)(-1) mL(-1) at 24 h and a specific growth rate of 0.082 h(-1). The CA activity was four to fourteen times higher than those by LB-IPTG. The E. coli expressing CA grown on the glucose-AIM showed highest activity at pH8.5 while it kept high stability up to 40°C and an inlet CO2 concentration of 6%. These findings indicate that the glucose-AIM would be a cost-effective medium to support high cell growth, CA activity and stability for effective CO2 capture. PMID:26264623

  7. Carbon dioxide and light regulation of promoters controlling the expression of mitochondrial carbonic anhydrase in Chlamydomonas reinhardtii.

    PubMed

    Villand, P; Eriksson, M; Samuelsson, G

    1997-10-01

    Nuclear genes coding for carbonic anhydrase, a major mitochondrial constituent in Chlamydomonas reinhardtii grown under limited CO2, were characterized. Two genes, ca1 and ca2, were found within 7 kb of genomic DNA, organized 'head to head' in a large inverted repeat. The DNA sequences for the two genes were very similar, even in the promoter regions and in introns, indicating that the repeat is a result of a recent duplication. To study gene regulation, elements from the upstream region of ca1 were fused to the arylsulphatase reporter gene. After transformation, the expression of arylsulphatase was regulated similarly to the endogenous ca1/ca2 genes, even when the promoter was trimmed down to 194 nt. Expression could not be detected when 5% CO2 was bubbled into the growth medium, but was induced within hours after transfer to air. The ca1 promoter was not induced in low light, but at intermediate light levels its activity was dependent on the irradiance. O2 concentration had no effect on the promoter activity, indicating that photorespiratory metabolites are not triggering the response. The availability of cells transformed with a CO2-regulated reporter gene should facilitate further studies on the metabolic adaptations that occur in some green algae in response to the external CO2 level. PMID:9355734

  8. High expression and biosilica encapsulation of alkaline-active carbonic anhydrase for CO2 sequestration system development.

    PubMed

    Min, Ki-Ha; Son, Ryeo Gang; Ki, Mi-Ran; Choi, Yoo Seong; Pack, Seung Pil

    2016-01-01

    Carbonic anhydrase (CA) is a biocatalyst for CO2 sequestration because of its distinctive ability to accelerate CO2 hydration. High production and efficient immobilization of alkaline-active CAs are required, because one potential application of CA is its use in the alkaline solvent-based CO2 absorption/desorption process. Here, we designed and applied an α-type CA from Hahella chejuensis (HCA), which was reported as highly active in alkaline conditions, but was mostly expressed as insoluble forms. We found that the signal peptide-removed form of HCA [HCA(SP-)] was successfully expressed in the soluble form [∼70mg of purified HCA(SP-) per L of culture]. HCA(SP-) also displayed high pH stability in alkaline conditions, with maximal activity at pH 10; at this pH, ∼90% activity was maintained for 2h. Then, we prepared HCA(SP-)-encapsulated silica particles [HCA(SP-)@silica] via a spermine-mediated bio-inspired silicification method. HCA(SP-)@silica exhibited high-loading and highly stable CA activity. In addition, HCA(SP-)@silica retained more than 90% of the CA activity even after 10 cycles of use in mild conditions, and ∼80% in pH 10 conditions. These results will be useful for the development of practical CO2 sequestration processes employing CA. PMID:26206748

  9. Carbonic anhydrase inhibitors: Design, synthesis and structural characterization of new heteroaryl-N-carbonylbenzenesulfonamides targeting druggable human carbonic anhydrase isoforms.

    PubMed

    Buemi, Maria Rosa; De Luca, Laura; Ferro, Stefania; Bruno, Elvira; Ceruso, Mariangela; Supuran, Claudiu T; Pospíšilová, Klára; Brynda, Jiří; Řezáčová, Pavlína; Gitto, Rosaria

    2015-09-18

    A set of heteroaryl-N-carbonylbenzenesulfonamides has been designed, synthesized, and screened as inhibitors of human carbonic anhydrases (hCAs). The new sulfonamide derivatives were tested against hCA I, hCA II, hCA VII, hCA IX, and hCA XII isoforms using acetazolamide (AAZ, 1) and topiramate (TPM, 2) as reference compounds. Six compounds were low nanomolar inhibitors of tumor-associated hCA IX isoform (Ki values < 10 nM); among them we identified three arylsulfonamides showing unexpected inefficacy over brain distributed hCA VII isoform (hCA IX/hCA VII selectivity ratio > 1500 for compound 5c). Thus, these compounds can offer the opportunity to highlight the interactions preventing the inhibition of hCA VII mainly expressed in central nervous system. Thereby, we used structural and computational techniques to study in depth the interaction with hCAs. In an effort to confirm the inhibitory action we determined crystal structures of five selected heteroaryl-N-carbonylbenzenesulfonamides (4a, 4b, 4e, 5c, and 5e) in complex with hCA II. Moreover, to explore the lack of inhibitory effects of selected compounds (e.g.4b and 5c) we also performed docking studies into hCA VII catalytic site. PMID:26276436

  10. A Lotus japonicus beta-type carbonic anhydrase gene expression pattern suggests distinct physiological roles during nodule development.

    PubMed

    Flemetakis, Emmanouil; Dimou, Maria; Cotzur, Daniela; Aivalakis, Georgios; Efrose, Rodica C; Kenoutis, Christos; Udvardi, Michael; Katinakis, Panagiotis

    2003-08-25

    A full-length cDNA clone, designated Ljca1, coding for a beta-type carbonic anhydrase (CA; EC: 4.2.1.1) was isolated from a Lotus japonicus nodule cDNA library. Semi-quantitative RT-PCR analysis revealed that Ljca1 codes for a nodule-specific CA, transcripts of which accumulate at maximum levels in young nodules at 14 days post-infection (d.p.i.). In situ hybridization and immunolocalization revealed that Ljca1 transcripts and LjCA1 polypeptides were present at high levels in all cell types of young nodules. In contrast, in mature nodules both transcripts and polypeptides were confined in a few cell layers of the nodules inner cortex. However, the central infected tissue of both young and mature nodules exhibited high CA activity, indicating the presence of additional CA isoforms of plant and/or microbial origin. This was supported by the finding that a putative Mesorhizobium loti CA gene was transiently expressed during nodule development. In addition, the temporal and spatial accumulation of phosphoenolpyruvate carboxylase (PEPC; EC: 4.1.1.31) was determined by semi-quantitative RT-PCR and immunolocalization. The results suggest that LjCA1 might fulfill different physiological needs during L. japonicus nodule development. PMID:12932831

  11. Improved expression of recombinant human factor IX by co-expression of GGCX, VKOR and furin.

    PubMed

    Liu, Jianming; Jonebring, Anna; Hagström, Jonas; Nyström, Ann-Christin; Lövgren, Ann

    2014-04-01

    Recombinant human FIX concentrates (rhFIX) are essential in the treatment and prevention of bleeding in the bleeding disorder haemophilia B. However, due to the complex nature of FIX production yields are low which leads to high treatment costs. Here we report the production of rhFIX with substantially higher yield by co-expressing human FIX with GGCX (γ-glutamyl carboxylase), VKOR (vitamin K epoxide reductase) and furin (paired basic amino acid cleaving enzyme) in Chinese hamster ovary (CHO) cells. Our results show that controlled co-expression of GGCX with FIX is critical to obtain high rhFIX titre, and, that co-expression of VKOR further increased the yield of active rhFIX. Furin co-expression improved processing of the leader peptide of rhFIX but had a minor effect on yield of active rhFIX. The optimal expression level of GGCX was surprisingly low and required unusual engineering of expression vector elements. For VKOR and furin the control of expression was less critical and could be achieved by standard vector element. Using our expression vectors an rhFIX-producing clone with an expression level of up to 30 mg/L of active rhFIX was obtained. In addition an efficient single step purification method was developed to obtain pure and active rhFIX with up to 94% yield. PMID:24567122

  12. Expression of carbonic anhydrase, cystic fibrosis transmembrane regulator (CFTR) and V-H(+)-ATPase in the lancelet Branchiostoma lanceolatum (Pallas, 1774).

    PubMed

    Pederzoli, Aurora; Mandrioli, Mauro; Mola, Lucrezia

    2014-04-01

    Sequencing of the amphioxus genome revealed that it contains a basic set of chordate genes involved in development and cell signaling. Despite the availability of genomic data, up till now no studies have been addressed on the comprehension of the amphioxus osmoregulation. Using primers designed on Branchiostoma floridae carbonic anhydrase (CA) II, cystic fibrosis transmembrane regulator (CFTR) and V-H(+)-ATPase, a 100bp long region, containing the protein region recognized by the respective antibodies, has been amplified and sequenced in B. lanceolatum indicating the presence of hortologous V-ATPase, CFTR and carbonic anhydrase II genes in Branchiostoma lanceolatum. Immunohistochemical results showed that all three transporting proteins are expressed in almost 90% of epithelial cells of the skin in B. lanceolatum adults with a different degree of positivity in different regions of body wall and with a different localization in the cells. The comparison of results between young and adult lancelets showed that the distribution of these transporters is quite different. Indeed, in the young specimens the expression pattern of all tested molecules appears concentrated at the gut level, whereas in adult the gut loses its key role that is mostly supported by skin. PMID:24220283

  13. Glioblastomas with copy number gains in EGFR and RNF139 show increased expressions of carbonic anhydrase genes transformed by ENO1

    PubMed Central

    Beckner, Marie E.; Pollack, Ian F.; Nordberg, Mary L.; Hamilton, Ronald L.

    2015-01-01

    Background Prominence of glycolysis in glioblastomas may be non-specific or a feature of oncogene-related subgroups (i.e. amplified EGFR, etc.). Relationships between amplified oncogenes and expressions of metabolic genes associated with glycolysis, directly or indirectly via pH, were therefore investigated. Methods Using multiplex ligation-dependent probe amplification, copy numbers (CN) of 78 oncogenes were quantified in 24 glioblastomas. Related expressions of metabolic genes encoding lactate dehydrogenases (LDHA, LDHC), carbonic anhydrases (CA3, CA12), monocarboxylate transporters (SLC16A3 or MCT4, SLC16A4 or MCT5), ATP citrate lyase (ACLY), glycogen synthase1 (GYS1), hypoxia inducible factor-1A (HIF1A), and enolase1 (ENO1) were determined in 22 by RT-qPCR. To obtain supra-glycolytic levels and adjust for heterogeneity, concurrent ENO1 expression was used to mathematically transform the expression levels of metabolic genes already normalized with delta-delta crossing threshold methodology. Results Positive correlations with EGFR occurred for all metabolic genes. Significant differences (Wilcoxon Rank Sum) for oncogene CN gains in tumors of at least 2.00-fold versus less than 2.00-fold occurred for EGFR with CA3's expression (p < 0.03) and for RNF139 with CA12 (p < 0.004). Increased CN of XIAP associated negatively. Tumors with less than 2.00-fold CN gains differed from those with gains for XIAP with CA12 (p < 0.05). Male gender associated with CA12 (p < 0.05). Conclusions Glioblastomas with CN increases in EGFR had elevated CA3 expression. Similarly, tumors with RNF149 CN gains had elevated CA12 expression. General significance In larger studies, subgroups of glioblastomas may emerge according to oncogene-related effects on glycolysis, such as control of pH via effects on carbonic anhydrases, with prognostic and treatment implications. PMID:27051584

  14. Expression of human factor IX in rabbit hepatocytes by retrovirus-mediated gene transfer: Potential for gene therapy of hemophilia B

    SciTech Connect

    Thompson, A.R. Puget Sound Blood Center, Seattle, WA ); Darlington, G. ); Armentano, D.; Woo, S.L.C.

    1990-08-01

    Hemophilia B (Christmas disease) is a chromosome X-linked blood clotting disorder which results when factor IX is deficient or functionally defective. The enzyme is synthesized in the liver, and the existence of animal models for this genetic disease will permit the development of somatic gene therapy protocols aimed at transfer of the functional gene into the liver. The authors report the construction of an N2-based recombinant retroviral vector, NCMVFIX, for efficient transfer and expression of human factor IX cDNA in primary rabbit hepatocytes. In this construct the human cytomegalovirus immediate early promoter directs the expression of factor IX. Hepatocytes were isolated from 3-week-old New Zealand White rabbits, infected with the recombinant virus, and analyzed for secretion of active factor IX. The infected rabbit hepatocytes produced human factor IX that is indistinguishable from enzyme derived from normal human plasma. The recombinant protein is sufficiently {gamma}-carboxylated and is functionally active in clotting assays. These results establish the feasibility of using infected hepatocytes for the expression of this protein and are a step toward the goal of correcting hemophilia B by hepatic gene transfer.

  15. Progressive renal injury from transgenic expression of human carbonic anhydrase IV folding mutants is enhanced by deficiency of p58IPK.

    PubMed

    Datta, Rupak; Shah, Gul N; Rubbelke, Timothy S; Waheed, Abdul; Rauchman, Michael; Goodman, Alan G; Katze, Michael G; Sly, William S

    2010-04-01

    Mutations in the human carbonic anhydrase IV (hCAIV) have been associated with retinal degeneration in an autosomal-dominant form of retinitis pigmentosa (RP17). Prior in vitro cell culture studies confirmed that all of the RP17-associated hCAIV mutations cause protein misfolding, leading to endoplasmic reticulum (ER) stress-induced apoptosis in cells expressing the mutant proteins. To evaluate the physiological impacts of these folding mutants in other carbonic anhydrase IV-producing tissues, we generated two transgenic mouse lines expressing R219S or R14W hCAIV under control of the endogenous hCAIV promoter. Expression of either of these mutant proteins in kidneys caused progressive renal injury in male transgenic mice as evidenced by an age-dependent increase in the tubule cell apoptosis starting at approximately 20 weeks of age and vacuolization throughout the renal cortex in older mice. Up-regulation of the ER chaperone, BiP, was observed in the cells of the renal cortex of the male transgenic mice, suggesting ER stress as a causal factor for the renal injury. The renal injury inflicted by expression of the folding mutants was markedly enhanced by haploinsufficiency of the ER cochaperone p58(IPK). The transgenic mice expressing the hCAIV folding mutants on a p58(IPK) heterozygous background showed extensive renal tubular apoptosis by approximately 10 weeks of age in both male and female mice. These data indicate that expression of the RP17-associated folding mutants of hCAIV can adversely affect tissues beyond the retina and their in vivo proteotoxicity is sensitive to modulation of the protein folding environment of the ER. PMID:20308551

  16. Progressive renal injury from transgenic expression of human carbonic anhydrase IV folding mutants is enhanced by deficiency of p58IPK

    PubMed Central

    Datta, Rupak; Shah, Gul N.; Rubbelke, Timothy S.; Waheed, Abdul; Rauchman, Michael; Goodman, Alan G.; Katze, Michael G.; Sly, William S.

    2010-01-01

    Mutations in the human carbonic anhydrase IV (hCAIV) have been associated with retinal degeneration in an autosomal-dominant form of retinitis pigmentosa (RP17). Prior in vitro cell culture studies confirmed that all of the RP17-associated hCAIV mutations cause protein misfolding, leading to endoplasmic reticulum (ER) stress–induced apoptosis in cells expressing the mutant proteins. To evaluate the physiological impacts of these folding mutants in other carbonic anhydrase IV–producing tissues, we generated two transgenic mouse lines expressing R219S or R14W hCAIV under control of the endogenous hCAIV promoter. Expression of either of these mutant proteins in kidneys caused progressive renal injury in male transgenic mice as evidenced by an age-dependent increase in the tubule cell apoptosis starting at approximately 20 weeks of age and vacuolization throughout the renal cortex in older mice. Up-regulation of the ER chaperone, BiP, was observed in the cells of the renal cortex of the male transgenic mice, suggesting ER stress as a causal factor for the renal injury. The renal injury inflicted by expression of the folding mutants was markedly enhanced by haploinsufficiency of the ER cochaperone p58IPK. The transgenic mice expressing the hCAIV folding mutants on a p58IPK heterozygous background showed extensive renal tubular apoptosis by approximately 10 weeks of age in both male and female mice. These data indicate that expression of the RP17-associated folding mutants of hCAIV can adversely affect tissues beyond the retina and their in vivo proteotoxicity is sensitive to modulation of the protein folding environment of the ER. PMID:20308551

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

    PubMed

    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. PMID:19694814

  18. A carbonic anhydrase gene is induced in the nodule primordium and its cell-specific expression is controlled by the presence of Rhizobium during development.

    PubMed

    Coba de la Peña, T; Frugier, F; McKhann, H I; Bauer, P; Brown, S; Kondorosi, A; Crespi, M

    1997-03-01

    Under nitrogen starvation, Rhizobium meliloti is able to induce nitrogen-fixing nodules on alfalfa roots. Certain alfalfa cultivars spontaneously develop pseudonodules in the absence of bacteria. A transcript, Msca1, expressed in spontaneous and R. meliloti-induced nodules, that codes for a carbonic anhydrase (CA), an enzyme catalyzing the hydration of CO2 has been identified. This is the first CA gene cloned from a non-photosynthetic tissue in plants. Msca1 was activated initially in all cells of the bacterium-induced nodule primordium and was also induced by cytokinin treatment of alfalfa roots. The presence of CA enzymatic activity in different nodule types was demonstrated. Thus, Msca1 is a new early nodulin gene with a function possibly related to the increased amyloplast deposition of the dividing cortical cells. Msca1 transcripts were subsequently found mainly in a peripheral envelope of cells in developing and mature nodules. This novel pattern of gene expression is controlled by the presence of the bacterium inside the nodule. Sucrose synthase and phosphoenol pyruvate carboxylase (PEPC), other genes of the carbon fixation metabolism, were expressed in the same peripheral cells and even more strongly in the nitrogen-fixing region. Analysis of expression patterns of these genes indicated that early CA function may not be related to carbon fixation through PEPC. CA might be acting in pH regulation and/or CO2/HCO3-transport during nodule initiation. Thus, carbonic anhydrase may play different roles at several stages of nodule development and function. PMID:9107031

  19. Salivary carbonic anhydrase isoenzyme VI

    PubMed Central

    Kivelä, Jyrki; Parkkila, Seppo; Parkkila, Anna-Kaisa; Leinonen, Jukka; Rajaniemi, Hannu

    1999-01-01

    The carbonic anhydrases (CAs) participate in the maintenance of pH homeostasis in various tissues and biological fluids of the human body by catalysing the reversible reaction CO2+ H2O ⇌ HCO3−+ H+ (Davenport & Fisher, 1938; Davenport, 1939; Maren, 1967). Carbonic anhydrase isoenzyme VI (CA VI) is the only secretory isoenzyme of the mammalian CA gene family. It is exclusively expressed in the serous acinar cells of the parotid and submandibular glands, from where it is secreted into the saliva. In this review, we will discuss recent advances in research focused on the physiological role of salivary CA VI in the oral cavity and upper alimentary canal. PMID:10523402

  20. Increased expression of mitochondrial benzodiazepine receptors following low-level light treatment facilitates enhanced protoporphyrin IX production in glioma-derived cells in vitro

    NASA Astrophysics Data System (ADS)

    Bisland, S. K.; Hassanali, N. S.; Johnson, C.; Wilson, B. C.

    2007-02-01

    This study investigates whether low level light treatment (LLLT) can enhance the expression of Peripheral-type mitochondrial benzodiazepine receptors (PBRs) on the glioma-derived tumour cell line, CNS-1, and by doing so promote the synthesis of protoporphyrin IX (PpIX) and increase the photodynamic therapy (PDT)-induced cell kill using 5-aminolevulinic acid (ALA). The endogenous photosensitizer, (PpIX) and related metabolites including coproporphyrin III are known to traffic via the PBRs on the outer mitochondrial membrane on their passage into or out of the mitochondria. Astrocyte-derived cells within the brain express PBRs, while neurons express the central-type of benzodiazepine receptor. CNS-1 cells were exposed to a range of differing low-level light protocols immediately prior to PDT. LLLT involved using broad-spectrum light or monochromatic laser light specific to 635 or 905 nm wavelength. Cells (5μ10 5) were exposed to a range of LLLT doses (0, 1 or 5 J/cm2) using a fixed intensity of 10 mW/cm2 and subsequently harvested for cell viability, immunofluorescence or western blot analysis of PBR expression. The amount of PpIX within the cells was determined using chemical extraction techniques. Results confirm the induction of PBR following LLLT is dependent on the dose and wavelength of light used. Broadspectrum light provided the greatest cell kill following PDT, although LLLT with 635 nm or 905 nm also increased cell kill as compared to PDT alone. All LLLT regimens increased PBR expression compared to controls with corresponding increases in PpIX production. These data suggest that by selectively increasing PBR expression in tumour cells, LLLT may facilitate enhanced cell kill using ALA-PDT without damaging surrounding normal brain.

  1. Molecular cloning and sequence analysis of two carbonic anhydrase in the swimming crab Portunus trituberculatus and its expression in response to salinity and pH stress.

    PubMed

    Pan, Luqing; Hu, Dongxu; Liu, Maoqi; Hu, Yanyan; Liu, Shengnan

    2016-01-15

    Carbonic anhydrase (CA) is involved in ion transport, acid-base balance and pH regulation by catalyzing the interconversion of CO2 and HCO3(-). In this study, full-length cDNA sequences of two CA isoforms were identified from Portunus trituberculatus. One was Portunus trituberculatus cytoplasmic carbonic anydrase (PtCAc) and the other one was Portunus trituberculatus glycosyl-phosphatidylinositol-linked carbonic anhydrase (PtCAg). The sequence of PtCAc was formed by an ORF of 816 bp, encoding a protein of 30.18 kDa. The PtCAg was constituted by an ORF of 927 bp, encoding a protein of 34.09 kDa. The deduced amino acid sequences of the two CA isoforms were compared to other crustacean' CA sequences. Both of them reflected high conservation of the residues and domains essential to the function of the two enzymes. The tissue expression analysis of PtCAc and PtCAg were detected in gill, muscle, hepatopancreas, hemocytes and gonad. PtCAc and PtCAg gene expressions were studied under salinity and pH challenge. The results showed that when salinity decreased (30 to 20 ppt), the mRNA expression of PtCAc increased significantly at 24 and 48 h, and the highest value appeared at 24h. The mRNA expression of PtCAg had the same situation with PtCAc. However, when salinity increased (30 to 35 ppt), only the mRNA expression of PtCAc increased significantly at 48 h. When pH changed, only the mRNA expression of PtCAc increased significantly at 12h, which was under low pH situation. The mRNA expression of PtCAg increased significantly at 12-48 h, and there was no significant difference of the expression between the pH challenged group and the control group in other experimental time. The results provided the base of understanding CA' function and the underlying mechanism in response to environmental changes in crustaceans. PMID:26526129

  2. Carbonic Anhydrase 9 Expression Increases with Vascular Endothelial Growth Factor–Targeted Therapy and Is Predictive of Outcome in Metastatic Clear Cell Renal Cancer

    PubMed Central

    Stewart, Grant D.; O’Mahony, Fiach C.; Laird, Alexander; Rashid, Sukaina; Martin, Sarah A.; Eory, Lel; Lubbock, Alexander L.R.; Nanda, Jyoti; O’Donnell, Marie; Mackay, Alan; Mullen, Peter; McNeill, S. Alan; Riddick, Antony C.P.; Aitchison, Michael; Berney, Daniel; Bex, Axel; Overton, Ian M.; Harrison, David J.; Powles, Thomas

    2014-01-01

    Background There is a lack of biomarkers to predict outcome with targeted therapy in metastatic clear cell renal cancer (mccRCC). This may be because dynamic molecular changes occur with therapy. Objective To explore if dynamic, targeted-therapy-driven molecular changes correlate with mccRCC outcome. Design, setting, and participants Multiple frozen samples from primary tumours were taken from sunitinib-naïve (n = 22) and sunitinib-treated mccRCC patients (n = 23) for protein analysis. A cohort (n = 86) of paired, untreated and sunitinib/pazopanib-treated mccRCC samples was used for validation. Array comparative genomic hybridisation (CGH) analysis and RNA interference (RNAi) was used to support the findings. Intervention Three cycles of sunitinib 50 mg (4 wk on, 2 wk off). Outcome measurements and statistical analysis Reverse phase protein arrays (training set) and immunofluorescence automated quantitative analysis (validation set) assessed protein expression. Results and limitations Differential expression between sunitinib-naïve and treated samples was seen in 30 of 55 proteins (p < 0.05 for each). The proteins B-cell CLL/lymphoma 2 (BCL2), mutL homolog 1 (MLH1), carbonic anhydrase 9 (CA9), and mechanistic target of rapamycin (mTOR) (serine/threonine kinase) had both increased intratumoural variance and significant differential expression with therapy. The validation cohort confirmed increased CA9 expression with therapy. Multivariate analysis showed high CA9 expression after treatment was associated with longer survival (hazard ratio: 0.48; 95% confidence interval, 0.26–0.87; p = 0.02). Array CGH profiles revealed sunitinib was associated with significant CA9 region loss. RNAi CA9 silencing in two cell lines inhibited the antiproliferative effects of sunitinib. Shortcomings of the study include selection of a specific protein for analysis, and the specific time points at which the treated tissue was analysed. Conclusions CA9 levels increase with

  3. Plant Carbonic Anhydrases

    PubMed Central

    Atkins, C. A.; Patterson, B. D.; Graham, D.

    1972-01-01

    On the basis of polyacrylamide gradient gel electrophoresis of leaf extracts from 24 species of higher plants, two main forms of carbonic anhydrase (EC 4.2.1.1) were recognized; the “dicotyledon” type and the “monocotyledon” type. More than one band of enzyme was found on gels from most species, suggesting the possibility of carbonic anhydrase isoenzymes in higher plants. Images PMID:16658144

  4. Regulation of photosynthesis and stomatal and mesophyll conductance under water stress and recovery in olive trees: correlation with gene expression of carbonic anhydrase and aquaporins

    PubMed Central

    Perez-Martin, Alfonso; Michelazzo, Chiara; Torres-Ruiz, Jose M.; Flexas, Jaume; Fernández, José E.; Sebastiani, Luca; Diaz-Espejo, Antonio

    2014-01-01

    The hypothesis that aquaporins and carbonic anhydrase (CA) are involved in the regulation of stomatal (g s) and mesophyll (g m) conductance to CO2 was tested in a short-term water-stress and recovery experiment in 5-year-old olive plants (Olea europaea) growing outdoors. The evolution of leaf gas exchange, chlorophyll fluorescence, and plant water status, and a quantitative analysis of photosynthesis limitations, were followed during water stress and recovery. These variables were correlated with gene expression of the aquaporins OePIP1.1 and OePIP2.1, and stromal CA. At mild stress and at the beginning of the recovery period, stomatal limitations prevailed, while the decline in g m accounted for up to 60% of photosynthesis limitations under severe water stress. However, g m was restored to control values shortly after rewatering, facilitating the recovery of the photosynthetic rate. CA was downregulated during water stress and upregulated after recovery. The use of structural equation modelling allowed us to conclude that both OePIP1.1 and OePIP2.1 expression could explain most of the variations observed for g s and g m. CA expression also had a small but significant effect on g m in olive under water-stress conditions. PMID:24799563

  5. Regulation of photosynthesis and stomatal and mesophyll conductance under water stress and recovery in olive trees: correlation with gene expression of carbonic anhydrase and aquaporins.

    PubMed

    Perez-Martin, Alfonso; Michelazzo, Chiara; Torres-Ruiz, Jose M; Flexas, Jaume; Fernández, José E; Sebastiani, Luca; Diaz-Espejo, Antonio

    2014-07-01

    The hypothesis that aquaporins and carbonic anhydrase (CA) are involved in the regulation of stomatal (g s) and mesophyll (g m) conductance to CO2 was tested in a short-term water-stress and recovery experiment in 5-year-old olive plants (Olea europaea) growing outdoors. The evolution of leaf gas exchange, chlorophyll fluorescence, and plant water status, and a quantitative analysis of photosynthesis limitations, were followed during water stress and recovery. These variables were correlated with gene expression of the aquaporins OePIP1.1 and OePIP2.1, and stromal CA. At mild stress and at the beginning of the recovery period, stomatal limitations prevailed, while the decline in g m accounted for up to 60% of photosynthesis limitations under severe water stress. However, g m was restored to control values shortly after rewatering, facilitating the recovery of the photosynthetic rate. CA was downregulated during water stress and upregulated after recovery. The use of structural equation modelling allowed us to conclude that both OePIP1.1 and OePIP2.1 expression could explain most of the variations observed for g s and g m. CA expression also had a small but significant effect on g m in olive under water-stress conditions. PMID:24799563

  6. Cloning, expression, purification and sulfonamide inhibition profile of the complete domain of the η-carbonic anhydrase from Plasmodium falciparum.

    PubMed

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

    2016-09-01

    We report the cloning, purification and characterization of the full domain of carbonic anhydrase (CA, EC 4.2.1.1) from Plasmodium falciparum, which incorporates 358 amino acid residues (from 181 to 538, in the sequence of this 600 amino acid long protein), called PfCAdom. The enzyme, which belongs to the η-CA class showed the following kinetic parameters: kcat of 3.8×10(5)s(-1) and kcat/Km of 7.2×10(7)M(-1)×s(-1), being 13.3 times more effective as a catalyst compared to the truncated form PfCA. PfCAdom is more effective than the human (h) isoform hCA I, being around 50% less effective compared to hCA II, one of the most catalytically efficient enzymes known so far. Intriguingly, the sulfonamides CA inhibitors generally showed much weaker inhibitory activity against PfCAdom compared to PfCA, prompting us to hypothesize that the 69 amino acid residues insertion present in the active site of this η-CA is crucial for the active site architecture. The best sulfonamide inhibitors for PfCAdom were acetazolamide, methazolamide, metanilamide and sulfanilamide, with KIs in the range of 366-808nM. PMID:27485387

  7. Coral Carbonic Anhydrases: Regulation by Ocean Acidification

    PubMed Central

    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

  8. Coral Carbonic Anhydrases: Regulation by Ocean Acidification.

    PubMed

    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

  9. Expression and regulation of carbonic anhydrases in the marine diatom Thalassiosira pseudonana and in natural phytoplankton assemblages from Great Bay, New Jersey.

    PubMed

    McGinn, Patrick J; Morel, François M M

    2008-05-01

    BLAST searches of expressed sequence tag libraries have revealed putative homologs of the archetypal diatom delta-carbonic anhydrase (CA) TWCA1 (for Thalassiosira weissflogii CA) in a broad range of eukaryotic phytoplankton including haptophytes, prasinophytes and dinoflagellates. Four putative homologs of TWCA1 are also reported and described from a search of the genomic sequence of Thalassiosira pseudonana and designated TWCA(Tp1-4). The delta-CA class is therefore more widely distributed in marine phytoplankton than previously thought. In particular, it is not restricted to the diatoms like the cadmium-containing enzyme, CDCA, seems to be (zeta-CA class). Zinc status strongly influences growth rate in marine diatoms. We observed a decrease in the specific growth rate of T. pseudonana from 2.1 to 1.3 day(-1) when the unchelated Zn concentration (Zn') was lowered from 20 to 5 pM. In the same cultures, we detected a drop in whole-cell CA activity of about 50% in the most Zn-limited cells that occurred simultaneously with a large downregulation of TWCA(Tp1), TWCA(Tp2) and CDCA(Tp) gene transcripts and protein. These three genes were also found to be strongly upregulated by low pCO(2) in a manner typical of many algal CA enzymes. We have also conducted field experiments in diatom-dominated natural phytoplankton assemblages sampled from Great Bay of the coast of New Jersey. We observed increased total CA activity in parallel with increased expression of homologous twca and cdca gene transcripts in water incubated at increasingly higher pH values. Immunoblot and transcript expression analyses demonstrated a clear upregulation of CDCA transcript and protein as incubation pH increased both in the lab and in the field indicating that this CA is expressed under a broad range of environmental conditions and not restricted to low pCO(2) and low Zn. PMID:18405334

  10. Unexpected expression of carbonic anhydrase I and selenium-binding protein as the only major non-heme proteins in erythrocytes of the subterranean mole rat (Spalax ehrenbergi).

    PubMed

    Yang, H; Nevo, E; Tashian, R E

    1998-07-01

    Chromatographic separation of the non-heme proteins from the erythrocytes of the subterranean mole rat belonging to the superspecies Spalax ehrenbergi from Israel revealed two major peaks. On sequence analyses, the larger peak corresponded to a 56 kDa selenium-binding protein (SeBP) previously characterized from mouse and human liver, and the second peak to the low-activity carbonic anhydrase (CA) isozyme, CA I. There was no evidence of the high-activity CA II isozyme normally found in the red cells of all amniotes tested to date. Thus, the mole rat appears to be the first mammalian species to express both a SeBP and the low-activity CA I isozyme, as the major non-heme proteins in its red blood cells. It is possible that the absence of the high-activity CA II isozyme may be advantageous to the mole rat in adapting to the low O2 and high CO2 environment of its underground burrows. It is also likely that the 56 kDa SeBP may play an important adaptive role in the physiology of the red cell. PMID:9688568

  11. Effect of CO{sub 2} concentration on carbonic anhydrase and ribulose-1,5-bisphosphate carboxylase/oxygenase expression in pea

    SciTech Connect

    Majeau, N.; Coleman, J.R.

    1996-10-01

    The effect of external CO{sub 2} concentration on the expression of carbonic anhydrase (CA) and ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) was examined in pea (Pisum sativum cv Little Marvel) leaves. Enzyme activities and their transcript levels were reduced in plants grown at 1000 {mu}L/L CO{sub 2} compared with plants grown in ambient air. Growth at 160 {mu}L/L CO{sub 2} also appeared to reduce steady-state transcript levels for the rbcS, the gene encoding the small subunit of Rubisco, and for ca, the gene encoding CA; however, rbcS transcripts were reduced to a greater extent at this concentration. Rubisco activity was slightly lower in plants grown at 160 {mu}L/L CO{sub 2}, and CA activity was significantly higher than that observed in air-grown plants. Transfer of plants from 1000 {mu}L/L to air levels of CO{sub 2} resulted in a rapid increase in both ca and rbcS transcript abundance in fully expanded leaves, followed by an increase in enzyme activity. Plants transferred from air to high-CO{sub 2} concentrations appeared to modulate transcript abundance and enzyme activity less quickly. Foliar carbohydrate levels were also examined in plants grown continuously at high and ambient CO{sub 2}, and following changes in growth conditions that rapidly altered ca and rbcS transcript abundance and enzyme activities. 39 refs., 2 figs., 3 tabs.

  12. Pairwise Comparison of 89Zr- and 124I-labeled cG250 Based on Positron Emission Tomography Imaging and Non-Linear Immunokinetic Modeling: In Vivo Carbonic Anhydrase IX Receptor Binding and Internalization in Mouse Xenografts of Clear Cell Renal Carcinoma

    PubMed Central

    Cheal, Sarah M.; Punzalan, Blesida; Doran, Michael G.; Evans, Michael J.; Osborne, Joseph R.; Lewis, Jason S.; Zanzonico, Pat; Larson, Steven M.

    2014-01-01

    Purpose The positron-emitting tomography (PET) tracer, 124I-cG250, directed against carbonic anhydrase IX (CAIX) shows promise for pre-surgical diagnosis of clear renal cell carcinoma (cRCC) [1, 2]. The radiometal zirconium-89 (89Zr), however, may offer advantages as a surrogate PET nuclide over 124I in terms of greater tumor uptake and retention [3]. In the current report, we have developed a non-linear immunokinetic model to facilitate a quantitative comparison of absolute uptake and antibody turnover between 124I-cG250 and 89Zr- cG250 using a human cRCC xenograft tumor model in mice. We believe that his unique model better relates quantitative imaging data to the salient biologic features of tumor antibody-antigen binding and turnover. Methods We conducted experiments with 89Zr-cG250 and 124I-cG250 using a human ccRCC cell line (SK-RC-38) to characterize the binding affinity and internalization kinetics of the two tracers in vitro. Serial-PET imaging was performed in mice bearing sub-cutaneous cRCC tumors to simultaneously detect and quantify time-dependent tumor uptake in vivo. Using the known specific activities of the two tracers, the equilibrium rates of antibody internalization and turnover in the tumor were derived from the PET images using non-linear compartmental modeling. Results The two tracers demonstrate virtually identical tumor-cell binding and internalization but with markedly different retentions in vitro. Superior PET images were obtained using 89Zr-cG250, owing to the more prolonged trapping of the radiolabel in the tumor and simultaneous wash-out from normal tissues. Estimates of cG250-CAIX complex turnover were 1.35–5.51 × 1012 molecules per hour per gram of tumor (20% of receptors internalized per hour), and the ratio of 124I/89Zr atoms released per unit time by tumor was 17.5. Conclusions Pairwise evaluation of 89Zr-cG250 and 124I-cG250 provided the basis for a non-linear immunokinetic model which yielded quantitative information about

  13. A two-component system regulates gene expression of the type IX secretion component proteins via an ECF sigma factor

    PubMed Central

    Kadowaki, Tomoko; Yukitake, Hideharu; Naito, Mariko; Sato, Keiko; Kikuchi, Yuichiro; Kondo, Yoshio; Shoji, Mikio; Nakayama, Koji

    2016-01-01

    The periodontopathogen Porphyromonas gingivalis secretes potent pathogenic proteases, gingipains, via the type IX secretion system (T9SS). This system comprises at least 11 components; however, the regulatory mechanism of their expression has not yet been elucidated. Here, we found that the PorY (PGN_2001)-PorX (PGN_1019)-SigP (PGN_0274) cascade is involved in the regulation of T9SS. Surface plasmon resonance (SPR) analysis revealed a direct interaction between a recombinant PorY (rPorY) and a recombinant PorX (rPorX). rPorY autophosphorylated and transferred a phosphoryl group to rPorX in the presence of Mn2+. These results demonstrate that PorX and PorY act as a response regulator and a histidine kinase, respectively, of a two component system (TCS), although they are separately encoded on the chromosome. T9SS component-encoding genes were down-regulated in a mutant deficient in a putative extracytoplasmic function (ECF) sigma factor, PGN_0274 (SigP), similar to the porX mutant. Electrophoretic gel shift assays showed that rSigP bound to the putative promoter regions of T9SS component-encoding genes. The SigP protein was lacking in the porX mutant. Co-immunoprecipitation and SPR analysis revealed the direct interaction between SigP and PorX. Together, these results indicate that the PorXY TCS regulates T9SS-mediated protein secretion via the SigP ECF sigma factor. PMID:26996145

  14. A two-component system regulates gene expression of the type IX secretion component proteins via an ECF sigma factor.

    PubMed

    Kadowaki, Tomoko; Yukitake, Hideharu; Naito, Mariko; Sato, Keiko; Kikuchi, Yuichiro; Kondo, Yoshio; Shoji, Mikio; Nakayama, Koji

    2016-01-01

    The periodontopathogen Porphyromonas gingivalis secretes potent pathogenic proteases, gingipains, via the type IX secretion system (T9SS). This system comprises at least 11 components; however, the regulatory mechanism of their expression has not yet been elucidated. Here, we found that the PorY (PGN_2001)-PorX (PGN_1019)-SigP (PGN_0274) cascade is involved in the regulation of T9SS. Surface plasmon resonance (SPR) analysis revealed a direct interaction between a recombinant PorY (rPorY) and a recombinant PorX (rPorX). rPorY autophosphorylated and transferred a phosphoryl group to rPorX in the presence of Mn(2+). These results demonstrate that PorX and PorY act as a response regulator and a histidine kinase, respectively, of a two component system (TCS), although they are separately encoded on the chromosome. T9SS component-encoding genes were down-regulated in a mutant deficient in a putative extracytoplasmic function (ECF) sigma factor, PGN_0274 (SigP), similar to the porX mutant. Electrophoretic gel shift assays showed that rSigP bound to the putative promoter regions of T9SS component-encoding genes. The SigP protein was lacking in the porX mutant. Co-immunoprecipitation and SPR analysis revealed the direct interaction between SigP and PorX. Together, these results indicate that the PorXY TCS regulates T9SS-mediated protein secretion via the SigP ECF sigma factor. PMID:26996145

  15. The Flaveria bidentis β-Carbonic Anhydrase Gene Family Encodes Cytosolic and Chloroplastic Isoforms Demonstrating Distinct Organ-Specific Expression Patterns1[OA

    PubMed Central

    Tetu, Sasha G.; Tanz, Sandra K.; Vella, Nicole; Burnell, James N.; Ludwig, Martha

    2007-01-01

    Carbonic anhydrase (CA) catalyzes the interconversion of CO2 and bicarbonate, the forms of inorganic carbon used by the primary carboxylating enzymes of C3 and C4 plants, respectively. Multiple forms of CA are found in both photosynthetic subtypes; however, the number of isoforms and the location and function of each have not been elucidated for any single plant species. Genomic Southern analyses showed that the C4 dicotyledon Flaveria bidentis ‘Kuntze’ contains a small gene family encoding β-CA and cDNAs encoding three distinct β-CAs, named CA1, CA2, and CA3, were isolated. Quantitative reverse transcription-polymerase chain reactions showed that each member of this β-CA family has a specific expression pattern in F. bidentis leaves, roots, and flowers. CA3 transcripts were at least 50 times more abundant than CA2 or CA1 transcripts in leaves. CA2 transcripts were detected in all organs examined and were the most abundant CA transcripts in roots. CA1 mRNA levels were similar to those of CA2 in leaves, but were considerably lower in roots and flowers. In vitro import assays showed CA1 was imported into isolated pea (Pisum sativum) chloroplasts, whereas CA2 and CA3 were not. These results support the following roles for F. bidentis CAs: CA3 is responsible for catalyzing the first step in the C4 pathway in the mesophyll cell cytosol; CA2 provides bicarbonate for anapleurotic reactions involving nonphotosynthetic forms of phosphoenolpyruvate carboxylase in the cytosol of cells in both photosynthetic and nongreen tissues; and CA1 carries out nonphotosynthetic functions demonstrated by C3 chloroplastic β-CAs, including lipid biosynthesis and antioxidant activity. PMID:17496111

  16. Production of transgenic goats expressing human coagulation factor IX in the mammary glands after nuclear transfer using transfected fetal fibroblast cells.

    PubMed

    Amiri Yekta, Amir; Dalman, Azam; Eftekhari-Yazdi, Poopak; Sanati, Mohammad Hossein; Shahverdi, Abdol Hossein; Fakheri, Rahman; Vazirinasab, Hamed; Daneshzadeh, Mohammad Taghi; Vojgani, Mahdi; Zomorodipour, Alireza; Fatemi, Nayeralsadat; Vahabi, Zeinab; Mirshahvaladi, Shahab; Ataei, Fariba; Bahraminejad, Elmira; Masoudi, Najmehsadat; Rezazadeh Valojerdi, Mojtaba; Gourabi, Hamid

    2013-02-01

    There are growing numbers of recombinant proteins that have been expressed in milk. Thus one can consider the placement of any gene of interest under the control of the regulatory elements of a milk protein gene in a dairy farm animal. Among the transgene introducing techniques, only nuclear transfer (NT) allows 100 % efficiency and bypasses the mosaicism associated with counterpart techniques. In this study, in an attempt to produce a transgenic goat carrying the human coagulation factor IX (hFIX) transgene, goat fetal fibroblasts were electroporated with a linearized marker-free construct in which the transgene was juxtaposed to β-casein promoter designed to secret the recombinant protein in goat milk. Two different lines of transfected cells were used as donors for NT to enucleated oocytes. Two transgenic goats were liveborn. DNA sequencing of the corresponding transgene locus confirmed authenticity of the cloning procedure and the complementary experiments on the whey demonstrated expression of human factor IX in the milk of transgenic goats. In conclusion, our study has provided the groundwork for a prosperous and promising approach for large-scale production and therapeutic application of hFIX expressed in transgenic goats. PMID:22869287

  17. In Vitro Evaluation of ESE-15-ol, an Estradiol Analogue with Nanomolar Antimitotic and Carbonic Anhydrase Inhibitory Activity

    PubMed Central

    Stander, Barend Andre; Joubert, Fourie; Tu, Chingkuang; Sippel, Katherine H.; McKenna, Robert; Joubert, Annie Margaretha

    2012-01-01

    Antimitotic compounds are still one of the most widely used chemotherapeutic anticancer drugs in the clinic today. Given their effectiveness against cancer it is beneficial to continue enhancing these drugs. One way is to improve the bioavailability and efficacy by synthesizing derivatives that reversibly bind to carbonic anhydrase II (CAII) in red blood cells followed by a slow release into the blood circulation system. In the present study we describe the in vitro biological activity of a reduced derivative of 2-ethyl-3-O-sulphamoyl-estradiol (2EE), 2-ethyl-3-O-sulphamoyl-estra-1,3,5(10),15-tetraen-17-ol (ESE-15-ol). ESE-15-ol is capable of inhibiting carbonic anhydrase activity in the nanomolar range and is selective towards a mimic of carbonic anhydrase IX when compared to the CAII isoform. Docking studies using Autodock Vina suggest that the dehydration of the D-ring plays a role towards the selectivity of ESE-15-ol to CAIX and that the binding mode of ESE-15-ol is substantially different when compared to 2EE. ESE-15-ol is able to reduce cell growth to 50% after 48 h at 50–75 nM in MCF-7, MDA-MB-231, and MCF-12A cells. The compound is the least potent against the non-tumorigenic MCF-12A cells. In vitro mechanistic studies demonstrate that the newly synthesized compound induces mitochondrial membrane depolarization, abrogates the phosphorylation status of Bcl-2 and affects gene expression of genes associated with cell death and mitosis. PMID:23300615

  18. Fluorescent Silica Nanoparticles with Multivalent Inhibitory Effects towards Carbonic Anhydrases.

    PubMed

    Touisni, Nadia; Kanfar, Nasreddine; Ulrich, Sébastien; Dumy, Pascal; Supuran, Claudiu T; Mehdi, Ahmad; Winum, Jean-Yves

    2015-07-13

    Multifunctional silica nanoparticles decorated with fluorescent and sulfonamide carbonic anhydrase (CA) inhibitors were prepared and investigated as multivalent enzyme inhibitors against the cytosolic isoforms hCA I and II and the transmembrane tumor-associated ones hCA IX and XII. Excellent inhibitory effects were observed with these nanoparticles, with KI values in the low nanomolar range (6.2-0.67 nM) against all tested isozymes. A significant multivalency effect was seen for the inhibition of the monomeric enzymes hCA I and II compared to the dimeric hCA IX and hCA XII isoforms, where no multivalent effect was observed, suggesting that the multivalent binding is occurring through enzyme clustering. PMID:25965260

  19. Title IX Resource Guide

    ERIC Educational Resources Information Center

    Office for Civil Rights, US Department of Education, 2015

    2015-01-01

    Title IX of the Education Amendments of 1972 (Title IX) prohibits discrimination based on sex in education programs and activities in federally funded schools at all levels. If any part of a school district or college receives any Federal funds for any purpose, all of the operations of the district or college are covered by Title IX. The essence…

  20. Homology modeling and QSAR analysis of 1,3,4-thiadiazole and 1,3,4-triazole derivatives as carbonic anhydrase inhibitors.

    PubMed

    Akula, N V Murali Krishna; Kumar, Surendra; Singh, Vineet; Tiwari, Meena

    2010-08-01

    Carbonic anhydrase (CA) inhibitors are very interesting target for designing anticancer (hypoxic) and antiglaucoma drugs. In the present study, a 3D homology modeling of human carbonic anhydrase-IX (hCA-IX) isozyme, based upon the crystal structure of murine CA-XIVA (PDB CODE 1RJ5) was performed, as no experimental 3D structures are available. A homology model of hCA-IX was developed and validated. To explore the responsible physicochemical properties of 1,3,4-thiadiazole and 1,3,4-triazole derivatives for carbonic anhydrase inhibition, a quantitative structure activity relationship (QSAR) study was performed having hCA-II and hCA-IX inhibitory activity respectively. In hCA-II and hCA-IX inhibitory activities, four significant models with good correlations (> or = 0.945 & > or = 0.926) were obtained; two models (models 1 and 3) were selected based on statistical criterion. The QSAR study revealed that in case of hCA-II, overall increase in size and volume of molecule, introduction of electropositive surfaces might increase the inhibitory activity, whereas in case of hCA-IX, decreasing the hydrophobicity and introduction of electron releasing substituents might increase the hCA-IX inhibitory activity. PMID:21174951

  1. Carbonic anhydrases inhibitory effects of new benzenesulfonamides synthesized by using superacid chemistry.

    PubMed

    Liu, Fei; Martin-Mingot, Agnès; Lecornué, F; Jouannetaud, Marie-Paule; Maresca, Alfonso; Thibaudeau, Sebastien; Supuran, Claudiu T

    2012-12-01

    A series of benzofused sultams and fluorinated benzenesulfonamides were synthesized in superacid HF/SbF(5) from simple N-allylic derivatives. Almost all of these original compounds showed micromolar inhibitory activities against carbonic anhydrases I and II. The fluorinated derivatives inhibit better the tumor-associated isoforms IX and XII, and one of the tested compounds showed inhibition in the nanomolar range. PMID:22168802

  2. Overexpression of Intrinsic Hypoxia Markers HIF1{alpha} and CA-IX Predict for Local Recurrence in Stage T1-T2 Glottic Laryngeal Carcinoma Treated With Radiotherapy

    SciTech Connect

    Schrijvers, M.L.; Laan, B.F.A.M. van der; Bock, G.H. de; Pattje, W.J.; Mastik, M.F.; Menkema, L.; Langendijk, J.A.; Kluin, P.M.; Schuuring, E.; Wal, J.E. van der

    2008-09-01

    Purpose: To examine the prognostic value of three endogenous hypoxia markers (hypoxia inducible factor 1 {alpha} subunit [HIF1{alpha}], carbonic anhydrase IX [CA-IX], and glucose transporter type 1 [GLUT-1]) on the clinical outcome in patients with early-stage glottic carcinoma primarily treated with radiotherapy (RT) and to determine the predictive hypoxic profile to choose the optimal treatment of early-stage laryngeal carcinoma. Methods and Materials: Immunohistochemistry for HIF1{alpha}, CA-IX, and GLUT-1 was performed on formalin-fixed, paraffin-embedded, pretreatment tissue samples of 91 glottic squamous cell carcinoma specimens. The patient group consisted only of those with early-stage (T1-T2) glottic carcinoma, and all patients were treated with RT only. Relative tumor staining was scored on the tissue samples. Receiver operating curve analysis was performed to determine the optimal cutoff value for each tumor marker. Cox regression analyses for the variables HIF1{alpha}, CA-IX, GLUT-1, gender, age, hemoglobin level, T category, N category, tobacco use, and alcohol use were performed with local control and overall survival as endpoints. Results: HIF1{alpha} overexpression in early-stage glottic carcinoma correlated significantly with worse local control (hazard ratio [HR], 3.05; p = 0.021) and overall survival (HR, 2.92; p = 0.016). CA-IX overexpression correlated significantly with worse local control (HR, 2.93; p = 0.020). GLUT-1 overexpression did not show any correlation with the clinical outcome parameters. Tumors with a nonhypoxic profile (defined as low HIF1{alpha} and low CA-IX expression) had significantly better local control (HR, 6.32; p 0.013). Conclusion: The results of our study have shown that early-stage glottic laryngeal carcinomas with low HIF1{alpha} and CA-IX expression are highly curable with RT. For this group, RT is a good treatment option. For tumors with HIF1{alpha} or CA-IX overexpression, hypoxic modification before RT or primary

  3. N-Nitrosulfonamides: A new chemotype for carbonic anhydrase inhibition.

    PubMed

    Nocentini, Alessio; Vullo, Daniela; Bartolucci, Gianluca; Supuran, Claudiu T

    2016-08-15

    A series of N(1)-substituted aromatic sulfonamides was obtained by applying a selective sulfonamide nitration synthetic strategy leading to Ar-SO2NHNO2 derivatives which were investigated as carbonic anhydrase (CA, EC 4.2.1.1) inhibitors. Two human (h) hCA isoforms, the cytosolic hCA II and the transmembrane hCA IX, in addition to the fungal enzyme from Malassezia globosa, MgCA, were included in the study. Most of the new compounds reported selectively inhibited hCA IX over hCA II and at the same time showed effective MgCA inhibitory properties, with KIs ranging between 0.22 and 8.09μM. The N-nitro sulfonamides are a new chemotype with CA inhibitory effects. As hCA IX was recently validated as antitumor/antimetastatic drug target, its selective inhibition could be exploited for interesting biomedical applications. Moreover, due to the effective MgCAs inhibitory properties of the N-nitro sulfonamides, of considerable interest in the cosmetics field as potential anti-dandruff agents, the N-nitro sulfonamides may be considered as interesting leads for the design of more efficient compounds targeting fungal enzymes. PMID:27290692

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

    PubMed

    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. PMID:26226178

  5. Association of Reduced Type IX Collagen Gene Expression in Human Osteoarthritic Chondrocytes With Epigenetic Silencing by DNA Hypermethylation

    PubMed Central

    Imagawa, Kei; de Andrés, María C; Hashimoto, Ko; Itoi, Eiji; Otero, Miguel; Roach, Helmtrud I; Goldring, Mary B; Oreffo, Richard O C

    2014-01-01

    Objective To investigate whether the changes in collagen gene expression in osteoarthritic (OA) human chondrocytes are associated with changes in the DNA methylation status in the COL2A1 enhancer and COL9A1 promoter. Methods Expression levels were determined using quantitative reverse transcription–polymerase chain reaction, and the percentage of DNA methylation was quantified by pyrosequencing. The effect of CpG methylation on COL9A1 promoter activity was determined using a CpG-free vector; cotransfections with expression vectors encoding SOX9, hypoxia-inducible factor 1α (HIF-1α), and HIF-2α were carried out to analyze COL9A1 promoter activities in response to changes in the methylation status. Chromatin immunoprecipitation assays were carried out to validate SOX9 binding to the COL9A1 promoter and the influence of DNA methylation. Results Although COL2A1 messenger RNA (mRNA) levels in OA chondrocytes were 19-fold higher than those in the controls, all of the CpG sites in the COL2A1 enhancer were totally demethylated in both samples. The levels of COL9A1 mRNA in OA chondrocytes were 6,000-fold lower than those in controls; 6 CpG sites of the COL9A1 promoter were significantly hypermethylated in OA patients as compared with controls. Treatment with 5-azadeoxycitidine enhanced COL9A1 gene expression and prevented culture-induced hypermethylation. In vitro methylation decreased COL9A1 promoter activity. Mutations in the 5 CpG sites proximal to the transcription start site decreased COL9A1 promoter activity. Cotransfection with SOX9 enhanced COL9A1 promoter activity; CpG methylation attenuated SOX9 binding to the COL9A1 promoter. Conclusion This first demonstration that hypermethylation is associated with down-regulation of COL9A1 expression in OA cartilage highlights the pivotal role of epigenetics in OA, involving not only hypomethylation, but also hypermethylation, with important therapeutic implications for OA treatment. PMID:25048791

  6. Synthesis of sulfonamide conjugates of Cu(II), Ga(III), In(III), Re(V) and Zn(II) complexes: carbonic anhydrase inhibition studies and cellular imaging investigations.

    PubMed

    Dilworth, Jonathan R; Pascu, Sofia I; Waghorn, Philip A; Vullo, Daniela; Bayly, Simon R; Christlieb, Martin; Sun, Xin; Supuran, Claudiu T

    2015-03-21

    Carbonic anhydrase IX (CA IX) is currently generating great interest as a marker of tumour hypoxia and a potential chemotherapeutic target. In order to test the principle that a CA IX inhibitor could be used for targeting PET or SPECT metallic radioisotopes to tumours we have prepared a number of conjugates involving aryl-sulfonamides or an acetazolamide derivative linked to a range of copper, indium, rhenium, 99m-technetium and zinc complexes. Radiolabelled (64)Cu and (99m)Tc analogues of the 'cold' Cu and some of the Re complexes were prepared in good radiochemical incorporation. Inhibition of various human carbonic anhydrase isoforms (I, II, IX and XII) was tested with the 'cold', non-radiolabelled complexes, and compared with an acetazolamide standard (AZA). The molecular structure of a new, tri-sulfonated porphyrin-labeled sulfonamide was determined using synchrotron X-ray crystallography. PMID:25711495

  7. Genetic modification of bone-marrow mesenchymal stem cells and hematopoietic cells with human coagulation factor IX-expressing plasmids.

    PubMed

    Sam, Mohammad Reza; Azadbakhsh, Azadeh Sadat; Farokhi, Farrah; Rezazadeh, Kobra; Sam, Sohrab; Zomorodipour, Alireza; Haddad-Mashadrizeh, Aliakbar; Delirezh, Nowruz; Mokarizadeh, Aram

    2016-05-01

    Ex-vivo gene therapy of hemophilias requires suitable bioreactors for secretion of hFIX into the circulation and stem cells hold great potentials in this regard. Viral vectors are widely manipulated and used to transfer hFIX gene into stem cells. However, little attention has been paid to the manipulation of hFIX transgene itself. Concurrently, the efficacy of such a therapeutic approach depends on determination of which vectors give maximal transgene expression. With this in mind, TF-1 (primary hematopoietic lineage) and rat-bone marrow mesenchymal stem cells (BMSCs) were transfected with five hFIX-expressing plasmids containing different combinations of two human β-globin (hBG) introns inside the hFIX-cDNA and Kozak element and hFIX expression was evaluated by different methods. In BMSCs and TF-1 cells, the highest hFIX level was obtained from the intron-less and hBG intron-I,II containing plasmids respectively. The highest hFIX activity was obtained from the cells that carrying the hBG intron-I,II containing plasmids. BMSCs were able to produce higher hFIX by 1.4 to 4.7-fold increase with activity by 2.4 to 4.4-fold increase compared to TF-1 cells transfected with the same constructs. BMSCs and TF-1 cells could be effectively bioengineered without the use of viral vectors and hFIX minigene containing hBG introns could represent a particular interest in stem cell-based gene therapy of hemophilias. PMID:26928674

  8. Zoledronate inhibits receptor activator of nuclear factor kappa-B ligand-induced osteoclast differentiation via suppression of expression of nuclear factor of activated T-cell c1 and carbonic anhydrase 2.

    PubMed

    Nakagawa, Takayuki; Ohta, Kouji; Kubozono, Kazumi; Ishida, Yoko; Naruse, Takako; Takechi, Masaaki; Kamata, Nobuyuki

    2015-04-01

    Bisphosphonates (BPs) are widely used in the prevention of skeletal-related events (SRE), including osteoporosis, skeletal metastases of malignant tumours, and multiple myeloma. Osteonecrosis of the jaw (ONJ) is frequently reported as a major adverse effect induced by BP treatment. The receptor activator of the nuclear factor kappa-B ligand (RANKL) inhibitor, denosumab, has recently been used to prevent SRE, but the frequency of ONJ induced by denosumab is similar to that by BPs. This finding suggests that the inhibition of RANKL-mediated osteoclastogenesis may have a close relationship with the occurrence of ONJ. We therefore investigated the expression status of RANKL-inducible genes in zoledronate-treated mouse osteoclast precursor cells. The molecular targets of zoledronate in the RANKL signal pathway and additional factors associated with osteoclastogenesis were analysed by genome-wide screening. Microarray analysis identified that among 31 genes on 44 entities of RANKL-inducible genes, the mRNA expression level of two genes, i.e., nuclear factor of activated T-cells c1 (NFATc1) and carbonic anhydrase 2 (CAII), was decreased in zoledronate-treated cells. Subsequent analyses verified that these two genes were significantly silenced by zoledronate treatment and that their expression was restored following inhibition of zoledronate action by geranylgeraniol. Zoledronate inhibited RANKL-induced osteoclast differentiation by suppression of NFATc1 and CAII gene expression. Our results suggest that these genes might be common targets for zoledronate and denosumab in the mechanism underlying RANKL-induced osteoclast differentiation. A clear understanding of the common molecular mechanisms of bone-remodelling agents is thus essential for prevention of ONJ. PMID:25601046

  9. Functions of AAV-CMV-F.IX And AAV-EF1alpha-F.IX in gene therapy for hemophilia B.

    PubMed

    Wiwanitkit, Viroj

    2007-02-01

    There has been substantial progress in using gene therapy to treat animals with hemophilia. Adeno-associated viral (AAV) gene transfer of coagulation factor IX to skeletal muscle and liver of murine and canine models of hemophilia has resulted in sustained systemic expression and, in several studies, in complete cure of the bleeding disorder. Two AAV vectors widely used at present are AAV-CMV-F.IX and AAV-EF1alpha-F.IX. This work compares the predicted molecular functions of AAV-CMV-F.IX and AAV-EF1alpha -F.IX by sequence docking and gene ontology. It is shown that both AAV-CMV-F.IX and AAV-EF1alpha -F.IX induce coagulation factor IXa activity; however, AAV-CMV-F.IX administration also yields coagulation factor XIa activity and AAV-EF1alpha -F.IX treatment results in coagulation factor Xa activity. Therefore, AAV-CMV-F.IX might be useful for factor XI deficiency. AAV-CMV-F.IX has several additional molecular functions and processes compared with AAV-CMV-F.IX. PMID:17266422

  10. Carbonic Anhydrase Inhibition with Benzenesulfonamides and Tetrafluorobenzenesulfonamides Obtained via Click Chemistry

    PubMed Central

    2014-01-01

    A series of novel benzene- and 2,3,5,6-tetrafluorobenzenesulfonamide was synthesized by using a click chemistry approach starting from azido-substituted sulfonamides and alkynes, incorporating aryl, alkyl, cycloalkyl, and amino-/hydroxy-/halogenoalkyl moieties. The new compounds were medium potency inhibitors of the cytosolic carbonic anhydrase (CA, EC 4.2.1.1) isoforms I and II and low nanomolar/subnanomolar inhibitors of the tumor-associated hCA IX and XII isoforms. The X-ray crystal structure of two such sulfonamides in adduct with hCA II allowed us to understand the factors governing inhibitory power. PMID:25147616

  11. Dithiocarbamates: a new class of carbonic anhydrase inhibitors. Crystallographic and kinetic investigations.

    PubMed

    Carta, Fabrizio; Aggarwal, Mayank; Maresca, Alfonso; Scozzafava, Andrea; McKenna, Robert; Supuran, Claudiu T

    2012-02-11

    The zinc enzyme carbonic anhydrase (CA, EC 4.2.1.1) is inhibited by several classes of zinc-binders (sulfonamides, sulfamates, and sulfamides) as well as by compounds which do not interact with the metal ion (phenols, polyamines and coumarins). Here we report a new class of potent CA inhibitors which bind the zinc ion: the dithiocarbamates (DTCs). They coordinate to the zinc ion from the enzyme active site in monodentate manner and establish many favorable interactions with amino acid residues nearby. Several low nanomolar CA I, II and IX inhibitors were detected. PMID:22218610

  12. Title IX Lawsuits.

    ERIC Educational Resources Information Center

    Tungate, David E.; Orie, Daniel P.

    1998-01-01

    Since Brown University lost its four-year court battle over athletic program equality issues, most colleges and secondary schools have learned to settle when sued under Title IX. Virginia Tech, University of Kansas, and Howard University are illustrative cases. Since nearly all high schools and colleges are vulnerable, it is wise to prepare for…

  13. Xanthates and trithiocarbonates strongly inhibit carbonic anhydrases and show antiglaucoma effects in vivo.

    PubMed

    Carta, Fabrizio; Akdemir, Atilla; Scozzafava, Andrea; Masini, Emanuela; Supuran, Claudiu T

    2013-06-13

    Dithiocarbamates (DTCs) were recently discovered as carbonic anhydrase (CA, EC 4.2.1.1) inhibitors. A series of xanthates and a trithiocarbonate, structurally related to the DTCs, were prepared by reaction of alcohols/thiols with carbon disulfide in the presence of bases. These compounds were tested for the inhibition of four human (h) isoforms, hCA I, II, IX, and XII, involved in pathologies such as glaucoma (CA II and XII) or cancer (CA IX). Several low nanomolar xanthate/trithiocarbonate inhibitors targeting these CAs were detected. A docking study of some xanthates within the CA II active site showed that these compounds bind in a similar manner with the dithiocarbamates, coordinating monodentately to the Zn(II) ion from the enzyme active site. Several xanthates showed potent intraocular pressure lowering activity in two animal models of glaucoma via the topical administration. Xanthates and thioxanthates represent two novel, promising classes of CA inhibitors. PMID:23647428

  14. Dithiocarbamates strongly inhibit carbonic anhydrases and show antiglaucoma action in vivo.

    PubMed

    Carta, Fabrizio; Aggarwal, Mayank; Maresca, Alfonso; Scozzafava, Andrea; McKenna, Robert; Masini, Emanuela; Supuran, Claudiu T

    2012-02-23

    A series of dithiocarbamates were prepared by reaction of primary/secondary amines with carbon disulfide in the presence of bases. These compounds were tested for the inhibition of four human (h) isoforms of the zinc enzyme carbonic anhydrase, CA (EC 4.2.1.1), hCA I, II, IX, and XII, involved in pathologies such as glaucoma (CA II and XII) or cancer (CA IX). Several low nanomolar inhibitors targeting these CAs were detected. The X-ray crystal structure of the hCA II adduct with morpholine dithiocarbamate evidenced the inhibition mechanism of these compounds, which coordinate to the metal ion through a sulfur atom from the dithiocarbamate zinc-binding function. Some dithiocarbamates showed an effective intraocular pressure lowering activity in an animal model of glucoma. PMID:22276570

  15. Dithiocarbamates strongly inhibit carbonic anhydrases and show antiglaucoma action in vivo#

    PubMed Central

    Carta, Fabrizio; Aggarwal, Mayank; Maresca, Alfonso; Scozzafava, Andrea; McKenna, Robert; Masini, Emanuela; Supuran, Claudiu T.

    2012-01-01

    A series of dithiocarbamates was prepared by reaction of primary/secondary amines with carbon disulfide in the presence of bases. These compounds were tested for the inhibition of 4 human (h) isoforms of the zinc enzyme carbonic anhydrase, CA (EC 4.2.1.1), hCA I, II, IX and XII, involved in pathologies such as glaucoma (CA II and XII) or cancer (CA IX). Several low nanomolar inhibitors targeting these CAs were detected. X-ray crystal structure of hCA II adduct with morpholine dithiocarbamate evidenced the inhibition mechanism of these compounds, which coordinate to the metal ion through a sulfur atom from the dithiocarbamate zinc-binding function. Some dithiocarbamates showed effective intraocular pressure lowering activity in an animal model of glucoma. PMID:22276570

  16. Structural study of interaction between brinzolamide and dorzolamide inhibition of human carbonic anhydrases.

    PubMed

    Pinard, Melissa A; Boone, Christopher D; Rife, Brittany D; Supuran, Claudiu T; McKenna, Robert

    2013-11-15

    Carbonic anhydrases (CAs, EC 4.2.1.1) are metalloenzymes that catalyze the reversible hydration of carbon dioxide and bicarbonate. Their pivotal role in metabolism, ubiquitous nature, and multiple isoforms (CA I-XIV) has made CAs an attractive drug target in clinical applications. The usefulness of CA inhibitors (CAIs) in the treatment of glaucoma and epilepsy are well documented. In addition several isoforms of CAs (namely, CA IX) also serve as biological markers for certain tumors, and therefore they have the potential for useful applications in the treatment of cancer. This is a structural study on the binding interactions of the widely used CA inhibitory drugs brinzolamide (marketed as Azopt®) and dorzolamide (marketed as Trusopt®) with CA II and a CA IX-mimic, which was created via site-directed mutagenesis of CA II cDNA such that the active site resembles that of CA IX. Also the inhibition of CA II and CA IX and molecular docking reveal brinzolamide to be a more potent inhibitor among the other catalytically active CA isoforms compared to dorzolamide. The structures show that the tail end of the sulfonamide inhibitor is critical in forming stabilizing interactions that influence tight binding; therefore, for future drug design it is the tail moiety that will ultimately determine isoform specificity. PMID:24090602

  17. Carbonic anhydrases as targets for medicinal chemistry.

    PubMed

    Supuran, Claudiu T; Scozzafava, Andrea

    2007-07-01

    Carbonic anhydrases (CAs, EC 4.2.1.1) are zinc enzymes acting as efficient catalysts for the reversible hydration of carbon dioxide to bicarbonate. 16 different alpha-CA isoforms were isolated in mammals, where they play crucial physiological roles. Some of them are cytosolic (CA I, CA II, CA III, CA VII, CA XIII), others are membrane-bound (CA IV, CA IX, CA XII, CA XIV and CA XV), CA VA and CA VB are mitochondrial, and CA VI is secreted in saliva and milk. Three acatalytic forms are also known, the CA related proteins (CARP), CARP VIII, CARP X and CARP XI. Representatives of the beta-delta-CA family are highly abundant in plants, diatoms, eubacteria and archaea. The catalytic mechanism of the alpha-CAs is understood in detail: the active site consists of a Zn(II) ion co-ordinated by three histidine residues and a water molecule/hydroxide ion. The latter is the active species, acting as a potent nucleophile. For beta- and gamma-CAs, the zinc hydroxide mechanism is valid too, although at least some beta-class enzymes do not have water directly coordinated to the metal ion. CAs are inhibited primarily by two classes of compounds: the metal complexing anions and the sulfonamides/sulfamates/sulfamides possessing the general formula RXSO(2)NH(2) (R=aryl; hetaryl; perhaloalkyl; X=nothing, O or NH). Several important physiological and physio-pathological functions are played by CAs present in organisms all over the phylogenetic tree, related to respiration and transport of CO(2)/bicarbonate between metabolizing tissues and the lungs, pH and CO(2) homeostasis, electrolyte secretion in a variety of tissues/organs, biosynthetic reactions, such as the gluconeogenesis and ureagenesis among others (in animals), CO(2) fixation (in plants and algae), etc. The presence of these ubiquitous enzymes in so many tissues and in so different isoforms represents an attractive goal for the design of inhibitors with biomedical applications. Indeed, CA inhibitors are clinically used as

  18. [Targeting of type IV carbonic anhydrases in Capan-1 human pancreatic duct cells is concomitant of the polarization].

    PubMed

    Mairal, A; Fanjul, M; Hollande, E

    1996-01-01

    Carbonic anhydrases II and IV play an essential role in the synthesis and secretion of HCO3- ions in pancreatic duct cells. Secretion of these ions is regulated by the CFTR (cystic fibrosis transmembrane conductance regulator) chloride channel. In the present study, the expression of carbonic anhydrases IV and their targeting to plasma membranes were examined during the growth of human pancreatic duct cells in vitro. Human cancerous pancreatic duct cells of Capan-1 cell line which polarize during their growth were used. We show that: a) these cells express carbonic anhydrases IV continuously during growth in culture, and the expression depends on the stage of growth and the conformation of the cells; b) carbonic anhydrases IV are seen in the cytoplasm in non-polarized cells, but become progressively anchored to plasma membranes as the cells polarize, being targeted to the apical membranes of polarized cells; c) the subcellular distribution of carbonic anhydrases IV indicates that these enzymes are synthetized in rough endoplasmic reticulum and then transported towards the plasma membrane using the classical secretory pathway through the Golgi apparatus. The results indicated that targeting of carbonic anhydrases IV in Capan-1 cells is linked to cellular polarization. PMID:8881572

  19. Title IX: Boom or Bust?

    ERIC Educational Resources Information Center

    Mather, Marilyn J.

    2003-01-01

    Athletics has been significantly impacted by Title IX through an increase the number of female athletes, the number of teams available, and indirectly, the development of women's professional leagues. However, women in leadership positions in athletics have declined significantly since Title IX was signed into law. A concern about the…

  20. Highly stable beta-class carbonic anhydrases useful in carbon capture systems

    DOEpatents

    Alvizo, Oscar; Benoit, Mike; Novick, Scott

    2013-04-16

    The present disclosure relates to .beta.-class carbonic anhydrase polypeptides having improved properties including increased thermostability and/or stability in the presence of amine compounds, ammonia, or carbonate ion. The present disclosure also provides formulations and uses of the polypeptides for accelerating the absorption of carbon dioxide from a gas stream into a solution as well as for the release of the absorbed carbon dioxide for further treatment and/or sequestering. Also provided are polynucleotides encoding the carbonic anhydrase polypeptides and host cells capable of expressing them.

  1. Highly stable beta-class carbonic anhydrases useful in carbon capture systems

    SciTech Connect

    Alvizo, Oscar; Benoit, Michael R; Novick, Scott J

    2013-08-20

    The present disclosure relates to .beta.-class carbonic anhydrase polypeptides having improved properties including increased thermostability and/or stability in the presence of amine compounds, ammonia, or carbonate ion. The present disclosure also provides formulations and uses of the polypeptides for accelerating the absorption of carbon dioxide from a gas stream into a solution as well as for the release of the absorbed carbon dioxide for further treatment and/or sequestering. Also provided are polynucleotides encoding the carbonic anhydrase polypeptides and host cells capable of expressing them.

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

    NASA Astrophysics Data System (ADS)

    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

  3. Increased oxidation-related glutathionylation and carbonic anhydrase activity in endometriosis.

    PubMed

    Andrisani, Alessandra; Donà, Gabriella; Brunati, Anna Maria; Clari, Giulio; Armanini, Decio; Ragazzi, Eugenio; Ambrosini, Guido; Bordin, Luciana

    2014-06-01

    permeability and adhesion molecule expression, thus contributing to ongoing inflammation. Due to their main cellular functions--delivery of O2 from lung to tissue and removal of CO2 from tissue to lung--red blood cells (RBC) are exposed to oxidative stress. Carbon dioxide in tissue capillaries diffuses into red cells, where it is rapidly hydrated by the action of cytosolic carbonic anhydrase. Analysis of the oxidation status of endometriotic RBC membranes showed a high content of glutathionylated proteins, indicating pre-existing oxidation-related alterations. The increase in glutathionylated proteins was correlated to increased carbonic anhydrase activity in endometriotic RBC compared with healthy controls. Carbonic anhydrase is a family of metalloenzymes involved in many physiological processes such as acid-base homeostasis, respiration, carbon dioxide and ion transport, and bone resorption, and in the regulation of ureagenesis, gluconeogenesis, lipogenesis and tumourigenesis. Due to the potential implication of carbonic anhydrase activation in many pathologies, such as glaucoma, hypertension, obesity and infections, carbonic anhydrase activity should be closely monitored in endometriosis to prevent possible complications and/or worsening of related conditions. PMID:24746440

  4. Human MN/CA9 gene, a novel member of the carbonic anhydrase family: Structure and exon to protein domain relationships

    SciTech Connect

    Opavsky, R.; Pastorekova, S.; Zelnik, V.

    1996-05-01

    We have isolated, sequenced, and characterized a human MN/CA9 gene. This gene is a novel member of the carbonic anhydrase (CA) family, which codes for widely distributed catalysts of the reversible conversion of carbon dioxide to carbonic acid. So far, MN/CA IX is the only tumor-associated CA isoenzyme. The entire genomic sequence of MN/CA9, including the 5{prime}-flanking region, encompasses 10.9 kb. The coding sequence is divided into 11 exons, whose organization and relationships to predicted protein domains suggest that the gene arose by exon shuffling. Exon 1 encodes a signal peptide and a proteoglycan-related region. Exons 2-8 code for a CA domain with a highly conserved active site. The exon/intron pattern of the CA coding region is similar but not identical to other described animal kingdom {alpha}-CA genes. Exons 10 and 11 encode a transmembrane anchor and an intracytoplasmic tail, respectively. We have also determined the transcription initiation and termination sites by RNase protection assay and analyzed the 3.5-kb region upstream of the MN/CA9 gene. Sequence of the proximate 5{prime} end of the flanking regions shows extensive homology to the long terminal repeats of HERV-K endogenous retroviruses. The putative MN/CA9 promoter immediately preceding the transcription start site does not possess a TATA box, but contains consensus sequences for the AP1, AP2, p53, and Inr transcription start site does not possess a TATA box, but contains consensus sequences for the AP1, AP2, p53, and Inr transcription factors. This study will allow further investigations of the molecular events regulating expression of MN/CA IX as well as elucidation of its biological function. 36 refs., 6 figs., 1 tab.

  5. Structure-based drug discovery of carbonic anhydrase inhibitors.

    PubMed

    Supuran, Claudiu T

    2012-12-01

    Inhibition of the metalloenzyme carbonic anhydrase (CA; EC 4.2.1.1) has pharmacologic applications in the field of anti-glaucoma, anti-convulsant and anti-cancer agents. But recently, it has also emerged that these enzymes have the potential for designing anti-infective drugs (anti-fungal and anti-bacterial agents) with a novel mechanism of action. Sulphonamides and their isosteres (sulphamates/sulphamides) constitute the main class of CA inhibitors (CAIs), which bind to the metal ion from the enzyme active site. Recently, the dithiocarbamates (DTCs), possessing a similar mechanism of action, were reported as a new class of inhibitors. These types of CAIs will be discussed in detail in this review. Novel drug design strategies have been reported ultimately based on the tail approach for obtaining sulphonamides/DTCs, 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. Most of the promising data have been obtained by combining x-ray crystallography of enzyme-inhibitor adducts with novel synthetic approaches for generating chemical diversity. Whereas sulphonamide - NO donating hybrid drugs were reported as effective anti-glaucoma agents, most of the interesting new inhibitors were designed for inhibiting specifically the tumour-associated isoforms CA IX and XII, validated targets for imaging and treatment of hypoxic tumours. Promising compounds that inhibit CAs from bacterial and fungal pathogens, of the DTC and carboxylate types, will be also reviewed. PMID:22468747

  6. Monothiocarbamates Strongly Inhibit Carbonic Anhydrases in Vitro and Possess Intraocular Pressure Lowering Activity in an Animal Model of Glaucoma.

    PubMed

    Vullo, Daniela; Durante, Mariaconcetta; Di Leva, Francesco Saverio; Cosconati, Sandro; Masini, Emanuela; Scozzafava, Andrea; Novellino, Ettore; Supuran, Claudiu T; Carta, Fabrizio

    2016-06-23

    A series of monothiocarbamates (MTCs) were prepared from primary/secondary amines and COS as potential carbonic anhydrase (CA, EC 4.2.1.1) inhibitors, using the dithiocarbamates, the xanthates, and the trithiocarbonates as lead compounds. The MTCs effectively inhibited the pharmacologically relevant human (h) hCAs isoforms I, II, IX, and XII in vitro and showed KIs spanning between the low and medium nanomolar range. By means of a computational study, the MTC moiety binding mode on the CAs was explained. Furthermore, a selection of MTCs were evaluated in a normotensive glaucoma rabbit model for their intraocular pressure (IOP) lowering effects and showed interesting activity. PMID:27253845

  7. Phytoestrogen Suppresses Efflux of the Diagnostic Marker Protoporphyrin IX in Lung Carcinoma.

    PubMed

    Fujita, Hirofumi; Nagakawa, Keisuke; Kobuchi, Hirotsugu; Ogino, Tetsuya; Kondo, Yoichi; Inoue, Keiji; Shuin, Taro; Utsumi, Toshihiko; Utsumi, Kozo; Sasaki, Junzo; Ohuchi, Hideyo

    2016-04-01

    One promising method to visualize cancer cells is based on the detection of the fluorescent photosensitizer protoporphyrin IX (PpIX) synthesized from 5-aminolevulinic acid (ALA), but this method cannot be used in cancers that exhibit poor PpIX accumulation. PpIX appears to be pumped out of cancer cells by the ABC transporter G2 (ABCG2), which is associated with multidrug resistance. Genistein is a phytoestrogen that appears to competitively inhibit ABCG2 activity. Therefore, we investigated whether genistein can promote PpIX accumulation in human lung carcinoma cells. Here we report that treatment of A549 lung carcinoma cells with genistein or a specific ABCG2 inhibitor promoted ALA-mediated accumulation of PpIX by approximately 2-fold. ABCG2 depletion and overexpression studies further revealed that genistein promoted PpIX accumulation via functional repression of ABCG2. After an extended period of genistein treatment, a significant increase in PpIX accumulation was observed in A549 cells (3.7-fold) and in other cell lines. Systemic preconditioning with genistein in a mouse xenograft model of lung carcinoma resulted in a 1.8-fold increase in accumulated PpIX. Long-term genistein treatment stimulated the expression of genes encoding enzymes involved in PpIX synthesis, such as porphobilinogen deaminase, uroporphyrinogen decarboxylase, and protoporphyrinogen oxidase. Accordingly, the rate of PpIX synthesis was also accelerated by genistein pretreatment. Thus, our results suggest that genistein treatment effectively enhances ALA-induced PpIX accumulation by preventing the ABCG2-mediated efflux of PpIX from lung cancer cells and may represent a promising strategy to improve ALA-based diagnostic approaches in a broader set of malignancies. Cancer Res; 76(7); 1837-46. ©2016 AACR. PMID:26837765

  8. Carbonic anhydrases in industrial applications.

    PubMed

    González, Javier M; Fisher, S Zoë

    2014-01-01

    Carbonic anhydrases (CAs) catalyze a fundamental reaction: the reversible hydration and dehydration of carbon dioxide (CO2) and bicarbonate ([Formula: see text]), respectively. Current methods for CO2 capture and sequestration are harsh, expensive, and require prohibitively large energy inputs, effectively negating the purpose of removing CO2 from the atmosphere. Due to CA's activity on CO2 there is increasing interest in using CAs for industrial applications such as carbon sequestration and biofuel production. A lot of work in the last decade has focused on immobilizing CA onto various supports for incorporation into CO2 scrubbing applications or devices. Although the proof of principle has been validated, current CAs being tested do not withstand the harsh industrial conditions. The advent of large-scale genome sequencing projects has resulted in several emerging efforts seeking out novel CAs from a variety of microorganisms, including bacteria, micro-, and macro-algae. CAs are also being investigated for their use in medical applications, such drug delivery systems and artificial lungs. This review also looks at possible downstream uses of captured and sequestered CO2, from using it to enhance oil recovery to incorporating it into useful and financially viable products. PMID:24146390

  9. Carbonic anhydrase inhibitors drug design.

    PubMed

    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. PMID:24146385

  10. Oxygen Availability for Porphyrin Biosynthesis Enzymes Determines the Production of Protoporphyrin IX (PpIX) during Hypoxia.

    PubMed

    Otsuka, Shimpei; Matsumoto, Kentaro; Nakajima, Motowo; Tanaka, Tohru; Ogura, Shun-Ichiro

    2015-01-01

    5-Aminolevulinic acid (ALA), a precursor of porphyrin, is specifically converted to the fluorescent substance protoporphyrin IX (PpIX) in tumors to be used as a prodrug for photodynamic therapy and diagnosis. Hypoxia, a common feature of solid tumors, decreases the efficacy of ALA-based photodynamic therapy and diagnosis. This decrease results from the excretion of porphyrin precursor coproporphyrinogen III (CPgenIII), an intermediate in the biosynthesis of PpIX. However, the mechanism of CPgenIII excretion during hypoxia remains unclear. In this study, we revealed the importance of mitochondrial respiration for the production of PpIX during hypoxia. Porphyrin concentrations were estimated in human gastric cancer cell lines by HPLC. Expression levels of porphyrin biosynthesis genes were measured by qRT-PCR and immunoblotting. Blockage of porphyrin biosynthesis was an oxygen-dependent phenomenon resulting from decreased PpIX production in mitochondria under hypoxic conditions. PpIX production was increased by the inhibition of mitochondrial respiration complexes, which indicates that the enzymes of porphyrin biosynthesis compete with respiration complexes for molecular oxygen. Our results indicate that targeting the respiration complexes is a rationale for enhancing the effect of ALA-mediated treatment and diagnosis. PMID:26717566

  11. Oxygen Availability for Porphyrin Biosynthesis Enzymes Determines the Production of Protoporphyrin IX (PpIX) during Hypoxia

    PubMed Central

    Otsuka, Shimpei; Matsumoto, Kentaro; Nakajima, Motowo; Tanaka, Tohru; Ogura, Shun-ichiro

    2015-01-01

    5-Aminolevulinic acid (ALA), a precursor of porphyrin, is specifically converted to the fluorescent substance protoporphyrin IX (PpIX) in tumors to be used as a prodrug for photodynamic therapy and diagnosis. Hypoxia, a common feature of solid tumors, decreases the efficacy of ALA-based photodynamic therapy and diagnosis. This decrease results from the excretion of porphyrin precursor coproporphyrinogen III (CPgenIII), an intermediate in the biosynthesis of PpIX. However, the mechanism of CPgenIII excretion during hypoxia remains unclear. In this study, we revealed the importance of mitochondrial respiration for the production of PpIX during hypoxia. Porphyrin concentrations were estimated in human gastric cancer cell lines by HPLC. Expression levels of porphyrin biosynthesis genes were measured by qRT-PCR and immunoblotting. Blockage of porphyrin biosynthesis was an oxygen-dependent phenomenon resulting from decreased PpIX production in mitochondria under hypoxic conditions. PpIX production was increased by the inhibition of mitochondrial respiration complexes, which indicates that the enzymes of porphyrin biosynthesis compete with respiration complexes for molecular oxygen. Our results indicate that targeting the respiration complexes is a rationale for enhancing the effect of ALA-mediated treatment and diagnosis. PMID:26717566

  12. Heterocyclic compounds as carbonic anhydrase inhibitor.

    PubMed

    Husain, Asif; Madhesia, Diwakar

    2012-12-01

    The carbonic anhydrases (CAs, EC 4.2.1.1) constitute interesting targets for the design of pharmacological agents useful in the treatment or prevention of a variety of disorders such as, glaucoma, acid-base disequilibria, epilepsy, and other neuromuscular diseases, altitude sickness, edema, and obesity. A quite new and unexpected application of the CA inhibitors (CAIs) is with regard to their potential use in the management (imaging and treatment) of hypoxic tumors. A series of sulfonamides, including some clinically used derivatives like acetazolamide, methazolamide, ethoxzolamide, dichlorophenamide, dorzolamide, brinzolamide, benzolamide, and sulpiride, or indisulam, a compound in clinical development as antitumor drug, as well as the sulfamate antiepileptic drug topiramate have been reported to inhibit various human carbonic anhydrase isozyme. Various heterocyclic sulfonamides have been reported in this review with their potency to inhibit different carbonic anhydrases isozymes. PMID:21981003

  13. Atomic resolution studies of carbonic anhydrase II

    SciTech Connect

    Behnke, Craig A.; Le Trong, Isolde; Godden, Jeff W.; Merritt, Ethan A.; Teller, David C.; Bajorath, Jürgen; Stenkamp, Ronald E.

    2010-05-01

    The structure of human carbonic anhydrase II has been solved with a sulfonamide inhibitor at 0.9 Å resolution. Structural variation and flexibility is seen on the surface of the protein and is consistent with the anisotropic ADPs obtained from refinement. Comparison with 13 other atomic resolution carbonic anhydrase structures shows that surface variation exists even in these highly ordered isomorphous crystals. Carbonic anhydrase has been well studied structurally and functionally owing to its importance in respiration. A large number of X-ray crystallographic structures of carbonic anhydrase and its inhibitor complexes have been determined, some at atomic resolution. Structure determination of a sulfonamide-containing inhibitor complex has been carried out and the structure was refined at 0.9 Å resolution with anisotropic atomic displacement parameters to an R value of 0.141. The structure is similar to those of other carbonic anhydrase complexes, with the inhibitor providing a fourth nonprotein ligand to the active-site zinc. Comparison of this structure with 13 other atomic resolution (higher than 1.25 Å) isomorphous carbonic anhydrase structures provides a view of the structural similarity and variability in a series of crystal structures. At the center of the protein the structures superpose very well. The metal complexes superpose (with only two exceptions) with standard deviations of 0.01 Å in some zinc–protein and zinc–ligand bond lengths. In contrast, regions of structural variability are found on the protein surface, possibly owing to flexibility and disorder in the individual structures, differences in the chemical and crystalline environments or the different approaches used by different investigators to model weak or complicated electron-density maps. These findings suggest that care must be taken in interpreting structural details on protein surfaces on the basis of individual X-ray structures, even if atomic resolution data are available.

  14. Thermostable Carbonic Anhydrases in Biotechnological Applications

    PubMed Central

    Di Fiore, Anna; Alterio, Vincenzo; Monti, Simona M.; De Simone, Giuseppina; D’Ambrosio, Katia

    2015-01-01

    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. PMID:26184158

  15. Thermostable Carbonic Anhydrases in Biotechnological Applications.

    PubMed

    Di Fiore, Anna; Alterio, Vincenzo; Monti, Simona M; De Simone, Giuseppina; D'Ambrosio, Katia

    2015-01-01

    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. PMID:26184158

  16. Furazan and furoxan sulfonamides are strong α-carbonic anhydrase inhibitors and potential antiglaucoma agents.

    PubMed

    Chegaev, Konstantin; Lazzarato, Loretta; Tamboli, Yasinalli; Boschi, Donatella; Blangetti, Marco; Scozzafava, Andrea; Carta, Fabrizio; Masini, Emanuela; Fruttero, Roberta; Supuran, Claudiu T; Gasco, Alberto

    2014-08-01

    A series of furazan and furoxan sulfonamides were prepared and studied for their ability to inhibit human carbonic anhydrase (CA, EC 4.2.1.1) isoforms hCA I, hCA II, hCA IX, and hCA XII. The simple methyl substituted products 3-5 were potent inhibitors. Differing structural modifications of these leads had differing effects on potency and selectivity. In particular, products in which the sulfonamide group is separated from the hetero ring by a phenylene bridge retained high potency only on the hCA XII isoform. The sulfonamides 3-5 exerted intraocular pressure (IOP) lowering effects in vivo in hypertensive rabbits more efficiently than dorzolamide. Some other products (39-42), although less effective in vitro hCA II/XII inhibitors, also effectively lowered IOP in two different animal models of glaucoma. PMID:25022971

  17. Oncogenic roles of carbonic anhydrase 8 in human osteosarcoma cells.

    PubMed

    Wang, Tze-Kai; Lin, Yu-Ming; Lo, Che-Min; Tang, Chih-Hsin; Teng, Chieh-Lin Jerry; Chao, Wei-Ting; Wu, Min Huan; Liu, Chin-San; Hsieh, Mingli

    2016-06-01

    Carbonic anhydrase 8 (CA8), a member of the carbonic anhydrase family, is one of the three isozymes that do not catalyze the reversible hydration of carbon dioxide due to the lack of one important histidine. In the present study, we observed increased expression of CA8 in more aggressive types of human osteosarcoma (OS) cells and found that CA8 expression is correlated with disease stages, such that more intense expression occurs in the disease late stage. We also demonstrated that overexpression of CA8 in human OS (HOS) cells significantly increased cell proliferation both in vitro and in vivo. Downregulated CA8 sensitized cells to apoptotic stress induced by staurosporine and cisplatin, suggesting a specific role of CA8 to protect cells from stresses. In addition, downregulation of CA8 in HOS cells reduced cell invasion and colony formation ability in soft agar and further decreased matrix metalloproteinase 9 and focal adhesion kinase expression, indicating that CA8 might facilitate cancer cell invasion via the activation of FAK-MMP9 signaling. Interestingly, HOS cells with CA8 knockdown showed a significant decrease in glycolytic activity and cell death under glucose withdrawal, further indicating that CA8 may be involved in regulating aerobic glycolysis and enhancing cell viability. Knockdown of CA8 significantly decreased phosphorylated Akt expression suggesting that the oncogenic role of CA8 may be mediated by the regulation of Akt activation through p-Akt induction. Importantly, the inhibition of glycolysis by 2-deoxyglucose sensitized CA8 HOS-CA8-myc cells to cisplatin treatment under low glucose condition, highlighting a new therapeutic option for OS cancer. PMID:26711783

  18. Reconsidering the Status of Title IX.

    ERIC Educational Resources Information Center

    Hammer, Ben

    2003-01-01

    Discusses the controversy over Title IX and women's participation in college athletics. Critics say the mandate shortchanges men's teams, while proponents say that women's sports programs remain underfunded in spite of Title IX. Describes some proposed modifications to Title IX and their potential effects. (SLD)

  19. The Transmembrane Domains of β and IX Subunits Mediate the Localization of the Platelet Glycoprotein Ib-IX Complex to the Glycosphingolipid-enriched Membrane Domain.

    PubMed

    Xu, Guofeng; Shang, Dan; Zhang, Zuping; Shaw, Tanner S; Ran, Yali; López, José A; Peng, Yuandong

    2015-09-01

    We have previously reported that the structural elements of the GP Ib-IX complex required for its localization to glycosphingolipid-enriched membranes (GEMs) reside in the Ibβ and IX subunits. To identify them, we generated a series of cell lines expressing mutant GP Ibβ and GP IX where 1) the cytoplasmic tails (CTs) of either or both GP Ibβ and IX are truncated, and 2) the transmembrane domains (TMDs) of GP Ibβ and GP IX were swapped with the TMD of a non-GEMs associating molecule, human transferrin receptor. Sucrose density fractionation analysis showed that the removal of either or both of the CTs from GP Ibβ and GP IX does not alter GP Ibα-GEMs association when compared with the wild type. In contrast, swapping of the TMDs of either GP Ibβ or GP IX with that of transferrin receptor results in a significant loss (∼ 50%) of GP Ibα from the low density GEMs fractions, with the largest effect seen in the dual TMD-replaced cells (> 80% loss) when compared with the wild type cells (100% of GP Ibα present in the GEMs fractions). Under high shear flow, the TMD-swapped cells adhere poorly to a von Willebrand factor-immobilized surface to a much lesser extent than the previously reported disulfide linkage dysfunctional GP Ibα-expressing cells. Thus, our data demonstrate that the bundle of GP Ibβ and GP IX TMDs instead of their individual CTs is the structural element that mediates the β/IX complex localization to the membrane GEMs, which through the α/β disulfide linkage brings GP Ibα into the GEMs. PMID:26203189

  20. Non-Classical Inhibition of Carbonic Anhydrase

    PubMed Central

    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

  1. Non-Classical Inhibition of Carbonic Anhydrase.

    PubMed

    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

  2. Benzenesulfonamides incorporating bulky aromatic/heterocyclic tails with potent carbonic anhydrase inhibitory activity.

    PubMed

    Bozdag, Murat; Alafeefy, Ahmed M; Vullo, Daniela; Carta, Fabrizio; Dedeoglu, Nurcan; Al-Tamimi, Abdul-Malek S; Al-Jaber, Nabila A; Scozzafava, Andrea; Supuran, Claudiu T

    2015-12-15

    Three series of sulfonamides incorporating long, bulky tails were obtained by applying synthetic strategies in which substituted anthranilic acids, quinazolines and aromatic sulfonamides have been used as starting materials. They incorporate long, bulky diamide-, 4-oxoquinazoline-3-yl- or quinazoline-4-yl moieties in their molecules, and were investigated for the inhibition of four physiologically relevant carbonic anhydrase (CA, EC 4.2.1.1) isoforms, the cytosolic human (h) hCA I and II, as well as the transmembrane hCA IX and XII. Most of the new sulfonamides showed excellent inhibitory effects against the four isoforms, with KIs of 7.6-322nM against hCA I, of 0.06-85.4nM against hCA II; of 6.7-152nM against hCA IX and of 0.49-237nM against hCA XII; respectively. However no relevant isoform-selective behavior has been observed for any of them, although hCA II and XII, isoforms involved in glaucoma-genesis were the most inhibited ones. The structure-activity relationship for inhibiting the four CAs with these derivatives is discussed in detail. PMID:26639945

  3. Synthesis and carbonic anhydrase inhibitory properties of sulfamides structurally related to dopamine.

    PubMed

    Aksu, Kadir; Nar, Meryem; Tanc, Muhammet; Vullo, Daniela; Gülçin, Ilhami; Göksu, Süleyman; Tümer, Ferhan; Supuran, Claudiu T

    2013-06-01

    A series of novel sulfamides incorporating the dopamine scaffold were synthesized. Reaction of amines and tert-butyl-alcohol/benzyl alcohol in the presence of chlorosulfonyl isocyanate (CSI) afforded sulfamoyl carbamates, which were converted to the title compounds by treatment with trifluoroacetic acid or by palladium-catalyzed hydrogenolysis. Inhibition of six α-carbonic anhydrases (CAs, EC 4.2.1.1), that is, CA I, CA II, CA VA, CA IX, CA XII and CA XIV, and two β-CAs from Candida glabrata (CgCA) and Mycobacterium tuberculosis (Rv3588) with these sulfamides was investigated. All CA isozymes were inhibited in the low micromolar to nanomolar range by the dopamine sulfamide analogues. K(i)s were in the range of 0.061-1.822 μM for CA I, 1.47-2.94 nM for CA II, 2.25-3.34 μM for CA VA, 0.041-0.37 μM for CA IX, 0.021-1.52 μM for CA XII, 0.007-0.219 μM for CA XIV, 0.35-5.31 μM for CgCA and 0.465-4.29 μM for Rv3588. The synthesized sulfamides may lead to inhibitors targeting medicinally relevant CA isoforms with potential applications as antiepileptic, antiobesity antitumor agents or anti-infective. PMID:23623256

  4. More effective dithiocarbamate derivatives inhibiting carbonic anhydrases, generated by QSAR and computational design.

    PubMed

    Avram, Speranta; Milac, Adina Luminita; Carta, Fabrizio; Supuran, Claudiu T

    2013-04-01

    Dithiocarbamates (DTC) are promising compounds with potential applications in antitumoral and glaucoma therapy. Our aim is to understand molecular features affecting DTC interaction with carbonic anhydrases (CAs), zinc-containing enzymes maintaining acid-base balance in blood and other tissues. To this end, we generate QSAR models based on a compound series containing 25 DTC, inhibitors of four human (h) CAs isoforms: hCA I, II, IX and XII. We establish that critical physicochemical parameters for DTC inhibitory activity are: hydrophobic, electronic, steric, topological and shape. The predictive power of our QSAR models is indicated by significant values of statistical coefficients: cross-validated correlation q(2) (0.55-0.73), fitted correlation r(2) (0.75-0.84) and standard error of prediction (0.47-0.23). Based on the established QSAR equations, we analyse 22 new DTC derivatives and identify DTC dicarboxilic acids derivatives and their esters as potentially improved inhibitors of CA I, II, IX and XII. PMID:23116520

  5. Evolution of carbonic anhydrase in C4 plants.

    PubMed

    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. PMID:27016649

  6. Methods of producing protoporphyrin IX and bacterial mutants therefor

    DOEpatents

    Zhou, Jizhong; Qiu, Dongru; He, Zhili; Xie, Ming

    2016-03-01

    The presently disclosed inventive concepts are directed in certain embodiments to a method of producing protoporphyrin IX by (1) cultivating a strain of Shewanella bacteria in a culture medium under conditions suitable for growth thereof, and (2) recovering the protoporphyrin IX from the culture medium. The strain of Shewanella bacteria comprises at least one mutant hemH gene which is incapable of normal expression, thereby causing an accumulation of protoporphyrin IX. In certain embodiments of the method, the strain of Shewanella bacteria is a strain of S. loihica, and more specifically may be S. loihica PV-4. In certain embodiments, the mutant hemH gene of the strain of Shewanella bacteria may be a mutant of shew_2229 and/or of shew_1140. In other embodiments, the presently disclosed inventive concepts are directed to mutant strains of Shewanella bacteria having at least one mutant hemH gene which is incapable of normal expression, thereby causing an accumulation of protoporphyrin IX during cultivation of the bacteria. In certain embodiments the strain of Shewanella bacteria is a strain of S. loihica, and more specifically may be S. loihica PV-4. In certain embodiments, the mutant hemH gene of the strain of Shewanella bacteria may be a mutant of shew_2229 and/or shew_1140.

  7. Kinetic and X-ray crystallographic investigations of substituted 2-thio-6-oxo-1,6-dihydropyrimidine-benzenesulfonamides acting as carbonic anhydrase inhibitors.

    PubMed

    Vullo, Daniela; Supuran, Claudiu T; Scozzafava, Andrea; De Simone, Giuseppina; Monti, Simona Maria; Alterio, Vincenzo; Carta, Fabrizio

    2016-08-15

    Herein we report an in vitro kinetic evaluation against the most relevant human carbonic anhydrase (hCA, EC 4.2.1.1) isoforms (I, II, IX and XII) of a small series of lactate dehydrogenase (LDH, EC 1.1.1.27) inhibitors. All compounds contain a primary sulfonamide zinc-binding group (ZBG) substituted with the 2-thio-6-oxo-1,6-dihydropyrimidine scaffold. By means of X-ray crystallographic experiments we explored the ligand-enzyme binding modes, thus highlighting the contribution of the 2-thio-6-oxo-1,6-dihydropyrimidine moiety to the stabilization of the complex. PMID:27316543

  8. Expression and Prognostic Significance of a Panel of Tissue Hypoxia Markers in Head-and-Neck Squamous Cell Carcinomas

    SciTech Connect

    Le, Quynh-Thu Kong, Christina; Lavori, Phillip W.; O'Byrne, Ken; Erler, Janine T.; Huang Xin; Chen Yijun; Cao Hongbin; Tibshirani, Robert; Denko, Nic; Giaccia, Amato J.; Koong, Albert C.

    2007-09-01

    Purpose: To investigate the expression pattern of hypoxia-induced proteins identified as being involved in malignant progression of head-and-neck squamous cell carcinoma (HNSCC) and to determine their relationship to tumor pO{sub 2} and prognosis. Methods and Materials: We performed immunohistochemical staining of hypoxia-induced proteins (carbonic anhydrase IX [CA IX], BNIP3L, connective tissue growth factor, osteopontin, ephrin A1, hypoxia inducible gene-2, dihydrofolate reductase, galectin-1, I{kappa}B kinase {beta}, and lysyl oxidase) on tumor tissue arrays of 101 HNSCC patients with pretreatment pO{sub 2} measurements. Analysis of variance and Fisher's exact tests were used to evaluate the relationship between marker expression, tumor pO{sub 2}, and CA IX staining. Cox proportional hazard model and log-rank tests were used to determine the relationship between markers and prognosis. Results: Osteopontin expression correlated with tumor pO{sub 2} (Eppendorf measurements) (p = 0.04). However, there was a strong correlation between lysyl oxidase, ephrin A1, and galectin-1 and CA IX staining. These markers also predicted for cancer-specific survival and overall survival on univariate analysis. A hypoxia score of 0-5 was assigned to each patient, on the basis of the presence of strong staining for these markers, whereby a higher score signifies increased marker expression. On multivariate analysis, increasing hypoxia score was an independent prognostic factor for cancer-specific survival (p = 0.015) and was borderline significant for overall survival (p = 0.057) when adjusted for other independent predictors of outcomes (hemoglobin and age). Conclusions: We identified a panel of hypoxia-related tissue markers that correlates with treatment outcomes in HNSCC. Validation of these markers will be needed to determine their utility in identifying patients for hypoxia-targeted therapy.

  9. Fluorescent sulfonamide carbonic anhydrase inhibitors incorporating 1,2,3-triazole moieties: Kinetic and X-ray crystallographic studies.

    PubMed

    Carta, Fabrizio; Ferraroni, Marta; Scozzafava, Andrea; Supuran, Claudiu T

    2016-01-15

    Fluorescent sulfonamide carbonic anhydrase (CA, EC 4.2.1.1) inhibitors (CAIs) were essential for demonstrating the role played by the tumor-associated isoform CA IX in acidification of tumors, cancer progression towards metastasis and for the development of imaging and therapeutic strategies for the management of hypoxic tumors which overexpress CA IX. However, the presently available such compounds are poorly water soluble which limits their use. Here we report new fluorescent sulfonamides 7, 8 and 10 with increased water solubility. The new derivatives showed poor hCA I inhibitory properties, but were effective inhibitors against the hCA II (KIs of 366-127 nM), CA IX (KIs of 8.1-36.9 nM), CA XII (KIs of 4.1-20.5 nM) and CA XIV (KIs of 12.8-53.6 nM). A high resolution X-ray crystal structure of one of these compounds bound to hCA II revealed the factors associated with the good inhibitory properties. Furthermore, this compound showed a three-fold increase of water solubility compared to a similar derivative devoid of the triazole moiety, making it an interesting candidate for ex vivo/in vivo studies. PMID:26682703

  10. Synthesis of a new series of dithiocarbamates with effective human carbonic anhydrase inhibitory activity and antiglaucoma action.

    PubMed

    Bozdag, Murat; Carta, Fabrizio; Vullo, Daniela; Akdemir, Atilla; Isik, Semra; Lanzi, Cecilia; Scozzafava, Andrea; Masini, Emanuela; Supuran, Claudiu T

    2015-05-15

    A new series of dithiocarbamates (DTCs) was prepared from primary/secondary amines incorporating amino/hydroxyl-alkyl, mono- and bicyclic aliphatic ring systems based on the quinuclidine, piperidine, hydroxy-/carboxy-/amino-substituted piperidine, morpholine and piperazine scaffolds, and carbon disulfide. The compounds were investigated for the inhibition of four mammalian α-carbonic anhydrases (CAs, EC 4.2.1.1) of pharmacologic relevance, that is, the human (h) hCA I, II, IX and XII, drug targets for antiglaucoma (hCA II and XII) or antitumor (hCA IX/XII) agents. The compounds were moderate or inefficient hCA I inhibitors (off-target isoform for both applications), efficiently inhibited hCA II, whereas some of them were low nanomolar/subnanomolar hCA IX/XII inhibitors. One DTC showed excellent intraocular pressure (IOP) lowering properties in an animal model of glaucoma, with a two times better efficiency compared to the clinically used sulfonamide dorzolamide. PMID:25846066

  11. Reconstitution of Platelet Glycoprotein Ib-IX Complex in Phospholipid Bilayer Nanodiscs†

    PubMed Central

    Yan, Rong; Mo, Xi; Paredes, Angel M.; Dai, Kesheng; Lanza, Francois; Cruz, Miguel A.; Li, Renhao

    2012-01-01

    Glycoprotein (GP)Ib-IX complex expressed on platelet plasma membrane is involved in thrombosis and hemostasis by initiating platelet adhesion to von Willebrand factor (VWF) exposed at the injured vessel wall. While most of the knowledge for GPIb-IX is obtained from studies on platelets and transfected mammalian cells expressing GPIb-IX, there is not an in vitro membrane system that allows systematic analysis of this receptor. The phospholipid bilayer Nanodisc composed of a patch of phospholipid surrounded by membrane scaffold protein is an attractive tool for membrane protein study. We show here that GPIb-IX purified from human platelets has been reconstituted into the Nanodisc. Nanodisc-reconstituted GPIb-IX was able to bind various conformation-sensitive monoclonal antibodies. Furthermore, it bound to VWF in the presence of botrocetin with an apparent Kd of 0.73 ± 0.07 nM. The binding to VWF was inhibited by anti-GPIbα antibodies with epitopes overlapping with the VWF-binding site, but not by anti-GPIbβ monoclonal antibody RAM.1. Finally, Nanodisc-reconstituted GPIb-IX exhibited similar ligand-binding activity as the isolated extracellular domain of GPIbα. In conclusion, GPIb-IX in Nanodiscs adopts native-like conformation and possesses the ability to bind its natural ligands, thus making Nanodisc a suitable in vitro platform for further investigation on this hemostatically important receptor complex. PMID:22080766

  12. Why Is Carbonic Anhydrase Essential to Escherichia coli?

    PubMed Central

    Merlin, Christophe; Masters, Millicent; McAteer, Sean; Coulson, Andrew

    2003-01-01

    The can (previously yadF) gene of Escherichia coli encodes a β-class carbonic anhydrase (CA), an enzyme which interconverts CO2 and bicarbonate.Various essential metabolic processes require either CO2 or bicarbonate and, although carbon dioxide and bicarbonate spontaneously equilibrate in solution, the low concentration of CO2 in air and its rapid diffusion from the cell mean that insufficient bicarbonate is spontaneously made in vivo to meet metabolic and biosynthetic needs. We calculate that demand for bicarbonate is 103- to 104-fold greater than would be provided by uncatalyzed intracellular hydration and that enzymatic conversion of CO2 to bicarbonate is therefore necessary for growth. We find that can expression is ordinarily required for growth in air. It is dispensable if the atmospheric partial pressure of CO2 is high or during anaerobic growth in a closed vessel at low pH, where copious CO2 is generated endogenously. CynT, the single E. coli Can paralog, can, when induced with azide, replace Can; also, the γ-CA from Methanosarcina thermophila can at least partially replace it. Expression studies showed that can transcription does not appear to respond to carbon dioxide concentration or to be autoregulated. However, can expression is influenced by growth rate and the growth cycle; it is expressed best in slow-growing cultures and at higher culture densities. Expression can vary over a 10-fold range during the growth cycle and is also elevated during starvation or heat stress. PMID:14563877

  13. Identification, sequencing, and localization of a new carbonic anhydrase transcript from the hydrothermal vent tubeworm Riftia pachyptila.

    PubMed

    Sanchez, Sophie; Andersen, Ann C; Hourdez, Stéphane; Lallier, François H

    2007-10-01

    The vestimentiferan annelid Riftia pachyptila forms dense populations at hydrothermal vents along the East Pacific Rise at a depth of 2600 m. It harbors CO(2)-assimilating sulfide-oxidizing bacteria that provide all of its nutrition. To find specific host transcripts that could be important for the functioning of this symbiosis, we used a subtractive suppression hybridization approach to identify plume- or trophosome-specific proteins. We demonstrated the existence of carbonic anhydrase transcripts, a protein endowed with an essential role in generating the influx of CO(2) required by the symbionts. One of the transcripts was previously known and sequenced. Our quantification analyses showed a higher expression of this transcript in the trophosome compared to the branchial plume or the body wall. A second transcript, with 69.7% nucleotide identity compared to the previous one, was almost only expressed in the branchial plume. Fluorescent in situ hybridization confirmed the coexpression of the two transcripts in the branchial plume in contrast with the trophosome where only one transcript could be detected. An alignment of these translated carbonic anhydrase cDNAs with vertebrate and nonvertebrate carbonic anhydrase protein sequences revealed the conservation of most amino acids involved in the catalytic site. According to the phylogenetic analyses, the two R. pachyptila transcripts clustered together but not all nonvertebrate sequences grouped together. Complete sequencing of the new carbonic anhydrase transcript revealed the existence of two slightly divergent isoforms probably coded by two different genes. PMID:17892492

  14. 34 CFR Subject Index to Title Ix... - Subject Index to Title IX Preamble and Regulation 1

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    2002-07-01

    ... 34 Education 1 2002-07-01 2002-07-01 false Subject Index to Title IX Preamble and Regulation 1 Index Subject Index to Title IX Preamble and Regulation 1 Regulations of the Offices of the Department.... Subject Index Subject Index to Title IX Preamble and Regulation 1 1 Preamble paragraph numbers are...

  15. 45 CFR Subject Index to Title Ix... - Subject Index to Title IX Preamble and Regulation \\1\\

    Code of Federal Regulations, 2010 CFR

    1996-10-01

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  16. 45 CFR Subject Index to Title Ix... - Subject Index to Title IX Preamble and Regulation \\1\\

    Code of Federal Regulations, 2010 CFR

    2000-10-01

    ... 45 Public Welfare 1 2000-10-01 2000-10-01 false Subject Index to Title IX Preamble and Regulation \\1\\ Index Subject Index to Title IX Preamble and Regulation \\1\\ Public Welfare DEPARTMENT OF.... Pt. 86, Index Subject Index to Title IX Preamble and Regulation \\1\\ 1 Preamble paragraph numbers...

  17. 45 CFR Subject Index to Title Ix... - Subject Index to Title IX Preamble and Regulation 1

    Code of Federal Regulations, 2010 CFR

    2008-10-01

    ... 45 Public Welfare 1 2008-10-01 2008-10-01 false Subject Index to Title IX Preamble and Regulation 1 Index Subject Index to Title IX Preamble and Regulation 1 Public Welfare DEPARTMENT OF HEALTHAND... to Title IX Preamble and Regulation 1 1 Preamble paragraph numbers are in brackets . A Access...

  18. 34 CFR Subject Index to Title Ix... - Subject Index to Title IX Preamble and Regulation 1

    Code of Federal Regulations, 2010 CFR

    2009-07-01

    ... 34 Education 1 2009-07-01 2009-07-01 false Subject Index to Title IX Preamble and Regulation 1 Index Subject Index to Title IX Preamble and Regulation 1 Education Regulations of the Offices of the.... Subject Index Subject Index to Title IX Preamble and Regulation 1 1 Preamble paragraph numbers are...

  19. 45 CFR Subject Index to Title Ix... - Subject Index to Title IX Preamble and Regulation 1

    Code of Federal Regulations, 2010 CFR

    2009-10-01

    ... 45 Public Welfare 1 2009-10-01 2009-10-01 false Subject Index to Title IX Preamble and Regulation 1 Index Subject Index to Title IX Preamble and Regulation 1 Public Welfare DEPARTMENT OF HEALTH AND... to Title IX Preamble and Regulation 1 1 Preamble paragraph numbers are in brackets . A Access...

  20. 45 CFR Subject Index to Title Ix... - Subject Index to Title IX Preamble and Regulation 1

    Code of Federal Regulations, 2010 CFR

    2007-10-01

    ... 45 Public Welfare 1 2007-10-01 2007-10-01 false Subject Index to Title IX Preamble and Regulation 1 Index Subject Index to Title IX Preamble and Regulation 1 Public Welfare DEPARTMENT OF HEALTHAND... to Title IX Preamble and Regulation 1 1 Preamble paragraph numbers are in brackets . A Access...

  1. 45 CFR Subject Index to Title Ix... - Subject Index to Title IX Preamble and Regulation 1

    Code of Federal Regulations, 2010 CFR

    2002-10-01

    ... 45 Public Welfare 1 2002-10-01 2002-10-01 false Subject Index to Title IX Preamble and Regulation 1 Index Subject Index to Title IX Preamble and Regulation 1 Public Welfare GENERAL ADMINISTRATION... FINANCIAL ASSISTANCE Procedures Interim procedures. Pt. 86, Index Subject Index to Title IX Preamble...

  2. 34 CFR Subject Index to Title Ix... - Subject Index to Title IX Preamble and Regulation 1

    Code of Federal Regulations, 2010 CFR

    2007-07-01

    ... 34 Education 1 2007-07-01 2007-07-01 false Subject Index to Title IX Preamble and Regulation 1 Index Subject Index to Title IX Preamble and Regulation 1 Education Regulations of the Offices of the.... Subject Index Subject Index to Title IX Preamble and Regulation 1 1 Preamble paragraph numbers are...

  3. 34 CFR Subject Index to Title Ix... - Subject Index to Title IX Preamble and Regulation 1

    Code of Federal Regulations, 2010 CFR

    2003-07-01

    ... 34 Education 1 2003-07-01 2003-07-01 false Subject Index to Title IX Preamble and Regulation 1 Index Subject Index to Title IX Preamble and Regulation 1 Education Regulations of the Offices of the.... Subject Index Subject Index to Title IX Preamble and Regulation 1 1 Preamble paragraph numbers are...

  4. 45 CFR Subject Index to Title IX... - Subject Index to Title IX Preamble and Regulation 1

    Code of Federal Regulations, 2010 CFR

    2015-10-01

    ... 45 Public Welfare 1 2015-10-01 2015-10-01 false Subject Index to Title IX Preamble and Regulation 1 Index Subject Index to Title IX Preamble and Regulation 1 Public Welfare Department of Health and... Subject Index to Title IX Preamble and Regulation 1 1 Preamble paragraph numbers are in brackets [ ]....

  5. 45 CFR Subject Index to Title Ix... - Subject Index to Title IX Preamble and Regulation 1

    Code of Federal Regulations, 2010 CFR

    2003-10-01

    ... 45 Public Welfare 1 2003-10-01 2003-10-01 false Subject Index to Title IX Preamble and Regulation 1 Index Subject Index to Title IX Preamble and Regulation 1 Public Welfare DEPARTMENT OF HEALTHAND..., Index Subject Index to Title IX Preamble and Regulation 1 1 Preamble paragraph numbers are in...

  6. 34 CFR Subject Index to Title Ix... - Subject Index to Title IX Preamble and Regulation 1

    Code of Federal Regulations, 2010 CFR

    2008-07-01

    ... 34 Education 1 2008-07-01 2008-07-01 false Subject Index to Title IX Preamble and Regulation 1 Index Subject Index to Title IX Preamble and Regulation 1 Education Regulations of the Offices of the.... Subject Index Subject Index to Title IX Preamble and Regulation 1 1 Preamble paragraph numbers are...

  7. 45 CFR Subject Index to Title IX... - Subject Index to Title IX Preamble and Regulation 1

    Code of Federal Regulations, 2010 CFR

    2006-10-01

    ... 45 Public Welfare 1 2006-10-01 2006-10-01 false Subject Index to Title IX Preamble and Regulation 1 Index Subject Index to Title IX Preamble and Regulation 1 Public Welfare DEPARTMENT OF HEALTHAND... Subject Index to Title IX Preamble and Regulation 1 1 Preamble paragraph numbers are in brackets [ ]....

  8. 45 CFR Subject Index to Title Ix... - Subject Index to Title IX Preamble and Regulation 1

    Code of Federal Regulations, 2010 CFR

    2005-10-01

    ... 45 Public Welfare 1 2005-10-01 2005-10-01 false Subject Index to Title IX Preamble and Regulation 1 Index Subject Index to Title IX Preamble and Regulation 1 Public Welfare DEPARTMENT OF HEALTH AND... to Title IX Preamble and Regulation 1 1 Preamble paragraph numbers are in brackets . A Access...

  9. 45 CFR Subject Index to Title Ix... - Subject Index to Title IX Preamble and Regulation \\1\\

    Code of Federal Regulations, 2010 CFR

    1999-10-01

    ... 45 Public Welfare 1 1999-10-01 1999-10-01 false Subject Index to Title IX Preamble and Regulation \\1\\ Index Subject Index to Title IX Preamble and Regulation \\1\\ Public Welfare DEPARTMENT OF.... Pt. 86, Index Subject Index to Title IX Preamble and Regulation \\1\\ 1 Preamble paragraph numbers...

  10. 45 CFR Subject Index to Title Ix... - Subject Index to Title IX Preamble and Regulation \\1\\

    Code of Federal Regulations, 2010 CFR

    1998-10-01

    ... 45 Public Welfare 1 1998-10-01 1998-10-01 false Subject Index to Title IX Preamble and Regulation \\1\\ Index Subject Index to Title IX Preamble and Regulation \\1\\ GENERAL ADMINISTRATION... FINANCIAL ASSISTANCE Procedures Interim procedures. Pt. 86, Index Subject Index to Title IX Preamble...

  11. 34 CFR Subject Index to Title IX... - Subject Index to Title IX Preamble and Regulation 1

    Code of Federal Regulations, 2010 CFR

    2015-07-01

    ... 34 Education 1 2015-07-01 2015-07-01 false Subject Index to Title IX Preamble and Regulation 1 Index Subject Index to Title IX Preamble and Regulation 1 Education Regulations of the Offices of the...] Procedures. Subject Index Subject Index to Title IX Preamble and Regulation 1 1 Preamble paragraph...

  12. 34 CFR Subject Index to Title Ix... - Subject Index to Title IX Preamble and Regulation 1

    Code of Federal Regulations, 2010 CFR

    2004-07-01

    ... 34 Education 1 2004-07-01 2004-07-01 false Subject Index to Title IX Preamble and Regulation 1 Index Subject Index to Title IX Preamble and Regulation 1 Education Regulations of the Offices of the.... Subject Index Subject Index to Title IX Preamble and Regulation 1 1 Preamble paragraph numbers are...

  13. 45 CFR Subject Index to Title Ix... - Subject Index to Title IX Preamble and Regulation 1

    Code of Federal Regulations, 2010 CFR

    2001-10-01

    ... 45 Public Welfare 1 2001-10-01 2001-10-01 false Subject Index to Title IX Preamble and Regulation 1 Index Subject Index to Title IX Preamble and Regulation 1 Public Welfare DEPARTMENT OF HEALTHAND..., Index Subject Index to Title IX Preamble and Regulation 1 1 Preamble paragraph numbers are in...

  14. 34 CFR Subject Index to Title Ix... - Subject Index to Title IX Preamble and Regulation 1

    Code of Federal Regulations, 2010 CFR

    2006-07-01

    ... 34 Education 1 2006-07-01 2006-07-01 false Subject Index to Title IX Preamble and Regulation 1 Index Subject Index to Title IX Preamble and Regulation 1 Education Regulations of the Offices of the.... Subject Index Subject Index to Title IX Preamble and Regulation 1 1 Preamble paragraph numbers are...

  15. 45 CFR Subject Index to Title Ix... - Subject Index to Title IX Preamble and Regulation \\1\\

    Code of Federal Regulations, 2010 CFR

    1997-10-01

    ... 45 Public Welfare 1 1997-10-01 1997-10-01 false Subject Index to Title IX Preamble and Regulation \\1\\ Index Subject Index to Title IX Preamble and Regulation \\1\\ GENERAL ADMINISTRATION... FINANCIAL ASSISTANCE Procedures Interim procedures. Pt. 86, Index Subject Index to Title IX Preamble...

  16. 34 CFR Subject Index to Title Ix... - Subject Index to Title IX Preamble and Regulation 1

    Code of Federal Regulations, 2010 CFR

    2005-07-01

    ... 34 Education 1 2005-07-01 2005-07-01 false Subject Index to Title IX Preamble and Regulation 1 Index Subject Index to Title IX Preamble and Regulation 1 Education Regulations of the Offices of the.... Subject Index Subject Index to Title IX Preamble and Regulation 1 1 Preamble paragraph numbers are...

  17. 45 CFR Subject Index to Title Ix... - Subject Index to Title IX Preamble and Regulation 1

    Code of Federal Regulations, 2010 CFR

    2004-10-01

    ... 45 Public Welfare 1 2004-10-01 2004-10-01 false Subject Index to Title IX Preamble and Regulation 1 Index Subject Index to Title IX Preamble and Regulation 1 Public Welfare DEPARTMENT OF HEALTHAND..., Index Subject Index to Title IX Preamble and Regulation 1 1 Preamble paragraph numbers are in...

  18. Title IX: A Brief History. 25 Years of Title IX. WEEA Digest.

    ERIC Educational Resources Information Center

    Valentin, Iram

    This brief history of Title IX points out that the role of women and girls in education and the work force began to change significantly with the passage of Title IX as part of the Education Amendments to the Civil Rights Act of 1964. Title IX ensures legal protection against discrimination for students and employees. This article discusses the…

  19. 34 CFR Subject Index to Title Ix... - Subject Index to Title IX Preamble and Regulation 1

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false Subject Index to Title IX Preamble and Regulation 1 Index Subject Index to Title IX Preamble and Regulation 1 Education Regulations of the Offices of the.... Subject Index Subject Index to Title IX Preamble and Regulation 1 1 Preamble paragraph numbers are...

  20. 34 CFR Subject Index to Title Ix... - Subject Index to Title IX Preamble and Regulation 1

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 34 Education 1 2012-07-01 2012-07-01 false Subject Index to Title IX Preamble and Regulation 1 Index Subject Index to Title IX Preamble and Regulation 1 Education Regulations of the Offices of the.... Subject Index Subject Index to Title IX Preamble and Regulation 1 1 Preamble paragraph numbers are...

  1. 34 CFR Subject Index to Title Ix... - Subject Index to Title IX Preamble and Regulation 1

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 34 Education 1 2014-07-01 2014-07-01 false Subject Index to Title IX Preamble and Regulation 1 Index Subject Index to Title IX Preamble and Regulation 1 Education Regulations of the Offices of the.... Subject Index Subject Index to Title IX Preamble and Regulation 1 1 Preamble paragraph numbers are...

  2. 34 CFR Subject Index to Title Ix... - Subject Index to Title IX Preamble and Regulation 1

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 34 Education 1 2011-07-01 2011-07-01 false Subject Index to Title IX Preamble and Regulation 1 Index Subject Index to Title IX Preamble and Regulation 1 Education Regulations of the Offices of the.... Subject Index Subject Index to Title IX Preamble and Regulation 1 1 Preamble paragraph numbers are...

  3. 34 CFR Subject Index to Title Ix... - Subject Index to Title IX Preamble and Regulation 1

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 34 Education 1 2013-07-01 2013-07-01 false Subject Index to Title IX Preamble and Regulation 1 Index Subject Index to Title IX Preamble and Regulation 1 Education Regulations of the Offices of the.... Subject Index Subject Index to Title IX Preamble and Regulation 1 1 Preamble paragraph numbers are...

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

    PubMed

    Hu, Honghong; Boisson-Dernier, Aurélien; Israelsson-Nordström, Maria; Böhmer, Maik; Xue, Shaowu; Ries, Amber; Godoski, Jan; Kuhn, Josef M; Schroeder, Julian I

    2010-01-01

    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. PMID:20010812

  5. Accelerating Mineral Carbonation Using Carbonic Anhydrase.

    PubMed

    Power, Ian M; Harrison, Anna L; Dipple, Gregory M

    2016-03-01

    Carbonic anhydrase (CA) enzymes have gained considerable attention for their potential use in carbon dioxide (CO2) capture technologies because they are able to catalyze rapidly the interconversion of aqueous CO2 and bicarbonate. However, there are challenges for widespread implementation including the need to develop mineralization process routes for permanent carbon storage. Mineral carbonation of highly reactive feedstocks may be limited by the supply rate of CO2. This rate limitation can be directly addressed by incorporating enzyme-catalyzed CO2 hydration. This study examined the effects of bovine carbonic anhydrase (BCA) and CO2-rich gas streams on the carbonation rate of brucite [Mg(OH)2], a highly reactive mineral. Alkaline brucite slurries were amended with BCA and supplied with 10% CO2 gas while aqueous chemistry and solids were monitored throughout the experiments (hours to days). In comparison to controls, brucite carbonation using BCA was accelerated by up to 240%. Nesquehonite [MgCO3·3H2O] precipitation limited the accumulation of hydrated CO2 species, apparently preventing BCA from catalyzing the dehydration reaction. Geochemical models reproduce observed reaction progress in all experiments, revealing a linear correlation between CO2 uptake and carbonation rate. Data demonstrates that carbonation in BCA-amended reactors remained limited by CO2 supply, implying further acceleration is possible. PMID:26829491

  6. Chemically modified carbonic anhydrases useful in carbon capture systems

    SciTech Connect

    Novick, Scott; Alvizo, Oscar

    2013-01-15

    The present disclosure relates to chemically modified carbonic anhydrase polypeptides and soluble compositions, homogenous liquid formulations comprising them. The chemically modified carbonic anhydrase polypeptides have improved properties relative to the same carbonic anhydrase polypeptide that is not chemically modified including the improved properties of increased activity and/or stability in the presence of amine compounds, ammonia, or carbonate ion. The present disclosure also provides methods of preparing the chemically modified polypeptides and methods of using the chemically modified polypeptides for accelerating the absorption of carbon dioxide from a gas stream into a solution as well as for the release of the absorbed carbon dioxide for further treatment and/or sequestering.

  7. Statistical Evidence and Compliance with Title IX

    ERIC Educational Resources Information Center

    Cheslock, John J.; Eckes, Suzanne E.

    2008-01-01

    The scope of Title IX clearly includes all aspects of education, but the legislation's application to college athletics receives the most attention. Athletics programs, unlike most academic activities, are sex segregated, so the proper interpretation of the intercollegiate athletics provisions of Title IX is less clear-cut. This article examines…

  8. Title IX and Sex Discrimination. Revised.

    ERIC Educational Resources Information Center

    Office for Civil Rights (ED), Washington, DC.

    Title IX of the Education Amendments of 1972 protects people from discrimination based on sex in education programs or activities that receive Federal financial assistance. This brochure outlines the responsibilities of education programs and activities covered by Title IX, the responsibilities of the Office for Civil Rights (OCR) in enforcing…

  9. Metabolic Effect of Estrogen Receptor Agonists on Breast Cancer Cells in the Presence or Absence of Carbonic Anhydrase Inhibitors

    PubMed Central

    Belkaid, Anissa; Čuperlović-Culf, Miroslava; Touaibia, Mohamed; Ouellette, Rodney J.; Surette, Marc E.

    2016-01-01

    Metabolic shift is one of the major hallmarks of cancer development. Estrogen receptor (ER) activity has a profound effect on breast cancer cell growth through a number of metabolic changes driven by its effect on transcription of several enzymes, including carbonic anhydrases, Stearoyl-CoA desaturase-1, and oncogenes including HER2. Thus, estrogen receptor activators can be expected to lead to the modulation of cell metabolism in estrogen receptor positive cells. In this work we have investigated the effect of 17β-estradiol, an ER activator, and ferulic acid, a carbonic anhydrase inhibitor, as well as ER activator, in the absence and in the presence of the carbonic anhydrase inhibitor acetazolamide on the metabolism of MCF7 cells and MCF7 cells, stably transfected to express HER2 (MCF7HER2). Metabolic profiles were studied using 1D and 2D metabolomic Nuclear Magnetic Resonance (NMR) experiments, combined with the identification and quantification of metabolites, and the annotation of the results in the context of biochemical pathways. Overall changes in hydrophilic metabolites were largest following treatment of MCF7 and MC7HER2 cells with 17β-estradiol. However, the carbonic anhydrase inhibitor acetazolamide had the largest effect on the profile of lipophilic metabolites. PMID:27240414

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

    SciTech Connect

    Mitterberger, Maria C.; Kim, Geumsoo; Rostek, Ursula; Levine, Rodney L.; Zwerschke, Werner

    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.

  11. Carbonic Anhydrase Catalysis: An Experiment on Enzyme Kinetics.

    ERIC Educational Resources Information Center

    Spyridis, Greg T.; And Others

    1985-01-01

    Describes an undergraduate enzyme kinetics experiment which uses bovine erythrocyte carbonic anhydrase, a very stable enzyme commercially available in lyophilized form. Includes background information, reactions involved, procedures used, and the calculation of typical results obtained. (JN)

  12. Somatic mosaicism and female-to-female transmission in a kindred with hemophilia B (factor IX deficiency)

    SciTech Connect

    Taylor, S.A.M.; Deugau, K.V.; Lillicrap, D.P. )

    1991-01-01

    Studies have shown that hemophilia B (Christmas disease; factor IX deficiency) results from many different mutations in the factor IX gene, of which {gt}95% are single nulceotide substitutions. This study has identified a previously unreported form of hemophilia B in a patient who was a somatic mosaic for a guanine-to-cytosine transversion at nucleotide 31,170 in the factor IX gene. This point mutation changes the codon for residue 350 in the catalytic domain of factor IX from a cysteine to a serine. The authors used differential termination of primer extension to confirm and measure the degree of mosaicism. The study shows that a varying proportion of cells from hepatic, renal, smooth muscle, and hematopoietic populations possessed normal as well as mutant factor IX sequences. These results indicate that the mutation in this patient occurred either as an uncorrected half-chromatid mutation in the female gamete or as a replication or postreplication error in the initial mitotic divisions of the zygote preceding implantation. In addition, this kindred also contains two females in successive generations who have moderately severe factor IX deficiency. The molecular pathogenesis of this latter phenomenon has been studied and seems to relate to the unaccompanied expression of the mutant factor IX gene consequent upon a second, as yet undefined, genetic event that has prevented inactivation of sequences including the mutant factor IX gene on the X chromosome inherited from the affected male.

  13. Regression of established renal cell carcinoma in nude mice using lentivirus-transduced human T cells expressing a human anti-CAIX chimeric antigen receptor

    PubMed Central

    Lo, Agnes Shuk-Yee; Xu, Chen; Murakami, Akikazu; Marasco, Wayne A

    2014-01-01

    Carbonic anhydrase IX (CAIX) is a tumor-associated antigen and marker of hypoxia that is overexpressed on > 90% of clear-cell type renal cell carcinoma (RCC) but not on neighboring normal kidney tissue. Here, we report on the construction of two chimeric antigen receptors (CARs) that utilize a carbonic anhydrase (CA) domain mapped, human single chain antibody (scFv G36) as a targeting moiety but differ in their capacity to provide costimulatory signaling for optimal T cell proliferation and tumor cell killing. The resulting anti-CAIX CARs were expressed on human primary T cells via lentivirus transduction. CAR-transduced T cells (CART cells) expressing second-generation G36-CD28-TCRζ exhibited more potent in vitro antitumor effects on CAIX+ RCC cells than first-generation G36-CD8-TCRζ including cytotoxicity, cytokine secretion, proliferation, and clonal expansion. Adoptive G36-CD28-TCRζ CART cell therapy combined with high-dose interleukin (IL)-2 injection also lead to superior regression of established RCC in nude mice with evidence of tumor cell apoptosis and tissue necrosis. These results suggest that the fully human G36-CD28-TCRζ CARs should provide substantial improvements over first-generation mouse anti-CAIX CARs in clinical use through reduced human anti-mouse antibody responses against the targeting scFv and administration of lower doses of T cells during CART cell therapy of CAIX+ RCC. PMID:27119093

  14. Regression of established renal cell carcinoma in nude mice using lentivirus-transduced human T cells expressing a human anti-CAIX chimeric antigen receptor.

    PubMed

    Lo, Agnes Shuk-Yee; Xu, Chen; Murakami, Akikazu; Marasco, Wayne A

    2014-01-01

    Carbonic anhydrase IX (CAIX) is a tumor-associated antigen and marker of hypoxia that is overexpressed on > 90% of clear-cell type renal cell carcinoma (RCC) but not on neighboring normal kidney tissue. Here, we report on the construction of two chimeric antigen receptors (CARs) that utilize a carbonic anhydrase (CA) domain mapped, human single chain antibody (scFv G36) as a targeting moiety but differ in their capacity to provide costimulatory signaling for optimal T cell proliferation and tumor cell killing. The resulting anti-CAIX CARs were expressed on human primary T cells via lentivirus transduction. CAR-transduced T cells (CART cells) expressing second-generation G36-CD28-TCRζ exhibited more potent in vitro antitumor effects on CAIX(+) RCC cells than first-generation G36-CD8-TCRζ including cytotoxicity, cytokine secretion, proliferation, and clonal expansion. Adoptive G36-CD28-TCRζ CART cell therapy combined with high-dose interleukin (IL)-2 injection also lead to superior regression of established RCC in nude mice with evidence of tumor cell apoptosis and tissue necrosis. These results suggest that the fully human G36-CD28-TCRζ CARs should provide substantial improvements over first-generation mouse anti-CAIX CARs in clinical use through reduced human anti-mouse antibody responses against the targeting scFv and administration of lower doses of T cells during CART cell therapy of CAIX(+) RCC. PMID:27119093

  15. A novel mouse PKC{delta} splice variant, PKC{delta}IX, inhibits etoposide-induced apoptosis

    SciTech Connect

    Kim, Jung D.; Seo, Kwang W.; Lee, Eun A.; Quang, Nguyen N.; Cho, Hong R.; Kwon, Byungsuk

    2011-07-01

    Highlights: {yields} A novel PKC{delta} isoform, named PKC{delta}IX, that lacks the C1 domain and the ATP-binding site is ubiquitously expressed. {yields} PKC{delta}IX inhibits etoposide-induced apoptosis. {yields} PKC{delta}IX may function as an endogenous dominant negative isoform for PKC{delta}. -- Abstract: Protein kinase C (PKC) {delta} plays an important role in cellular proliferation and apoptosis. The catalytic fragment of PKC{delta} generated by caspase-dependent cleavage is essential for the initiation of etoposide-induced apoptosis. In this study, we identified a novel mouse PKC{delta} isoform named PKC{delta}IX (Genebank Accession No. (HQ840432)). PKC{delta}IX is generated by alternative splicing and is ubiquitously expressed, as seen in its full-length PKC{delta}. PKC{delta}IX lacks the C1 domain, the caspase 3 cleavage site, and the ATP binding site but preserves an almost intact c-terminal catalytic domain and a nuclear localization signal (NLS). The structural characteristics of PKC{delta}IX provided a possibility that this PKC{delta} isozyme functions as a novel dominant-negative form for PKC{delta} due to its lack of the ATP-binding domain that is required for the kinase activity of PKC{delta}. Indeed, overexpression of PKC{delta}IX significantly inhibited etoposide-induced apoptosis in NIH3T3 cells. In addition, an in vitro kinase assay showed that recombinant PKC{delta}IX protein could competitively inhibit the kinase activity of PKC{delta}. We conclude that PKC{delta}IX can function as a natural dominant-negative inhibitor of PKC{delta}in vivo.

  16. Association between FBP1 and hypoxia-related gene expression in clear cell renal cell carcinoma

    PubMed Central

    NING, XIANG-HUI; LI, TENG; GONG, YAN-QING; HE, QUN; SHEN, QI; PENG, SHUANG-HE; WANG, JIANG-YI; CHEN, JIN-CHAO; GUO, YING-LU; GONG, KAN

    2016-01-01

    Fructose-1,6-bisphosphatase 1 (FBP1) is a rate-limiting enzyme in gluconeogenesis. Recently, the catalytic activity-independent function of FBP1, hypoxia-induced factor (HIF) repression in the nucleus, was identified. The aim of the present study was to investigate the association between FBP1 and hypoxia-related gene expression in clear cell renal cell carcinoma (ccRCC). The protein expression levels of FBP1, HIF-1α, HIF-2α, erythropoietin (EPO) and carbonic anhydrase IX (CA9) were assessed by immunohistochemical staining of ccRCC paraffin blocks from 123 patients using the tissue microarray technique. The expression level of FBP1 was then correlated with various clinicopathological factors, and the protein expression levels of HIF-1α, HIF-2α, EPO and CA9. Clinicopathological factors, including age, gender, T stage and Fuhrman grade, were not significantly different between patients with low and high FBP1 expression in ccRCC (P>0.05). FBP1 protein expression level was significantly correlated with the expression levels of HIF-1α (P=0.005) and EPO (P=0.010), but not significantly correlated with the expression levels of HIF-2α (P=0.123) and CA9 (P=0.513) in ccRCC tissues. The current findings confirm the association between FBP1 and hypoxia-related gene expression, and may facilitate understanding of the mechanisms of ccRCC tumorigenesis. PMID:27313747

  17. Carbon Dioxide "Trapped" in a β-Carbonic Anhydrase.

    PubMed

    Aggarwal, Mayank; Chua, Teck Khiang; Pinard, Melissa A; Szebenyi, Doletha M; McKenna, Robert

    2015-11-01

    Carbonic anhydrases (CAs) are enzymes that catalyze the hydration/dehydration of CO2/HCO3(-) with rates approaching diffusion-controlled limits (kcat/KM ∼ 10(8) M(-1) s(-1)). This family of enzymes has evolved disparate protein folds that all perform the same reaction at near catalytic perfection. Presented here is a structural study of a β-CA (psCA3) expressed in Pseudomonas aeruginosa, in complex with CO2, using pressurized cryo-cooled crystallography. The structure has been refined to 1.6 Å resolution with R(cryst) and R(free) values of 17.3 and 19.9%, respectively, and is compared with the α-CA, human CA isoform II (hCA II), the only other CA to have CO2 captured in its active site. Despite the lack of structural similarity between psCA3 and hCA II, the CO2 binding orientation relative to the zinc-bound solvent is identical. In addition, a second CO2 binding site was located at the dimer interface of psCA3. Interestingly, all β-CAs function as dimers or higher-order oligomeric states, and the CO2 bound at the interface may contribute to the allosteric nature of this family of enzymes or may be a convenient alternative binding site as this pocket has been previously shown to be a promiscuous site for a variety of ligands, including bicarbonate, sulfate, and phosphate ions. PMID:26457866

  18. Carbon dioxide "trapped" in a β-carbonic anhydrase

    DOE PAGESBeta

    Aggarwal, Mayank; Chua, Teck Khiang; Pinard, Melissa A.; Szebenyi, Doletha M.; McKenna, Robert

    2015-10-12

    Carbonic anhydrases (CAs) are enzymes that catalyze the hydration/ dehydration of CO2/HCO3- with rates approaching diffusion-controlled limits (kcat/KM ~ 108 M–1s–1). Here, this family of enzymes has evolved disparate protein folds that all perform the same reaction at near catalytic perfection. Presented here is a structural study of a beta-CA (psCA3) expressed in Pseudomonas aeruginosa, in complex with CO2, using pressurized cryocooled crystallography. The structure has been refined to 1.6 angstrom resolution with Rcryst and Rfree values of 17.3 and 19.9%, respectively, and is compared with the α-CA, human CA isoform II (hCA II), the only other CA to havemore » CO2, captured in its active site. Despite the lack of structural similarity between psCA3 and hCA II, the CO2, binding orientation relative to the zinc-bound solvent is identical. In addition, a second CO2, binding site was located at the dimer interface of psCA3. Interestingly, all β-CAs function as dirners or higher-order oligomeric states, and the CO2, bound at the interface may contribute to the allosteric nature of this family of enzymes or may be a convenient alternative binding site as this pocket has been previously shown to be a promiscuous site for a variety of ligands, including bicarbonate, sulfate, and phosphate ions.« less

  19. A Class of 4-Sulfamoylphenyl-ω-aminoalkyl Ethers with Effective Carbonic Anhydrase Inhibitory Action and Antiglaucoma Effects

    PubMed Central

    2015-01-01

    We report a series of 4-sulfamoylphenyl-ω-aminoalkyl ethers as carbonic anhydrase (CA, EC 4.2.1.1) inhibitors. The structure–activity relationship was drawn for the inhibition of four physiologically relevant isoforms: hCA I, II, IX, and XII. Many of these compounds were highly effective, low nanomolar inhibitors of all CA isoforms, whereas several isoform-selective were also identified. X-ray crystal structures of two new sulfonamides bound to the physiologically dominant CA II isoform showed the tails of these derivatives bound within the hydrophobic half of the enzyme active site through van der Waals contacts with Val135, Leu198, Leu204, Trp209, Pro201, and Pro202 amino acids. One of the highly water-soluble compound (as trifluoroacetate salt) showed effective IOP lowering properties in an animal model of glaucoma. Several fluorescent sulfonamides incorporating either the fluorescein-thiourea (7a–c) or tetramethylrhodamine-thiourea (9a,b) moieties were also obtained and showed interesting CA inhibitory properties for the tumor-associated isoforms CA IX and XII. PMID:25358036

  20. An Unusual Natural Product Primary Sulfonamide: Synthesis, Carbonic Anhydrase Inhibition, and Protein X-ray Structures of Psammaplin C.

    PubMed

    Mujumdar, Prashant; Teruya, Kanae; Tonissen, Kathryn F; Vullo, Daniela; Supuran, Claudiu T; Peat, Thomas S; Poulsen, Sally-Ann

    2016-06-01

    Psammaplin C is one of only two described natural product primary sulfonamides. Here we report the synthesis of psammaplin C and evaluate the inhibition profile against therapeutically relevant carbonic anhydrase (CA) zinc metalloenzymes. The compound exhibited unprecedented inhibition of an important cancer-associated isozyme, hCA XII, with a Ki of 0.79 nM. The compound also displayed good isoform selectivity for hCA XII over other CAs. We present the first reported protein X-ray crystal structures of psammaplin C in complex with human CAs. We engineered the easily crystallized hCA II enzyme to mimic both the hCA IX and hCA XII binding sites and then utilized protein X-ray crystallography to determine the binding pose of psammaplin C within the hCA II, hCA IX, and hCA XII mimic active sites, all to high resolution. This is the first time a natural product primary sulfonamide inhibitor has been assessed for inhibition and binding to CAs. PMID:27172398

  1. Spectral action for Bianchi type-IX cosmological models

    NASA Astrophysics Data System (ADS)

    Fan, Wentao; Fathizadeh, Farzad; Marcolli, Matilde

    2015-10-01

    A rationality result previously proved for Robertson-Walker metrics is extended to a homogeneous anisotropic cosmological model, namely the Bianchi type-IX minisuperspace. It is shown that the Seeley-de Witt coefficients appearing in the expansion of the spectral action for the Bianchi type-IX geometry are expressed in terms of polynomials with rational coefficients in the cosmic evolution factors w 1( t) , w 2( t) , w 3( t) , and their higher derivates with respect to time. We begin with the computation of the Dirac operator of this geometry and calculate the coefficients a 0 ,a 2 ,a 4 of the spectral action by using heat kernel methods and parametric pseudodifferential calculus. An efficient method is devised for computing the Seeley-de Witt coefficients of a geometry by making use of Wodzicki's noncommutative residue, and it is confirmed that the method checks out for the cosmological model studied in this article. The advantages of the new method are discussed, which combined with symmetries of the Bianchi type-IX metric, yield an elegant proof of the rationality result.

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

    ERIC Educational Resources Information Center

    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)

  3. Endosialin and Associated Protein Expression in Soft Tissue Sarcomas: A Potential Target for Anti-Endosialin Therapeutic Strategies

    PubMed Central

    Dai, Hongyue; Mitchell, Melissa; Huntsman, Shane; Brantley, Stephen; Fenstermacher, David

    2016-01-01

    Endosialin (CD248, TEM-1) is expressed in pericytes, tumor vasculature, tumor fibroblasts, and some tumor cells, including sarcomas, with limited normal tissue expression, and appears to play a key role in tumor-stromal interactions, including angiogenesis. Monoclonal antibodies targeting endosialin have entered clinical trials, including soft tissue sarcomas. We evaluated a cohort of 94 soft tissue sarcoma samples to assess the correlation between gene expression and protein expression by immunohistochemistry for endosialin and PDGFR-β, a reported interacting protein, across available diagnoses. Correlations between the expression of endosialin and 13 other genes of interest were also examined. Within cohorts of soft tissue diagnoses assembled by tissue type (liposarcoma, leiomyosarcoma, undifferentiated sarcoma, and other), endosialin expression was significantly correlated with a better outcome. Endosialin expression was highest in liposarcomas and lowest in leiomyosarcomas. A robust correlation between protein and gene expression data for both endosialin and PDGFR-β was observed. Endosialin expression positively correlated with PDGFR-β and heparin sulphate proteoglycan 2 and negatively correlated with carbonic anhydrase IX. Endosialin likely interacts with a network of extracellular and hypoxia activated proteins in sarcomas and other tumor types. Since expression does vary across histologic groups, endosialin may represent a selective target in soft tissue sarcomas. PMID:27057137

  4. Polymorphism of normal factor IX detected by mouse monoclonal antibodies.

    PubMed Central

    Wallmark, A; Ljung, R; Nilsson, I M; Holmberg, L; Hedner, U; Lindvall, M; Sjögren, H O

    1985-01-01

    Hemophilia B is an X-chromosomal recessive disease due to deficiency of coagulation factor IX. Three monoclonal antibodies against factor IX were prepared and used to develop immunoradiometric assays (IRMAs) of factor IX antigen (IX-Ag). IX-Ag was measured in 65 normal individuals with one IRMA based on polyclonal anti-IX antibodies and two IRMAs based on three monoclonal anti-IX antibodies. One of the monoclonal antibodies differed in specificity since it neutralized less than 50% of the clotting activity of factor IX (IX-C), whereas the other two monoclonal antibodies neutralized 80-95%. When the former antibody was used as the solid phase in IRMA, two groups of normal individuals were distinguished: group A with measurable IX-Ag, and group B without demonstrable IX-Ag. There were no differences between the groups either in IX-C or in IX-Ag measured with polyclonal antibodies. A subgroup comprising only women could be distinguished in group A, in whom intermediate IX-Ag concentrations were found. Family studies showed the group B variant of normal factor IX to be transmitted according to the pattern of X-linked recessive inheritance. The allelic frequency of group A was 0.66, and that of group B was 0.34. PMID:3873655

  5. An unusual complication in a gravida with factor IX deficiency: case report with review of the literature.

    PubMed

    Guy, G P; Baxi, L V; Hurlet-Jensen, A; Chao, C R

    1992-09-01

    Factor IX deficiency (hemophilia B, Christmas disease) is an X-linked recessive coagulation disorder. It occurs in one out of every 25,000-30,000 male births and requires even rarer genetic circumstances for phenotypic expression in females. We report the occurrence of a large, late-trimester subchorionic hematoma in a gravida with factor IX deficiency and with laboratory evidence of consumptive coagulopathy during treatment. The patient was managed conservatively and had a successful outcome at term. The only four reported cases of antepartum management of factor IX deficiency in the English literature are reviewed. PMID:1495722

  6. Development of 3-(4-aminosulphonyl)-phenyl-2-mercapto-3H-quinazolin-4-ones as inhibitors of carbonic anhydrase isoforms involved in tumorigenesis and glaucoma.

    PubMed

    Alafeefy, Ahmed M; Carta, Fabrizio; Ceruso, Mariangela; Al-Tamimi, Abdul-Malek S; Al-Kahtani, Abdulla A; Supuran, Claudiu T

    2016-03-15

    A series of heterocyclic benzenesulfonamides incorporating 2-mercapto-3H-quinazolin-4-one tails were prepared by condensation of substituted anthranilic acids with 4-isothiocyanato-benzenesulfonamide. These sulfonamides were investigated as inhibitors of the human carbonic anhydrase (hCA, EC 4.2.1.1) isoforms hCA I and II (cytosolic isozymes), as well as hCA IX and XII (trans-membrane, tumor-associated enzymes). They acted as medium potency inhibitors of hCA I (KIs of 81.0-3084 nM), being highly effective as hCA II (KIs in the range of 0.25-10.8 nM), IX (KIs of 3.7-50.4 nM) and XII (KIs of 0.60-52.9 nM) inhibitors. These compounds should thus be of interest as preclinical candidates in pathologies in which the activity of these enzymes should be inhibited, such as glaucoma (CA II and XII as targets) or some tumors in which the activity of three isoforms (CA II, IX and XII) is dysregulated. PMID:26875933

  7. El Titulo IX y La Discriminacion por Sexo (Title IX and Sex Discrimination).

    ERIC Educational Resources Information Center

    Office for Civil Rights (ED), Washington, DC.

    Title IX of the Education Amendments of 1972 protects people from discrimination based on sex in education programs or activities that receive Federal financial assistance. This brochure outlines the responsibilities of education programs and activities covered by Title IX, the responsibilities of the Office for Civil Rights (OCR) in enforcing…

  8. 45 CFR Subject Index to Title Ix... - Subject Index to Title IX Preamble and Regulation 1

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 45 Public Welfare 1 2012-10-01 2012-10-01 false Subject Index to Title IX Preamble and Regulation 1 Index Subject Index to Title IX Preamble and Regulation 1 Public Welfare DEPARTMENT OF HEALTH AND... ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Procedures Interim procedures. Pt. 86, Index Subject...

  9. 45 CFR Subject Index to Title Ix... - Subject Index to Title IX Preamble and Regulation 1

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 45 Public Welfare 1 2013-10-01 2013-10-01 false Subject Index to Title IX Preamble and Regulation 1 Index Subject Index to Title IX Preamble and Regulation 1 Public Welfare DEPARTMENT OF HEALTH AND... ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Procedures Interim procedures. Pt. 86, Index Subject...

  10. 45 CFR Subject Index to Title Ix... - Subject Index to Title IX Preamble and Regulation 1

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Subject Index to Title IX Preamble and Regulation 1 Index Subject Index to Title IX Preamble and Regulation 1 Public Welfare DEPARTMENT OF HEALTH AND... ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Procedures Interim procedures. Pt. 86, Index Subject...

  11. 45 CFR Subject Index to Title Ix... - Subject Index to Title IX Preamble and Regulation 1

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 45 Public Welfare 1 2014-10-01 2014-10-01 false Subject Index to Title IX Preamble and Regulation 1 Index Subject Index to Title IX Preamble and Regulation 1 Public Welfare Department of Health and... ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Procedures Interim procedures. Pt. 86, Index Subject...

  12. 45 CFR Subject Index to Title Ix... - Subject Index to Title IX Preamble and Regulation 1

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 1 2011-10-01 2011-10-01 false Subject Index to Title IX Preamble and Regulation 1 Index Subject Index to Title IX Preamble and Regulation 1 Public Welfare DEPARTMENT OF HEALTH AND... ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Procedures Interim procedures. Pt. 86, Index Subject...

  13. Molecular and biochemical characterization of carbonic anhydrases of Paracoccidioides

    PubMed Central

    Tomazett, Mariana Vieira; Zanoelo, Fabiana Fonseca; Bailão, Elisa Flávia Cardoso; Bailão, Alexandre Melo; Borges, Clayton Luiz; Soares, Célia Maria de Almeida

    2016-01-01

    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. PMID:27560991

  14. Molecular and biochemical characterization of carbonic anhydrases of Paracoccidioides.

    PubMed

    Tomazett, Mariana Vieira; Zanoelo, Fabiana Fonseca; Bailão, Elisa Flávia Cardoso; Bailão, Alexandre Melo; Borges, Clayton Luiz; Soares, Célia Maria de Almeida

    2016-07-25

    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. PMID:27459262

  15. Molecular and biochemical characterization of carbonic anhydrases of Paracoccidioides.

    PubMed

    Tomazett, Mariana Vieira; Zanoelo, Fabiana Fonseca; Bailão, Elisa Flávia Cardoso; Bailão, Alexandre Melo; Borges, Clayton Luiz; Soares, Célia Maria de Almeida

    2016-01-01

    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. PMID:27560991

  16. Structure and function of carbonic anhydrases.

    PubMed

    Supuran, Claudiu T

    2016-07-15

    Carbonic anhydrases (CAs, EC 4.2.1.1) catalyse the interconversion between CO2 and bicarbonate as well as other hydrolytic reactions. Among the six genetic families known to date, the α-, β-, γ-, δ-, ζ- and η-CAs, detailed kinetic and X-ray crystallographic studies have allowed a deep understanding of the structure-function relationship in this superfamily of proteins. A metal hydroxide nucleophilic species of the enzyme, and a unique active site architecture, with half of it hydrophilic and the opposing part hydrophobic, allow these enzymes to act as some of the most effective catalysts known in Nature. The CA activation and inhibition mechanisms are also known in detail, with a large number of new inhibitor classes being described in the last years. Apart from the zinc binders, some classes of inhibitors anchor to the metal ion coordinated nucleophile, others occlude the entrance of the active site cavity and more recently, compounds binding outside the active site were described. CA inhibition has therapeutic applications for drugs acting as diuretics, antiepileptics, antiglaucoma, antiobesity and antitumour agents. Targeting such enzymes from pathogens may lead to novel anti-infectives. Successful structure-based drug design campaigns allowed the discovery of highly isoform selective CA inhibitors (CAIs), which may lead to a new generation of drugs targeting these widespread enzymes. The use of CAs in CO2 capture processes for mitigating the global temperature rise has also been investigated more recently. PMID:27407171

  17. Dispensabilities of carbonic anhydrase in proteobacteria.

    PubMed

    Ueda, Kenji; Nishida, Hiromi; Beppu, Teruhiko

    2012-01-01

    Carbonic anhydrase (CA) (E.C. 4.2.1.1) is a ubiquitous enzyme catalysing interconversion between CO(2) and bicarbonate. The irregular distribution of the phylogenetically distinct classes of CA in procaryotic genome suggests its complex evolutionary history in procaryotes. Genetic evidence regarding the dispensability of CA under high-CO(2) air in some model organisms indicates that CA-deficient microorganisms can persist in the natural environment by choosing high-CO(2) niches. In this study, we studied the distribution of CA in the genome of Proteobacteria. While a large majority of the genome-sequenced Proteobacteria retained a CA gene(s), intracellular bacterial genera such as Buchnera and Rickettsia contained CA-defective strains. Comparison between CA-retaining and CA- deficient genomes showed the absence of whole coding sequence in some strains and the presence of frameshifted coding sequence in other strains. The evidence suggests that CA is inactivated and lost in some proteobacteria during the course of evolution based on its dispensability. PMID:22675650

  18. Improved Induction of Immune Tolerance to Factor IX by Hepatic AAV-8 Gene Transfer

    PubMed Central

    Cooper, Mario; Nayak, Sushrusha; Hoffman, Brad E.; Terhorst, Cox; Cao, Ou

    2009-01-01

    Abstract Gene therapy for hemophilia B has been shown to result in long-term expression and immune tolerance to factor IX (F.IX) after in vivo transduction of hepatocytes with adeno-associated viral (AAV-2) vectors in experimental animals. An optimized protocol was effective in several strains of mice with a factor 9 gene deletion (F9−/−). However, immune responses against F.IX were repeatedly observed in C3H/HeJ F9−/− mice. We sought to establish a gene transfer protocol that results in sustained expression without a requirement for additional manipulation of the immune system. Compared with AAV-2, AAV-8 was more efficient in transgene expression and induction of tolerance to F.IX in three different strains of wild-type mice. At equal vector doses, AAV-8 induced transgene product-specific regulatory CD4+CD25+FoxP3+ T cells at significantly higher frequency. Moreover, sustained correction of hemophilia B in C3H/HeJ F9−/− mice without antibody formation was documented in all animals treated with ≥4 × 1011 vector genomes (VG)/kg and in 80% of mice treated with 8 × 1010 VG/kg. Therefore, it is possible to develop a gene transfer protocol that reliably induces tolerance to F.IX largely independent of genetic factors. A comparison with other studies suggests that additional parameters besides plateau levels of F.IX expression contributed to the improved success rate of tolerance induction. PMID:19309290

  19. Molecularly imprinted cryogels for carbonic anhydrase purification from bovine erythrocyte.

    PubMed

    Uygun, Murat; Karagözler, A Alev; Denizli, Adil

    2014-04-01

    Molecularly imprinted PHEMAH cryogels were synthesized and used for purification of carbonic anhydrase from bovine erythrocyte. Cryogels were prepared with free radical cryopolymerization of 2-hydroxyethyl methacrylate and methacryloylamido histidine and characterized by swelling degree, macroporosity, FTIR, SEM, surface area and elemental analysis. Maximum carbonic anhydrase adsorption of molecularly imprinted PHEMAH cryogel was found to be 3.16 mg/g. Selectivity of the molecularly imprinted cryogel was investigated using albumin, hemoglobin, IgG, γ-globulin, and lysozyme as competitor proteins and selectivity ratios were found to be 15.26, 60.05, 21.88, 17.61, and 17.42, respectively. Carbonic anhydrase purity was demonstrated by SDS-PAGE and zymogram results. PMID:24528406

  20. Characteristics of recombinant α-carbonic anhydrase of polyextremophilic bacterium Bacillus halodurans TSLV1.

    PubMed

    Faridi, Shazia; Satyanarayana, T

    2016-08-01

    Carbonic anhydrase (CA) is a biocatalyst that catalyzes the hydration of CO2 to bicarbonate and protons, thus useful in mitigating green house effect by sequestering CO2 from various point sources. An alkalistable and moderately thermostable α- carbonic anhydrase encoding gene (BhCA) from Bacillus halodurans TSLV1 has been cloned and expressed in Escherichia coli. A 31.4-fold enhancement in CA production was achieved due to cloning and expression in E. coli. About 50% of the CA produced was secreted when recombinant E. coli with BhCA-pET22b was cultivated in a medium with EDTA and lysozyme because of the efficient pelB leader sequence. rBhCA is a ∼75kDa homodimeric protein with a Tm of 72°C and T1/2 values of 66 and 24min at 50 and 60°C, respectively. SDM analysis revealed that H137, H139, H156 and H110 present in the active site play an important role in catalysis. Mineralization of CO2 using rBhCA led to the accelerated precipitation of CaCO3 in calcite form. rBhCA also functions as an efficient virtual peroxidase when Zn(2+) is substituted with Mn(2+). PMID:27174908

  1. Engineered Escherichia coli with Periplasmic Carbonic Anhydrase as a Biocatalyst for CO2 Sequestration

    PubMed Central

    Jo, Byung Hoon; Kim, Im Gyu; Seo, Jeong Hyun; Kang, Dong Gyun

    2013-01-01

    Carbonic anhydrase is an enzyme that reversibly catalyzes the hydration of carbon dioxide (CO2). It has been suggested recently that this remarkably fast enzyme can be used for sequestration of CO2, a major greenhouse gas, making this a promising alternative for chemical CO2 mitigation. To promote the economical use of enzymes, we engineered the carbonic anhydrase from Neisseria gonorrhoeae (ngCA) in the periplasm of Escherichia coli, thereby creating a bacterial whole-cell catalyst. We then investigated the application of this system to CO2 sequestration by mineral carbonation, a process with the potential to store large quantities of CO2. ngCA was highly expressed in the periplasm of E. coli in a soluble form, and the recombinant bacterial cell displayed the distinct ability to hydrate CO2 compared with its cytoplasmic ngCA counterpart and previously reported whole-cell CA systems. The expression of ngCA in the periplasm of E. coli greatly accelerated the rate of calcium carbonate (CaCO3) formation and exerted a striking impact on the maximal amount of CaCO3 produced under conditions of relatively low pH. It was also shown that the thermal stability of the periplasmic enzyme was significantly improved. These results demonstrate that the engineered bacterial cell with periplasmic ngCA can successfully serve as an efficient biocatalyst for CO2 sequestration. PMID:23974145

  2. Use of Cre/loxP recombination to swap cell binding motifs on the adenoviral capsid protein IX

    SciTech Connect

    Poulin, Kathy L.; Tong, Grace; Vorobyova, Olga; Pool, Madeline; Kothary, Rashmi; Parks, Robin J.

    2011-11-25

    We used Cre/loxP recombination to swap targeting ligands present on the adenoviral capsid protein IX (pIX). A loxP-flanked sequence encoding poly-lysine (pK-binds heparan sulfate proteoglycans) was engineered onto the 3'-terminus of pIX, and the resulting fusion protein allowed for routine virus propagation. Growth of this virus on Cre-expressing cells removed the pK coding sequence, generating virus that could only infect through alternative ligands, such as a tyrosine kinase receptor A (TrkA)-binding motif engineered into the capsid fibre protein for enhanced infection of neuronal cells. We used a similar approach to swap the pK motif on pIX for a sequence encoding a single-domain antibody directed towards CD66c for targeted infection of cancer cells; Cre-mediated removal of the pK-coding sequence simultaneously placed the single-domain antibody coding sequence in frame with pIX. Thus, we have developed a simple method to propagate virus lacking native viral tropism but containing cell-specific binding ligands. - Highlights: > We describe a method to grow virus lacking native tropism but containing novel cell-binding ligands. > Cre/loxP recombination was used to modify the adenovirus genome. > A targeting ligand present on capsid protein IX was removed or replaced using recombination. > Cre-loxP was also used to 'swap' the identity of the targeting ligand present on pIX.

  3. In vivo evaluation of battery-operated light-emitting diode-based photodynamic therapy efficacy using tumor volume and biomarker expression as endpoints.

    PubMed

    Mallidi, Srivalleesha; Mai, Zhiming; Rizvi, Imran; Hempstead, Joshua; Arnason, Stephen; Celli, Jonathan; Hasan, Tayyaba

    2015-04-01

    In view of the increase in cancer-related mortality rates in low- to middle-income countries (LMIC), there is an urgent need to develop economical therapies that can be utilized at minimal infrastructure institutions. Photodynamic therapy (PDT), a photochemistry-based treatment modality, offers such a possibility provided that low-cost light sources and photosensitizers are available. In this proof-of-principle study, we focus on adapting the PDT light source to a low-resource setting and compare an inexpensive, portable, battery-powered light-emitting diode (LED) light source with a standard, high-cost laser source. The comparison studies were performed in vivo in a xenograft murine model of human squamous cell carcinoma subjected to 5-aminolevulinic acid-induced protoporphyrin IX PDT. We observed virtually identical control of the tumor burden by both the LED source and the standard laser source. Further insights into the biological response were evaluated by biomarker analysis of necrosis, microvessel density, and hypoxia [carbonic anhydrase IX (CAIX) expression] among groups of control, LED-PDT, and laser-PDT treated mice. There is no significant difference in the percent necrotic volume and CAIX expression in tumors that were treated with the two different light sources. These encouraging preliminary results merit further investigations in orthotopic animal models of cancers prevalent in LMICs. PMID:25909707

  4. In vivo evaluation of battery-operated light-emitting diode-based photodynamic therapy efficacy using tumor volume and biomarker expression as endpoints

    NASA Astrophysics Data System (ADS)

    Mallidi, Srivalleesha; Mai, Zhiming; Rizvi, Imran; Hempstead, Joshua; Arnason, Stephen; Celli, Jonathan; Hasan, Tayyaba

    2015-04-01

    In view of the increase in cancer-related mortality rates in low- to middle-income countries (LMIC), there is an urgent need to develop economical therapies that can be utilized at minimal infrastructure institutions. Photodynamic therapy (PDT), a photochemistry-based treatment modality, offers such a possibility provided that low-cost light sources and photosensitizers are available. In this proof-of-principle study, we focus on adapting the PDT light source to a low-resource setting and compare an inexpensive, portable, battery-powered light-emitting diode (LED) light source with a standard, high-cost laser source. The comparison studies were performed in vivo in a xenograft murine model of human squamous cell carcinoma subjected to 5-aminolevulinic acid-induced protoporphyrin IX PDT. We observed virtually identical control of the tumor burden by both the LED source and the standard laser source. Further insights into the biological response were evaluated by biomarker analysis of necrosis, microvessel density, and hypoxia [carbonic anhydrase IX (CAIX) expression] among groups of control, LED-PDT, and laser-PDT treated mice. There is no significant difference in the percent necrotic volume and CAIX expression in tumors that were treated with the two different light sources. These encouraging preliminary results merit further investigations in orthotopic animal models of cancers prevalent in LMICs.

  5. In vivo evaluation of battery-operated light-emitting diode-based photodynamic therapy efficacy using tumor volume and biomarker expression as endpoints

    PubMed Central

    Mallidi, Srivalleesha; Mai, Zhiming; Rizvi, Imran; Hempstead, Joshua; Arnason, Stephen; Celli, Jonathan; Hasan, Tayyaba

    2015-01-01

    Abstract. In view of the increase in cancer-related mortality rates in low- to middle-income countries (LMIC), there is an urgent need to develop economical therapies that can be utilized at minimal infrastructure institutions. Photodynamic therapy (PDT), a photochemistry-based treatment modality, offers such a possibility provided that low-cost light sources and photosensitizers are available. In this proof-of-principle study, we focus on adapting the PDT light source to a low-resource setting and compare an inexpensive, portable, battery-powered light-emitting diode (LED) light source with a standard, high-cost laser source. The comparison studies were performed in vivo in a xenograft murine model of human squamous cell carcinoma subjected to 5-aminolevulinic acid-induced protoporphyrin IX PDT. We observed virtually identical control of the tumor burden by both the LED source and the standard laser source. Further insights into the biological response were evaluated by biomarker analysis of necrosis, microvessel density, and hypoxia [carbonic anhydrase IX (CAIX) expression] among groups of control, LED-PDT, and laser-PDT treated mice. There is no significant difference in the percent necrotic volume and CAIX expression in tumors that were treated with the two different light sources. These encouraging preliminary results merit further investigations in orthotopic animal models of cancers prevalent in LMICs. PMID:25909707

  6. How many carbonic anhydrase inhibition mechanisms exist?

    PubMed

    Supuran, Claudiu T

    2016-01-01

    Six genetic families of the enzyme carbonic anhydrase (CA, EC 4.2.1.1) were described to date. Inhibition of CAs has pharmacologic applications in the field of antiglaucoma, anticonvulsant, anticancer, and anti-infective agents. New classes of CA inhibitors (CAIs) were described in the last decade with enzyme inhibition mechanisms differing considerably from the classical inhibitors of the sulfonamide or anion type. Five different CA inhibition mechanisms are known: (i) the zinc binders coordinate to the catalytically crucial Zn(II) ion from the enzyme active site, with the metal in tetrahedral or trigonal bipyramidal geometries. Sulfonamides and their isosters, most anions, dithiocarbamates and their isosters, carboxylates, and hydroxamates bind in this way; (ii) inhibitors that anchor to the zinc-coordinated water molecule/hydroxide ion (phenols, carboxylates, polyamines, 2-thioxocoumarins, sulfocoumarins); (iii) inhibitors which occlude the entrance to the active site cavity (coumarins and their isosters), this binding site coinciding with that where CA activators bind; (iv) compounds which bind out of the active site cavity (a carboxylic acid derivative was seen to inhibit CA in this manner), and (v) compounds for which the inhibition mechanism is not known, among which the secondary/tertiary sulfonamides as well as imatinib/nilotinib are the most investigated examples. As CAIs are used clinically in many pathologies, with a sulfonamide inhibitor (SLC-0111) in Phase I clinical trials for the management of metastatic solid tumors, this review updates the recent findings in the field which may be useful for a structure-based drug design approach of more selective/potent modulators of the activity of these enzymes. PMID:26619898

  7. Carbon dioxide "trapped" in a β-carbonic anhydrase

    SciTech Connect

    Aggarwal, Mayank; Chua, Teck Khiang; Pinard, Melissa A.; Szebenyi, Doletha M.; McKenna, Robert

    2015-10-12

    Carbonic anhydrases (CAs) are enzymes that catalyze the hydration/ dehydration of CO2/HCO3- with rates approaching diffusion-controlled limits (kcat/KM ~ 108 M–1s–1). Here, this family of enzymes has evolved disparate protein folds that all perform the same reaction at near catalytic perfection. Presented here is a structural study of a beta-CA (psCA3) expressed in Pseudomonas aeruginosa, in complex with CO2, using pressurized cryocooled crystallography. The structure has been refined to 1.6 angstrom resolution with Rcryst and Rfree values of 17.3 and 19.9%, respectively, and is compared with the α-CA, human CA isoform II (hCA II), the only other CA to have CO2, captured in its active site. Despite the lack of structural similarity between psCA3 and hCA II, the CO2, binding orientation relative to the zinc-bound solvent is identical. In addition, a second CO2, binding site was located at the dimer interface of psCA3. Interestingly, all β-CAs function as dirners or higher-order oligomeric states, and the CO2, bound at the interface may contribute to the allosteric nature of this family of enzymes or may be a convenient alternative binding site as this pocket has been previously shown to be a promiscuous site for a variety of ligands, including bicarbonate, sulfate, and phosphate ions.

  8. Quantum supersymmetric Bianchi IX cosmology

    NASA Astrophysics Data System (ADS)

    Damour, Thibault; Spindel, Philippe

    2014-11-01

    We study the quantum dynamics of a supersymmetric squashed three-sphere by dimensionally reducing (to one timelike dimension) the action of D =4 simple supergravity for a S U (2 ) -homogeneous (Bianchi IX) cosmological model. The quantization of the homogeneous gravitino field leads to a 64-dimensional fermionic Hilbert space. After imposition of the diffeomorphism constraints, the wave function of the Universe becomes a 64-component spinor of spin(8,4) depending on the three squashing parameters, which satisfies Dirac-like, and Klein-Gordon-like, wave equations describing the propagation of a "quantum spinning particle" reflecting off spin-dependent potential walls. The algebra of the supersymmetry constraints and of the Hamiltonian one is found to close. One finds that the quantum Hamiltonian is built from operators that generate a 64-dimensional representation of the (infinite-dimensional) maximally compact subalgebra of the rank-3 hyperbolic Kac-Moody algebra A E3 . The (quartic-in-fermions) squared-mass term μ^ 2 entering the Klein-Gordon-like equation has several remarkable properties: (i) it commutes with all the other (Kac-Moody-related) building blocks of the Hamiltonian; (ii) it is a quadratic function of the fermion number NF; and (iii) it is negative in most of the Hilbert space. The latter property leads to a possible quantum avoidance of the singularity ("cosmological bounce"), and suggests imposing the boundary condition that the wave function of the Universe vanish when the volume of space tends to zero (a type of boundary condition which looks like a final-state condition when considering the big crunch inside a black hole). The space of solutions is a mixture of "discrete-spectrum states" (parametrized by a few constant parameters, and known in explicit form) and of continuous-spectrum states (parametrized by arbitrary functions entering some initial-value problem). The predominantly negative values of the squared-mass term lead to a "bottle

  9. The Carbonic Anhydrase Inhibitor Ethoxzolamide Inhibits the Mycobacterium tuberculosis PhoPR Regulon and Esx-1 Secretion and Attenuates Virulence

    PubMed Central

    Johnson, Benjamin K.; Colvin, Christopher J.; Needle, David B.; Mba Medie, Felix; Champion, Patricia A. DiGiuseppe

    2015-01-01

    Mycobacterium tuberculosis must sense and adapt to host environmental cues to establish and maintain an infection. The two-component regulatory system PhoPR plays a central role in sensing and responding to acidic pH within the macrophage and is required for M. tuberculosis intracellular replication and growth in vivo. Therefore, the isolation of compounds that inhibit PhoPR-dependent adaptation may identify new antivirulence therapies to treat tuberculosis. Here, we report that the carbonic anhydrase inhibitor ethoxzolamide inhibits the PhoPR regulon and reduces pathogen virulence. We show that treatment of M. tuberculosis with ethoxzolamide recapitulates phoPR mutant phenotypes, including downregulation of the core PhoPR regulon, altered accumulation of virulence-associated lipids, and inhibition of Esx-1 protein secretion. Quantitative single-cell imaging of a PhoPR-dependent fluorescent reporter strain demonstrates that ethoxzolamide inhibits PhoPR-regulated genes in infected macrophages and mouse lungs. Moreover, ethoxzolamide reduces M. tuberculosis growth in both macrophages and infected mice. Ethoxzolamide inhibits M. tuberculosis carbonic anhydrase activity, supporting a previously unrecognized link between carbonic anhydrase activity and PhoPR signaling. We propose that ethoxzolamide may be pursued as a new class of antivirulence therapy that functions by modulating expression of the PhoPR regulon and Esx-1-dependent virulence. PMID:25987613

  10. The Carbonic Anhydrase Inhibitor Ethoxzolamide Inhibits the Mycobacterium tuberculosis PhoPR Regulon and Esx-1 Secretion and Attenuates Virulence.

    PubMed

    Johnson, Benjamin K; Colvin, Christopher J; Needle, David B; Mba Medie, Felix; Champion, Patricia A DiGiuseppe; Abramovitch, Robert B

    2015-08-01

    Mycobacterium tuberculosis must sense and adapt to host environmental cues to establish and maintain an infection. The two-component regulatory system PhoPR plays a central role in sensing and responding to acidic pH within the macrophage and is required for M. tuberculosis intracellular replication and growth in vivo. Therefore, the isolation of compounds that inhibit PhoPR-dependent adaptation may identify new antivirulence therapies to treat tuberculosis. Here, we report that the carbonic anhydrase inhibitor ethoxzolamide inhibits the PhoPR regulon and reduces pathogen virulence. We show that treatment of M. tuberculosis with ethoxzolamide recapitulates phoPR mutant phenotypes, including downregulation of the core PhoPR regulon, altered accumulation of virulence-associated lipids, and inhibition of Esx-1 protein secretion. Quantitative single-cell imaging of a PhoPR-dependent fluorescent reporter strain demonstrates that ethoxzolamide inhibits PhoPR-regulated genes in infected macrophages and mouse lungs. Moreover, ethoxzolamide reduces M. tuberculosis growth in both macrophages and infected mice. Ethoxzolamide inhibits M. tuberculosis carbonic anhydrase activity, supporting a previously unrecognized link between carbonic anhydrase activity and PhoPR signaling. We propose that ethoxzolamide may be pursued as a new class of antivirulence therapy that functions by modulating expression of the PhoPR regulon and Esx-1-dependent virulence. PMID:25987613

  11. A gene homologous to beta-type carbonic anhydrase is essential for the growth of Corynebacterium glutamicum under atmospheric conditions.

    PubMed

    Mitsuhashi, S; Ohnishi, J; Hayashi, M; Ikeda, M

    2004-02-01

    Carbonic anhydrase catalyzes the interconversion of CO(2) and bicarbonate. We focused on this enzyme in the amino acid-producing organism Corynebacterium glutamicum in order to assess the availability of bicarbonate for carboxylation reactions essential to growth and for those required for L-lysine overproduction. A whole-genome sequence revealed two genes encoding putative beta-type and gamma-type carbonic anhydrases in C. glutamicum. These genes encode polypeptides containing zinc ligands strictly conserved in each type of carbonic anhydrase and were designated bca and gca, respectively. Internal deletion of the chromosomal bca gene resulted in a phenotype showing severely reduced growth under atmospheric conditions (0.04% CO(2)) on both complete and minimal media. The growth defect of the Delta bca strain was restored under elevated CO(2) conditions (5% CO(2)). Introduction of the red alga Porphyridium purpureum carbonic anhydrase gene ( pca) could compensate for the bca deletion, allowing normal growth under an atmospheric level of CO(2). In contrast, the Delta gca strain behaved identically to the wild-type strain with respect to growth, irrespective of the CO(2) conditions. Attempts to increase the dosage of bca, gca, and pca in the defined L-lysine-producing strain C. glutamicum AHD-2 led to no discernable effects on growth and production. Northern blot analysis indicated that the bca transcript in strain AHD-2 and another L-lysine producer, C. glutamicum B-6, was present at a much higher level than in the wild-type strain, particularly during exponential growth phases. These results indicate that: (1) the bca product is essential to achieving normal growth under ordinary atmospheric conditions, and this effect is most likely due to the bca product's ability to maintain favorable intracellular bicarbonate/CO(2) levels, and (2) the expression of bca is induced during exponential growth phases and also in the case of L-lysine overproduction, both of which are

  12. Fluorescence Analysis of Sulfonamide Binding to Carbonic Anhydrase

    ERIC Educational Resources Information Center

    Wang, Sheila C.; Zamble, Deborah B.

    2006-01-01

    A practical laboratory experiment is described that illustrates the application of fluorescence resonance energy transfer to the study of protein-ligand binding. The affinities of wild-type and mutant human carbonic anhydrase II for dansylamide were determined by monitoring the increase in ligand fluorescence that occurs due to energy transfer…

  13. Fluorescent Silica Nanoparticles with Multivalent Inhibitory Effects towards Carbonic Anhydrases.

    PubMed

    Touisni, Nadia; Kanfar, Nasreddine; Ulrich, Sébastien; Dumy, Pascal; Supuran, Claudiu T; Mehdi, Ahmad; Winum, Jean-Yves

    2015-07-13

    Invited for the cover of this issue are Jean-Yves Winum and co-workers at University of Montpellier (France) and University of Florence (Italy). The image depicts the multivalency approach applied to zinc metalloenzyme carbonic anhydrases. Read the full text of the article at 10.1002/chem.201501037. PMID:26061872

  14. Identification and characterization of a gene encoding a vertebrate-type carbonic anhydrase in cyanobacteria.

    PubMed Central

    Soltes-Rak, E; Mulligan, M E; Coleman, J R

    1997-01-01

    A gene (designated ecaA) encoding a vertebrate-like (alpha-type) carbonic anhydrase (CA) has been isolated from two disparate cyanobacteria, Anabaena sp. strain PCC 7120 and Synechococcus sp. strain PCC 7942. The deduced amino acid sequences correspond to proteins of 29 and 26 kDa, respectively, and revealed significant sequence similarity to human CAI and CAII, as well as Chlamydomonas CAHI, including conservation of most active-site residues identified in the animal enzymes. Structural similarities between the animal and cyanobacterial enzymes extend to the levels of antigenicity, as the Anabaena protein cross-reacts with antisera derived against chicken CAII. Expression of the cyanobacterial ecaA is regulated by CO2 concentration and is highest in cells grown at elevated levels of CO2. Immunogold localization using an antibody derived against the ecaA protein indicated an extracellular location. Preliminary analysis of Synechococcus mutants in which ecaA has been inactivated by insertion of a drug resistance cassette suggests that extracellular carbonic anhydrase plays a role in inorganic-carbon accumulation by maintaining equilibrium levels of CO2 and HCO3- in the periplasm. PMID:9006032

  15. Title IX: With New Opportunities, Girls' Interest Rises

    ERIC Educational Resources Information Center

    Toporek, Bryan

    2012-01-01

    On June 23, 1972, President Richard M. Nixon signed into law Title IX of the Education Amendments of 1972, which prohibits gender discrimination in any federally financed education program or activity. Title IX is far-reaching, but the law is most often associated with school and college athletics. Title IX allows schools to prove their athletic…

  16. The Restoration of Title IX: Implications for Higher Education.

    ERIC Educational Resources Information Center

    Sandler, Bernice R.

    This booklet helps institutions understand the restoration of Title IX of the Education Amendments of 1972 and changes resulting from the Civil Rights Restoration Act. Title IX prohibits sex discrimination in federally assisted education programs. A 1984 ruling held that Title IX covers only programs or activities funded with federal money. In…

  17. Deletion of the carbonic anhydrase-like gene NCE103 of the yeast Saccharomyces cerevisiae causes an oxygen-sensitive growth defect.

    PubMed

    Götz, R; Gnann, A; Zimmermann, F K

    1999-07-01

    The yeast protein Nce103p encoded by the gene NCE103 (YNL036w) was described by Cleves et al. (1996) as a substrate of the non-classical export pathway which acts independently of the classical pathway through the ER and the Golgi compartments. However, the predicted amino acid sequence of Nce103p shows high levels of identities to carbonic anhydrases of pro- and eukaryotes. A nce103-Delta deletion strain did not grow on a rich peptone-yeast extract-glucose medium under normal aerobic conditions at pH values of 3.0-8.0, but grew like wild-type in an oxygen-free nitrogen or oxygen-reduced atmosphere over this pH range, and was more sensitive to H(2)O(2) than wild-type. No carbonic anhydrase activity could be detected in crude extracts prepared from wild-type, nce103-Delta mutants or in strains transformed with a multicopy plasmid carrying the NCE103 gene. Expression of the Medicago sativa carbonic anhydrase gene (Coba de la Peña et al., 1997), in a yeast expression cassette on a multicopy plasmid, complemented the growth defects caused by the nce103-Delta deletion and carbonic anhydrase activity could be readily detected in the crude extract. The ability of the nce103-Delta deletion strain to grow like wild-type under anaerobic conditions suggests that the protein encoded by NCE103 is required for protection against certain products of an oxidative metabolism and can be replaced in this function by the Medicago sativa carbonic anhydrase. A NCE103 promoter-LacZ fusion in a wild-type background showed that NCE103 is poorly transcribed under aerobic conditions and at an undetectable level under anaerobic conditions. PMID:10407265

  18. Probing the Surface of Human Carbonic Anhydrase for Clues towards the Design of Isoform Specific Inhibitors

    PubMed Central

    Pinard, Melissa A.

    2015-01-01

    The alpha carbonic anhydrases (α-CAs) are a group of structurally related zinc metalloenzymes that catalyze the reversible hydration of CO2 to HCO3−. Humans have 15 different α-CAs with numerous physiological roles and expression patterns. Of these, 12 are catalytically active, and abnormal expression and activities are linked with various diseases, including glaucoma and cancer. Hence there is a need for CA isoform specific inhibitors to avoid off-target CA inhibition, but due to the high amino acid conservation of the active site and surrounding regions between each enzyme, this has proven difficult. However, residues towards the exit of the active site are variable and can be exploited to design isoform selective inhibitors. Here we discuss and characterize this region of “selective drug targetability” and how these observations can be utilized to develop isoform selective CA inhibitors. PMID:25811028

  19. Ares I-X Vibroacoustic Environments

    NASA Technical Reports Server (NTRS)

    Larsen, Curtis E.; Schuster, David M.; Kaufman, Daniel S.

    2009-01-01

    This paper provides a summary of the NASA Engineering and Safety Center (NESC) team recommendations and observations following participation with the Ares I-X Vibroacoustic (VA) Environments Panel in meetings at the Kennedy Space Center (KSC) and the Marshall Space Flight Center (MSFC) in March and April 2008, respectively.

  20. Open to All: Title IX at 30.

    ERIC Educational Resources Information Center

    Department of Education, Washington, DC. Office of the Secretary.

    This document is a report to the secretary of education on the findings of the Secretary's Commission on Opportunities in Athletics. The Commission was charged with examining Title IX. Starting in June 2002, the 15-member commission collected information, analyzed issues, and obtained broad public input directed at improving the application of…

  1. Calculation of Electronic Transitions in S IX

    NASA Astrophysics Data System (ADS)

    Bogdanovich, P.; Karpuškienė, R.; Rudzikas, Z.

    Wavelengths and oscillator strengths of electric dipole transitions from the 2p33l configurations of S IX are calculated. Relativistic and correlation effects are accounted for in Hartree-Fock-Pauli approximation and in the basis of transformed radial orbitals. Fairly high accuracy of results is achieved.

  2. Title IX Enforcement Called 'Deeply Troubling'

    ERIC Educational Resources Information Center

    Lipka, Sara; Wolverton, Brad

    2007-01-01

    The government agency responsible for enforcing gender equity in college sports is falling down on the job, according to a report released by the National Women's Law Center. Over the past five years, the U.S. Education Department's Office for Civil Rights -- the administrative guardian of Title IX of the Education Amendments of 1972, the law that…

  3. Feminizing Science: The Alchemy of Title IX

    ERIC Educational Resources Information Center

    Hausman, Patricia

    2008-01-01

    The author scrutinizes the National Academy of Sciences report "Beyond Bias and Barriers: Fulfilling the Potential of Women in Academic Science and Engineering" and its dangerous call to place the sciences under the sledgehammer of Title IX. Her findings: A one-sided, inaccurate, and internally contradictory report prepared by a committee lacking…

  4. Title IX Indian Education Toolkit. A Step-by-Step Guide to the Title IX Indian Education Formula Grant.

    ERIC Educational Resources Information Center

    Beller, Floyd

    Title IX is a federal Indian Education Formula Grant Program approved in 1972 and reauthorized five times, most recently in 1994. Title IX formula grants assist groups in providing sound educational programs and opportunities for American Indian and Alaska Native students. A 1997-98 survey of Title IX grantees revealed their need for help in…

  5. Inhibition of mammalian carbonic anhydrase isoforms I-XIV with a series of phenolic acid esters.

    PubMed

    Maresca, Alfonso; Akyuz, Gulay; Osman, Sameh M; AlOthman, Zeid; Supuran, Claudiu T

    2015-11-15

    A series of phenolic acid esters incorporating caffeic, ferulic, and p-coumaric acid, and benzyl, m/p-hydroxyphenethyl- as well as p-hydroxy-phenethoxy-phenethyl moieties were investigated for their inhibitory effects against the metalloenzyme carbonic anhydrase (CA, EC 4.2.1.1). Many of the mammalian isozymes of human (h) or murine (m) origin, hCA I-hCA XII, mCA XIII and hCA XIV, were inhibited in the submicromolar range by these derivatives (with KIs of 0.31-1.03 μM against hCA VA, VB, VI, VII, IX and XIV). The off-target, highly abundant isoforms hCA I and II, as well as hCA III, IV and XII were poorly inhibited by many of these esters, although the original phenolic acids were micromolar inhibitors. These phenols, like others investigated earlier, possess a CA inhibition mechanism distinct of the sulfonamides/sulfamates, clinically used drugs for the treatment of a multitude of pathologies, but with severe side effects due to hCA I/II inhibition. Unlike the sulfonamides, which bind to the catalytic zinc ion, phenols are anchored at the Zn(II)-coordinated water molecule, binding more externally within the active site cavity, and making contacts with amino acid residues at the entrance of the active site. As this is the region with the highest variability between the many CA isozymes found in mammals, this class of compounds shows isoform-selective inhibitory profiles, which may be exploited for obtaining pharmacological agents with less side effects compared to other classes of inhibitors. PMID:26498394

  6. In Vivo Gene Therapy of Hemophilia B: Sustained Partial Correction in Factor IX-Deficient Dogs

    NASA Astrophysics Data System (ADS)

    Kay, Mark A.; Rothenberg, Steven; Landen, Charles N.; Bellinger, Dwight A.; Leland, Frances; Toman, Carol; Finegold, Milton; Thompson, Arthur R.; Read, M. S.; Brinkhous, Kenneth M.; Woo, Savio L. C.

    1993-10-01

    The liver represents a model organ for gene therapy. A method has been developed for hepatic gene transfer in vivo by the direct infusion of recombinant retroviral vectors into the portal vasculature, which results in the persistent expression of exogenous genes. To determine if these technologies are applicable for the treatment of hemophilia B patients, preclinical efficacy studies were done in a hemophilia B dog model. When the canine factor IX complementary DNA was transduced directly into the hepatocytes of affected dogs in vivo, the animals constitutively expressed low levels of canine factor IX for more than 5 months. Persistent expression of the clotting. factor resulted in reductions of whole blood clotting and partial thromboplastin times of the treated animals. Thus, long-term treatment of hemophilia B patients may be feasible by direct hepatic gene therapy in vivo.

  7. Electron Impact Collision Strength in Si IX

    NASA Astrophysics Data System (ADS)

    Noman, Hala; Gokce, Y.; Nahar, Sultana; Pradhan, Anil

    2016-05-01

    Results from work in progress under Iron Project on the electron impact excitation collision strengths and rate coefficients for transitions between the fine-structure levels of the 2s2 2p2 , 2 s 2p3 , 2p4 , 2s2 2 p 3 s , 2s2 2 p 3 p , and 2s2 2 p 3 d configurations in Si IX will be presented. The fine structure collision strength has been calculated at very fine energy mesh using relativistic effects in Breit-Pauli R-matrix method. Maxwellian averaged collision strengths have been tabulated for all possible transitions among all 46 enrgy levels. We made comparisions of our results with the previously reported results in the literature and found significant differences in low the temperature range (Te < 106 K) for few of the transitions. The correction to the previous reported values results due to more extensive expansion for Si IX target states.

  8. Amido/ureidosubstituted benzenesulfonamides-isatin conjugates as low nanomolar/subnanomolar inhibitors of the tumor-associated carbonic anhydrase isoform XII.

    PubMed

    Eldehna, Wagdy M; Fares, Mohamed; Ceruso, Mariangela; Ghabbour, Hazem A; Abou-Seri, Sahar M; Abdel-Aziz, Hatem A; Abou El Ella, Dalal A; Supuran, Claudiu T

    2016-03-01

    By using a molecular hybridization approach, two series of amido/ureidosubstituted benzenesulfonamides incorporating substituted-isatin moieties were synthesized. The prepared derivatives were in vitro evaluated for their inhibitory activity against human carbonic anhydrase (hCA, EC 4.2.1.1) I, II (cytosolic) and IX, XII (transmembrane, tumor-associated) isoforms. All these isoforms were inhibited in variable degrees by the sulfonamides reported here. hCA I was inhibited with KIs in the range of 7.9-894 nM, hCA II in the range of 7.5-1645 nM (with one compound having a KI > 10 μM); hCA IX in the range of 5.0-240 nM, whereas hCA XII in the range of 0.47-2.83 nM. As all these isoforms are involved in various pathologies, in which their inhibition can be exploited therapeutically, the derivatives reported here may represent interesting extensions to the field of CA inhibitors of the sulfonamide type. PMID:26840366

  9. The Complex Relationship between Metals and Carbonic Anhydrase: New Insights and Perspectives

    PubMed Central

    Lionetto, Maria Giulia; Caricato, Roberto; Giordano, Maria Elena; Schettino, Trifone

    2016-01-01

    Carbonic anhydrase is a ubiquitous metalloenzyme, which catalyzes the reversible hydration of CO2 to HCO3− and H+. Metals play a key role in the bioactivity of this metalloenzyme, although their relationships with CA have not been completely clarified to date. The aim of this review is to explore the complexity and multi-aspect nature of these relationships, since metals can be cofactors of CA, but also inhibitors of CA activity and modulators of CA expression. Moreover, this work analyzes new insights and perspectives that allow translating new advances in basic science on the interaction between CA and metals to applications in several fields of research, ranging from biotechnology to environmental sciences. PMID:26797606

  10. Rational engineering of a mesohalophilic carbonic anhydrase to an extreme halotolerant biocatalyst.

    PubMed

    Warden, Andrew C; Williams, Michelle; Peat, Thomas S; Seabrook, Shane A; Newman, Janet; Dojchinov, Greg; Haritos, Victoria S

    2015-01-01

    Enzymes expressed by highly salt-tolerant organisms show many modifications compared with salt-affected counterparts including biased amino acid and lower α-helix content, lower solvent accessibility and negative surface charge. Here, we show that halotolerance can be generated in an enzyme solely by modifying surface residues. Rational design of carbonic anhydrase II is undertaken in three stages replacing 18 residues in total, crystal structures confirm changes are confined to surface residues. Catalytic activities and thermal unfolding temperatures of the designed enzymes increase at high salt concentrations demonstrating their shift to halotolerance, whereas the opposite response is found in the wild-type enzyme. Molecular dynamics calculations reveal a key role for sodium ions in increasing halotolerant enzyme stability largely through interactions with the highly ordered first Na(+) hydration shell. For the first time, an approach to generate extreme halotolerance, a trait with broad application in industrial biocatalysis, in a wild-type enzyme is demonstrated. PMID:26687908

  11. Rational engineering of a mesohalophilic carbonic anhydrase to an extreme halotolerant biocatalyst

    PubMed Central

    Warden, Andrew C.; Williams, Michelle; Peat, Thomas S.; Seabrook, Shane A.; Newman, Janet; Dojchinov, Greg; Haritos, Victoria S.

    2015-01-01

    Enzymes expressed by highly salt-tolerant organisms show many modifications compared with salt-affected counterparts including biased amino acid and lower α-helix content, lower solvent accessibility and negative surface charge. Here, we show that halotolerance can be generated in an enzyme solely by modifying surface residues. Rational design of carbonic anhydrase II is undertaken in three stages replacing 18 residues in total, crystal structures confirm changes are confined to surface residues. Catalytic activities and thermal unfolding temperatures of the designed enzymes increase at high salt concentrations demonstrating their shift to halotolerance, whereas the opposite response is found in the wild-type enzyme. Molecular dynamics calculations reveal a key role for sodium ions in increasing halotolerant enzyme stability largely through interactions with the highly ordered first Na+ hydration shell. For the first time, an approach to generate extreme halotolerance, a trait with broad application in industrial biocatalysis, in a wild-type enzyme is demonstrated. PMID:26687908

  12. Identification of the endothelial cell binding site for factor IX.

    PubMed Central

    Cheung, W F; van den Born, J; Kühn, K; Kjellén, L; Hudson, B G; Stafford, D W

    1996-01-01

    We previously demonstrated that the primary region of factor IX and IXa responsible for saturable specific binding to bovine aortic endothelial cells resides in residues 3-11 at the amino terminus of factor IX. We also demonstrated that mutations of lysine to alanine at residue 5, factor IX K5A, or valine to lysine at residue 10, factor IX V10K, resulted in a molecule unable to bind to endothelial cells. Moreover, a mutation with lysine to arginine at residue 5, factor IX K5R, resulted in a factor IX molecule with increased affinity for the endothelial cell binding site. In this paper we report that collagen IV is a strong candidate for the factor IX binding site on endothelial cells. Factor IX and factor IX K5R compete with 125I-labeled factor IX for binding to tetrameric collagen IV immobilized on microtiter plates, while factor X, factor VII, and factor IX K5A or V10K fail to compete. The Kd for wild-type factor IX binding to collagen IV in the presence of heparin was 6.8 +/- 2 nM, and the Kd for factor IX K5R was 1.1 +/- 0.2 nM, which agrees well with our previously published Kd values of 7.4 and 2.4 nM for binding of the same proteins to endothelial cells. Our working assumption is that we have identified the endothelial cell binding site and that it is collagen IV. Its physiological relevance remains to be determined. PMID:8855310

  13. Disorders of Cranial Nerves IX and X

    PubMed Central

    Erman, Audrey B.; Kejner, Alexandra E.; Hogikyan, Norman D.; Feldman, Eva L.

    2014-01-01

    The glossopharyngeal and vagus nerves mediate the complex interplay between the many functions of the upper aerodigestive tract. Defects may occur anywhere from the brainstem to the peripheral nerve and can result in significant impairment in speech, swallowing, and breathing. Multiple etiologies can produce symptoms. This review will broadly examine the normal functions, clinical examination, and various pathologies of cranial nerves IX and X. PMID:19214937

  14. Experimental Mg IX photorecombination rate coefficient

    NASA Astrophysics Data System (ADS)

    Schippers, S.; Schnell, M.; Brandau, C.; Kieslich, S.; Müller, A.; Wolf, A.

    2004-07-01

    The rate coefficient for radiative and dielectronic recombination of beryllium-like magnesium ions was measured with high resolution at the Heidelberg heavy-ion storage ring TSR. In the electron-ion collision energy range 0-207 eV resonances due to 2s -> 2p (Δ N = 0) and 2s -> 3l (Δ N=1) core excitations were detected. At low energies below 0.15 eV the recombination rate coefficient is dominated by strong 1s2 (2s 2p 3P) 7l resonances with the strongest one occuring at an energy of only 21 meV. These resonances decisively influence the Mg IX recombination rate coefficient in a low temperature plasma. The experimentally derived Mg IX dielectronic recombination rate coefficient (±15% systematical uncertainty) is compared with the recommendation by Mazzotta et al. (1998, A&AS, 133, 403) and the recent calculations by Gu (2003, ApJ, 590, 1131) and by Colgan et al. (2003, A&A, 412, 597). These results deviate from the experimental rate coefficient by 130%, 82% and 25%, respectively, at the temperature where the fractional abundance of Mg IX is expected to peak in a photoionized plasma. At this temperature a theoretical uncertainty in the 1s2 (2s 2p 3P) 7l resonance positions of only 100 meV would translate into an uncertainty of the plasma rate coefficient of almost a factor 3. This finding emphasizes that an accurate theoretical calculation of the Mg IX recombination rate coefficient from first principles is challenging.

  15. Ares I-X 30 Day Report

    NASA Technical Reports Server (NTRS)

    Ess, Bob; Smith, Marshall

    2009-01-01

    This slide presentation represents the 30 day report on the Ares I-X test flight. Included in the review is information on the following areas: (1) Ground Systems, (2) Guidance, Navigation and Control, (3) Roll Response, (4) Vehicle Response, (5) Control System Performance, (6) Structural Damping, (7) Thrust Oscillation, (8) Stage Separation, (9) Connector Assessment, (10) USS Splashdown, (11) Data Recorder and (12) FS Hardware Assessment.

  16. CO2 Removal using a Synthetic Analogue of Carbonic Anhydrase

    SciTech Connect

    Cordatos, Harry

    2010-09-14

    Project attempts to develop a synthetic analogue for carbonic anhydrase and incorporate it in a membrane for separation of CO2 from coal power plant flue gas. Conference poster presents result of first 9 months of project progress including concept, basic system architecture and membrane properties target, results of molecular modeling for analogue - CO2 interaction, and next steps of testing analogue resistance to flue gas contaminants.

  17. [Ultrasmall nanoparticles for radiotherapy: AGuIX].

    PubMed

    Lux, F; Detappe, A; Dufort, S; Sancey, L; Louis, C; Carme, S; Tillement, O

    2015-10-01

    Since twenty years, many nanoparticles based on high atomic number elements have been developed as radiosensitizers. The design of these nanoparticles is limited by the classical rules associated with the development of nanoparticles for oncology and by the specific ones associated to radiosensitizers, which aim to increase the effect of the dose in the tumor area and to spare the health tissues. For this application, systemic administration of nanodrugs is possible. This paper will discuss the development of AGuIX nanoparticles and will emphasize on this example the critical points for the development of a nanodrug for this application. AGuIX nanoparticles display hydrodynamic diameters of a few nanometers and are composed of polysiloxane and gadolinium chelates. This particle has been used in many preclinical studies and is evaluated for a further phase I clinical trial. Finally, in addition to its high radiosensitizing potential, AGuIX display MRI functionality and can be used as theranostic nanodrug for personalized medicine. PMID:26343033

  18. An Update on Natural Products with Carbonic Anhydrase Inhibitory Activity.

    PubMed

    Karioti, Anastasia; Carta, Fabrizio; Supuran, Claudiu T

    2016-01-01

    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 processes. They represent a typical example of enzyme convergent evolution, as six genetically unrelated families of such enzymes were described so far. It is more than 70 years that synthetic compounds, mainly sulfonamides, have been used in clinical practice as diuretics and systemic acting antiglaucoma drugs. Recent studies using natural product libraries and isolated constituents from natural sources (such as fungi and plants) have disclosed novel chemotypes possessing carbonic anhydrase inhibition activities. These natural sources offer new opportunities in the search for new and more effective carbonic anhydrase inhibitors, and may serve as new leads for the design and development of future drugs. This review will discuss the most recent advances in the search of naturally occurring products and their synthetic derivatives that inhibit the CAs and their mechanisms of action at molecular level. Plant extracts are not considered in the present review. PMID:26654592

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

    PubMed

    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. PMID:24385198

  20. Carbonic Anhydrases in Cnidarians: Novel Perspectives from the Octocorallian Corallium rubrum

    PubMed Central

    Le Goff, Carine; Ganot, Philippe; Zoccola, Didier; Caminiti-Segonds, Natacha; Allemand, Denis; Tambutté, Sylvie

    2016-01-01

    Although the ability to elaborate calcium carbonate biominerals was apparently gained independently during animal evolution, members of the alpha carbonic anhydrases (α-CAs) family, which catalyze the interconversion of CO2 into HCO3-, are involved in the biomineralization process across metazoans. In the Mediterranean red coral Corallium rubrum, inhibition studies suggest an essential role of CAs in the synthesis of two biominerals produced in this octocoral, the axial skeleton and the sclerites. Hitherto no molecular characterization of these enzymes was available. In the present study we determined the complete set of α-CAs in C. rubrum by data mining the genome and transcriptome, and measured their differential gene expression between calcifying and non-calcifying tissues. We identified six isozymes (CruCA1-6), one cytosolic and five secreted/membrane-bound among which one lacked two of the three zinc-binding histidines and was so referred to as a carbonic anhydrase related protein (CARP). One secreted isozyme (CruCA4) showed specific expression both by qPCR and western-blot in the calcifying tissues, suggesting its involvement in biomineralization. Moreover, phylogenetic analyses of α-CAs, identified in six representative cnidarians with complete genome, support an independent recruitment of α-CAs for biomineralization within anthozoans. Finally, characterization of cnidarian CARPs highlighted two families: the monophyletic cytosolic CARPs, and the polyphyletic secreted CARPs harboring a cnidarian specific cysteine disulfide bridge. Alignment of the cytosolic CARPs revealed an evolutionary conserved R-H-Q motif in place of the characteristic zinc-binding H-H-H necessary for the catalytic function of α-CAs. PMID:27513959

  1. Carbonic Anhydrases in Cnidarians: Novel Perspectives from the Octocorallian Corallium rubrum.

    PubMed

    Le Goff, Carine; Ganot, Philippe; Zoccola, Didier; Caminiti-Segonds, Natacha; Allemand, Denis; Tambutté, Sylvie

    2016-01-01

    Although the ability to elaborate calcium carbonate biominerals was apparently gained independently during animal evolution, members of the alpha carbonic anhydrases (α-CAs) family, which catalyze the interconversion of CO2 into HCO3-, are involved in the biomineralization process across metazoans. In the Mediterranean red coral Corallium rubrum, inhibition studies suggest an essential role of CAs in the synthesis of two biominerals produced in this octocoral, the axial skeleton and the sclerites. Hitherto no molecular characterization of these enzymes was available. In the present study we determined the complete set of α-CAs in C. rubrum by data mining the genome and transcriptome, and measured their differential gene expression between calcifying and non-calcifying tissues. We identified six isozymes (CruCA1-6), one cytosolic and five secreted/membrane-bound among which one lacked two of the three zinc-binding histidines and was so referred to as a carbonic anhydrase related protein (CARP). One secreted isozyme (CruCA4) showed specific expression both by qPCR and western-blot in the calcifying tissues, suggesting its involvement in biomineralization. Moreover, phylogenetic analyses of α-CAs, identified in six representative cnidarians with complete genome, support an independent recruitment of α-CAs for biomineralization within anthozoans. Finally, characterization of cnidarian CARPs highlighted two families: the monophyletic cytosolic CARPs, and the polyphyletic secreted CARPs harboring a cnidarian specific cysteine disulfide bridge. Alignment of the cytosolic CARPs revealed an evolutionary conserved R-H-Q motif in place of the characteristic zinc-binding H-H-H necessary for the catalytic function of α-CAs. PMID:27513959

  2. Structural insights on carbonic anhydrase inhibitory action, isoform selectivity, and potency of sulfonamides and coumarins incorporating arylsulfonylureido groups.

    PubMed

    Bozdag, Murat; Ferraroni, Marta; Carta, Fabrizio; Vullo, Daniela; Lucarini, Laura; Orlandini, Elisabetta; Rossello, Armando; Nuti, Elisa; Scozzafava, Andrea; Masini, Emanuela; Supuran, Claudiu T

    2014-11-13

    Sulfonamides and coumarins incorporating arylsulfonylureido tails were prepared and assayed as inhibitors of the metalloenzyme carbonic anhydrase (CA, EC 4.2.1.1). Some derivatives incorporating 3-pyridinesulfonamide and arylsulfonylureoido fragments were low nanomolar inhibitors of isoforms CA II and XII (upregulated or overexpressed in glaucoma) and showed effective in vivo intraocular pressure lowering effects in an animal model of the disease, which were several times better compared to those of the antiglaucoma drug dorzolamide. By means of X-ray crystallography of adducts of several sulfonamides with CA II, the effective inhibitory properties were rationalized at the molecular level. The coumarins were ineffective as hCA I and II inhibitors but showed low nanomolar activity for the inhibition of the tumor-associated isoforms hCA IX and XII. The presence of arylsulfonylureido tails in these CA inhibitors possessing quite different mechanisms of action led to highly effective and isoform-selective compounds targeting enzymes involved in severe pathologies such as glaucoma or cancer. PMID:25310626

  3. Zinc protoporphyrin IX enhances chemotherapeutic response of hepatoma cells to cisplatin

    PubMed Central

    Liu, Yang-Sui; Li, Huan-Song; Qi, Dun-Feng; Zhang, Jun; Jiang, Xin-Chun; Shi, Kui; Zhang, Xiao-Jun; Zhang, Xin-Hui

    2014-01-01

    AIM: To investigate the effect of zinc protoporphyrin IX on the response of hepatoma cells to cisplatin and the possible mechanism involved. METHODS: Cytotoxicity was determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Apoptosis was determined by a flow cytometric assay. Western blotting was used to measure protein expression. Heme oxygenase (HO)-1 activity was measured by determining the level of bilirubin generated in isolated microsomes. Reactive oxygen species (ROS) production was monitored by flow cytometry. Caspase-3 activity was measured with a colorimetric assay kit. Mice were inoculated with 1 × 107 tumor cells subcutaneously into the right flanks. All mice were sacrificed 6 wk after the first treatment and tumors were weighed and measured. RESULTS: Overexpression of HO-1 in HepG2 cell line was associated with increased chemoresistance to cis-diaminedichloroplatinum (cisplatin; CDDP) compared to other cell lines in vitro. Inhibition of HO-1 expression or activity by zinc protoporphyrin IX (ZnPP IX) markedly augmented CDDP-mediated cytotoxicity towards all liver cancer cell lines in vitro and in vivo. In contrast, induction of HO-1 with hemin increased resistance of tumor cells to CDDP-mediated cytotoxicity in vitro and in vivo. Furthermore, cells treated with ZnPP IX plus CDDP exhibited marked production of intracellular ROS and caspase-3 activity, which paralleled the incidence of cell apoptosis, whereas hemin decreased cellular ROS and caspase-3 activity induced by CDDP. CONCLUSION: ZnPP IX increases cellular sensitivity and susceptibility of liver cancer cell lines to CDDP and this may represent a mechanism of increasing ROS. PMID:25024611

  4. Coexistent loss of INI1 and BRG1 expression in a rhabdoid renal cell carcinoma (RCC): implications for a possible role of SWI/SNF complex in the pathogenesis of RCC.

    PubMed

    Rao, Qiu; Xia, Qiu-Yuan; Shen, Qin; Shi, Shan-Shan; Tu, Pin; Shi, Qun-Li; Zhou, Xiao-Jun

    2014-01-01

    In this study, we analyzed the immunohistochemical and molecular profiles of an unusual RCC showed coexistent absence of INI1 and BRG1 expression, rhabdoid morphology, and poor prognosis. Histologically, the tumor had rhabdoid features, which were demonstrated by large round to polygonal cells with eccentric nuclei, prominent nucleoli, and eosinophilic cytoplasm varying from abundant to scanty. Immunohistochemically, the tumor were positive for BRM, PBRM1, ARID1A, CD10, CKpan, Vimentin, carbonic anhydrase IX (CA-IX), and P504S (AMACR) but negative for INI1, BRG1, HMB45, melan A, CK7, CD117, Ksp-cadherin, TFEB, TFE3, and Cathepsin K. We detected all three exons status of the VHL gene of the tumor and observed 1 somatic mutations in 1st exon. Chromosome 3p deletion, coupled with polysomy of chromosome 3 was also found. Based on these findings, it is further indicated that in some cases, rhabdoid RCC may arise from clear cell RCC. SWI/SNF chromatin remodeling complex may be an attractive candidate for being the "second hit" in RCCs and may play an important role during tumor progression. The role of SWI/SNF complex in rhabdoid RCC should be further studied on a larger number of cases. PMID:24817979

  5. Carbonic anhydrase II deficiency: Single-base deletion in exon 7 is the predominant mutation in Caribbean Hispanic patients

    SciTech Connect

    Hu, P.Y.; Ernst, A.R.; Sly, W.S. ); Venta, P.J. ); Skaggs, L.A.; Tashian, R.E. )

    1994-04-01

    To date, three different structural gene mutations have been identified in patients with carbonic anhydrase II deficiency (osteopetrosis with renal tubular acidosis and cerebral calcification). These include a missense mutation (H107Y) in two families, a splice junction mutation in intron 5 in one of these families, and a splice junction mutation in intron 2 for which many Arabic patients are homozygous. The authors report here a novel mutation for which carbonic anhydrase II-deficient patients from seven unrelated Hispanic families were found to be homozygous. The proband was a 2 1/2-year-old Hispanic girl of Puerto Rican ancestry who was unique clinically, in that she had no evidence of renal tubular acidosis, even though she did have osteopetrosis, developmental delay, and cerebral calcification. She proved to be homozygous for a single-base deletion in the coding region of exon 7 that produces a frameshift that changes the next 12 amino acids before leading to chain termination and that also introduces a new MaeIII restriction site. The 27-kD truncated enzyme produced when the mutant cDNA was expressed in COS cells was enzymatically inactive, present mainly in insoluble aggregates, and detectable immunologically at only 5% the level of the 29-kD normal carbonic anhydrase II expressed from the wild-type cDNA. Metabolic labeling revealed that this 27-kD mutant protein has an accelerated rate of degradation. Six subsequent Hispanic patients of Caribbean ancestry, all of whom had osteopetrosis and renal tubular acidosis but who varied widely in clinical severity, were found to be homozygous for the same mutation. These findings identify a novel mutation common to Hispanic patients from the Caribbean islands and provide a ready means for PCR-based diagnosis of the [open quotes]Hispanic mutation.[close quotes] The basis for their phenotypic variability is not yet clear. 15 refs., 5 figs., 1 tab.

  6. The catalytic properties of murine carbonic anhydrase VII.

    PubMed

    Earnhardt, J N; Qian, M; Tu, C; Lakkis, M M; Bergenhem, N C; Laipis, P J; Tashian, R E; Silverman, D N

    1998-07-28

    Carbonic anhydrase VII (CA VII) appears to be the most highly conserved of the active mammalian carbonic anhydrases. We have characterized the catalytic activity and inhibition properties of a recombinant murine CA VII. CA VII has steady-state constants similar to two of the most active isozymes of carbonic anhydrase, CA II and IV; also, it is very strongly inhibited by the sulfonamides ethoxzolamide and acetazolamide, yielding the lowest Ki values measured by the exchange of 18O between CO2 and water for any of the mammalian isozymes of carbonic anhydrase. The catalytic measurements of the hydration of CO2 and the dehydration of HCO3- were made by stopped-flow spectrophotometry and the exchange of 18O using mass spectrometry. Unlike the other isozymes of this class of CA, for which Kcat/K(m) is described by the single ionization of zinc-bound water, CA VII exhibits a pH profile for Kcat/K(m) for CO2 hydration described by two ionizations at pKa 6.2 and 7.5, with a maximum approaching 8 x 10(7) M-1 s-1. The pH dependence of kcat/K(m) for the hydrolysis of 4-nitrophenyl acetate could also be described by these two ionizations, yielding a maximum of 71 M-1 s-1 at pH > 9. Using a novel method that compares rates of 18O exchange and dehydration of HCO3-, we assigned values for the apparent pKa at 6.2 to the zinc-bound water and the pKa of 7.5 to His 64. The magnitude of Kcat, its pH profile, 18O-exchange data for both wild-type and a H64A mutant, and inhibition by CuSO4 and acrolein suggest that the histidine at position 64 is functioning as a proton-transfer group and is responsible for one of the observed ionizations. A truncation mutant of CA VII, in which 23 residues from the amino-terminal end were deleted, has its rate constant for intramolecular proton transfer decreased by an order of magnitude with no change in Kcat/K(m). This suggests a role for the amino-terminal end in enhancing proton transfer in catalysis by carbonic anhydrase. PMID:9692974

  7. 21 CFR 866.5200 - Carbonic anhydrase B and C immunological test system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Carbonic anhydrase B and C immunological test system. 866.5200 Section 866.5200 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND.... Measurements of carbonic anhydrase B and C aid in the diagnosis of abnormal hemoglobin metabolism....

  8. Removal of Zinc Form Carbonic Anhydrase: A Kinetics Experiment for Upper-Level Chemistry Laboratories

    ERIC Educational Resources Information Center

    Williams, Kathryn R.; Adhyaru, Bhavin

    2004-01-01

    An experiment on kinetics of deactivation of carbonic anhydrase by removal of zinc is demonstrated. Carbonic anhydrase, the enzyme that catalyzes the interconversion of carbon dioxide and bicarbonate, requires on Zn(II) ion in its active site, and removal of the zinc cofactor by complexion to another ligand leaves the apoenzyme, which is totally…

  9. Preferential accumulation of 5-aminolevulinic acid-induced protoporphyrin IX in breast cancer: a comprehensive study on six breast cell lines with varying phenotypes

    NASA Astrophysics Data System (ADS)

    Millon, Stacy R.; Ostrander, Julie H.; Yazdanfar, Siavash; Brown, J. Quincy; Bender, Janelle E.; Rajeha, Anita; Ramanujam, Nirmala

    2010-01-01

    We describe the potential of 5-aminolevulinic acid (ALA)-induced protoporphyrin IX (PpIX) fluorescence as a source of contrast for margin detection in commonly diagnosed breast cancer subtypes. Fluorescence intensity of PpIX in untreated and ALA-treated normal mammary epithelial and breast cancer cell lines of varying estrogen receptor expression were quantitatively imaged with confocal microscopy. Percentage change in fluorescence intensity integrated over 610-700 nm (attributed to PpIX) of posttreated compared to pretreated cells showed statistically significant differences between four breast cancer and two normal mammary epithelial cell lines. However, a direct comparison of post-treatment PpIX fluorescence intensities showed no differences between breast cancer and normal mammary epithelial cell lines due to confounding effects by endogenous fluorescence from flavin adenine dinucleotide (FAD). Clinically, it is impractical to obtain pre- and post-treatment images. Thus, spectral imaging was demonstrated as a means to remove the effects of endogenous FAD fluorescence allowing for discrimination between post-treatment PpIX fluorescence of four breast cancer and two normal mammary epithelial cell lines. Fluorescence spectral imaging of ALA-treated breast cancer cells showed preferential PpIX accumulation regardless of malignant phenotype and suggests a useful contrast mechanism for discrimination of residual cancer at the surface of breast tumor margins.

  10. Carbonic anhydrase enzyme as a potential therapeutic target for experimental trichinellosis.

    PubMed

    Saad, Abeer E; Ashour, Dalia S; Abou Rayia, Dina M; Bedeer, Asmaa E

    2016-06-01

    Trichinellosis is a globally distributed helminthic infection. There is a considerable interest in developing new anti-helminthic drugs affecting all the developmental stages of Trichinella. Acetazolamide (carbonic anhydrase (CA) inhibitor) involves a novel mechanism of action by inhibiting such an essential enzyme for parasite metabolism. This work aimed to study the effect of acetazolamide against different stages of T. spiralis in experimental animals. Mice were divided into three groups: group I: infected and treated with acetazolamide on day 2 post infection (P.I.), group II: infected and treated with acetazolamide on day 12 P.I., and group III: infected non-treated. From each group, small intestine and muscles were removed for histopathological and immunohistochemical studies. Also, total adult and muscle larval count were estimated. We found that acetazolamide was effective in reduction of both adult and muscle larval counts. When given early, the effect was more pronounced on the adults (62.7 %). However, the efficacy of the drug against muscle larvae was increased when given late (63 %). Improvement of the intestinal histopathological changes was observed in all the treated groups. Degeneration of encysted larvae with minimal pathologic changes of infected skeletal muscle was observed in the treated groups. Expression of matrix metalloproteinase-9 showed a statistically significant decrease in the intestinal and muscle tissues in all treated groups as compared to the control group. In conclusion, the present study revealed that acetazolamide, carbonic anhydrase inhibitor, could be a promising drug against both adults and larvae of T. spiralis. PMID:26979731

  11. Carbonic Anhydrase 9 mRNA/microRNA34a Interplay in Hypoxic Human Mammospheres.

    PubMed

    De Carolis, Sabrina; Bertoni, Sara; Nati, Marina; D'Anello, Laura; Papi, Alessio; Tesei, Anna; Cricca, Monica; Bonafé, Massimiliano

    2016-07-01

    The hypoxic environment is a crucial component of the cancer stem cell niche and it is capable of eliciting stem cell features in cancer cells. We previously reported that SNAI2 up-regulates the expression of Carbonic Anhydrase iso-enzyme 9 (CA9) in hypoxic MCF7 cells. Here we show that SNAI2 down-regulates miR34a expression in hypoxic MCF7 cell-derived mammospheres. Next, we report on the capability of miR34a to decrease CA9 mRNA stability and CA9 protein expression. We also convey that the over-expression of cloned CA9-mRNA-3'UTR increases the mRNA half-life and protein levels of two miR34a targets JAGGED1 and NOTCH3. The data here reported shows that the SNAI2-dependent down-regulation of miR34a substantially contributes to the post-transcriptional up-regulation of CA9, and that CA9-mRNA-3'UTR acts as an endogenous microRNA sponge. We conclude that CA9/miR34 interplay shares in the hypoxic regulation of mammospheres and therefore, may play a relevant role in the hypoxic breast cancer stem cell niche. PMID:26553365

  12. Cytosolic carbonic anhydrase in the Gulf toadfish is important for tolerance to hypersalinity.

    PubMed

    Sattin, G; Mager, E M; Beltramini, M; Grosell, M

    2010-06-01

    Carbonic anhydrase (CA) is a ubiquitous enzyme involved in acid-base regulation and osmoregulation. Many studies have demonstrated a role for this enzyme in fish osmoregulation in seawater as well as freshwater. However, to date CA responses of marine fish exposed to salinities exceeding seawater (approximately 35 ppt) have not been examined. Consequently, the aim of the present study was to examine CA expression and activity in osmoregulatory tissues of the Gulf Toadfish, Opsanus beta, following transfer to 60 ppt. A gene coding, for CAc of 1827 bp with an open reading frame of 260 amino acids was cloned and showed high expression in all intestinal segments and gills. CAc showed higher expression in posterior intestine and rectum than in anterior and mid intestine and in gills of fish exposed to 60 ppt for up to 4 days. The enzymatic activity, in contrast, was higher in all examined tissues two weeks following transfer to 60 ppt. Comparing early expression and later activity levels of acclimated fish reveals a very different response to hypersalinity among tissues. Results highlight a key role of CAc in osmoregulation especially in distal regions of the intestine; moreover, CAc play a role in the gill in hypersaline environments possibly supporting elevated branchial acid extrusion seen under such conditions. PMID:20152924

  13. Construction of a pIX-modified Adenovirus Vector Able to Effectively Bind to Nanoantibodies for Targeting.

    PubMed

    Garas, M N; Tillib, S V; Zubkova, O V; Rogozhin, V N; Ivanova, T I; Vasilev, L A; Logunov, D Yu; Shmarov, M M; Tutykhina, I L; Esmagambetov, I B; Gribova, I Yu; Bandelyuk, A S; Naroditsky, B S; Gintsburg, A L

    2014-04-01

    Current targeting strategies for genetic vectors imply the creation of a specific vector for every targeted receptor, which is time-consuming and expensive. Therefore, the development of a universal vector system whose surface can specifically bind molecules to provide efficient targeting is of particular interest. In this study, we propose a new approach in creating targeted vectors based on the genome of human adenovirus serotype 5 carrying the modified gene of the capsid protein pIX (Ad5-EGFP-pIX-ER): recombinant pseudoadenoviral nanoparticles (RPANs). The surfaces of such RPANs are able to bind properly modified chimeric nanoantibodies that specifically recognize a particular target antigen (carcinoembryonic antigen (CEA)) with high affinity. The efficient binding of nanoantibodies (aCEA-RE) to the RPAN capsid surfaces has been demonstrated by ELISA. The ability of the constructed vector to deliver target genes has been confirmed by experiments with the tumor cell lines A549 and Lim1215 expressing CEA. It has been shown that Ad5-EGFP-pIX-ER carrying aCEA-RE on its surface penetrates into the tumor cell lines A549 and Lim1215 via the CAR-independent pathway three times more efficiently than unmodified RPAN and Ad5-EGFP-pIX-ER without nanoantibodies on the capsid surface. Thus, RPAN Ad5-EGFP-pIX-ER is a universal platform that may be useful for targeted gene delivery in specific cells due to "nanoantibody-modified RPAN" binding. PMID:25093116

  14. Cleavage and activation of human factor IX by serine proteases

    SciTech Connect

    Enfield, D.L.; Thompson, A.R.

    1984-10-01

    Human factor IX circulates as a single-chain glycoprotein. Upon activation in vitro, it is cleaved into disulfide-linked light and heavy chains and an activation peptide. After reduction of activated /sup 125/I-factor IX, the heavy and light chains are readily identified by gel electrophoresis. A direct, immunoradiometric assay for factor IXa was developed to assess activation of factor IX for proteases that cleaved it. The assay utilized radiolabeled antithrombin III with heparin to identify the active site and antibodies to distinguish factor IX. After cleavage of factor IX by factor XIa, factor VIIa-tissue thromboplastin complex, or the factor X-activating enzyme from Russell's viper venom, antithrombin III bound readily to factor IXa. Cleavage of /sup 125/I-factor IX by trypsin, chymotrypsin, and granulocyte elastase in the presence of calcium yielded major polypeptide fragments of the sizes of the factor XIa-generated light and heavy chains. When the immunoradiometric assay was used to assess trypsin-cleaved factor IX, the product bound antithrombin III, but not maximally. After digesting with insolubilized trypsin, clotting activity confirmed activation. In evaluating activation of factor IX, physical evidence of activation cleavages does not necessarily correlate with generation of an active site.

  15. A Model Community College Grievance Procedure for Title IX.

    ERIC Educational Resources Information Center

    Noonan, Roberta L.

    Through a review of the literature, analysis of eleven Title IX grievance plans, and interviews with four compliance officers, twelve criteria essential to an effective grievance procedure for use by students were identified and incorporated into a model Title IX grievance procedure for Moraine Valley Community College (Illinois). The twelve…

  16. Rape on College Campuses: Reform through Title IX.

    ERIC Educational Resources Information Center

    Steinberg, Terry Nicole

    1991-01-01

    This article first, analyzes the growing problem of campus rape; second, evaluates some college rape reduction programs; third, uses case law to demonstrate that rape should be considered sex discrimination under Title IX; and, fourth, suggests an amendment to Title IX, defining rape as sex discrimination. Appropriate implementation measures by…

  17. Tilting the Playing Field: Schools, Sports, Sex and Title IX.

    ERIC Educational Resources Information Center

    Gavora, Jessica

    This book suggests that Title IX of the Education Amendments is not creating more female athletes but instead eliminating some of the most prestigious men's sports programs in the name of gender equity. It shows how Title IX has affected every aspect of education, from kindergarten through graduate school, making profound changes in areas as…

  18. School Environment and Academic Achievement of Standard IX Students

    ERIC Educational Resources Information Center

    Lawrence, A. S. Arul; Vimala, A.

    2012-01-01

    The present study School Environment and Academic Achievement of standard IX students was probed to find the relationship between School Environment and Academic Achievement of standard IX students. Data for the study were collected using self-made School Environment Scale (SES). The investigator used stratified random sampling technique for…

  19. ARES I-X USS Fracture Analysis Loads Spectra Development

    NASA Technical Reports Server (NTRS)

    Larsen, Curtis; Mackey, Alden

    2008-01-01

    This report describes the development of a set of bounding load spectra for the ARES I-X launch vehicle. These load spectra are used in the determination of the critical initial flaw size (CIFS) of the welds in the ARES I-X upper stage simulator (USS).

  20. A License for Bias: Sex Discrimination, Schools, and Title IX.

    ERIC Educational Resources Information Center

    Morse, Susan Ed.

    This report discusses non-sports-related Title IX complaints filed with the Department of Education's Office for Civil Rights (OCR) from 1993-1997. Its purpose is to dispel the popular belief that Title IX is a sports-equity law and to determine the effectiveness of the legislation. The document examines the kinds of complaints filed, the status…

  1. 77 FR 64401 - Order of Succession for HUD Region IX

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-19

    ... URBAN DEVELOPMENT Order of Succession for HUD Region IX AGENCY: Office of Field Policy and Management, HUD. ACTION: Notice of Order of Succession. SUMMARY: In this notice, the Assistant Deputy Secretary... Succession for the San Francisco Regional Office and its Field Offices (Region IX). This Order of...

  2. "North Haven" and "Dougherty": Narrowing the Scope of Title IX.

    ERIC Educational Resources Information Center

    Salomone, Rosemary C.

    1981-01-01

    Compares the recent opinions of the Second and Fifth Circuit Courts concerning the legislative intent of Title IX with earlier opinions of the First, Sixth, and Eighth Circuits, which declared the Title IX employment regulations invalid. A middle approach to interpretation of the law is proposed. (Author/MLF)

  3. Ares I-X Ground Diagnostic Prototype

    NASA Technical Reports Server (NTRS)

    Schwabacher, Mark A.; Martin, Rodney Alexander; Waterman, Robert D.; Oostdyk, Rebecca Lynn; Ossenfort, John P.; Matthews, Bryan

    2010-01-01

    The automation of pre-launch diagnostics for launch vehicles offers three potential benefits: improving safety, reducing cost, and reducing launch delays. The Ares I-X Ground Diagnostic Prototype demonstrated anomaly detection, fault detection, fault isolation, and diagnostics for the Ares I-X first-stage Thrust Vector Control and for the associated ground hydraulics while the vehicle was in the Vehicle Assembly Building at Kennedy Space Center (KSC) and while it was on the launch pad. The prototype combines three existing tools. The first tool, TEAMS (Testability Engineering and Maintenance System), is a model-based tool from Qualtech Systems Inc. for fault isolation and diagnostics. The second tool, SHINE (Spacecraft Health Inference Engine), is a rule-based expert system that was developed at the NASA Jet Propulsion Laboratory. We developed SHINE rules for fault detection and mode identification, and used the outputs of SHINE as inputs to TEAMS. The third tool, IMS (Inductive Monitoring System), is an anomaly detection tool that was developed at NASA Ames Research Center. The three tools were integrated and deployed to KSC, where they were interfaced with live data. This paper describes how the prototype performed during the period of time before the launch, including accuracy and computer resource usage. The paper concludes with some of the lessons that we learned from the experience of developing and deploying the prototype.

  4. Enhancing protoporphyrin IX-induced PDT

    NASA Astrophysics Data System (ADS)

    Curnow, Alison; Pye, Andrew; Campbell, Sandra

    2009-06-01

    Photodynamic therapy (PDT) using porphyrin precursors is commonly used in dermatology. Evidence indicates that good clinical outcomes (associated with excellent cosmesis) can be achieved in superficial precancers and basal cell carcinoma (BCC), however, efficacy appears less favorable for thicker nodular BCC (nBCC) unless multiple PDT treatment cycles are performed. Enhancement is therefore required if nBCC lesions are to be treated effectively with a single PDT treatment. The most common technique currently being routinely employed clinically is the use of aminolevulinic acid (ALA) esters (usually methyl (MAL) or hexyl (HAL)). Standard dermatological PDT employing these porphyrin precursors already manipulates the normal heme biosynthesis pathway resulting in a temporary accumulation of the natural photosensitizer, protoporphyrin IX (PpIX). Further manipulation using iron chelating agents is possible however. In normal and malignant human cells in vitro, the novel iron chelating agent CP94 produced greater PPIX fluorescence when administered with ALA or MAL than either congener produced alone. CP94 was also significantly more effective than the clinically established iron chelating agent desferrioxamine (DFO). Topical application of ALA+CP94 to clinical nBCC lesions was a simple and safe treatment modification which produced a significant increase in clinical clearance when CP94 was included in the cream.

  5. Cranial Nerves IX, X, XI, and XII

    PubMed Central

    Sanders, Richard D.

    2010-01-01

    This article concludes the series on cranial nerves, with review of the final four (IX–XII). To summarize briefly, the most important and common syndrome caused by a disorder of the glossopharyngeal nerve (craniel nerve IX) is glossopharyngeal neuralgia. Also, swallowing function occasionally is compromised in a rare but disabling form of tardive dyskinesia called tardive dystonia, because the upper motor portion of the glossopharyngel nerve projects to the basal ganglia and can be affected by lesions in the basal ganglia. Vagus nerve funtion (craniel nerve X) can be compromised in schizophrenia, bulimia, obesity, and major depression. A cervical lesion to the nerve roots of the spinal accessory nerve (craniel nerve XI) can cause a cervical dystonia, which sometimes is misdiagnosed as a dyskinesia related to neuroleptic use. Finally, unilateral hypoglossal (craniel nerve XII) nerve palsy is one of the most common mononeuropathies caused by brain metastases. Supranuclear lesions of cranial nerve XII are involved in pseudobulbar palsy and ALS, and lower motor neuron lesions of cranial nerve XII can also be present in bulbar palsy and in ALS patients who also have lower motor neuron involvement. This article reviews these and other syndromes related to cranial nerves IX through XII that might be seen by psychiatry. PMID:20532157

  6. Ares I-X Ascent Base Environments

    NASA Technical Reports Server (NTRS)

    Mobley, B. L.; Bender, R. L.; Canabal, F.; Smith, Sheldon D.

    2011-01-01

    Plume induced base heating environments were measured during the flight of the NASA Constellation Ares I-X developmental launch vehicle, successfully flown on October 28, 2009. The Ares IX first stage is a four segment Space Shuttle derived booster with base consisting of a flared aft skirt, deceleration and tumble motors, and a thermal curtain surrounding the first stage 7.2 area ratio nozzle. Developmental Flight Instrumentation (DFI) consisted of radiometers, calorimeters, pressure transducers and gas temperature probes installed on the aft skirt and nozzle to measure the base environments. In addition, thermocouples were also installed between the layers of the flexible thermal curtain to provide insight into the curtain response to the base environments and to assist in understanding curtain failure during reentry. Plume radiation environment predictions were generated by the Reverse Monte Carlo (RMC) code and the convective base heating predictions utilized heritage MSFC empirical methods. These predictions were compared to the DFI data and results from the flight videography. Radiation predictions agreed with the flight measured data early in flight but gauge failures prevented high altitude comparisons. The convective environment comparisons demonstrated the need to improve the prediction methodology; particularly for low altitude, local plume recirculation. The convective comparisons showed relatively good agreement at altitudes greater than 50,000 feet.

  7. Electron Impact Exciation of Fe IX

    NASA Astrophysics Data System (ADS)

    Tayal, Swaraj; Zatsarinny, Oleg

    2015-05-01

    Transition probabilities and electron impact excitation collision strengths and rates for astrophysically important extreme ultraviolet lines of Fe IX are calculated. The 322 fine-structure levels of the 3s2 3p6 , 3s2 3p5 3 d , 3 s 3p6 3 d , 3s2 3p5 4 s , and 3s2 3p4 3d2 configurations are included in our calculations. The collision strengths have been calculated using the B-spline Breit-Pauli R-matrix method for all fine-structure transitions among the 322 levels. The mass, Darwin, and spin-orbit relativistic effects are included in the Breit-Pauli Hamiltonian in the scattering calculation. The one-body and two-body relativistic operators are included in the multi-configuration Hartree-Fock calculations of transition probabilities. Several sets of non-orthogonal spectroscopic and correlation radial orbitals are used to obtain accurate description of Fe IX levels and to represent the scattering functions. The calculated excitation energies are in very good agreement with experiment and represents an improvement over the previous calculations. The present collision strengths show reasonable agreement with the previously available R-matrix and distorted-wave calculations. This research is supported by NASA grant from the Solar and Heliophysics Program.

  8. Ares I-X Ground Diagnostic Prototype

    NASA Technical Reports Server (NTRS)

    Schwabacher, Mark; Martin, Rodney; Waterman, Robert; Oostdyk, Rebecca; Ossenfort, John; Matthews, Bryan

    2010-01-01

    Automating prelaunch diagnostics for launch vehicles offers three potential benefits. First, it potentially improves safety by detecting faults that might otherwise have been missed so that they can be corrected before launch. Second, it potentially reduces launch delays by more quickly diagnosing the cause of anomalies that occur during prelaunch processing. Reducing launch delays will be critical to the success of NASA's planned future missions that require in-orbit rendezvous. Third, it potentially reduces costs by reducing both launch delays and the number of people needed to monitor the prelaunch process. NASA is currently developing the Ares I launch vehicle to bring the Orion capsule and its crew of four astronauts to low-earth orbit on their way to the moon. Ares I-X will be the first unmanned test flight of Ares I. It is scheduled to launch on October 27, 2009. The Ares I-X Ground Diagnostic Prototype is a prototype ground diagnostic system that will provide anomaly detection, fault detection, fault isolation, and diagnostics for the Ares I-X first-stage thrust vector control (TVC) and for the associated ground hydraulics while it is in the Vehicle Assembly Building (VAB) at John F. Kennedy Space Center (KSC) and on the launch pad. It will serve as a prototype for a future operational ground diagnostic system for Ares I. The prototype combines three existing diagnostic tools. The first tool, TEAMS (Testability Engineering and Maintenance System), is a model-based tool that is commercially produced by Qualtech Systems, Inc. It uses a qualitative model of failure propagation to perform fault isolation and diagnostics. We adapted an existing TEAMS model of the TVC to use for diagnostics and developed a TEAMS model of the ground hydraulics. The second tool, Spacecraft Health Inference Engine (SHINE), is a rule-based expert system developed at the NASA Jet Propulsion Laboratory. We developed SHINE rules for fault detection and mode identification. The prototype

  9. Labeled factor IX kinetics in patients with hemophilia-B

    SciTech Connect

    Smith, K.J.; Thompson, A.R.

    1981-09-01

    Labeled factor IX was infused five time into four patients with hemophilia-B. Ten-minute plasma recovery average 35% (SD +/- 2) and the mean T 1/2 beta-phase elimination was 23 hr (+/- 5). No alteration in the postinfusion 125I-factor-IX could be detected by radioautography of plasma samples run on polyacrylamide gels or on crossed-immunoelectrophoresis. Label was excreted into the urine as free 125I-iodide. Kinetics were similar when the labeled preparation was infused alone or with a commercial concentrate containing unlabeled factor IX. Infusion of factor IX in man is best described by a two-compartment open pharmacokinetic model where factor IX is distributed in a space larger than the plasma volume.

  10. Role of carbonic anhydrase in bone resorption induced by prostaglandin E2 in vitro

    NASA Technical Reports Server (NTRS)

    Hall, G. E.; Kenny, A. D.

    1985-01-01

    The possible role of carbonic anhydrase in bone resorption induced by prostaglandin E2 (PGE2) was studied using an in vitro neonatal mouse calvarial culture system. PGE2 (10 to the -6th M) was effective in stimulating resorption, as assessed by calcium release into culture media. This enhanced resorption was accompanied by significant increases in calvarial carbonic anhydrase activity over control values at 48 and 96 h. At 48 h, bones treated with PGE2 had 20 percent more carbonic anhydrase activity than controls. By 96 h, treated bones contained 79 percent more carbonic anhydrase activity than controls. PGE2-induced bone resorption was inhibited by the carbonic anhydrase inhibitor acetazolamide in a dose-dependent fashion from 10 to the -5th to 10 to the -4th M with 77 percent inhibition observed at 10 to the -4th M. The acetazolamide analogue CL 13,850 (N-t-butylacetazolamide), which does not inhibit carbonic anhydrase, failed to inhibit PGE2-induced resorption. These results are consistent with the hypothesis that carbonic anhydrase is a necessary component of the osteoclastic bone resorptive mechanism.

  11. The structure of a tetrameric α-carbonic anhydrase from Thermovibrio ammonificans reveals a core formed around intermolecular disulfides that contribute to its thermostability.

    PubMed

    James, Paul; Isupov, Michail N; Sayer, Christopher; Saneei, Vahid; Berg, Svein; Lioliou, Maria; Kotlar, Hans Kristian; Littlechild, Jennifer A

    2014-10-01

    Carbonic anhydrase enzymes catalyse the reversible hydration of carbon dioxide to bicarbonate. A thermophilic Thermovibrio ammonificans α-carbonic anhydrase (TaCA) has been expressed in Escherichia coli and structurally and biochemically characterized. The crystal structure of TaCA has been determined in its native form and in two complexes with bound inhibitors. The tetrameric enzyme is stabilized by a unique core in the centre of the molecule formed by two intersubunit disulfides and a single lysine residue from each monomer that is involved in intersubunit ionic interactions. The structure of this core protects the intersubunit disulfides from reduction, whereas the conserved intrasubunit disulfides are not formed in the reducing environment of the E. coli host cytosol. When oxidized to mimic the environment of the periplasmic space, TaCA has increased thermostability, retaining 90% activity after incubation at 70°C for 1 h, making it a good candidate for industrial carbon-dioxide capture. The reduction of all TaCA cysteines resulted in dissociation of the tetrameric molecule into monomers with lower activity and reduced thermostability. Unlike other characterized α-carbonic anhydrases, TaCA does not display esterase activity towards p-nitrophenyl acetate, which appears to result from the increased rigidity of its protein scaffold. PMID:25286845

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

    PubMed

    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. PMID:19816790

  13. Increased water flux induced by an aquaporin-1/carbonic anhydrase II interaction

    PubMed Central

    Vilas, Gonzalo; Krishnan, Devishree; Loganathan, Sampath Kumar; Malhotra, Darpan; Liu, Lei; Beggs, Megan Rachele; Gena, Patrizia; Calamita, Giuseppe; Jung, Martin; Zimmermann, Richard; Tamma, Grazia; Casey, Joseph Roman; Alexander, Robert Todd

    2015-01-01

    Aquaporin-1 (AQP1) enables greatly enhanced water flux across plasma membranes. The cytosolic carboxy terminus of AQP1 has two acidic motifs homologous to known carbonic anhydrase II (CAII) binding sequences. CAII colocalizes with AQP1 in the renal proximal tubule. Expression of AQP1 with CAII in Xenopus oocytes or mammalian cells increased water flux relative to AQP1 expression alone. This required the amino-terminal sequence of CAII, a region that binds other transport proteins. Expression of catalytically inactive CAII failed to increase water flux through AQP1. Proximity ligation assays revealed close association of CAII and AQP1, an effect requiring the second acidic cluster of AQP1. This motif was also necessary for CAII to increase AQP1-mediated water flux. Red blood cell ghosts resealed with CAII demonstrated increased osmotic water permeability compared with ghosts resealed with albumin. Water flux across renal cortical membrane vesicles, measured by stopped-flow light scattering, was reduced in CAII-deficient mice compared with wild-type mice. These data are consistent with CAII increasing water conductance through AQP1 by a physical interaction between the two proteins. PMID:25609088

  14. Inhibition of carbonic anhydrase by parathyroid hormone and cyclic AMP in rat renal cortex in vitro.

    PubMed Central

    Beck, N; Kim, K S; Wolak, M; Davis, B B

    1975-01-01

    It has been demonstrated that parathyroid hormone (PTH) inhibits the proximal tubular reabsorption of bicarbonate, and increases the urinary excretion of that ion. There is also a qualitative similarity between the alterations of the proximal tubular reabsorption of phosphate, sodium, and water after PTH administration and after acetazolamide administration. These findings suggest that the renal effect of PTH is possibly mediated through the inhibition of carbonic anhydrase in proximal tubules. Therefore, a possible inhibitory effect of PTH on carbonic anhydrase was evaluated in the homogenate of rat renal cortex by an indicator titration method. Incubation of cortical homogenates with PTH for 10 min at 37degreesC inhibited carbonic anhydrase activity. The inhibitory effect of PTH was ATP-, Mg++-, and K+-dependent and temperature-dependent; inactivation of PTH by heating at 100degreesC abolished the effect of PTH both to activate adenylate cyclase and to inhibit carbonic anhydrase. Calcium 5 mM also partially abolished effects of PTH to activate adenylate cyclase and to inhibit carbonic anhydrase. The inhibitory effect of PTH on carbonic anhydrase was specific to renal cortex. Cyclic AMP, the intracellular messenger substance for PTH, also inhibited carbonic anhydrase in renal cortex. The cyclic AMP-induced inhibition was also Mg++ dependent and temperature dependent, and required preincubation at 37degreesC. But 5'-AMP, a metabolic derivative of cyclic AMP without its biological effect, had no inhibitory effect on carbonic anhydrase. All the above results are consistent with the hypothesis that PTH inhibits proximal tubular reabsorption of bicarbonate and phosphate through the inhibition of carbonic anhydrase, and that inhibitory effect is mediated through the cyclic AMP system. PMID:233968

  15. The effects of some bromophenols on human carbonic anhydrase isoenzymes.

    PubMed

    Taslimi, Parham; Gülçin, İlhami; Öztaşkın, Necla; Çetinkaya, Yasin; Göksu, Süleyman; Alwasel, Saleh H; Supuran, Claudiu T

    2016-08-01

    Carbonic anhydrases (CAs, EC 4.2.1.1), which are involved in a variety of physiological and pathological processes, are ubiquitous metalloenzymes mainly catalyzing the reversible hydration of carbon dioxide (CO2) to bicarbonate ([Formula: see text]) and proton (H(+)). In this study, a dozen of bromophenol derivatives (1-12) were evaluated as metalloenzyme CA (EC 4.2.1.1) inhibitors against the human carbonic anhydrase isoenzymes I and II (hCA I and II). Cytosolic hCA I and II isoenzymes were effectively inhibited by bromophenol derivatives (1-12) with Kis in the low nanomolar range of 1.85 ± 0.58 to 5.04 ± 1.46 nM against hCA I and in the range of 2.01 ± 0.52 to 2.94 ± 1.31 nM against hCA II, respectively. PMID:26133541

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

    SciTech Connect

    Fisher, S. Z. Kovalevsky, A. Y.; Domsic, J.; Mustyakimov, M.; Silverman, D. N.; McKenna, R.; Langan, P.

    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.

  17. Crystal structure of E. coli beta-carbonic anhydrase, an enzyme with an unusual pH-dependent activity.

    PubMed

    Cronk, J D; Endrizzi, J A; Cronk, M R; O'neill, J W; Zhang, K Y

    2001-05-01

    Carbonic anhydrases fall into three distinct evolutionary and structural classes: alpha, beta, and gamma. The beta-class carbonic anhydrases (beta-CAs) are widely distributed among higher plants, simple eukaryotes, eubacteria, and archaea. We have determined the crystal structure of ECCA, a beta-CA from Escherichia coli, to a resolution of 2.0 A. In agreement with the structure of the beta-CA from the chloroplast of the red alga Porphyridium purpureum, the active-site zinc in ECCA is tetrahedrally coordinated by the side chains of four conserved residues. These results confirm the observation of a unique pattern of zinc ligation in at least some beta-CAS: The absence of a water molecule in the inner coordination sphere is inconsistent with known mechanisms of CA activity. ECCA activity is highly pH-dependent in the physiological range, and its expression in yeast complements an oxygen-sensitive phenotype displayed by a beta-CA-deletion strain. The structural and biochemical characterizations of ECCA presented here and the comparisons with other beta-CA structures suggest that ECCA can adopt two distinct conformations displaying widely divergent catalytic rates. PMID:11316870

  18. Quantitative determination of Zn protoporphyrin IX, heme and protoporphyrin IX in Parma ham by HPLC.

    PubMed

    Wakamatsu, Jun-Ichi; Odagiri, Hiroko; Nishimura, Takanori; Hattori, Akihito

    2009-05-01

    We measured the contents of Zn protoporphyrin IX (ZPP), heme and protoporphyrin IX (PPIX) in Parma ham by simultaneous analysis using high-performance liquid chromatography (HPLC). Extraction with ethyl acetate-acetic acid (4:1) was suitable for the quantitative analysis of ZPP. The contents of heme, ZPP and PPIX in Parma ham were 15.0-29.9, 27.7-47.0 and 0.4-1.1μg/g, respectively, and total content of porphyrin was 43.7-76.6μg/g. The amount of ZPP in Parma ham was larger than that of heme, and ZPP accounted for 60-70% of all porphyrins. PMID:20416611

  19. Nitric oxide inhibits the formation of zinc protoporphyrin IX and protoporphyrin IX.

    PubMed

    Wakamatsu, Jun-ichi; Hayashi, Nobutaka; Nishimura, Takanori; Hattori, Akihito

    2010-01-01

    The aim of this study was to elucidate the mechanism by which curing agents, especially nitrite, inhibit the formation of zinc protoporphyrin IX (ZPP) in dry-cured hams such as Parma ham. The oxidation-reduction potential of model solutions was increased by the addition of nitrite, but it was not clear whether the formation of ZPP is inhibited by the oxidizing property of nitrite. The effect of nitric oxide (NO) produced from nitrite on the formation of ZPP was examined. The amount of ZPP formed was decreased by the addition of NO donors. The amount of protoporphyrin IX (PPIX), which is the precursor of ZPP, was also decreased by the addition of NO donors. It is concluded that NO produced from nitrite inhibited the formation of PPIX and ZPP was therefore not formed in cured meat products with the addition of nitrite or nitrate. PMID:20374763

  20. Ares I-X USS Material Testing

    NASA Technical Reports Server (NTRS)

    Dawicke, David S.; Smith, Stephen W.; Raju, Ivatury S.

    2008-01-01

    An independent assessment was conducted to determine the critical initial flaw size (CIFS) for the flange-to-skin weld in the Ares I-X Upper Stage Simulator (USS). Material characterization tests were conducted to quantify the material behavior for use in the CIFS analyses. Fatigue crack growth rate, Charpy impact, and fracture tests were conducted on the parent and welded A516 Grade 70 steel. The crack growth rate tests confirmed that the material behaved in agreement with literature data and that a salt water environment would not significantly degrade the fatigue resistance. The Charpy impact tests confirmed that the fracture resistance of the material did not have a significant reduction for the expected operational temperatures of the vehicle.

  1. ALA-induced PpIX fluorescence in epileptogenic tissue

    NASA Astrophysics Data System (ADS)

    Kleen, Jonathan K.; Valdes, Pablo A.; Harris, Brent T.; Holmes, Gregory L.; Paulsen, Keith D.; Roberts, David W.

    2011-03-01

    Astrogliotic tissue displays markedly increased levels of ALA-induced PpIX fluorescence, making it useful for fluorescence-guided resection in glioma surgery. In patients with temporal lobe epilepsy (TLE) and corresponding animal models, there are areas of astrogliosis that often co-localize with the epileptic focus, which can be resected to eliminate seizures in the majority of treated patients. If this epileptogenic tissue can exhibit PpIX fluorescence that is sufficiently localized, it could potentially help identify margins in epilepsy surgery. We tested the hypothesis that ALA-induced PpIX fluorescence could visually accentuate epileptogenic tissue, using an established animal model of chronic TLE. An acute dose of pilocarpine was used to induce chronic seizure activity in a rat. This rat and a normal control were given ALA, euthanized, and brains examined post-mortem for PpIX fluorescence and neuropathology. Preliminary evidence indicates increased PpIX fluorescence in areas associated with chronic epileptic changes and seizure generation in TLE, including the hippocampus and parahippocampal areas. In addition, strong PpIX fluorescence was clearly observed in layer II of the piriform cortex, a region known for epileptic reorganization and involvement in the generation of seizures in animal studies. We are further investigating whether ALA-induced PpIX fluorescence can consistently identify epileptogenic zones, which could warrant the extension of this technique to clinical studies for use as an adjuvant guidance technology in the resection of epileptic tissue.

  2. Ares I-X Flight Test Philosophy

    NASA Technical Reports Server (NTRS)

    Davis, S. R.; Tuma, M. L.; Heitzman, K.

    2007-01-01

    In response to the Vision for Space Exploration, the National Aeronautics and Space Administration (NASA) has defined a new space exploration architecture to return humans to the Moon and prepare for human exploration of Mars. One of the first new developments will be the Ares I Crew Launch Vehicle (CLV), which will carry the Orion Crew Exploration Vehicle (CEV), into Low Earth Orbit (LEO) to support International Space Station (ISS) missions and, later, support lunar missions. As part of Ares I development, NASA will perform a series of Ares I flight tests. The tests will provide data that will inform the engineering and design process and verify the flight hardware and software. The data gained from the flight tests will be used to certify the new Ares/Orion vehicle for human space flight. The primary objectives of this first flight test (Ares I-X) are the following: Demonstrate control of a dynamically similar integrated Ares CLV/Orion CEV using Ares CLV ascent control algorithms; Perform an in-flight separation/staging event between an Ares I-similar First Stage and a representative Upper Stage; Demonstrate assembly and recovery of a new Ares CLV-like First Stage element at Kennedy Space Center (KSC); Demonstrate First Stage separation sequencing, and quantify First Stage atmospheric entry dynamics and parachute performance; and Characterize the magnitude of the integrated vehicle roll torque throughout the First Stage (powered) flight. This paper will provide an overview of the Ares I-X flight test process and details of the individual flight tests.

  3. Cell surface display of carbonic anhydrase on Escherichia coli using ice nucleation protein for CO₂ sequestration.

    PubMed

    Fan, Li-Hai; Liu, Ning; Yu, Ming-Rui; Yang, Shang-Tian; Chen, Huan-Lin

    2011-12-01

    Carbonic anhydrase (CA) has recently gained renewed interests for its potential as a mass-transfer facilitator for CO(2) sequestration. However, the low stability and high price severely limit its applications. In this work, the expression of α-CA from Helicobacter pylori on the outer membrane of Escherichia coli using a surface-anchoring system derived from ice nucleation protein (INP) from Pseudomonas syringae was developed. To find the best surface anchoring motif, full-length INP (114 kDa), truncated INP (INP-NC, 33 kDa), and INP's N-domain with first two subunits (INP-N, 22 kDa) were evaluated. Two vectors, pKK223-3 and pET22b(+), with different promoters (T7 and Tac) were used to construct the fusion genes, and for each vector, three recombinant strains, each expressing a different length of the fusion protein, were obtained. SDS-PAGE, Western blot, immunofluorescence microscopy, FACS, and whole-cell ELISA confirmed the expression of fusion proteins on the surface of E. coli. The smallest fusion protein with INP-N as the anchoring motif had the highest expression level and CA activity, suggesting that INP-N is the best carrying protein due to its smaller size. Also, the T7 promoter in pET22b(+) induced with 0.2 mM IPTG gave high protein expression levels, whereas the Tac promoter in pKK223-3 gave low expression levels. The surface displayed CA was at least twofold more stable than that of the free form, and did not show any adverse effect on cell growth and outer membrane integrity. Cells with surface displayed CA were successfully used to facilitate CO(2) sequestration in contained liquid membrane (CLM). PMID:21732326

  4. The plant S-adenosyl-L-methionine:Mg-protoporphyrin IX methyltransferase is located in both envelope and thylakoid chloroplast membranes.

    PubMed

    Block, Maryse A; Tewari, Arun Kumar; Albrieux, Catherine; Maréchal, Eric; Joyard, Jacques

    2002-01-01

    Chlorophyll biosynthesis requires a metabolic dialog between the chloroplast envelope and thylakoids where biosynthetic activities are localized. Here, we report the first plant S-adenosyl-l-methionine:Mg-protoporphyrin IX methyltransferase (MgP(IX)MT) sequence identified in the Arabidopsis genome owing to its similarity with the Synechocystis sp. MgP(IX)MT gene. After expression in Escherichia coli, the recombinant Arabidopsis thaliana cDNA was shown to encode a protein having MgP(IX)MT activity. The full-length polypeptide exhibits a chloroplast transit peptide that is processed during import into the chloroplast. The mature protein contains two functional regions. The C-terminal part aligns with the Synechocystis full-length protein. The corresponding truncated region binds to Ado-met, as assayed by UV crosslinking, and is shown to harbor the MgP(IX)MT activity. Downstream of the cleaved transit peptide, the 40 N-terminal amino acids of the mature protein are very hydrophobic and enhance the association of the protein with the membrane. In A. thaliana and spinach, the MgP(IX)MT protein has a dual localization in chloroplast envelope membranes as well as in thylakoids. The protein is active in each membrane and has the same apparent size corresponding to the processed mature protein. The protein is very likely a monotopic membrane protein embedded within one leaflet of the membrane as indicated by ionic and alkaline extraction of each membrane. The rationale for a dual localization of the protein in the chloroplast is discussed. PMID:11784318

  5. Title IX and Intercollegiate Athletics in the Federal Appellate Courts: Myth vs. Reality.

    ERIC Educational Resources Information Center

    Pieronek, Catherine

    2000-01-01

    Focuses on the enforcement of the nondiscrimination provisions of Title IX in higher education, and shows how the courts have wrestled with the application of Title IX to college athletic programs over the past decade. Provides a history of Title IX enforcement and describes current approaches to evaluating Title IX compliance. (SLD)

  6. IBM PC/IX operating system evaluation plan

    NASA Technical Reports Server (NTRS)

    Dominick, Wayne D. (Editor); Granier, Martin; Hall, Philip P.; Triantafyllopoulos, Spiros

    1984-01-01

    An evaluation plan for the IBM PC/IX Operating System designed for IBM PC/XT computers is discussed. The evaluation plan covers the areas of performance measurement and evaluation, software facilities available, man-machine interface considerations, networking, and the suitability of PC/IX as a development environment within the University of Southwestern Louisiana NASA PC Research and Development project. In order to compare and evaluate the PC/IX system, comparisons with other available UNIX-based systems are also included.

  7. Tobacco Nectarin III is a bifunctional enzyme with monodehydroascorbate reductase and carbonic anhydrase activities.

    PubMed

    Carter, Clay J; Thornburg, Robert W

    2004-02-01

    Tobacco plants secrete a limited array of proteins (nectarins) into their floral nectar. N-terminal sequencing of the Nectarin II ( NEC2; 35kD) and the Nectarin III ( NEC3; 40kD) proteins revealed that they both share identity with dioscorin, the major soluble protein of yam tubers. These sequences also revealed that NEC2 is a breakdown product of NEC3. Using these N-terminal peptide sequences, degenerate oligonucleotides were designed that permitted the isolation of a partial NEC3 cDNA. This cDNA was then used to probe a nectary specific cDNA library and a full-length NEC3 cDNA clone was isolated. Complete sequence analysis confirmed the identity of NEC3 as a dioscorin-like protein. MALDI-TOF mass spectrometric fingerprinting of tryptic peptides derived from the purified NEC3 confirmed that this protein was encoded by the isolated cDNA. NEC3 was shown to possess both carbonic anhydrase and monodehydroascorbate reductase activities. RT-PCR based expression analyses demonstrated that NEC3 transcript is expressed throughout nectary development as well as in other floral organs. A proposed function in the maintenance of pH and oxidative balance in nectar is discussed. PMID:15284496

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

    PubMed Central

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

    2013-01-01

    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. PMID:23760644

  9. Transcriptional Regulation of the β-Type Carbonic Anhydrase Gene bca by RamA in Corynebacterium glutamicum.

    PubMed

    Shah, Adnan; Eikmanns, Bernhard J

    2016-01-01

    Carbonic anhydrase catalyzes the reversible hydration of carbon dioxide to bicarbonate and maintains the balance of CO2/HCO3- in the intracellular environment, specifically for carboxylation/decarboxylation reactions. In Corynebacterium glutamicum, two putative genes, namely the bca (cg2954) and gca (cg0155) genes, coding for β-type and γ-type carbonic anhydrase, respectively, have been identified. We here analyze the transcriptional organization of these genes. The transcriptional start site (TSS) of the bca gene was shown to be the first nucleotide "A" of its putative translational start codon (ATG) and thus, bca codes for a leaderless transcript. The TSS of the gca gene was identified as an "A" residue located at position -20 relative to the first nucleotide of the annotated translational start codon of the cg0154 gene, which is located immediately upstream of gca. Comparative expression analysis revealed carbon source-dependent regulation of the bca gene, with 1.5- to 2-fold lower promoter activity in cells grown on acetate as compared to glucose as sole carbon source. Based on higher expression of bca in a mutant deficient of the regulator of acetate metabolism RamA as compared to the wild-type of C. glutamicum and based on the binding of His-tagged RamA protein to the bca promoter region, we here present evidence that RamA negatively regulates expression of bca in C. glutamicum. Functional characterization of a gca deletion mutant of C. glutamicum revealed the same growth characteristics of C. glutamicum ∆gca as that of wild-type C. glutamicum and no effect on expression of the bca gene. PMID:27119954

  10. Transcriptional Regulation of the β-Type Carbonic Anhydrase Gene bca by RamA in Corynebacterium glutamicum

    PubMed Central

    Shah, Adnan; Eikmanns, Bernhard J.

    2016-01-01

    Carbonic anhydrase catalyzes the reversible hydration of carbon dioxide to bicarbonate and maintains the balance of CO2/HCO3- in the intracellular environment, specifically for carboxylation/decarboxylation reactions. In Corynebacterium glutamicum, two putative genes, namely the bca (cg2954) and gca (cg0155) genes, coding for β-type and γ-type carbonic anhydrase, respectively, have been identified. We here analyze the transcriptional organization of these genes. The transcriptional start site (TSS) of the bca gene was shown to be the first nucleotide “A” of its putative translational start codon (ATG) and thus, bca codes for a leaderless transcript. The TSS of the gca gene was identified as an “A” residue located at position -20 relative to the first nucleotide of the annotated translational start codon of the cg0154 gene, which is located immediately upstream of gca. Comparative expression analysis revealed carbon source-dependent regulation of the bca gene, with 1.5- to 2-fold lower promoter activity in cells grown on acetate as compared to glucose as sole carbon source. Based on higher expression of bca in a mutant deficient of the regulator of acetate metabolism RamA as compared to the wild-type of C. glutamicum and based on the binding of His-tagged RamA protein to the bca promoter region, we here present evidence that RamA negatively regulates expression of bca in C. glutamicum. Functional characterization of a gca deletion mutant of C. glutamicum revealed the same growth characteristics of C. glutamicum ∆gca as that of wild-type C. glutamicum and no effect on expression of the bca gene. PMID:27119954

  11. Sclerostin regulates release of bone mineral by osteocytes by induction of carbonic anhydrase 2.

    PubMed

    Kogawa, Masakazu; Wijenayaka, Asiri R; Ormsby, Renee T; Thomas, Gethin P; Anderson, Paul H; Bonewald, Lynda F; Findlay, David M; Atkins, Gerald J

    2013-12-01

    The osteocyte product sclerostin is emerging as an important paracrine regulator of bone mass. It has recently been shown that osteocyte production of receptor activator of NF-κB ligand (RANKL) is important in osteoclastic bone resorption, and we reported that exogenous treatment of osteocytes with sclerostin can increase RANKL-mediated osteoclast activity. There is good evidence that osteocytes can themselves liberate mineral from bone in a process known as osteocytic osteolysis. In the current study, we investigated sclerostin-stimulated mineral dissolution by human primary osteocyte-like cells (hOCy) and mouse MLO-Y4 cells. We found that sclerostin upregulated osteocyte expression of carbonic anhydrase 2 (CA2/Car2), cathepsin K (CTSK/Ctsk), and tartrate-resistant acid phosphatase (ACP5/Acp5). Because acidification of the extracellular matrix is a critical step in the release of mineral from bone, we further examined the regulation by sclerostin of CA2. Sclerostin stimulated CA2 mRNA and protein expression in hOCy and in MLO-Y4 cells. Sclerostin induced a decrease in intracellular pH (pHi) in both cell types as well as a decrease in extracellular pH (pHo) and the release of calcium ions from mineralized substrate. These effects were reversed in the co-presence of the carbonic anhydrase inhibitor, acetozolamide. Car2-siRNA knockdown in MLO-Y4 cells significantly inhibited the ability of sclerostin to both reduce the pHo and release calcium from a mineralized substrate. Knockdown in MLO-Y4 cells of each of the putative sclerostin receptors, Lrp4, Lrp5 and Lrp6, using siRNA, inhibited the sclerostin induction of Car2, Catk and Acp5 mRNA, as well as pHo and calcium release. Consistent with this activity of sclerostin resulting in osteocytic osteolysis, human trabecular bone samples treated ex vivo with recombinant human sclerostin for 7 days exhibited an increased osteocyte lacunar area, an effect that was reversed by the co-addition of acetozolamide. These findings

  12. The role of carbonic anhydrase in the pathogenesis of vascular calcification in humans.

    PubMed

    Adeva-Andany, María M; Fernández-Fernández, Carlos; Sánchez-Bello, Rocío; Donapetry-García, Cristóbal; Martínez-Rodríguez, Julia

    2015-07-01

    Carbonic anhydrases are a group of isoenzymes that catalyze the reversible conversion of carbon dioxide into bicarbonate. They participate in a constellation of physiological processes in humans, including respiration, bone metabolism, and the formation of body fluids, including urine, bile, pancreatic juice, gastric secretion, saliva, aqueous humor, cerebrospinal fluid, and sweat. In addition, carbonic anhydrase may provide carbon dioxide/bicarbonate to carboxylation reactions that incorporate carbon dioxide to substrates. Several isoforms of carbonic anhydrase have been identified in humans, but their precise physiological role and the consequences of their dysfunction are mostly unknown. Carbonic anhydrase isoenzymes are involved in calcification processes in a number of biological systems, including the formation of calcareous spicules from sponges, the formation of shell in some animals, and the precipitation of calcium salts induced by several microorganisms, particularly urease-producing bacteria. In human tissues, carbonic anhydrase is implicated in calcification processes either directly by facilitating calcium carbonate deposition which in turn serves to facilitate calcium phosphate mineralization, or indirectly via its action upon γ-glutamyl-carboxylase, a carboxylase that enables the biological activation of proteins involved in calcification, such as matrix Gla protein, bone Gla protein, and Gla-rich protein. Carbonic anhydrase is implicated in calcification of human tissues, including bone and soft-tissue calcification in rheumatological disorders such as ankylosing spondylitis and dermatomyositis. Carbonic anhydrase may be also involved in bile and kidney stone formation and carcinoma-associated microcalcifications. The aim of this review is to evaluate the possible association between carbonic anhydrase isoenzymes and vascular calcification in humans. PMID:26005791

  13. 26. Photocopy of August 1918 photograph. Glass Negative Box IX, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    26. Photocopy of August 1918 photograph. Glass Negative Box IX, Tower Grove, Missouri Botanical Garden. ITALIAN GARDEN, LOOKING SOUTHWEST - Missouri Botanical Garden, 2345 Tower Grove Avenue, Saint Louis, Independent City, MO

  14. 29. Photocopy of 1921 photograph. Glass Negative Box IX, Tower ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    29. Photocopy of 1921 photograph. Glass Negative Box IX, Tower Grove, Missouri Botanical Garden. ITALIAN GARDEN AND NEW PALM HOUSE (DEMOLISHED), LOOKING NORTHEAST - Missouri Botanical Garden, 2345 Tower Grove Avenue, Saint Louis, Independent City, MO

  15. Bortezomib inhibits bacterial and fungal β-carbonic anhydrases.

    PubMed

    Supuran, Claudiu T

    2016-09-15

    Inhibition of the β-carbonic anhydrases (CAs, EC 4.2.1.1) from pathogenic fungi (Cryptococcus neoformans, Candida albicans, Candida glabrata, Malassezia globosa) and bacteria (three isoforms from Mycobacterium tuberculosis, Rv3273, Rv1284 and Rv3588), as well from the insect Drosophila melanogaster (DmeCA) and the plant Flaveria bidentis (FbiCA1) with the boronic acid peptidomimetic proteosome inhibitor bortezomib was investigated. Bortezomib was a micromolar inhibitor of all these enzymes, with KIs ranging between 1.12 and 11.30μM. Based on recent crystallographic data it is hypothesized that the B(OH)2 moiety of the inhibitor is directly coordinated to the zinc ion from the enzyme active site. The class of boronic acids, an under-investigated type of CA inhibitors, may lead to the development of anti-infectives with a novel mechanism of action, based on the pathogenic organisms CA inhibition. PMID:27469982

  16. Evaluation of a carbonic anhydrase mimic for industrial carbon capture.

    PubMed

    Floyd, William C; Baker, Sarah E; Valdez, Carlos A; Stolaroff, Joshuah K; Bearinger, Jane P; Satcher, Joe H; Aines, Roger D

    2013-09-01

    Zinc(II) cyclen, a small molecule mimic of the enzyme carbonic anhydrase, was evaluated under rigorous conditions resembling those in an industrial carbon capture process: high pH (>12), nearly saturated salt concentrations (45% K2CO3) and elevated temperatures (100-130 °C). We found that the catalytic activity of zinc cyclen increased with increasing temperature and pH and was retained after exposure to a 45% w/w K2CO3 solution at 130 °C for 6 days. However, high bicarbonate concentrations markedly reduced the activity of the catalyst. Our results establish a benchmark level of stability and provide qualitative insights for the design of improved small-molecule carbon capture catalysts. PMID:23883067

  17. Carbonic anhydrase in Acetobacterium woodii and other acetogenic bacteria.

    PubMed

    Braus-Stromeyer, S A; Schnappauf, G; Braus, G H; Gössner, A S; Drake, H L

    1997-11-01

    Acetobacterium woodii, Acetohalobium arabaticum, Clostridium formicoaceticum, and Sporomusa silvacetica were found to contain carbonic anhydrase (CA). Minimal to no CA activity was detected in Moorella thermoautotrophica, Moorella thermoacetica subsp. "pratumsolum," Sporomusa termitida, and Thermoanaerobacter kivui. Of the acetogens tested, A. woodii had the highest CA specific activity, approximately 14 U mg of protein(-1), in extracts of either glucose- or H2-CO2-cultivated cells. CA of A. woodii was cytoplasmic and was purified approximately 300-fold to a specific activity of 5,236 U mg of protein(-1). Intracellular acetate concentrations inhibited CA activity of A. woodii by 50 to 85%, indicating that intracellular acetate may affect in situ CA activity. PMID:9371472

  18. Carbonic anhydrase activity in isolated chloroplasts of chlamydomonas reinhardtii

    SciTech Connect

    Katzman, G.; Togasaki, R.K. ); Marcus, Y. ); Moroney, J.V. )

    1989-04-01

    In a new assay of carbonic anhydrase, NaH{sup 14}CO{sub 3} solution at the bottom of a sealed vessel releases {sup 14}CO{sub 3} which diffuses to the top of the vessel to be assimilated by actively photosynthesizing Chlamydomonas cells. The assay is initiated by illuminating cells and stopped by turning the light off and killing the cells with acid. Enzyme activity was estimated from acid stable radioactivity above the uncatalyzed background level. With bovine carbonic anhydrase, 1.5 Wilbur Anderson Unit (WAU) can be consistantly measured at 5-6 fold above background. Sonicated whole cells of air adapted wild type (+)gave 741.1 {plus minus} 12.4 WAU/mg chl. Intact washed cells of mixotrophically grown wall-less mutant CWD(-) and a high CO2 requiring wall-less double mutant CIA-3/CW15 (-) gave 7.1 {plus minus} 1.9 and 2.8 {plus minus} 7.8 WAU/mg chl respectively. Chloroplasts isolated from CWD and CIA-3/CW15 and subsequently disrupted gave 64.0 {plus minus} 14.7 and 2.8 {plus minus} 3.2 WAU/mg chl respectively. Chloroplast sonicate from another wall-less mutant CW15(-) gave activity comparable to CWD. Thus on a chlorophyll basis, enzyme activity in chloroplasts from mixotrophically grown cells is about 1/10th of the level found in air adapted wild type cells. CIA-3 seems to lack this activity.

  19. Anisotropic Bianchi types VIII and IX locally rotationally symmetric cosmologies

    SciTech Connect

    Assad, M.J.D.; Soares, I.D.

    1983-10-15

    We present a class of exact cosmological solutions of Einstein-Maxwell equations, which are anisotropic and spatially homogeneous of Bianchi types VIII and IX, and class IIIb in the Stewart-Ellis classification of locally rotationally symmetric models. If we take the electromagnetic field equal to zero, a class of Bianchi types VIII/IX spatially homogeneous anisotropic cosmological solutions with perfect fluid is obtained.

  20. Mitochondrial gamma carbonic anhydrases are required for complex I assembly and plant reproductive development.

    PubMed

    Fromm, Steffanie; Braun, Hans-Peter; Peterhansel, Christoph

    2016-07-01

    Complex I of the mitochondrial electron transport chain (mETC) in plants contains an extra domain that is made up from proteins homologous to prokaryotic gamma-carbonic anhydrases (γCA). This domain has been suggested to participate in complex I assembly or to support transport of mitochondrial CO2 to the chloroplast. Here, we generated mutants lacking CA1 and CA2 - two out of three CA proteins in Arabidopsis thaliana. Double mutants were characterized at the developmental and physiological levels. Furthermore, the composition and activity of the mETC were determined, and mutated CA versions were used for complementation assays. Embryo development of double mutants was strongly delayed and seed development stopped before maturation. Mutant plants could only be rescued on sucrose media, showed severe stress symptoms and never produced viable seeds. By contrast, callus cultures were only slightly affected in growth. Complex I was undetectable in the double mutants, but complex II and complex IV were upregulated concomitant with increased oxygen consumption in mitochondrial respiration. Ectopic expression of inactive CA variants was sufficient to complement the mutant phenotype. Data indicate that CA proteins are structurally required for complex I assembly and that reproductive development is dependent on the presence of complex I. PMID:26889912

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

    PubMed

    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. PMID:26421381

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

    NASA Astrophysics Data System (ADS)

    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.

  3. Anti-carbonic anhydrase II antibodies in systemic sclerosis: association with lung involvement.

    PubMed

    Alessandri, Cristiano; Bombardieri, Michele; Scrivo, Rossana; Viganego, Federico; Conti, Fabrizio; de Luca, Nicoletta; Riccieri, Valeria; Valesini, Guido

    2003-03-01

    Carbonic anhydrase II (CAII) is expressed on alveolar epithelium and participates to CO2 elimination, fluid secretion and post-capillary pH regulation. CAII is overexpressed in animal models of lung fibrosis in sites of epithelial injury. Autoantibodies directed against CAII (anti-CAII) have been described in sera from patients affected by systemic sclerosis (SSc), but no study focused on their clinical associations in this disease. The aim of this study was to assess the presence of anti-CAII in sera of SSc patients and to investigate their association with lung involvement. We performed ELISA to detect anti-CAII in 34 SSc patients who underwent pulmonary function tests (PFT) and Doppler echocardiography. We found increased prevalence and significantly elevated serum levels of anti-CAII in SSc patients affected by restrictive lung disease (RLD) compared to SSc patients without lung involvement and healthy controls. These findings suggest both a possible pathogenic role of anti-CAII in the development of lung damage and a potential clinical utility as serological marker of pulmonary involvement in SSc patients. PMID:12820690

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

    PubMed Central

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

    2016-01-01

    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. PMID:27385052

  5. Indazole, Pyrazole, and Oxazole Derivatives Targeting Nitric Oxide Synthases and Carbonic Anhydrases.

    PubMed

    Maccallini, Cristina; Di Matteo, Mauro; Vullo, Daniela; Ammazzalorso, Alessandra; Carradori, Simone; De Filippis, Barbara; Fantacuzzi, Marialuigia; Giampietro, Letizia; Pandolfi, Assunta; Supuran, Claudiu T; Amoroso, Rosa

    2016-08-19

    Nitric oxide (NO) is an essential endogenous mediator with a physiological role in the central nervous system as neurotransmitter and neuromodulator. A growing number of studies have demonstrated that abnormal nitrergic signaling is a crucial event in the development of neurodegeneration. In particular, the uncontrolled production of NO by neuronal nitric oxide synthase (nNOS) is observed in several neurodegenerative diseases. Moreover, it is well recognized that specific isoforms of human carbonic anhydrase (hCA) physiologically modulate crucial pathways of signal processing and that low expression of CA affects cognition, leading to mental retardation, Alzheimer's disease, and aging-related cognitive impairments. In light of this, dual agents that are able to target both NOS (inhibition) and CA (activation) could be useful drug candidates for the treatment of Alzheimer's disease, aging, and other neurodegenerative diseases. In the present work, we show the design, synthesis, and in vitro biological evaluation of new nitrogen-based heterocyclic compounds. Among the tested molecules, 2-amino-3-(4-hydroxyphenyl)-N-(1H-indazol-5-yl)propanamide hydrochloride (10 b) was revealed to be a potent dual agent, able to act as a selective nNOS inhibitor and activator of the hCA I isoform. PMID:27377568

  6. Monoclonal antibodies raised against 167-180 aa sequence of human carbonic anhydrase XII inhibit its enzymatic activity.

    PubMed

    Dekaminaviciute, Dovile; Kairys, Visvaldas; Zilnyte, Milda; Petrikaite, Vilma; Jogaite, Vaida; Matuliene, Jurgita; Gudleviciene, Zivile; Vullo, Daniela; Supuran, Claudiu T; Zvirbliene, Aurelija

    2014-12-01

    Abstract Human carbonic anhydrase XII (CA XII) is a single-pass transmembrane protein with an extracellular catalytic domain. This enzyme is being recognized as a potential biomarker for different tumours. The current study was aimed to generate monoclonal antibodies (MAbs) neutralizing the enzymatic activity of CA XII. Bioinformatics analysis of CA XII structure revealed surface-exposed sequences located in a proximity of its catalytic centre. Two MAbs against the selected antigenic peptide spanning 167-180 aa sequence of CA XII were generated. The MAbs were reactive with recombinant catalytic domain of CA XII expressed either in E. coli or mammalian cells. Inhibitory activity of the MAbs was demonstrated by a stopped flow CO2 hydration assay. The study provides new data on the surface-exposed linear CA XII epitope that may serve as a target for inhibitory antibodies with a potential immunotherapeutic application. PMID:24400872

  7. Serotype IX, a Proposed New Streptococcus agalactiae Serotype.

    PubMed

    Slotved, Hans-Christian; Kong, Fanrong; Lambertsen, Lotte; Sauer, Susanne; Gilbert, Gwendolyn L

    2007-09-01

    We identified three isolates of Streptococcus agalactiae (group B streptococcus [GBS]), of human origin, which failed to react with antisera against any of the nine known GBS serotypes. Polyclonal rabbit antisera raised against these isolates and standard GBS typing sera were used in capillary precipitation and Ouchterlony tests to compare the strains with known GBS serotype reference strains. All three previously nontypeable isolates reacted with all three new antisera, producing lines of identity in the Ouchterlony test. Weak cross-reactions with antisera against several GBS serotypes were observed but were removed by absorption with corresponding antigens. The new antisera were used to test 227 GBS isolates that had been nontypeable or difficult to type using standard antisera. Of these, five reacted with the new antisera. These results suggested that all eight isolates belong to the previously unrecognized GBS serotype. They were tested by Western blotting for the Calpha and Cbeta proteins and by PCR to identify molecular serotypes and surface protein antigen genes. Two segments of the cps gene cluster (3' end of cpsE-cpsF and 5' end of cpsG, approximately 700 bp; 3' end of cpsH and 5' end of cpsM, approximately 560 bp) were sequenced. All eight isolates expressed Calpha, and seven expressing the Cbeta protein and the corresponding genes, bca and bac, respectively, were identified. They all share the same, unique partial cps sequence. These results indicate that these eight isolates represent a new S. agalactiae serotype, which we propose should be designated serotype IX. PMID:17634306

  8. Zn protoporphyrin IX is formed not from heme but from protoporphyrin IX.

    PubMed

    Wakamatsu, Jun-Ichi; Okui, Jun; Hayashi, Nobutaka; Nishimura, Takanori; Hattori, Akihito

    2007-12-01

    We examined the effects of exogenous myoglobin, a bivalent chelator, and nitrite on Zn protoporphyrin IX (ZPP) formation by using model systems. ZPP was formed in a model solution without addition of exogenous myoglobin. After incubation, the amount of ZPP in a model solution was increased but that of heme was not decreased compared with the amounts before incubation. Protoporphyrin IX (PPIX) instead of ZPP also accumulated in a model solution with addition of EDTA, but the amount of heme was not reduced. These results suggested that ZPP was not formed by the Fe-Zn substitution in heme but was formed by the insertion of Zn into PPIX, which was formed independently. The fact that the effects of various factors in model systems with/without addition of a bivalent chelator were similar suggested that ZPP formation was strongly affected by PPIX formation. Inhibition of PPIX formation by nitrite might be the reason for the low levels of ZPP in cured meats. PMID:22061944

  9. Carbonic anhydrase induction in euryhaline crustaceans is rate-limited at the post-transcriptional level.

    PubMed

    Mitchell, Reed T; Henry, Raymond P

    2014-03-01

    The transfer of euryhaline crustaceans from full-strength seawater to low salinity results in both a rapid up-regulation of carbonic anhydrase (CA; EC 4.2.1.1) mRNA and a slow induction of CA activity. There is a delay of several days between the two processes, which is attributed to the time required to synthesize new enzyme. These delays may also be due to limitations in the cellular uptake of Zn, which is a required post-translational active site modification to CA. To investigate these processes, the euryhaline crabs, Callinectes sapidus and Carcinus maenas, were acclimated to salinities below their isosmotic points (22.5 and 25 ppt, respectively) for 7 days to activate the physiological and molecular mechanisms of osmoregulation. CA mRNA increased 90-fold in C. sapidus and 2-fold in C. maenas within 6h; whereas it took 48 h for the initial increases in CA activity (120% and 31%), and 4 to 7 days for new acclimated levels (300% and 100%, respectively). Crabs were then transferred to lower salinities (10 and 15 ppt) to induce further CA activity and to determine if previous increases in CA mRNA reduced the time required for subsequent CA induction. Additionally, the expression of the Zn transporter ZIP1 was examined in C. sapidus at 35 and 22.5 ppt. In both species, prior CA mRNA elevation failed to accelerate the rate of CA induction. Levels of CA mRNA did not change in either crab following transfer from intermediate to low salinity. Taken together, these results show that the timecourse of CA induction at low salinity is not limited by the expression of CA mRNA, but by the synthesis of new enzyme from an existing pool of mRNA. No increases in ZIP1 expression occurred at low salinity, therefore these delays may be due to the limits of cellular Zn uptake. PMID:24333600

  10. Imaging of CAIX-expressing xenografts in vivo using 99mTc-HEHEHE-ZCAIX:1 Affibody molecule

    PubMed Central

    HONARVAR, HADIS; GAROUSI, JAVAD; GUNNERIUSSON, ELIN; HÖIDÉN-GUTHENBERG, INGMARIE; ALTAI, MOHAMED; WIDSTRÖM, CHARLES; TOLMACHEV, VLADIMIR; FREJD, FREDRIK Y.

    2015-01-01

    Carbonic anhydrase IX (CAIX) is a transmembrane enzyme involved in regulation of tissue pH balance. In cancer, CAIX expression is associated with tumor hypoxia. CAIX is also overexpressed in renal cell carcinoma and is a molecular target for the therapeutic antibody cG250 (girentuximab). Radionuclide imaging of CAIX expression might be used for identification of patients who may benefit from cG250 therapy and from treatment strategies for hypoxic tumors. Affibody molecules are small (7 kDa) scaffold proteins having a high potential as probes for radionuclide molecular imaging. The aim of the present study was to evaluate feasibility of in vivo imaging of CAIX-expression using radiolabeled Affibody molecules. A histidine-glutamate-histidine-glutamate-histidine-glutamate (HE)3-tag-containing CAIX-binding Affibody molecule (HE)3-ZCAIX:1 was labeled with [99mTc(CO)3]+. Its binding properties were evaluated in vitro using CAIX-expressing SK-RC-52 renal carcinoma cells. 99mTc-(HE)3-ZCAIX:1 was evaluated in NMRI nu/nu mice bearing SK-RC-52 xenografts. The in vivo specificity test confirmed CAIX-mediated tumor targeting. 99mTc-(HE)3-ZCAIX:1 cleared rapidly from blood and normal tissues except for kidneys. At optimal time-point (4 h p.i.), the tumor uptake was 9.7±0.7% ID/g, and tumor-to-blood ratio was 53±10. Experimental imaging of CAIX-expressing SK-RC-52 xenografts at 4 h p.i. provided high contrast images. The use of radioiodine label for ZCAIX:1 enabled the reduction of renal uptake, but resulted in significantly lower tumor uptake and tumor-to-blood ratio. Results of the present study suggest that radiolabeled Affibody molecules are promising probes for imaging of CAIX-expression in vivo. PMID:25434612

  11. Phenolic compounds as antioxidants: carbonic anhydrase isoenzymes inhibitors.

    PubMed

    Gülçin, Ilhami; Beydemir, Şükrü

    2013-03-01

    Antioxidant compounds can scavenge free radicals and increase shelf life by retarding the process of lipid peroxidation, which is one of the major reasons for deterioration of food, medicine and pharmaceutical products during processing and storage. An antioxidant molecule has been defined as any substance when found in low concentrations compared to that of an oxidizable substrate significantly delays or inhibits the oxidation. The major antioxidant compounds are especially phenolics and flavonoids, which are responsible for their health benefits. Carbonic anhydrase (EC 4.2.1.1., CA) is a pH regulatory/metabolic enzyme in all life kingdoms, being found in organisms all over the phylogenetic tree. It catalyzes the hydration of carbon dioxide (CO(2)) to bicarbonate (HCO(3) -) and the corresponding dehydration of HCO(3) -in acidic medium with regeneration of CO(2). Also, CA isoforms are found in a variety of tissues where they participate in several important biological processes such as acid-base balance, respiration, carbon dioxide and ion transport, bone resorption, ureagenesis, gluconeogenesis, lipogenesis and electrolyte secretion. On the other hand, the phenyl moiety of phenol was found to lay in the hydrophobic part of the CA active site, where CO(2), the physiologic substrate of the CAs, binds in the precatalytic complex, explaining thus the behavior of phenol as a unique CO(2) competitive inhibitor. This review consists of two main sections. The first section is devoted to main phenolic antioxidant compounds in the foodstuffs and beverages. The second general section is about some definitions of CA inhibitory effects of the main phenolic compounds used for antioxidant activity. The phenolic compounds and acids had marked especially CA I and CA II inhibitory effects and might be used as leads for generating CA isoenzyme inhibitors. This class of compounds may lead to isoform-selective inhibitors targeting just one or few of the medicinally relevant CAs. In

  12. Triangulated loop quantum cosmology: Bianchi IX universe and inhomogeneous perturbations

    SciTech Connect

    Battisti, Marco Valerio; Marciano, Antonino; Rovelli, Carlo

    2010-03-15

    We develop the triangulated version of loop quantum cosmology, recently introduced in the literature. We focus on the dipole cosmology, where space is a three-sphere and the triangulation is formed by two tetrahedra. We show that the discrete fiducial connection has a simple and appealing geometrical interpretation and we correct the ansatz on the relation between the model variables and the Friedmann-Robertson-Walker scale factor. The modified ansatz leads to the convergence of the Hamiltonian constraint to the continuum one. We then ask which degrees of freedom are captured by this model. We show that the model is rich enough to describe the (anisotropic) Bianchi IX universe, and give the explicit relation between the Bianchi IX variables and the variables of the model. We discuss the possibility of using this path in order to define the quantization of the Bianchi IX universe. The model contains more degrees of freedom than Bianchi IX, and therefore captures some inhomogeneous degrees of freedom as well. Inhomogeneous degrees of freedom can be expanded in representations of the SU(2) Bianchi IX isometry group, and the dipole model captures the lowest integer representation of these, connected to hyperspherical harmonic of angular momentum j=1.

  13. Ares I-X Flight Test - The Future Begins Here

    NASA Technical Reports Server (NTRS)

    Davis, Stephan R.

    2008-01-01

    In less than two years, the National Aeronautics and Space Administration (NASA) will launch the Ares I-X mission. This will be the first flight of the Ares I crew launch vehicle, which, together with the Ares V cargo launch vehicle, will eventually send humans to the Moon, Mars, and beyond. As the countdown to this first Ares mission continues, personnel from across the Ares I-X Mission Management Office (MMO) are finalizing designs and fabricating vehicle hardware for an April 2009 launch. This paper will discuss the hardware and programmatic progress of the Ares I-X mission. Like the Apollo program, the Ares launch vehicles will rely upon extensive ground, flight, and orbital testing before sending the Orion crew exploration vehicle into space with humans on board. The first flight of Ares I, designated Ares I-X, will be a suborbital development flight test. Ares I-X gives NASA its first opportunity to gather critical data about the flight dynamics of the integrated launch vehicle stack; understand how to control its roll during flight; better characterize the severe stage separation environments that the upper stage engine will experience during future operational flights; and demonstrate the first stage recovery system. NASA also will begin modifying the launch infrastructure and fine-tuning ground and mission operations, as the agency makes the transition from the Space Shuttle to the Ares/Orion system.

  14. Apoptosis of THP-1 macrophages induced by protoporphyrin IX-mediated sonodynamic therapy

    PubMed Central

    Guo, Shuyuan; Sun, Xin; Cheng, Jiali; Xu, Haobo; Dan, Juhua; Shen, Jing; Zhou, Qi; Zhang, Yun; Meng, Lingli; Cao, Wenwu; Tian, Ye

    2013-01-01

    Background Sonodynamic therapy (SDT) was developed as a localized ultrasound-activated cytotoxic therapy for cancer. The ability of SDT to destroy target tissues selectively is especially appealing for atherosclerotic plaque, in which selective accumulation of the sonosensitizer, protoporphyrin IX (PpIX), had been demonstrated. Here we investigate the effects of PpIX-mediated SDT on macrophages, which are the main culprit in progression of atherosclerosis. Methods and results Cultured THP-1 derived macrophages were incubated with PpIX. Fluorescence microscopy showed that the intracellular PpIX concentration increased with the concentration of PpIX in the incubation medium. MTT assay demonstrated that SDT with PpIX significantly decreased cell viability, and this effect increased with duration of ultrasound exposure and PpIX concentration. PpIX-mediated SDT induced both apoptosis and necrosis, and the maximum apoptosis to necrosis ratio was obtained after SDT with 20 μg/mL PpIX and five minutes of sonication. Production of intracellular singlet oxygen and secondary disruption of the cytoskeleton were also observed after SDT with PpIX. Conclusion PpIX-mediated SDT had apoptotic effects on THP-1 macrophages via generation of intracellular singlet oxygen and disruption of the cytoskeleton. PpIX-mediated SDT may be a potential treatment to attenuate progression of atherosclerotic plaque. PMID:23818780

  15. Molecular cloning and biochemical characterization of carbonic anhydrase from Populus tremula x tremuloides.

    PubMed

    Larsson, S; Björkbacka, H; Forsman, C; Samuelsson, G; Olsson, O

    1997-07-01

    A leaf cDNA library from hybrid aspen, Populus tremula x tremuloides, was constructed. From this two different cDNA clones, denoted CA1a and CA1b, encoding a chloroplastic carbonic anhydrase (CA) were isolated and DNA sequenced. Analysis of the deduced amino acid sequences showed that the isolated CAs belong to the beta-CA family, and have identities around 70% to other dicotyledonous plant CAs. The two hybrid aspen cDNA clones display a high nucleotide sequence identity, only 12 nucleotides differ. Since only one gene copy of this soluble chloroplastic CA is present in the nuclear genome, we postulate that the two isolated cDNA clones are alleles. Northern blot hybridization revealed a CA transcript of ca. 1300 bases, 140 bases shorter than in pea. Western and northern blot hybridizations on crude protein extracts and on total RNA, respectively, isolated from stem and leaves, showed that hybrid aspen CA is expressed specifically in the leaf under the growth conditions used. Based on the deduced amino acid sequence, the mature hybrid aspen CA enzyme subunit has a molecular mass of 24.8 kDa. The enzyme was over-expressed in Escherichia coli, and purified by affinity chromatography. Biochemical characterization showed that the protein structure and the CO2-hydration activity are similar to the pea enzyme. Molecular characterization of a CA from a perennial plant has not previously been performed, and it demonstrates that both the structure and activity of hybrid aspen CA resembles CAs from annual plants. PMID:9247540

  16. Distinct Cellular Locations of Carbonic Anhydrases Mediate Carbon Dioxide Control of Stomatal Movements.

    PubMed

    Hu, Honghong; Rappel, Wouter-Jan; Occhipinti, Rossana; Ries, Amber; Böhmer, Maik; You, Lei; Xiao, Chuanlei; Engineer, Cawas B; Boron, Walter F; Schroeder, Julian I

    2015-10-01

    Elevated carbon dioxide (CO2) in leaves closes stomatal apertures. Research has shown key functions of the β-carbonic anhydrases (βCA1 and βCA4) in rapid CO2-induced stomatal movements by catalytic transmission of the CO2 signal in guard cells. However, the underlying mechanisms remain unclear, because initial studies indicate that these Arabidopsis (Arabidopsis thaliana) βCAs are targeted to distinct intracellular compartments upon expression in tobacco (Nicotiana benthamiana) cells. Which cellular location of these enzymes plays a key role in native guard cells in CO2-regulated stomatal movements remains unknown. Here, we express fluorescently tagged CAs in guard cells of ca1ca4 double-mutant plants and show that the specific locations of βCA4 at the plasma membrane and βCA1 in native guard cell chloroplasts each can mediate rapid CO2 control of stomatal movements. Localization and complementation analyses using a mammalian αCAII-yellow fluorescent protein in guard cells further show that cytoplasmic localization is also sufficient to restore CO2 regulation of stomatal conductance. Mathematical modeling of cellular CO2 catalysis suggests that the dynamics of the intracellular HCO3 (-) concentration change in guard cells can be driven by plasma membrane and cytoplasmic localizations of CAs but not as clearly by chloroplast targeting. Moreover, modeling supports the notion that the intracellular HCO3 (-) concentration dynamics in guard cells are a key mechanism in mediating CO2-regulated stomatal movements but that an additional chloroplast role of CAs exists that has yet to be identified. PMID:26243620

  17. Functional characterization of neuroendocrine regulation of branchial carbonic anhydrase induction in the euryhaline crab Callinectes sapidus.

    PubMed

    Mitchell, Reed T; Henry, Raymond P

    2014-12-01

    Carbonic anhydrase (CA) plays an essential role as a provider of counterions for Na(+)/H(+) and Cl(-)/HCO3 (-) exchange in branchial ionic uptake processes in euryhaline crustaceans. CA activity and gene expression are low in crabs acclimated to full-strength seawater, with transfer to low salinity resulting in large-scale inductions of mRNA and subsequent enzyme activity in the posterior ion-regulating gills (e.g., G7). In the green crab Carcinus maenas, CA has been shown to be under inhibitory neuroendocrine control by a putative hormone in the x-organ-sinus gland complex (XOSG), located in the eyestalk. This study characterizes the neuroendocrine regulation of CA induction in the blue crab Callinectes sapidus, a commonly used experimental organism for crustacean osmoregulation. In crabs acclimated to full-strength seawater, eyestalk ligation (ESL) triggered a 1.8- and 100-fold increase in CA activity and mRNA, respectively. Re-injection with eyestalk homogenates abolished increases in CA activity and fractionally reduced CA gene expression. ESL also enhanced CA induction by 33% after 96 h in crabs transferred to 15 ppt salinity. Injection of eyestalk homogenates into intact crabs transferred from 35 to 15 ppt diminished by 43% the CA induction stimulated by low salinity. These results point to the presence of a repressor hormone in the eyestalk. Separate injections of medullary tissue (MT) and sinus gland (SG), two components of the eyestalk, reduced salinity-stimulated CA activity by 22% and 49%, suggesting that the putative repressor is localized to the SG. Crabs injected with SG extract harvested from crabs acclimated to 5 ppt showed no decrease in CA activity, demonstrating that the hormone is down-regulated at low salinity. Our results show the presence in the XOSG of an inhibitory compound that regulates salinity-stimulated CA induction. PMID:25572216

  18. Characterization of an Alpha Type Carbonic Anhydrase from Paracentrotus lividus Sea Urchin Embryos.

    PubMed

    Karakostis, Konstantinos; Costa, Caterina; Zito, Francesca; Brümmer, Franz; Matranga, Valeria

    2016-06-01

    Carbonic anhydrases (CA) are zinc metalloenzymes that catalyze the reversible hydration of carbon dioxide to bicarbonate. In the sea urchin, CA has a role in the formation of the calcitic skeleton during embryo development. Here, we report a newly identified mRNA sequence from embryos of the sea urchin Paracentrotus lividus, referred to as Pl-can. The complete coding sequence was identified with the aid of both EST databases and experimental procedures. Pl-CAN is a 447 aa-long protein, with an estimated molecular mass of 48.5 kDa and an isoelectric point of 6.83. The in silico study of functional domains showed, in addition to the alpha type CA-specific domain, the presence of an unexpected glycine-rich region at the N-terminal of the molecule. This is not found in any other species described so far, but probably it is restricted to the sea urchins. The phylogenetic analysis indicated that Pl-CAN is evolutionarily closer to human among chordates than to other species. The putative role(s) of the identified domains is discussed. The Pl-can temporal and spatial expression profiles, analyzed throughout embryo development by comparative qPCR and whole-mount in situ hybridization (WMISH), showed that Pl-can mRNA is specifically expressed in the primary mesenchyme cells (PMC) of the embryo and levels increase along with the growth of the embryonic skeleton, reaching a peak at the pluteus stage. A recombinant fusion protein was produced in E. coli and used to raise specific antibodies in mice recognized the endogenous Pl-CAN by Western blot in embryo extracts from gastrula and pluteus. PMID:27230618

  19. Distinct Cellular Locations of Carbonic Anhydrases Mediate Carbon Dioxide Control of Stomatal Movements1[OPEN

    PubMed Central

    Hu, Honghong; Rappel, Wouter-Jan; Occhipinti, Rossana; Ries, Amber; Böhmer, Maik; You, Lei; Xiao, Chuanlei; Engineer, Cawas B.; Boron, Walter F.; Schroeder, Julian I.

    2015-01-01

    Elevated carbon dioxide (CO2) in leaves closes stomatal apertures. Research has shown key functions of the β-carbonic anhydrases (βCA1 and βCA4) in rapid CO2-induced stomatal movements by catalytic transmission of the CO2 signal in guard cells. However, the underlying mechanisms remain unclear, because initial studies indicate that these Arabidopsis (Arabidopsis thaliana) βCAs are targeted to distinct intracellular compartments upon expression in tobacco (Nicotiana benthamiana) cells. Which cellular location of these enzymes plays a key role in native guard cells in CO2-regulated stomatal movements remains unknown. Here, we express fluorescently tagged CAs in guard cells of ca1ca4 double-mutant plants and show that the specific locations of βCA4 at the plasma membrane and βCA1 in native guard cell chloroplasts each can mediate rapid CO2 control of stomatal movements. Localization and complementation analyses using a mammalian αCAII-yellow fluorescent protein in guard cells further show that cytoplasmic localization is also sufficient to restore CO2 regulation of stomatal conductance. Mathematical modeling of cellular CO2 catalysis suggests that the dynamics of the intracellular HCO3− concentration change in guard cells can be driven by plasma membrane and cytoplasmic localizations of CAs but not as clearly by chloroplast targeting. Moreover, modeling supports the notion that the intracellular HCO3− concentration dynamics in guard cells are a key mechanism in mediating CO2-regulated stomatal movements but that an additional chloroplast role of CAs exists that has yet to be identified. PMID:26243620

  20. Ares I-X: First Flight of a New Era

    NASA Technical Reports Server (NTRS)

    Davis, Stephen R.; Askins, Bruce R.

    2010-01-01

    Since 2005, NASA s Constellation Program has been designing, building, and testing the next generation of launch and space vehicles to carry humans beyond low-Earth orbit (LEO). The Ares Projects at Marshall Space Flight Center (MSFC) are developing the Ares I crew launch vehicle and Ares V cargo launch vehicle. On October 28, 2009, the first development flight test of the Ares I crew launch vehicle, Ares I-X, lifted off from a launch pad at Kennedy Space Center (KSC) on successful suborbital flight. Basing exploration launch vehicle designs on Ares I-X information puts NASA one step closer to full-up "test as you fly," a best practice in vehicle design. Although the final Constellation Program architecture is under review, the Ares I-X data and experience in vehicle design and operations can be applied to any launch vehicle. This paper presents the mission background as well as results and lessons learned from the flight.

  1. Photooxidation of dinitrophenylhistidine-200 human carbonic anhydrase B.

    PubMed

    Kandel, M; Gornall, A G; Lam, L K; Kandel, S I

    1975-05-01

    Partial inactivation of tau-dinitrophenylhistidine-200 human carbonic anhydrase B, induced by visible light, followed first order kinetics (k(app) = 6.05 times 10-2 min-1). After 50 min the tau-dinitrophenylhistidine (tau-DNP-histidine) content decreased to a negligible level, but the illuminated enzyme retained, at pH 7.6, approximately 9.2 percent of the esterase activity of the native enzyme. The following lines of evidence suggest that the loss of activity results from the destruction of tau-DNP-histidine-200. (1) No significant loss of amino acid other than tau-DNP-histidine was detected after illumination. (2) The rate of loss of activity correlated well with the loss of tau-DNP-histidine. (3) In the photooxidized enzyme the DNP moiety was retained but had lost the characteristic sensitivity of tau-DNP-histidine to nucleophilic attack. Titration of the illuminated enzyme with acetazolamide indicated that the residual activity is an intrinsic property of the modified enzyme. The chromatographically purified photooxidized enzyme migrated as a single band on isoelectrofocusing in polyacylamide gel, and at pH 7.6 possessed 7.5 percent esterase activity relative to the native enzyme. By establishing effective destruction of histidine-200, it can be concluded that neither the pi N nor, as previously shown, the tau N of histidine-200 is critical for the catalysis. PMID:237619

  2. Thermal inactivation and conformational lock of bovine carbonic anhydrase.

    PubMed

    Alaei, L; Moosavi-Movahedi, A A; Hadi, H; Saboury, A A; Ahmad, F; Amani, M

    2012-08-01

    The kinetics of thermal inactivation of bovine carbonic anhydrase (BCA) was studied in a 50 mM Tris-HCl buffer, pH 7.8 using p-nitrophenyl acetate as substrate in absorbance of 400 nm by UV-VIS spectrophotometry. The number of conformational locks and inter-subunit amino acid residues of BCA were obtained by thermal inactivation analysis. The cleavage bonds between dimers of BCA during thermal dissociation and type of interactions between specific amino acid residues were also detected. The thermal inactivation curves were plotted in temperatures ranging between 40-70°C. It was shown several phases for inactivation of BCA at 65°C. Analyses of the curves were done by the conformational lock theory. The subunits are dissociated and several intermediates appear during inactivation through increasing the temperature in comparison with native state. Dynamic light scattering measurements was done to study the changes in hydrodynamic radius during thermal inactivation. Three distinct zones were shown in DLS data. Biochemical computation using ligplot is performed to find the inter-subunit amino acid residues for BCA. PMID:22762185

  3. A magnificent enzyme superfamily: carbonic anhydrases, their purification and characterization.

    PubMed

    Ozensoy Guler, Ozen; Capasso, Clemente; Supuran, Claudiu T

    2016-10-01

    In this paper, we reviewed the purification and characterization methods of the α-carbonic anhydrase (CA, EC 4.2.1.1) class. Six genetic families (α-, β-, γ-, δ-, ζ- and η-CAs) all know to date, all encoding such enzymes in organisms widely distributed over the phylogenetic tree. Starting from the manuscripts published in the 1930s on the isolation and purification of α-CAs from blood and other tissues, and ending with the recent discovery of the last genetic family in protozoa, the η-CAs, considered for long time an α-CA, we present historically the numerous and different procedures which were employed for obtaining these catalysts in pure form. α-CAs possess important application in medicine (as many human α-CA isoforms are drug targets) as well as biotechnological processes, in which the enzymes are ultimately used for CO2 capture in order to mitigate the global warming effects due to greenhouse gases. Recently, it was discovered an involvement of CAs in cancerogenesis as well as infection caused by pathogenic agents such as bacteria, fungi and protozoa. Inhibition studies of CAs identified in the genome of the aforementioned organisms might lead to the discovery of innovative drugs with a novel mechanism of action. PMID:26118417

  4. Carbonic anhydrase and acetylcholinesterase inhibitory effects of carbamates and sulfamoylcarbamates.

    PubMed

    Göçer, Hülya; Akincioğlu, Akın; Göksu, Süleyman; Gülçin, İlhami; Supuran, Claudiu T

    2015-04-01

    Carbonic anhydrases (CA), as a family of metalloenzymes, are found in almost every type of tissue and play an important role in catalyzing the equilibration of carbon dioxide and carbonic acid. In this study, a series of carbamate derivative was synthesized, and their inhibition effects on hCA I, hCA II and acetylcholinesterase (AChE) enzymes were investigated. They were determined to be very good inhibitor against for both isoenzymes (hCA I and hCA II) and AChE. The hCA I and hCA II were effectively inhibited by the carbamate derivatives, with inhibition constants (Ki) in the range of 194.4-893.5 nM (for hCA I) and 103.9-835.7 nM (for hCA II). On the other hand, Ki parameters of these compounds for AChE enzyme inhibition were determined in the range of 12.0-61.3 nM. The results clearly showed that both CA isoenzymes and AChE were inhibited by carbamate derivatives at the nM levels. PMID:24964347

  5. The effects of some avermectins on bovine carbonic anhydrase enzyme.

    PubMed

    Kose, Leyla Polat; Gülçin, İlhami; Özdemir, Hasan; Atasever, Ali; Alwasel, Saleh H; Supuran, Claudiu T

    2016-10-01

    Avermectins are effective agricultural pesticides and antiparasitic agents that are widely employed in the agricultural, veterinary and medical fields. The aim of this study was to investigate the inhibitory effects of selected avermectins including abamectin, doramectin, emamectin, eprinomectin, ivermectin and moxidectin that are used as drugs against a wide variety of internal and external mammalian parasites, on the carbonic anhydrase enzyme (CA, EC 4.2.1.1.) purified from fresh bovine erythrocyte. CA catalyses the rapid interconversion of carbon dioxide (CO2) and water (H2O) to bicarbonate ([Formula: see text]) and protons (H(+)) and regulate the acidity of the local tissues. Bovine erythrocyte CA (bCA) enzyme was purified by Sepharose-4B affinity chromatography with a yield of 21.96% and 262.7-fold purification. The inhibition results obtained from this study showed Ki values of 9.73, 17.39, 20.43, 13.39, 16.44 and 17.73 nM for abamectin, doramectin, emamectin, eprinomectin, ivermectin and moxidectin, respectively. However, acetazolamide, well-known clinically established CA inhibitor, possessed a Ki value of 27.68 nM. PMID:26207514

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

    PubMed

    Arabaci, Betul; Gulcin, Ilhami; Alwasel, Saleh

    2014-01-01

    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. PMID:25014536

  7. Thermal-stable carbonic anhydrases: a structural overview.

    PubMed

    Alterio, Vincenzo; Monti, Simona Maria; De Simone, Giuseppina

    2014-01-01

    The potential of carbonic anhydrase (CA) family as target for the drug design of inhibitors with various medicinal chemistry applications has been recognized from long time, whereas the industrial interest in using these enzymes as biocatalysts for carbon dioxide sequestration and biofuel production is only recently emerging. However, an efficient utilization in these processes often requires stable enzymes, able to work in the harsh conditions typical of the CO2 capture process. In this context CAs active at very high temperatures are of extreme interest. In this chapter we have summarized in a comparative manner all existing data on thermostable CAs both isolated by extremophiles and obtained by protein engineering studies. Among the five CA-classes, the biochemical and structural features of thermostable α-, β- and γ-CAs have been discussed. Data show that so far α-CAs isolated from thermophilic organisms are the best candidates to be used in biotechnological processes, even if plenty of work can be still done in this field also with help of protein engineering. PMID:24146389

  8. Glaucoma and the applications of carbonic anhydrase inhibitors.

    PubMed

    Scozzafava, Andrea; Supuran, Claudiu T

    2014-01-01

    Inhibition of carbonic anhydrase (CA, EC 4.2.1.1) has pharmacologic applications in the treatment of glaucoma, a disease affecting a large number of people and characterized by an elevated intraocular pressure (IOP). At least three isoforms, CA II, IV and XII are targeted by the sulfonamide inhibitors, some of which are clinically used drugs. Acetazolamide, methazolamide and dichlorophenamide are first generation CA inhibitors (CAIs) still used as systemic drugs for the management of this disease. Dorzolamide and brinzolamide represent the second generation inhibitors, being used topically, as eye drops, with less side effects compared to the first generation drugs. Third generation inhibitors have been developed by using the tail approach, but they did not reach the clinics yet. The most promising such derivatives are the sulfonamides incorporating either tails with nitric oxide releasing moieties or hybrid drugs possessing prostaglandin (PG) F agonist moieties in their molecules. Recently, the dithiocarbamates have also been described as CAIs possessing IOP lowering effects in animal models of glaucoma. CAIs are used alone or in combination with other drugs such as adrenergic agonist/antagonists, or PG analogs, being an important component of the antiglaucoma drugs armamentarium. PMID:24146387

  9. Carbonic anhydrase enzymes regulate mast cell-mediated inflammation.

    PubMed

    Henry, Everett K; Sy, Chandler B; Inclan-Rico, Juan M; Espinosa, Vanessa; Ghanny, Saleena S; Dwyer, Daniel F; Soteropoulos, Patricia; Rivera, Amariliz; Siracusa, Mark C

    2016-08-22

    Type 2 cytokine responses are necessary for the development of protective immunity to helminth parasites but also cause the inflammation associated with allergies and asthma. Recent studies have found that peripheral hematopoietic progenitor cells contribute to type 2 cytokine-mediated inflammation through their enhanced ability to develop into mast cells. In this study, we show that carbonic anhydrase (Car) enzymes are up-regulated in type 2-associated progenitor cells and demonstrate that Car enzyme inhibition is sufficient to prevent mouse mast cell responses and inflammation after Trichinella spiralis infection or the induction of food allergy-like disease. Further, we used CRISPR/Cas9 technology and illustrate that genetically editing Car1 is sufficient to selectively reduce mast cell development. Finally, we demonstrate that Car enzymes can be targeted to prevent human mast cell development. Collectively, these experiments identify a previously unrecognized role for Car enzymes in regulating mast cell lineage commitment and suggest that Car enzyme inhibitors may possess therapeutic potential that can be used to treat mast cell-mediated inflammation. PMID:27526715

  10. Electropolymerized carbonic anhydrase immobilization for carbon dioxide capture.

    PubMed

    Merle, Geraldine; Fradette, Sylvie; Madore, Eric; Barralet, Jake E

    2014-06-17

    Biomimetic carbonation carried out with carbonic anhydrase (CA) in CO2-absorbing solutions, such as methyldiethanolamine (MDEA), is one approach that has been developed to accelerate the capture of CO2. However, there are several practical issues, such as high cost and limited enzyme stability, that need to be overcome. In this study, the capacity of CA immobilization on a porous solid support was studied to improve the instability in the tertiary amine solvent. We have shown that a 63% porosity macroporous carbon foam support makes separation and reuse facile and allows for an efficient supply and presentation of CO2 to an aqueous solvent and the enzyme catalytic center. These enzymatic supports conserved 40% of their initial activity after 42 days at 70 °C in an amine solvent, whereas the free enzyme shows no activity after 1 h in the same conditions. In this work, we have overcome the technical barrier associated with the recovery of the biocatalyst after operation, and most of all, these electropolymerized enzymatic supports have shown a remarkable increase of thermal stability in an amine-based CO2 sequestration solvent. PMID:24856780

  11. Combination of Protoporphyrin IX-mediated Sonodynamic Treatment with Doxorubicin Synergistically Induced Apoptotic Cell Death of a Multidrug-Resistant Leukemia K562/DOX Cell Line.

    PubMed

    Wang, Xiaobing; Jia, Yali; Su, Xiaomin; Wang, Pan; Zhang, Kun; Feng, Xiaolan; Liu, Quanhong

    2015-10-01

    The main objective of this study was to evaluate the efficacy of administration of doxorubicin (DOX) in combination with protoporphyrin IX (PpIX)-assisted low-level therapeutic ultrasound (US) in K562/DOX cells as a potential strategy in cancer therapy. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay was used to determine the cytotoxicity of different treatments. Apoptosis was analyzed using annexin V-PE/7-amino-actinomycin D staining. Changes in DNA fragmentation, intracellular reactive oxygen species production, cellular membrane permeability, P-glycoprotein expression and DOX uptake were analyzed with flow cytometry. Under optimal conditions, PpIX-US significantly aggravated DOX-induced K562/DOX cell death, compared with either monotherapy. Synergistic potentiation of DNA damage, generation of reactive oxygen species and P-glycoprotein inhibition were observed. Plasma membrane integrity changed slightly after US exposure, and DOX uptake was notably improved after PpIX-US exposure. The results indicate that PpIX-US could increase the susceptibility of tumors to antineoplastic drugs, suggesting a clinical potential method for sonodynamic therapy-mediated tumor chemotherapy. PMID:26166458

  12. The propeptide region of clotting factor IX is a signal for a vitamin K dependent carboxylase: evidence from protein engineering of amino acid -4.

    PubMed Central

    Galeffi, P; Brownlee, G G

    1987-01-01

    Homologous "propeptide" regions are present in a family of vitamin K-dependent mammalian proteins, including clotting factors II, VII, IX, X, protein C, protein S and bone "gla" proteins. To test the hypothesis that the propeptide is a signal for the correct gamma-carboxylation of the adjacent gamma-carboxy region, we have mutated amino acid -4 of human factor IX from an arginine to a glutamine residue, by M13-directed site-specific mutagenesis of a cDNA clone. After expression of mutant factor IX in dog kidney cells, we find that it is secreted into the medium in a precursor form containing the propeptide, and is inefficiently gamma-carboxylated compared to the control, wild-type, recombinant factor IX. This result supports the hypothesis that the propeptide region is required for efficient gamma-carboxylation of factor IX in dog kidney cells. Furthermore, it confirms previous results that arginine at amino acid -4 is required for correct propeptide processing. Images PMID:3684602

  13. 75 FR 18245 - Public Federal Regulatory Enforcement Fairness Hearing Region IX Regulatory Fairness Board

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-09

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Public Federal Regulatory Enforcement Fairness Hearing Region IX Regulatory Fairness Board.... Small Business Administration (SBA) Region IX Regulatory Fairness Board and the SBA Office of...

  14. Regional intravascular delivery of AAV-2-F.IX to skeletal muscle achieves long-term correction of hemophilia B in a large animal model.

    PubMed

    Arruda, Valder R; Stedman, Hansell H; Nichols, Timothy C; Haskins, Mark E; Nicholson, Matthew; Herzog, Roland W; Couto, Linda B; High, Katherine A

    2005-05-01

    In earlier work, we showed that adeno-associated virus-mediated delivery of a Factor IX gene to skeletal muscle by direct intramuscular injection resulted in therapeutic levels of circulating Factor IX in mice. However, achievement of target doses in humans proved impractical because of the large number of injections required. We used a novel intravascular delivery technique to achieve successful transduction of extensive areas of skeletal muscle in a large animal with hemophilia. We provide here the first report of long-term (> 3 years, with observation ongoing), robust Factor IX expression (circulating levels of 4%-14%) by muscle-directed gene transfer in a large animal, resulting in essentially complete correction of the bleeding disorder in hemophilic dogs. The results of this translational study establish an experimental basis for clinical studies of this delivery method in humans with hemophilia B. These findings also have immediate relevance for gene transfer in patients with muscular dystrophy. PMID:15479726

  15. Strong topical steroid, NSAID, and carbonic anhydrase inhibitor cocktail for treatment of cystoid macular edema

    PubMed Central

    Asahi, Masumi G; Bobarnac Dogaru, Gabriela L; Onishi, Spencer M; Gallemore, Ron P

    2015-01-01

    Purpose To report the combination cocktail of strong steroid, non-steroidal anti-inflammatory drug (NSAID), and carbonic anhydrase inhibitor drops for treatment of cystoid macular edema. Methods This is a retrospective case series of patients with cystoid macular edema managed with a topical combination of strong steroid (difluprednate), NSAID, and carbonic anhydrase inhibitor drops. The patients were followed with optical coherence tomography and fluorescein angiography. Results In our six cases, resolution of the cystic edema with improvement in visual acuity was achieved with the use of a combination cocktail of drops. Leakage on fluorescein angiography and cystic edema on optical coherence tomography both responded to treatment with the topical cocktail of drops. Conclusion A topical cocktail of strong steroid, NSAID, and carbonic anhydrase inhibitor drops are effective for managing cystoid macular edema. Further studies comparing this combination with more invasive treatments should be undertaken to determine the efficacy of this cocktail over other treatment options. PMID:26664246

  16. Ares I-X: First Flight of a New Generation

    NASA Technical Reports Server (NTRS)

    Davis, Stephan R.; Askins, Bruce R.

    2010-01-01

    The Ares I-X suborbital development flight test demonstrated NASA s ability to design, develop, launch and control a new human-rated launch vehicle (Figure 14). This hands-on missions experience will provide the agency with necessary skills and insights regardless of the future direction of space exploration. The Ares I-X team, having executed a successful launch, will now focus on analyzing the flight data and extracting lessons learned that will be used to support the development of future vehicles.

  17. Star Formation Rate in Holmberg IX Dwarf Galaxy

    NASA Astrophysics Data System (ADS)

    Andjelic, M. M.

    2011-12-01

    In this paper we use previously determined Hα fluxes for dwarf galaxy Holmberg IX (Arbutina et al. 2009) to calculate star formation rate (SFR) in this galaxy. We discuss possible contaminations of Hα flux and, for the first time, we take into account optical emission from supernova remnants (SNRs) as a possible source of contamination of Hα flux. Derived SFR for Holmberg IX is 3.4×10-4M_{⊙} yr-1. Our value is lower then in previous studies, due to luminous shock-heated source M&H 9-10, possible hypernova remnant, which we excluded from the total Hα flux in our calculation of SFR.

  18. Carbonic anhydrase inhibitors: Synthesis, characterization and inhibition activities of furan sulfonylhydrazones against carbonic anhydrase I (hCA I)

    NASA Astrophysics Data System (ADS)

    Gündüzalp, Ayla Balaban; Parlakgümüş, Gökhan; Uzun, Demet; Özmen, Ümmuhan Özdemir; Özbek, Neslihan; Sarı, Musa; Tunç, Tuncay

    2016-02-01

    The methane sulfonic acide hydrazide (1) was used to obtain furan sulfonylhydrazones; 2-acetylfuranmethanesulfonylhydrazone (2), 2-furaldehydemethanesulfonylhydrazone (3), 5-nitro-2-furaldehydemethanesulfonylhydrazone (4). The structures of furan sulfonylhydrazones were determined by using elemental analysis, FT-IR, 1H NMR, 13C NMR and UV-vis methods. The structure of 5-nitro-2-furaldehydemethanesulfonylhydrazone (4) was also supported with X-ray difraction method and found that compound 4 was crystallized in triclinic, space group P 1 bar . In order to gain insight into the structure of the compounds, we performed computational studies by using 6-311G(d,p) basic set in which B3LYP correlation function was implemented. The geometry of the sulfonylhydrazones were optimized at DFT method with Gaussian 09 program package and the global reactivity descriptors were also calculated by this basic set. The enzyme inhibition activities of the sulfonylhydrazones were investigated on carbonic anhydrase I (hCA I) isoenzyme and their activity parameters (Km, IC50 and Ki) were calculated by spectrophotometric method. And also, their inhibitor effects were also investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods. Inhibition results show that compound 4 containing electron withdrawing group (NO2) has higher inhibition effect on hCA I isoenzyme than other's.

  19. Effect of carbonic anhydrase on silicate weathering and carbonate formation at present day CO2 concentrations compared to primordial values

    PubMed Central

    Xiao, Leilei; Lian, Bin; Hao, Jianchao; Liu, Congqiang; Wang, Shijie

    2015-01-01

    It is widely recognized that carbonic anhydrase (CA) participates in silicate weathering and carbonate formation. Nevertheless, it is still not known if the magnitude of the effect produced by CA on surface rock evolution changes or not. In this work, CA gene expression from Bacillus mucilaginosus and the effects of recombination protein on wollastonite dissolution and carbonate formation under different conditions are explored. Real-time fluorescent quantitative PCR was used to explore the correlation between CA gene expression and sufficiency or deficiency in calcium and CO2 concentration. The results show that the expression of CA genes is negatively correlated with both CO2 concentration and ease of obtaining soluble calcium. A pure form of the protein of interest (CA) is obtained by cloning, heterologous expression, and purification. The results from tests of the recombination protein on wollastonite dissolution and carbonate formation at different levels of CO2 concentration show that the magnitudes of the effects of CA and CO2 concentration are negatively correlated. These results suggest that the effects of microbial CA in relation to silicate weathering and carbonate formation may have increased importance at the modern atmospheric CO2 concentration compared to 3 billion years ago. PMID:25583135

  20. Effect of carbonic anhydrase on silicate weathering and carbonate formation at present day CO2 concentrations compared to primordial values

    NASA Astrophysics Data System (ADS)

    Xiao, Leilei; Lian, Bin; Hao, Jianchao; Liu, Congqiang; Wang, Shijie

    2015-01-01

    It is widely recognized that carbonic anhydrase (CA) participates in silicate weathering and carbonate formation. Nevertheless, it is still not known if the magnitude of the effect produced by CA on surface rock evolution changes or not. In this work, CA gene expression from Bacillus mucilaginosus and the effects of recombination protein on wollastonite dissolution and carbonate formation under different conditions are explored. Real-time fluorescent quantitative PCR was used to explore the correlation between CA gene expression and sufficiency or deficiency in calcium and CO2 concentration. The results show that the expression of CA genes is negatively correlated with both CO2 concentration and ease of obtaining soluble calcium. A pure form of the protein of interest (CA) is obtained by cloning, heterologous expression, and purification. The results from tests of the recombination protein on wollastonite dissolution and carbonate formation at different levels of CO2 concentration show that the magnitudes of the effects of CA and CO2 concentration are negatively correlated. These results suggest that the effects of microbial CA in relation to silicate weathering and carbonate formation may have increased importance at the modern atmospheric CO2 concentration compared to 3 billion years ago.

  1. 45 CFR 83.5 - Effect of title IX of the Education Amendments of 1972.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 45 Public Welfare 1 2012-10-01 2012-10-01 false Effect of title IX of the Education Amendments of... Purposes; Definitions; Coverage § 83.5 Effect of title IX of the Education Amendments of 1972. The obligations imposed by this part are independent of obligations imposed by or pursuant to title IX of...

  2. 45 CFR 83.5 - Effect of title IX of the Education Amendments of 1972.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 45 Public Welfare 1 2013-10-01 2013-10-01 false Effect of title IX of the Education Amendments of... Purposes; Definitions; Coverage § 83.5 Effect of title IX of the Education Amendments of 1972. The obligations imposed by this part are independent of obligations imposed by or pursuant to title IX of...

  3. 45 CFR 83.5 - Effect of title IX of the Education Amendments of 1972.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 45 Public Welfare 1 2014-10-01 2014-10-01 false Effect of title IX of the Education Amendments of... Purposes; Definitions; Coverage § 83.5 Effect of title IX of the Education Amendments of 1972. The obligations imposed by this part are independent of obligations imposed by or pursuant to title IX of...

  4. The In Vitro and In Vivo Activity of the Microtubule Disruptor STX140 Is Mediated by Hif-1 Alpha and CAIX Expression.

    PubMed

    Stengel, Chloe; Newman, Simon P; Leese, Mathew P; Thomas, Mark P; Potter, Barry V L; Reed, Michael J; Purohit, Atul; Foster, Paul A

    2015-10-01

    Tumor neo-angiogenesis is regulated, in part, by the hypoxia-inducible gene HIF1. Evidence suggests HIF1 associates with polymerized microtubules and traffics to the nucleus. This study investigated the role of HIF1 in mediating the antitumor activity of two steroid-based sulfamate ester microtubule disruptors, STX140 and STX243, in vitro and in vivo. The effects of STX140, STX243 and the parental compound 2-methoxyestradiol (STX66) on HIF1α and HIF2α protein expression were assessed in vitro in MCF-7 and MDA-MB-231 cells cultured under hypoxia. More pertinently, their effects were examined on HIF1-regulated genes in vivo in mice bearing MCF-7 or MDA-MB-231 tumors. The level of mRNA expression of vascular endothelial growth factor (VEGF), glucose transporter 1 (GLUTI), phosphoglycerate kinase (PGK), ATP-binding cassette sub-family B member 1 (ABCB1) and carbonic anhydrase IX (CAIX) was quantified by Real-time Polymerase Chain Reaction (RT-PCR). Despite inhibiting nuclear HIF1α protein accumulation under hypoxia in vitro, STX140 and STX243 did not significantly regulate the expression of four out of five HIF1α-regulated genes in vitro and in vivo. Only CAIX mRNA expression was down-regulated both in vitro and in vivo. Immunoblot analysis showed that STX140 and STX243 reduced CAIX protein expression in vitro. These compounds had no effect on HIF2α translocation. The potential for inhibition of CAIX by STX140 and STX243 was examined by docking the ligands to the active site in comparison with a known sulfamate-based inhibitor. Microtubule disruption and antitumor activity of STX140 and STX243 is most likely HIF1-independent and may, at least in part, be mediated by inhibition of CAIX expression and activity. PMID:26408684

  5. Leadership in Honor Societies: The Effect of Title IX.

    ERIC Educational Resources Information Center

    Earwood-Smith, Glenda

    1985-01-01

    Single-sex honor societies changed membership requirements to admit members of both sexes in response to Title IX of the 1972 Education amendments. A 1982 study examining the effect of this transition on the sex make-up of members, officers, and faculty advisers revealed that women students were competing equally with men students for leadership…

  6. Title IX and Educational Equity: What Difference Does It Make?

    ERIC Educational Resources Information Center

    Golombisky, Kim

    Title IX, the 1972 United States federal law forbidding sex discrimination in education, has a rarely-talked-about but surprisingly tenuous history which illustrates how discourses of equality come to mean political powerlessness for diverse girls and women in school. Unfortunately, "sexual" debates such as women's sports and sexual harassment…

  7. Title IX and Sexual Harassment of Student Athletes.

    ERIC Educational Resources Information Center

    Wolohan, John T.

    1995-01-01

    This article reviews what constitutes sexual harassment in sports by examining Title IX of the Education Amendments of 1972 and the effect it has had on charges of sexual harrassment in educational institutions. Athletic administrators are provided with strategies and recommendations to help schools and athletic departments develop sexual…

  8. Ares I-X Flight Test Vehicle Modal Test

    NASA Technical Reports Server (NTRS)

    Buehrle, Ralph D.; Templeton, Justin D.; Reaves, Mercedes C.; Horta, Lucas G.; Gaspar, James L.; Bartolotta, Paul A.; Parks, Russel A.; Lazor, Daniel R.

    2010-01-01

    The first test flight of NASA's Ares I crew launch vehicle, called Ares I-X, was launched on October 28, 2009. Ares I-X used a 4-segment reusable solid rocket booster from the Space Shuttle heritage with mass simulators for the 5th segment, upper stage, crew module and launch abort system. Flight test data will provide important information on ascent loads, vehicle control, separation, and first stage reentry dynamics. As part of hardware verification, a series of modal tests were designed to verify the dynamic finite element model (FEM) used in loads assessments and flight control evaluations. Based on flight control system studies, the critical modes were the first three free-free bending mode pairs. Since a test of the free-free vehicle was not practical within project constraints, modal tests for several configurations during vehicle stacking were defined to calibrate the FEM. Test configurations included two partial stacks and the full Ares I-X flight test vehicle on the Mobile Launcher Platform. This report describes the test requirements, constraints, pre-test analysis, test execution and results for the Ares I-X flight test vehicle modal test on the Mobile Launcher Platform. Initial comparisons between pre-test predictions and test data are also presented.

  9. Gender Equity in Intercollegiate Athletics: Determinants of Title IX Compliance

    ERIC Educational Resources Information Center

    Anderson, Deborah J.; Cheslock, John Jesse; Ehrenberg, Ronald G.

    2006-01-01

    Using new data on intercollegiate athletes, this article shows that recent improvement in Title IX compliance among NCAA Division I institutions was previously overestimated, and provides the first estimates of compliance in Divisions II and III. In addition, regression analyses investigate how institutional characteristics relate to the extent of…

  10. A Guide for Title IX Self-Study.

    ERIC Educational Resources Information Center

    Boesdorfer, Kent; And Others

    This document is a set of guidelines on how to conduct the self-evaluation required by Title IX, the amendment prohibiting discrimination on the basis of sex. Its purpose is to help school districts comply with the necessity to evaluate policies and practices by providing a data base for decision-making. The paper is divided into these sections:…

  11. National Environmental/Energy Workforce Assessment for Region IX.

    ERIC Educational Resources Information Center

    National Field Research Center Inc., Iowa City, IA.

    This report represents a detailed summation of existing workforce levels, training programs, career potential, and staffing level projections through 1981 for EPA Region IX. This region serves the states of Arizona, California, Hawaii, and Nevada. The specific pollution programs considered include air, noise, pesticides, potable water, radiation…

  12. Ares I-X Malfunction Turn Range Safety Analysis

    NASA Technical Reports Server (NTRS)

    Beaty, J. R.

    2011-01-01

    Ares I-X was the designation given to the flight test version of the Ares I rocket which was developed by NASA (also known as the Crew Launch Vehicle (CLV) component of the Constellation Program). The Ares I-X flight test vehicle achieved a successful flight test on October 28, 2009, from Pad LC-39B at Kennedy Space Center, Florida (KSC). As part of the flight plan approval for the test vehicle, a range safety malfunction turn analysis was performed to support the risk assessment and vehicle destruct criteria development processes. Several vehicle failure scenarios were identified which could have caused the vehicle trajectory to deviate from its normal flight path. The effects of these failures were evaluated with an Ares I-X 6 degrees-of-freedom (6-DOF) digital simulation, using the Program to Optimize Simulated Trajectories Version II (POST2) simulation tool. The Ares I-X simulation analysis provided output files containing vehicle trajectory state information. These were used by other risk assessment and vehicle debris trajectory simulation tools to determine the risk to personnel and facilities in the vicinity of the launch area at KSC, and to develop the vehicle destruct criteria used by the flight test range safety officer in the event of a flight test anomaly of the vehicle. The simulation analysis approach used for this study is described, including descriptions of the failure modes which were considered and the underlying assumptions and ground rules of the study.

  13. Ares I-X Launch Vehicle Modal Test Overview

    NASA Technical Reports Server (NTRS)

    Buehrle, Ralph D.; Bartolotta, Paul A.; Templeton, Justin D.; Reaves, Mercedes C.; Horta, Lucas G.; Gaspar, James L.; Parks, Russell A.; Lazor, Daniel R.

    2010-01-01

    The first test flight of NASA's Ares I crew launch vehicle, called Ares I-X, is scheduled for launch in 2009. Ares IX will use a 4-segment reusable solid rocket booster from the Space Shuttle heritage with mass simulators for the 5th segment, upper stage, crew module and launch abort system. Flight test data will provide important information on ascent loads, vehicle control, separation, and first stage reentry dynamics. As part of hardware verification, a series of modal tests were designed to verify the dynamic finite element model (FEM) used in loads assessments and flight control evaluations. Based on flight control system studies, the critical modes were the first three free-free bending mode pairs. Since a test of the free-free vehicle is not practical within project constraints, modal tests for several configurations in the nominal integration flow were defined to calibrate the FEM. A traceability study by Aerospace Corporation was used to identify the critical modes for the tested configurations. Test configurations included two partial stacks and the full Ares I-X launch vehicle on the Mobile Launcher Platform. This paper provides an overview for companion papers in the Ares I-X Modal Test Session. The requirements flow down, pre-test analysis, constraints and overall test planning are described.

  14. Biosynthesis and intracellular processing of carbonic anhydrase in Chlamydomonas reinhardtii.

    PubMed

    Toguri, T; Muto, S; Miyachi, S

    1986-08-01

    Carbonic anhydrase (CA) of Chlamydomonas reinhardtii is a glycoprotein of 35 kDa which is localized outside the plasma membrane. The activity of CA was increased when the CO2 concentration during photoautotrophic growth was decreased to air level. After decreasing the CO2 concentration from 4% to 0.04%, several polypeptides including CA were induced continuously or transiently. To investigate the biosynthesis and intracellular processing of CA, the cells of wall-less mutant CW-15, which secretes CA into the culture medium, were pulse-labeled with radioactive arginine, chased, and radioactive proteins were immunoprecipitated with anti-CA serum. A 42-kDa polypeptide with isoelectric point (pI) of 7.1-7.3 was first synthesized. Within 5 min the molecular mass of this polypeptide was decreased to 35 kDa and it was then secreted into the culture medium within 30 min. This indicates that the former is the precursor form and the latter the mature form of CA. The primary translation product from poly(A)-rich RNA in a cell-free reticulocyte lysate system from a rabbit was a 38-kDa polypeptide. This was cotranslationally converted into the 42-kDa precursor in vitro in the presence of dog pancreatic microsomal membranes. As the 42-kDa precursor had a high affinity to concanavalin A, it was assumed to have a high-mannose-type oligosaccharide. The mature enzyme had a pI of 6.1-6.2 and was composed of more than two isoforms, which had a complex-type oligosaccharide with low affinity to concanavalin A. Chemical deglycosylation of the mature enzyme by trifluoromethanesulfonic acid indicated that the molecular mass of the polypeptide moiety was 32 kDa and the difference between this and the primary translation product suggests that cleavage of the polypeptide occurs during its biosynthesis. PMID:2874027

  15. Legionella pneumophila Carbonic Anhydrases: Underexplored Antibacterial Drug Targets.

    PubMed

    Supuran, Claudiu T

    2016-01-01

    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. PMID:27322334

  16. Legionella pneumophila Carbonic Anhydrases: Underexplored Antibacterial Drug Targets

    PubMed Central

    Supuran, Claudiu T.

    2016-01-01

    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. PMID:27322334

  17. Thermodynamics of binding of Zn2+ to carbonic anhydrase inhibitors

    NASA Astrophysics Data System (ADS)

    Remko, Milan; Garaj, Vladimír

    The Becke3LYP functional of DFT theory and the two-layered ONIOM (B3LYP/6-311+G(d,p): MNDO) method were used to characterize 46 gas-phase complexes of 34 neutral and anionic ligands (H2O, CH3OH, CH3COOH, CH3CONH2, HOSO2NH2, CO2, HSO2NH2, CH3SO2NH2, CH3C(=O)NHOH, imidazole, NH2SO2NH2, anions of 4-aminobenzenesulphonamide, saccharin, 1I9L, brinzolamide, dorzolamide, acetazolamide, further HO(-), CH3O(-), CH3COO(-), CH3CONH(-), N=N=N(-), S=C=N(-), CH3C(=O)NHO(-), HOCOO(-), imidazoleN(-), phenol-O(-), HOSO2NH(-), (-)OSO2NH(-), (-)OSO2NH2, H2NSO2NH(-), HSO2NH(-), CH3SO2NH(-), and CF3SO2NH(-), respectively) with Zn2+. Proton dissociation enthalpies and Gibbs energies of acidic inhibitors in the presence of zinc were computed. Their gas-phase acidity considerably increases upon chelation. Of the bases investigated, the weakest zinc affinity is exhibited by carbon dioxide (-313.5 kJ mol-1). Deprotonated inhibitors have higher affinities for zinc than the neutral ones. Compared to the other mono-deprotonated ligands the acetohydroxamic acid anion has the highest affinity for zinc (-1872.7 kJ mol-1). The zinc affinity of the acetazolamide anion computed using the hybrid ONIOM (B3LYP/6-311+G(d,p): MNDO) method is in very good agreement with the full DFT ones and this method can be adopted to model large complexes of inhibitors with the active site of carbonic anhydrase.

  18. Carbonic Anhydrase Protects Fatty Liver Grafts against Ischemic Reperfusion Damage

    PubMed Central

    Bejaoui, Mohamed; Pantazi, Eirini; De Luca, Viviana; Panisello, Arnau; Folch-Puy, Emma; Hotter, Georgina; Capasso, Clemente; T. Supuran, Claudiu; Rosselló-Catafau, Joan

    2015-01-01

    Carbonic anhydrases (CAs) are ubiquitous metalloenzymes that catalyze the reversible hydration of carbon dioxide to bicarbonate and a proton. CAs are involved in numerous physiological and pathological processes, including acid-base homeostasis, electrolyte balance, oxygen delivery to tissues and nitric oxide generation. Given that these processes are found to be dysregulated during ischemia reperfusion injury (IRI), and taking into account the high vulnerability of steatotic livers to preservation injury, we hypothesized a new role for CA as a pharmacological agent able to protect against ischemic damage. Two different aspects of the role of CA II in fatty liver grafts preservation were evaluated: 1) the effect of its addition to Institut Georges Lopez (IGL-1) storage solution after cold ischemia; 2) and after 24h of cold storage followed by two hours of normothermic ex-vivo perfusion. In all cases, liver injury, CA II protein concentration, CA II mRNA levels and CA II activity were determined. In case of the ex-vivo perfusion, we further assessed liver function (bile production, bromosulfophthalein clearance) and Western blot analysis of phosphorylated adenosine monophosphate activated protein kinase (AMPK), mitogen activated protein kinases family (MAPKs) and endoplasmic reticulum stress (ERS) parameters (GRP78, PERK, IRE, eIF2α and ATF6). We found that CA II was downregulated after cold ischemia. The addition of bovine CA II to IGL-1 preservation solution efficiently protected steatotic liver against cold IRI. In the case of reperfusion, CA II protection was associated with better function, AMPK activation and the prevention of ERS and MAPKs activation. Interestingly, CA II supplementation was not associated with enhanced CO2 hydration. The results suggest that CA II modulation may be a promising target for fatty liver graft preservation. PMID:26225852

  19. Role of Carbonic Anhydrase IV in the Bicarbonate-Mediated Activation of Murine and Human Sperm

    PubMed Central

    Mannowetz, Nadja; Becker, Holger M.; Deitmer, Joachim W.; Sly, William S.; Wennemuth, Gunther

    2010-01-01

    HCO3− is the signal for early activation of sperm motility. In vivo, this occurs when sperm come into contact with the HCO3− containing fluids in the reproductive tract. The activated motility enables sperm to travel the long distance to the ovum. In spermatozoa HCO3− stimulates the atypical sperm adenylyl cyclase (sAC) to promote the cAMP-mediated pathway that increases flagellar beat frequency. Stimulation of sAC may occur when HCO3− enters spermatozoa either directly by anion transport or indirectly via diffusion of CO2 with subsequent hydration by intracellular carbonic anhydrase (CA). We here show that murine sperm possess extracellular CA IV that is transferred to the sperm surface as the sperm pass through the epididymis. Comparison of CA IV expression by qRT PCR analysis confirms that the transfer takes place in the corpus epididymidis. We demonstrate murine and human sperm respond to CO2 with an increase in beat frequency, an effect that can be inhibited by ethoxyzolamide. Comparing CA activity in sperm from wild-type and CA IV−/− mice we found a 32.13% reduction in total CA activity in the latter. The CA IV−/− sperm also have a reduced response to CO2. While the beat frequency of wild-type sperm increases from 2.86±0.12 Hz to 6.87±0.34 Hz after CO2 application, beat frequency of CA IV−/− sperm only increases from 3.06±0.20 Hz to 5.29±0.47 Hz. We show, for the first time, a physiological role of CA IV that supplies sperm with HCO3−, which is necessary for stimulation of sAC and hence early activation of spermatozoa. PMID:21124840

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

    PubMed

    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. PMID:26005204

  1. An overview of the alpha-, beta- and gamma-carbonic anhydrases from Bacteria: can bacterial carbonic anhydrases shed new light on evolution of bacteria?

    PubMed

    Capasso, Clemente; Supuran, Claudiu T

    2015-04-01

    Carbonic anhydrases (CAs, EC 4.2.1.1) are metalloenzymes which catalyze a simple but physiologically crucial reaction in all life Domains, the carbon dioxide hydration to bicarbonate and protons: CO2 + H2O ⇔ HCO3(-)+ H(+). These enzymes are involved in many physiologic processes, such as photosynthesis, respiration, CO2 transport, as well as metabolism of xenobiotics. Five different, genetically distinct CA families are known to date: the α-, β-, γ-, δ- and ζ-CAs. α-, β- and δ-CAs use Zn(II) ions at the active site, the γ-CAs are probably Fe(II) enzymes (but they are active also with bound Zn(II) or Co(II) ions), whereas the ζ-class uses Cd(II) or Zn(II) to perform the physiologic reaction catalysis. Bacteria encode for enzymes belonging to the α-, β-, and γ-CA classes. They contain zinc ion (Zn(2+)) in their active site, coordinated by three histidine residues and a water molecule/hydroxide ion (in the α and γ) or by two cysteine and one histidine residues (in the β class), with the fourth ligand being a water molecule/hydroxide ion. Here we propose that bacterial CAs can be used as markers for understanding the evolution and genetic variability of the Gram-positive and Gram-negative bacteria. We addressed several questions such as: (1) why are α-CAs present only in the genome of Gram-negative bacteria; (2) why are α-CAs not present in all Gram-negative bacteria; (3) why do Bacteria show an intricate pattern of CA gene expression; (4) what are the physiologic roles of such diverse CAs in these prokaryotes. We proposed possible answers to the previous questions. Moreover, we speculated on the evolution of the CA classes (α, β and γ) identified in the Gram-negative and -positive bacteria. Our main hypothesis is that from the ancestral Ur-CA, the γ-class arose first, followed by the β-class; the α-class CAs came last it is found only in the Gram-negative bacteria. PMID:24766661

  2. Carbonic anhydrase 9 is associated with chemosensitivity and prognosis in breast cancer patients treated with taxane and anthracycline

    PubMed Central

    2014-01-01

    Background Neoadjuvant chemotherapy (NAC) is one of the standard care regimens for patients with resectable early-stage breast cancer. It would be advantageous to determine the chemosensitivity of tumors before initiating NAC. One of the parameters potentially compromising such chemosensitivity would be a hypoxic microenvironment of cancer cells. The aim of this study was thus to clarify the correlation between expression of the hypoxic marker carbonic anhydrase-9 (CA9) and chemosensitivity to NAC as well as prognosis of breast cancer patients. Methods A total of 102 patients with resectable early-stage breast cancer was treated with NAC consisting of FEC (5-fluorouracil, epirubicin, and cyclophosphamide) followed by weekly paclitaxel before surgery. Core needle biopsy (CNB) specimens and resected tumors were obtained from all patients before and after NAC, respectively. Chemosensitivity to NAC and the prognostic potential of CA9 expression were evaluated by immunohistochemistry. Results CA9 positivity was detected in the CNB specimens from 47 (46%) of 102 patients. The CA9 expression in CNB specimens was significantly correlated with pathological response, lymph node metastasis, and lymph-vascular invasion. Multivariate analysis revealed that the CA9 expression in CNB specimens was an independent predictive factor for pathological response. The Kaplan-Meier survival curve revealed a significant negative correlation (p = 0.013) between the disease-free survival (DFS) and the CA 9 expression in resected tissues after NAC. Multivariate regression analyses indicated that the CA9 expression in resected tissues was an independent prognostic factor for DFS. Conclusions CA9 expression in CNB specimens is a useful marker for predicting chemosensitivity, and CA9 expression in resected tissue is prognostic of DFS in patients with resectable early-stage breast cancer treated by sequential FEC and weekly paclitaxel prior to resection. PMID:24893880

  3. Carbonic Anhydrase Inhibitors. Part 461 Inhibition of Carbonic Anhydrase Isozymes I, II and IV With Trifluoromethylsulfonamide Derivatives and Their Zinc(II) and Copper(II) Complexes

    PubMed Central

    Mincione, Giovanna; Scozzafava, Andrea

    1997-01-01

    Reaction of aromatic/heterocyclic sulfonamides containing a free amino group with triflic anhydride afforded compounds possessing trifluoromethanesulfonamido moieties in their molecule. The Zn(II) and Cu(II) complexes of these new sulfonamides were prepared and characterized by standard procedures (elemental analysis, spectroscopic, magnetic, thermogravimetric and conductimetric measurements). The new derivatives showed good inhibitory activity against three isozymes of carbonic anhydrase (CA), i.e., CA I, II and IV. PMID:18475762

  4. Ares I-X Flight Data Evaluation: Executive Overview

    NASA Technical Reports Server (NTRS)

    Huebner, Lawrence D.; Waits, David A.; Lewis, Donny L.; Richards, James S.; Coates, R. H., Jr.; Cruit, Wendy D.; Bolte, Elizabeth J.; Bangham, Michal E.; Askins, Bruce R.; Trausch, Ann N.

    2011-01-01

    NASA's Constellation Program (CxP) successfully launched the Ares I-X flight test vehicle on October 28, 2009. The Ares I-X flight was a developmental flight test to demonstrate that this very large, long, and slender vehicle could be controlled successfully. The flight offered a unique opportunity for early engineering data to influence the design and development of the Ares I crew launch vehicle. As the primary customer for flight data from the Ares I-X mission, the Ares Projects Office (APO) established a set of 33 flight evaluation tasks to correlate flight results with prospective design assumptions and models. The flight evaluation tasks used Ares I-X data to partially validate tools and methodologies in technical disciplines that will ultimately influence the design and development of Ares I and future launch vehicles. Included within these tasks were direct comparisons of flight data with preflight predictions and post-flight assessments utilizing models and processes being applied to design and develop Ares I. The benefits of early development flight testing were made evident by results from these flight evaluation tasks. This overview provides summary information from assessment of the Ares I-X flight test data and represents a small subset of the detailed technical results. The Ares Projects Office published a 1,600-plus-page detailed technical report that documents the full set of results. This detailed report is subject to the International Traffic in Arms Regulations (ITAR) and is available in the Ares Projects Office archives files.

  5. Transforming the treatment for hemophilia B patients: update on the clinical development of recombinant fusion protein linking recombinant coagulation factor IX with recombinant albumin (rIX-FP).

    PubMed

    Santagostino, Elena

    2016-05-01

    Recombinant fusion protein linking recombinant coagulation factor IX with recombinant albumin (rIX-FP; Idelvion®(†)) is an innovative new treatment designed to extend the half-life of factor IX (FIX) and ease the burden of care for hemophilia B patients. The rIX-FP clinical development program - PROLONG-9FP - is in its advanced phases, with pivotal studies in previously treated adults, adolescents, and pediatrics now completed. Across all age groups studied, rIX-FP has demonstrated a markedly improved pharmacokinetic profile compared with plasma-derived and recombinant FIX treatments, with a 30-40% higher incremental recovery, an approximately 5-fold longer half-life, a lower clearance, and a greater area under the curve. rIX-FP has been very well tolerated with an excellent safety profile. In the pivotal studies, there have been no reports of FIX inhibitors or antidrug antibodies, and few treatment-related adverse events have been observed. Prophylactic regimens of rIX-FP administered once weekly to once every 14 days have been highly effective. When used for surgical prophylaxis, a single infusion of rIX-FP has been sufficient to maintain hemostasis, even during major orthopedic surgery. An ongoing study is now enrolling previously untreated patients and evaluating the possibility of extending the dosing interval to every 21 days. There is little doubt that rIX-FP will transform the treatment of hemophilia B. PMID:27288064

  6. EFFECTS OF SELECTED WATER TOXICANTS ON THE IN VITRO ACTIVITY OF FISH CARBONIC ANHYDRASE

    EPA Science Inventory

    Carbonic anhydrase (CA, carbonate hydro-lyase EC 4.2.1.1) from lysed red blood cells of the channel catfish (Ictalurus punctatus) was studied to determine physico-chemical kinetic properties and relative sensitivity to 56 chemicals of significance in water quality research. In ge...

  7. Human carbonic anhydrase II as a host for piano-stool complexes bearing a sulfonamide anchor.

    PubMed

    Monnard, Fabien W; Heinisch, Tillmann; Nogueira, Elisa S; Schirmer, Tilman; Ward, Thomas R

    2011-08-01

    d(6)-piano-stool complexes bearing an arylsulfonamide anchor display sub-micromolar affinity towards human Carbonic Anhydrase II (hCA II). The 1.3 Å resolution X-ray crystal structure of [(η(6)-C(6)Me(6))Ru(bispy 3)Cl](+)⊂ hCA II highlights the nature of the host-guest interactions. PMID:21706094

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

    SciTech Connect

    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.

  9. 21 CFR 866.5200 - Carbonic anhydrase B and C immunological test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... system. 866.5200 Section 866.5200 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunological Test... immunochemical techniques specific carbonic anhydrase protein molecules in serum and other body...

  10. 21 CFR 866.5200 - Carbonic anhydrase B and C immunological test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... system. 866.5200 Section 866.5200 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunological Test... immunochemical techniques specific carbonic anhydrase protein molecules in serum and other body...

  11. 21 CFR 866.5200 - Carbonic anhydrase B and C immunological test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... system. 866.5200 Section 866.5200 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunological Test... immunochemical techniques specific carbonic anhydrase protein molecules in serum and other body...

  12. 21 CFR 866.5200 - Carbonic anhydrase B and C immunological test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... system. 866.5200 Section 866.5200 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunological Test... immunochemical techniques specific carbonic anhydrase protein molecules in serum and other body...

  13. 40 CFR Appendix Ix to Part 268 - Extraction Procedure (EP) Toxicity Test Method and Structural Integrity Test (Method 1310B)

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 27 2014-07-01 2014-07-01 false Extraction Procedure (EP) Toxicity Test Method and Structural Integrity Test (Method 1310B) IX Appendix IX to Part 268 Protection of.... 268, App. IX Appendix IX to Part 268—Extraction Procedure (EP) Toxicity Test Method and...

  14. 40 CFR Appendix Ix to Part 268 - Extraction Procedure (EP) Toxicity Test Method and Structural Integrity Test (Method 1310B)

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 28 2012-07-01 2012-07-01 false Extraction Procedure (EP) Toxicity Test Method and Structural Integrity Test (Method 1310B) IX Appendix IX to Part 268 Protection of.... 268, App. IX Appendix IX to Part 268—Extraction Procedure (EP) Toxicity Test Method and...

  15. In-vivo fluorescence dosimetry of aminolevulinate-based protoporphyrin IX (PpIX) accumulation in human nonmelanoma skin cancers and precancers

    NASA Astrophysics Data System (ADS)

    Warren, Christine B.; Lohser, Sara; Chang, Sung; Bailin, Philip A.; Maytin, Edward V.

    2009-06-01

    PDT is clinically useful for precancers (actinic keratoses; AK) of the skin, but the optimal duration for 5-ALA application is still controversial. For basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), cure rates remain inferior to surgical excision. Lack of knowledge about regional levels of PpIX levels within target tissues clearly contribute to these suboptimal results. To investigate PpIX levels achievable in human skin neoplasias in-vivo, a clinical study to monitor PpIX accumulation in vivo was performed. PpIX-fluorescence in patients undergoing ALA-PDT for facial AK was monitored via real-time in-vivo fluorescence dosimetry, with measurements q20 min following application of 5-ALA (Levulan Kerastick). PpIX accumulation followed linear kinetics in nearly all cases. The slopes varied widely, and did not correlate with clinical outcome in all patients. Some patients with a low accumulation of PpIX fluorescence had a good response to therapy, whereas others with high PpIX accumulation required repeat treatment (although not necessarily of the same lesion). PpIX accumulation rates did correlate to a certain degree with the overall amount of erythema. We conclude that unknown factors besides PpIX levels must be critical for the response to treatment. To assess the relationship between PpIX levels in various skin cancers, patients undergoing routine Mohs surgery for BCC or SCC were measured by in-vivo dosimetry at 2 h after 5-ALA application. Overall, a progressive increase in PpIX signal during malignant progression was observed, in the following rank order: Normal skin < AK < SCC ~ BCC.

  16. The effect of ALA/PpIX PDT on putative cancer stem cells in tumor side populations

    NASA Astrophysics Data System (ADS)

    Morgan, Janet; Petrucci, Cara M.

    2009-06-01

    Protoporphyrin IX (PpIX) synthesized endogenously from 5-aminolevulinic acid (ALA), is effluxed from cells expressing the ATP-dependent transporter ABCG2. Side population (SP) cells (named for their low red/blue fluorescence distribution in flow cytometry plots with ABCG2 substrates such as Hoechst) are postulated to contain cancer stem cells (CSC). The SP in U87 (human gliblastoma cell line) were more resistant to ALA-PDT than NON-SP cells. Inhibiting ABCG2 activity with the tyrosine kinase inhibitor imatinib mesylate (IM, Gleevec) during incubation with ALA increased PpIX in the SP by preventing its efflux and decreased the SP after subsequent PDT, enhancing phototoxicity. Evasion of SP cells from ALA-PDT could cause tumor recurrence from CSC. Manipulation of ABCG2 levels on the SP with small molecule modulators may be a potential strategy for enhancing PDT by decreasing the amount of substrate photosensitizer extruded from cells and lowering the threshold for phototoxicity.

  17. The Development of the Ares I-X Flight Test

    NASA Technical Reports Server (NTRS)

    Ess, Robert H.

    2008-01-01

    The National Aeronautics and Space Administration (NASA) Constellation Program (CxP) has identified a series of tests to provide insight into the design and development of the Ares I Crew Launch Vehicle (CLV) and the Orion Crew Exploration Vehicle (CEV). Ares I-X was created as the first suborbital development flight test to help meet CxP objectives. The Ares I-X flight vehicle is an early operational model of Ares, with specific emphasis on Ares I and ground operation characteristics necessary to meet Ares I-X flight test objectives. Ares I-X will encompass the design and construction of an entire system that includes the Flight Test Vehicle (FTV) and associated operations. The FTV will be a test model based on the Ares I design. Select design features will be incorporated in the FTV design to emulate the operation of the CLV in order to meet the flight test objectives. The operations infrastructure and processes will be customized for Ares I-X, while still providing data to inform the developers of the launch processing system for Ares/Orion. The FTV is comprised of multiple elements and components that will be developed at different locations. The components will be delivered to the launch/assembly site, Kennedy Space Center (KSC), for assembly of the elements and components into an integrated, flight-ready, launch vehicle. The FTV will fly a prescribed trajectory in order to obtain the necessary data to meet the objectives. Ares I-X will not be commanded or controlled from the ground during flight, but the FTV will be equipped with telemetry systems, a data recording capability and a flight termination system (FTS). The in-flight part of the test includes a trajectory to simulate maximum dynamic pressure during flight and perform a stage separation representative of the CLV. The in-flight test also includes separation of the Upper Stage Simulator (USS) from the First Stage and recovery of the First Stage. The data retrieved from the flight test will be analyzed

  18. A NEW CALCULATION OF Ne IX LINE DIAGNOSTICS

    SciTech Connect

    Smith, Randall K.; Chen Guoxin; Kirby, Kate; Brickhouse, Nancy S.

    2009-07-20

    We describe the effect that new atomic calculations, including fully relativistic R-matrix calculations of collisional excitation rates and level-specific dielectronic and radiative recombination rates, have on line ratios from the astrophysically significant ion Ne IX. The new excitation rates systematically change some predicted Ne IX line ratios by 25% at temperatures at or below the temperature of maximum emissivity (4 x 10{sup 6} K), while the new recombination rates lead to systematic changes at higher temperatures. The new line ratios are shown to agree with observations of Capella and {sigma}{sup 2} CrB significantly better than older line ratios, showing that 25%-30% accuracy in atomic rates is inadequate for high-resolution X-ray observations from existing spectrometers.

  19. Hantavirus Prevalence in the IX Region of Chile

    PubMed Central

    Vial, Pablo C.; Castillo, Constanza H.; Godoy, Paula M.; Hjelle, Brian; Ferrés, Marcela G.

    2003-01-01

    An epidemiologic and seroprevalence survey was conducted (n=830) to assess proportion of persons exposed to hantavirus in IX Region Chile, which accounts for 25% of reported cases of hantavirus cardiopulmonary syndrome. This region has three geographic areas with different disease incidences and a high proportion of aboriginals. Serum samples were tested for immunoglobulin (Ig) G antibodies by enzyme-linked immunosorbent assay against Sin Nombre virus N antigen by strip immunoblot assay against Sin Nombre, Puumala, Río Mamoré, and Seoul N antigens. Samples from six patients were positive for IgG antibodies reactive with Andes virus; all patients lived in the Andes Mountains. Foresting was also associated with seropositivity; but not sex, age, race, rodent exposure, or farming activities. Exposure to hantavirus varies in different communities of IX Region. Absence of history of pneumonia or hospital admission in persons with specific IgG antibodies suggests that infection is clinically inapparent. PMID:12890323

  20. Ares I-X Thermal Model Correlation and Lessons Learned

    NASA Technical Reports Server (NTRS)

    Amundsen, Ruth M.

    2010-01-01

    The Ares I-X vehicle launched and flew successfully on October 28, 2009. This paper will describe the correlation of the vehicle thermal model to both ground testing and flight data. A main purpose of the vehicle model and ground testing was to ensure that the avionics within the vehicle were held within their thermal limits prior to launch and during flight. The correlation of the avionics box temperatures will be shown. Also, the lessons learned in the thermal discipline during the modeling, test, correlation to test, and flight of the Ares I-X flight test vehicle will be described. Lessons learned will cover thermal modeling, as well as management of the thermal discipline, thermal team, and thermal-related actions in design, testing, and flight.

  1. Ares I-X Best Estimated Trajectory Analysis and Results

    NASA Technical Reports Server (NTRS)

    Karlgaard, Christopher D.; Beck, Roger E.; Starr, Brett R.; Derry, Stephen D.; Brandon, Jay; Olds, Aaron D.

    2011-01-01

    The Ares I-X trajectory reconstruction produced best estimated trajectories of the flight test vehicle ascent through stage separation, and of the first and upper stage entries after separation. The trajectory reconstruction process combines on-board, ground-based, and atmospheric measurements to produce the trajectory estimates. The Ares I-X vehicle had a number of on-board and ground based sensors that were available, including inertial measurement units, radar, air-data, and weather balloons. However, due to problems with calibrations and/or data, not all of the sensor data were used. The trajectory estimate was generated using an Iterative Extended Kalman Filter algorithm, which is an industry standard processing algorithm for filtering and estimation applications. This paper describes the methodology and results of the trajectory reconstruction process, including flight data preprocessing and input uncertainties, trajectory estimation algorithms, output transformations, and comparisons with preflight predictions.

  2. Tetrapyrrole profiling in Arabidopsis seedlings reveals that retrograde plastid nuclear signaling is not due to Mg-protoporphyrin IX accumulation

    PubMed Central

    Moulin, Michael; McCormac, Alex C.; Terry, Matthew J.; Smith, Alison G.

    2008-01-01

    Chloroplast biogenesis involves careful coordination of both plastid and nuclear gene expression, which is achieved in part by retrograde signaling from the chloroplast to the nucleus. This can be demonstrated by the fact that the herbicide, Norflurazon (NF), which causes bleaching of chloroplasts, prevents the light induction of photosynthesis-related genes in the nucleus. It has been proposed that the tetrapyrrole pathway intermediate Mg-protoporphyrin IX acts as the signaling molecule in this pathway and accumulates in the chloroplasts and cytosol of the cell after NF treatment. Here we present data that demonstrate that this model is too simplistic. We have developed a sensitive liquid chromatography-mass spectrometry (LC/MS) method to measure tetrapyrrole intermediates and have shown that no Mg-protoporphyrin IX, nor indeed any other chlorophyll-biosynthesis intermediate, can be detected in NF-treated plants under conditions in which nuclear gene expression is repressed. Conversely when endogenous Mg-protoporphyrin IX levels are artificially increased by supplementation with the tetrapyrrole precursor, 5-aminolevulinic acid, the expression of nuclear-encoded photosynthetic genes is induced, not repressed. We also demonstrate that NF-treatment leads to a strong down-regulation of tetrapyrrole biosynthesis genes, consistent with the absence of an accumulation of tetrapyrrole intermediates. Finally, there is no correlation between nuclear-gene expression and any of the chlorophyll biosynthetic intermediates over a range of growth conditions and treatments. Instead, it is possible that a perturbation of tetrapyrrole synthesis may lead to localized ROS production or an altered redox state of the plastid, which could mediate retrograde signaling. PMID:18818314

  3. Effect of 5-aminolevulinic acid on kinetics of protoporphyrin IX production in CHO cells.

    PubMed

    Wołuń-Cholewa, M; Warchoł, W

    2004-01-01

    5-aminolevulinic acid (ALA) is utilized in a photodynamic therapy as a compound capable of augmenting intracellular pool of protoporphyrin IX (PpIX), which exhibits properties of a photosensitizer. The studies were aimed at monitoring accumulation of endogenous protoporphyrin IX in CHO cells under effect of various concentrations of ALA in culture medium and following removal of the compound from the culture medium. Cell content of PpIX was determined following incubation of the cells for 72 h in a culture medium containing different concentration of ALA. Moreover, the cells were preincubated for 2 h in ALA at various concentrations and separated from the compound by medium change and their PpIX content was monitored following incubation. PpIX content was defined by a fluorescent technique under the confocal microscope. In the course of continuous incubation of cells with ALA, biphasic alterations were noted in cellular PpIX concentration. Removal of ALA from the incubation medium resulted at first in a decrease in PpIX content in cells, which was followed by an evidently augmented accumulation of the compound in the cells. The results suggested that in the case of CHO cells, exogenous ALA was not an exclusive source of PpIX synthesis and that alterations in enzyme activities were responsible for production of PpIX. PMID:15253138

  4. Monoclonal antibodies to coagulation factor IX define a high-frequency polymorphism by immunoassays.

    PubMed Central

    Smith, K J

    1985-01-01

    Monoclonal antibodies have been used to demonstrate a polymorphism of human plasma coagulation factor IX antigen in double antibody solid-phase immunoradiometric assays. This polymorphism is detected in an assay where a monoclonal antibody (A-1) adsorbed to microtiter wells is used to bind factor IX from diluted plasma samples. Plasma samples with the factor IX polymorphism have less than 0.2 U/ml of apparent antigen when tested with the A-1 antibody, while assays with other monoclonal antibodies and assays with goat antisera to factor IX show normal amounts of factor IX antigen. Factor IX coagulant activity was normal in samples from donors with the polymorphism. The thin-layer polyacrylamide gel isoelectric focusing pattern of factor IX purified from a donor with the factor IX polymorphism (IXp) was identical to that obtained with factor IX prepared from a donor who did not have the polymorphism (IXn). Purified radiolabeled factor IX prepared from a donor with the polymorphism showed a Ka for the A-1 antibody that was threefold less than that measured for IXn. The gene frequency of IXp in male blood donors is 0.25. This polymorphism may be useful as a marker for the X chromosome in genetic studies on plasma samples. Further studies are necessary to determine the explanation for decreased reaction of IXp with the A-1 monoclonal antibody. Images Fig. 1 PMID:9556657

  5. Loop quantum cosmology of Bianchi type IX models

    SciTech Connect

    Wilson-Ewing, Edward

    2010-08-15

    The loop quantum cosmology 'improved dynamics' of the Bianchi type IX model are studied. The action of the Hamiltonian constraint operator is obtained via techniques developed for the Bianchi type I and type II models, no new input is required. It is shown that the big bang and big crunch singularities are resolved by quantum gravity effects. We also present effective equations which provide quantum geometry corrections to the classical equations of motion.

  6. Technical Progress on the Ares I-X Flight Test

    NASA Technical Reports Server (NTRS)

    Davis, S.R.; Robinson, K.F.; Flynn, K.C.

    2008-01-01

    Ares I-X will be NASA's first test flight for a new human-rated launch vehicle since 1981, and the team is well on its way toward completing the vehicle's design and hardware fabrication for an April 2009 launch. This uncrewed suborbital development test flight gives NASA its first opportunities to: gather critical data about the flight dynamics of the integrated launch vehicle; understand how to control its roll during flight; better characterize the stage separation environments during future flight; and demonstrate the first stage recovery system. The Ares I-X Flight Test Vehicle (FTV) incorporates a mix of flight and mockup hardware. It is powered by a four-segment solid rocket booster, and will be modified to include a fifth, spacer segment; the upper stage, Orion crew exploration vehicle, and launch abort system are simulator hardware to make the FTV aerodynamically similar to the same size, shape, and weight of Ares I. The Ares IX first stage includes an existing Shuttle solid rocket motor and thrust vector control system controlled by an Ascent Thrust Vector Controller (ATVC) designed and built by Honeywell International. The avionics system will be tested in a dedicated System Integration Laboratory located at Lockheed Martin Space Systems (LMSS) in Denver, Colorado. The Upper Stage Simulator (USS) is made up of cylindrical segments that will be stacked and integrated at Kennedy Space Center (KSC) for launch. Glenn Research Center is already building these segments, along with their internal access structures. The active Roll Control System (RoCS) includes two thruster units harvested from Peacekeeper missiles. Duty cycle testing for RoCS was conducted, and fuel tanking and detanking tests will occur at KSC in early 2008. This important flight will provide valuable experience for the ground operations team in integrating, stacking, and launching Ares I. Data from Ares I-X will ensure the safety and reliability of America's newest launch vehicle.

  7. Ares I-X: On the Threshold of Exploration

    NASA Technical Reports Server (NTRS)

    Davis, Stephan R.; Askins, Bruce

    2009-01-01

    Ares I-X, the first flight of the Ares I crew launch vehicle, is less than a year from launch. Ares I-X will test the flight characteristics of Ares I from liftoff to first stage separation and recovery. The flight also will demonstrate the computer hardware and software (avionics) needed to control the vehicle; deploy the parachutes that allow the first stage booster to land in the ocean safely; measure and control how much the rocket rolls during flight; test and measure the effects of first stage separation; and develop and try out new ground handling and rocket stacking procedures in the Vehicle Assembly Building (VAB) and first stage recovery procedures at Kennedy Space Center (KSC) in Florida. All Ares I-X major elements have completed their critical design reviews, and are nearing final fabrication. The first stage--four-segment solid rocket booster from the Space Shuttle inventory--incorporates new simulated forward structures to match the Ares I five-segment booster. The upper stage, Orion crew module, and launch abort system will comprise simulator hardware that incorporates developmental flight instrumentation for essential data collection during the mission. The upper stage simulator consists of smaller cylindrical segments, which were transported to KSC in fall 2008. The crew module and launch abort system simulator were shipped in December 2008. The first stage hardware, active roll control system (RoCS), and avionics components will be delivered to KSC in 2009. This paper will provide detailed statuses of the Ares I-X hardware elements as NASA's Constellation Program prepares for this first flight of a new exploration era in the summer of 2009.

  8. New polymorphic variants of human blood clotting factor IX

    SciTech Connect

    Surin, V.L.; Luk`yanenko, A.V.; Tagiev, A.F.; Smirnova, O.V.; Plutalov, O.V.; Berlin, Yu.A.

    1995-04-01

    The polymorphism of Alu-repeats, which are located in the introns of the human factor IX gene (copies 1-3), was studied. To identify polymorphic variants, direct sequencing of PCR products that contained appropriate repeats was used. In each case, 20 unrelated X chromosomes were studied. A polymorphic Dra I site was found near the 3{prime}-end of Alu copy 3 within the region of the polyA tract. A PCR-based testing system with internal control of restriction hydrolysis was suggested. Testing 81 unrelated X chromosomes revealed that the frequency of the polymorphic Dra I site is 0.23. Taq I polymorphism, which was revealed in Alu copy 4 of factor IX gene in our previous work, was found to be closely linked to Dra I polymorphism. Studies in linkage between different types of polymorphisms of the factor IX gene revealed the presence of a rare polymorphism in intron a that was located within the same minisatellite region as the known polymorphic insertion 50 bp/Dde I. However, the size of the insertion in our case was 26 bp. Only one polymorphic variant was found among over 150 unrelated X chromosomes derived from humans from Moscow and its vicinity. 10 refs., 4 figs., 1 tab.

  9. Atomic data and spectral line intensities for S IX

    NASA Astrophysics Data System (ADS)

    Bhatia, A. K.; Landi, E.

    2003-09-01

    Electron impact collision strengths, energy levels, oscillator strengths, and spontaneous radiative decay rates are calculated for the O-like ion S IX. The configurations used are 2s 22p 4, 2s2p 5, 2p 6, 2s 22p 33s, 2s 22p 33p, and 2s 22p 33d giving rise to 86 fine-structure levels in intermediate coupling. Collision strengths are calculated at five incident energies, 25, 50, 75, 100, and 125 Ry. Excitation rate coefficients are calculated by assuming a Maxwellian electron velocity distribution at several electron temperatures in the 5.6 ⩽log Te (K)⩽6.2 range, where S IX is formed. Using the excitation rate coefficients and the radiative transition rates, statistical equilibrium equations for level populations are solved at electron densities covering the range of 10 8-10 14 cm -3. Relative spectral line intensities are calculated. Proton excitation rates among the lowest three levels have been included in the statistical equilibrium equations. The predicted S IX line intensities are compared with SUMER (SOHO) observations of the quiet Sun.

  10. Bladder tissue diagnostics utilizing Protoporphyrin IX fluorescence detection

    NASA Astrophysics Data System (ADS)

    Stepp, Herbert G.; Baumgartner, Reinhold; Beyer, Wolfgang; Knuechel, Ruth; Rick, Kai; Steinbach, Pia; Kriegmair, M.

    1995-01-01

    Instillation of a solution of 5-aminolevulinic acid (5-ALA) into the urinary bladder leads to a tumorselective accumulation of fluorescing Protoporphyrin IX (PpIX) within hours. Upon fluorescence excitation using a Kr+- laser, cystoscopy provides high contrast images even of early stage tumors, that are invisible or hardly detectable by routine white light cystoscopy. Fluorescence can simply be judged by naked eyes or recorded with a target integrating camera in real color. Histological and fluorescence data of 91 patients were evaluated statistically, showing a sensitivity of 97% and a specificity of 68% for the detection of dysplastic lesions or malignant tumors. The detectability of a sufficient fluorescence contrast of suspicious versus normal tissue is not affected significantly by either short incubation times of less than 1 hour or prolonged retention times without 5-ALA in the instillation liquid of up to about 6 hours. The fluorescence intensity detected from the tissue surface is not only dependent on PpIX concentration. The additional influence of optical parameters of tissue and fluorochrome distribution on the fluorescence signal was determined using Monte Carlo computer simulations. Results show that 5-ALA induced fluorochrome detection is superior to the detection of fluorochromes that do not exclusively stain the epithelium. Using the ratio of fluorescence intensity to backscattered excitation light corrects for geometrical and absorption effects but would introduce a dependence on the scattering coefficient.

  11. 46 CFR 57.02-2 - Adoption of section IX of the ASME Code.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Adoption of section IX of the ASME Code. 57.02-2 Section... AND BRAZING General Requirements § 57.02-2 Adoption of section IX of the ASME Code. (a) The... in this part. Table 57.02-1(a)—Limitations and Modifications to the Adoption of section IX of...

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

    NASA Astrophysics Data System (ADS)

    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

  13. Isolation of a Putative Carboxysomal Carbonic Anhydrase Gene from the Cyanobacterium Synechococcus PCC7942 1

    PubMed Central

    Yu, Jian-Wei; Price, G. Dean; Song, Lirong; Badger, Murray R.

    1992-01-01

    The Type II mutants of the cyanobacterium Synechococcus PCC7942 (G.D. Price, M.R. Badger [1989] Plant Physiol 91: 514-525) are able to accumulate a large pool of inorganic carbon inside the cell, but are unable to utilize it for CO2 fixation, resulting in a high CO2-requiring phenotype. We have isolated a 3.5-kb BamHI clone (pT2) that complements the Type II mutants, and complementation analysis with DNA subclones indicated that the complementing region was located in the 0.75-kb XhoI-Bg/II fragment. This same region hybridized to the chloroplastic carbonic anhydrase (CA) gene from spinach on Southern blots and to a mRNA of approximate 1 kb on northern blots. Restriction mapping and sequence analysis revealed that pT2 is the same as a genomic clone (pBM3.8) that complements another high CO2-requiring (temperature sensitive) mutant, C3P-O (E. Suzuki, H. Fukuzawa, S. Miyachi [1991] Mol Gen Genet 226: 401-408). Recently, a 272-amino acid open reading frame showing 22% homology with pea and spinach chloroplast CA genes was identified in clone pBM3.8 (H. Fukuzawa, E. Suzuki, Y. Komukal, S. Miyachi [1992] Proc Natl Acad Sci USA 89: 4437-4441). CA activity was detected in Escherichia coli cells transformed with subclones of pT2 (pT2-A and pT2-A1) containing the HindIII-Bg/II fragment, and the expressed CA has properties similar to those of the CA activity associated with carboxysomes purified from Synechococcus PCC7942 (G.D. Price, J.R. Coleman, M.R. Badger [1992] Plant Physiol 100: 784-793). Therefore, it is reasonable to conclude that the HindIII-Bg/II fragment codes for the carboxysomal CA gene product. The result is discussed in the context of the role that carboxysomal CA plays in the operation of the CO2-concentrating mechanism in cyanobacteria. Images Figure 2 Figure 4 PMID:16653060

  14. Sulfa Drugs as Inhibitors of Carbonic Anhydrase: New Targets for the Old Drugs

    PubMed Central

    al-Rashida, Mariya; Hussain, Sajad; Hamayoun, Mehwish; Altaf, Aisha

    2014-01-01

    Sulfa drugs are well-known antibacterial agents containing N-substituted sulfonamide group on para position of aniline ring (NH2RSO2NHR′). In this study 2,4-dichloro-1,3,5-triazine derivatives of sulfa drugs, sulfamerazine (1b), sulfaquinoxaline (2b), sulfadiazine (3b), sulfadimidine (4b), and sulfachloropyrazine (5b) (1a–5a) were synthesized and characterized. Their carbonic anhydrase inhibition activity was evaluated against bovine cytosolic carbonic anhydrase isozyme II (bCA II). For the sake of comparison the CA inhibition activity of the parent sulfa drugs (1b–5b) was also evaluated. A significant increase in CA inhibition activity of sulfa drugs was observed upon substitution with 2,4-dichloro-1,3,5-triazine moiety. Molecular docking studies were carried out to highlight binding site interactions. ADME properties were calculated to evaluate drug likeness of the compounds. PMID:25538942

  15. Sulfa drugs as inhibitors of carbonic anhydrase: new targets for the old drugs.

    PubMed

    al-Rashida, Mariya; Hussain, Sajad; Hamayoun, Mehwish; Altaf, Aisha; Iqbal, Jamshed

    2014-01-01

    Sulfa drugs are well-known antibacterial agents containing N-substituted sulfonamide group on para position of aniline ring (NH2RSO2NHR'). In this study 2,4-dichloro-1,3,5-triazine derivatives of sulfa drugs, sulfamerazine (1b), sulfaquinoxaline (2b), sulfadiazine (3b), sulfadimidine (4b), and sulfachloropyrazine (5b) (1a-5a) were synthesized and characterized. Their carbonic anhydrase inhibition activity was evaluated against bovine cytosolic carbonic anhydrase isozyme II (bCA II). For the sake of comparison the CA inhibition activity of the parent sulfa drugs (1b-5b) was also evaluated. A significant increase in CA inhibition activity of sulfa drugs was observed upon substitution with 2,4-dichloro-1,3,5-triazine moiety. Molecular docking studies were carried out to highlight binding site interactions. ADME properties were calculated to evaluate drug likeness of the compounds. PMID:25538942

  16. [Mode of action, clinical profile and relevance of carbonic anhydrase inhibitors in glaucoma therapy].

    PubMed

    Eichhorn, M

    2013-02-01

    Since their introduction the local carbonic anhydrase inhibitors (CAH) dorzolamide and brinzolamide have become well established in the drug therapy of glaucoma. They lower intraocular pressure (IOP) by blocking specifically carbonic anhydrase in the ciliary epithelium and thereby the secretion of aqueous humor. The IOP lowering effect is comparable with that of beta-blockers, but less than that of prostaglandin agonists. Because of their specific mode of action they produce an additive pressure lowering effect with any other glaucoma drug. Therefore they are ideal for being combined with other drugs. In addition, CAH may improve perfusion of the posterior eye. Preliminary results in glaucoma patients under dorzolamide therapy suggesting a reduction in the risk of progression due to enhanced blood flow need further confirmation. PMID:23430679

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

    PubMed

    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. PMID:27494103

  18. Evaluation of in vitro effects of some analgesic drugs on erythrocyte and recombinant carbonic anhydrase I and II.

    PubMed

    Gökçe, Başak; Gençer, Nahit; Arslan, Oktay; Turkoğlu, Sumeyye Aydogan; Alper, Meltem; Köçkar, Feray

    2012-02-01

    The in vitro effects of the injectable form of analgesic drugs, dexketoprofen trometamol, dexamethasone sodium phosphate, metamizole sodium, diclofenac sodium, thiocolchicoside, on the activity of purified human carbonic anhydrase I and II were evaluated. The effect of these drugs on erythrocyte hCA I and hCA II was compared to recombinant hCA I and hCA II expressed in Ecoli. IC(50) values of the drugs that caused inhibition were determined by means of activity percentage diagrams. The IC(50) concentrations of dexketoprofen trometamol and dexamethasone sodium phosphate on hCA I were 683 μM and 4250 μM and for hCA II 950 μM and 6200 μM respectively. Conversely, the enzyme activity was increased by diflofenac sodium. In addition, thiocolchicoside has not any affect on hCA I and hCA II. The effect of these drugs on erythrocyte hCA I and hCA II were consistent with the inhibition of recombinant enzymes. PMID:21534860

  19. Structural insight into the inhibition of carbonic anhydrase by the COX-2-selective inhibitor polmacoxib (CG100649).

    PubMed

    Kim, Hyun Tae; Cha, Hyunju; Hwang, Kwang Yeon

    2016-09-01

    Polmacoxib is not only a selective COX-2 inhibitor but also a potent inhibitor of carbonic anhydrases (CAs). Both CA I and CA II are highly expressed in the GI tract and kidneys, organs that are also thought to be the sites at which selective COX-2 inhibitors show their side effects. By inhibition assays, we show that both CA I and CA II are strongly inhibited by polmacoxib, while CA II also demonstrates direct competition with COX-2. To understand, at the molecular level, how polmacoxib interacts with CA I and II, we solved the first crystal structures of CA I and CA II in complex with polmacoxib, at 2.0 Å and 1.8 Å, respectively. Interestingly, three polmacoxib molecules bind to the active site of CA I, whereas only one molecule binds CA II. In the active site, the three molecules of polmacoxib organize itself along hydrophobic interaction as "stack-on-formation", and fully occupy a cone-shaped active pocket in CA I. The binding mode of polmacoxib to CA II was found different than its binding to celecoxib and valdecoxib. Our results provide structural insight into inhibition of CA I and CA II by polmacoxib, to assess its potential clinical efficacy. PMID:27475498

  20. A Divalent PAMAM-Based Matrix Metalloproteinase/Carbonic Anhydrase Inhibitor for the Treatment of Dry Eye Syndrome.

    PubMed

    Richichi, B; Baldoneschi, V; Burgalassi, S; Fragai, M; Vullo, D; Akdemir, A; Dragoni, E; Louka, A; Mamusa, M; Monti, D; Berti, D; Novellino, E; De Rosa, G; Supuran, C T; Nativi, C

    2016-01-26

    Synthetic sulfonamide derivatives are a class of potent matrix metalloproteinase inhibitors (MMPI) that have potential for the treatment of diseases related to uncontrolled expression of these enzymes. The lack of selectivity of the large majority of such inhibitors, leading to the inhibition of MMPs in tissues other than the targeted one, has dramatically reduced the therapeutic interest in MMPIs. The recent development of efficient drug delivery systems that allow the transportation of a selected drug to its site of action has opened the way to new perspectives in the use of MMPIs. Here, a PAMAM-based divalent dendron with two sulfonamidic residues was synthesized. This nanomolar inhibitor binds to the catalytic domain of two MMPs as well as to the transmembrane human carbonic anhydrases (hCAs) XII, which is present in the eye and considered an antiglaucoma target. In the animal model of an experimental dry eye, no occurrence of dotted staining in eyes treated with our inhibitor was observed, indicating no symptoms of corneal desiccation. PMID:26692423

  1. The role of carbonic anhydrase VI in bitter taste perception: evidence from the Car6−/− mouse model

    PubMed Central

    2014-01-01

    Background Carbonic anhydrase VI (CA VI) is a secretory isozyme of the α-CA gene family. It is highly expressed in the salivary and mammary glands and secreted into saliva and milk. Although CA VI was first described as a gustatory protein, its exact functional roles have remained enigmatic. Interestingly, polymorphism of the CA6 gene was recently linked to bitter taste perception in humans. In this study, we compared the preference of Car6−/− and wild-type mice for different taste modalities in an IntelliCage monitoring environment. Morphologies of taste buds, tongue papillae, and von Ebner’s glands were evaluated by light microscopy. Cell proliferation and rate of apoptosis in tongue specimens were examined by Ki67 immunostaining and fluorescent DNA fragmentation staining, respectively. Results The behavioral follow up of the mice in an IntelliCage system revealed that Car6−/− mice preferred 3 μM quinine (bitter) solution, whereas wild type mice preferred water. When the quinine concentration increased, both groups preferentially selected water. Histological analysis, Ki67 immunostaining and detection of apoptosis did not reveal any significant changes between tongue specimens of the knockout and wild type mice. Conclusions Our knockout mouse model confirms that CA VI is involved in bitter taste perception. CA VI may be one of the factors which contribute to avoidance of bitter, potentially harmful, substances. PMID:25134447

  2. The endothelial cell binding determinant of human factor IX resides in the. gamma. -carboxyglutamic acid domain

    SciTech Connect

    Toomey, J.R.; Roberts, H.R.; Stafford, D.W. ); Smith, K.J. United Blood Services, Albuquerque, NM )

    1992-02-18

    The blood coagulation factor IX(a) binds specifically to a site on endothelial cells with a K{sub d} of 2.0-3.0 nM. A number of previous studies have attempted to define the region(s) of factor IX(a) that mediate this interaction. These studies suggested that there are two regions of factor IX(a), the {gamma}-carboxyglutamic acid (Gla) domain and the epidermal growth factor like (EGF-like) domains, that mediate high-affinity binding to endothelial cells. Recently, however, the participation of the EGF1 domain has been excluded from the interaction. This indicated that if there was an EGF component of factor IX contributing to the binding affinity, then it must be in the second EGF-like domain. In order to further evaluate this relationship, the authors performed competitive binding experiments between {sup 125}I plasma factor IX and a set of six chimeric proteins composed of portions of factor VII and factor IX. The data suggest that the high-affinity interaction between factor IX and the endothelial cell binding site is mediated by the factor IX Gla domain and that the factor IX EGF domains are not involved in binding specificity.

  3. DeltaPhage--a novel helper phage for high-valence pIX phagemid display.

    PubMed

    Nilssen, Nicolay R; Frigstad, Terje; Pollmann, Sylvie; Roos, Norbert; Bogen, Bjarne; Sandlie, Inger; Løset, Geir Å

    2012-09-01

    Phage display has been instrumental in discovery of novel binding peptides and folded domains for the past two decades. We recently reported a novel pIX phagemid display system that is characterized by a strong preference for phagemid packaging combined with low display levels, two key features that support highly efficient affinity selection. However, high diversity in selected repertoires are intimately coupled to high display levels during initial selection rounds. To incorporate this additional feature into the pIX display system, we have developed a novel helper phage termed DeltaPhage that allows for high-valence display on pIX. This was obtained by inserting two amber mutations close to the pIX start codon, but after the pVII translational stop, conditionally inactivating the helper phage encoded pIX. Until now, the general notion has been that display on pIX is dependent on wild-type complementation, making high-valence display unachievable. However, we found that DeltaPhage does facilitate high-valence pIX display when used with a non-suppressor host. Here, we report a side-by-side comparison with pIII display, and we find that this novel helper phage complements existing pIX phagemid display systems to allow both low and high-valence display, making pIX display a complete and efficient alternative to existing pIII phagemid display systems. PMID:22539265

  4. Evaluation of PpIX formation in Cervical Intraepithelial Neoplasia I (CIN) using widefield fluorescence images

    NASA Astrophysics Data System (ADS)

    Carbinatto, Fernanda M.; Inada, Natalia M.; Fortunato, Thereza C.; Lombardi, Welington; da Silva, Eduardo V.; Vollet Filho, José D.; Kurachi, Cristina; Pratavieira, Sebastião.; Bagnato, Vanderlei S.

    2016-03-01

    Optical techniques has been described as auxiliary technology for screening of neoplasia because shows the potential for tissues differentiation in real-time and it is a noninvasive detection and safe. However, only endogenous fluorophores presents the lesion may be insufficient and needed of the administration of the fluorophores synthesized, such as, precursor molecule of protoporphyrin IX (PpIX) induced by 5- aminolevulinic acid and your derivatives. Topical application of methylaminolevulinate (MAL), induces formation of the endogenous photosensitizer, PpIX in tissues where carcinogenesis has begun. The PpIX tend to accumulate in premalignant and malignant tissues and the illumination with light with appropriate wavelength beginning to excitation of PpIX fluorescence, which helps to localize PpIX-rich areas and identify potentially malignant tissues. The aim of the study is to evaluate the production of PpIX in the cervix with CIN I through of the fluorescence images captured after 1 hour of cream application. It was possible to visualize PpIX fluorescence in cervix and it was possible to observe the selectivity in fluorescence in squamous-columnar junction, which a pre-cancerous condition (CIN) and usually is localized. Through the image processing it was possible to quantify the increase of red fluorescence. For the CIN I the increase of red fluorescence was approximately of 4 times indicating a good PpIX formation.

  5. Cell cycle dependence of protophorphyrin IX generation in 9L rat gliosarcoma

    NASA Astrophysics Data System (ADS)

    Luo, Shiming; Da, Xing; Chen, Qun

    2006-09-01

    Photodynamic therapy (PDT) is a cancer therapy that utilizes optical energy to activate a photosensitizer drug in a target tissue. Always, the curative effect is dependent on the light fluence, the concentration of the photosensitizer and the concentration of the oxygen. To date, Protophorphyrin IX (PpIX) as the only one endogenous photosensitizer is widely used in PDT of brain tumors. Since PpIX is synthesized in intracellular structure, and is likely dependent on the phase of the cell cycle. The cell cycle dependence of PpIX production is thus investigated in the current work in 9L gliosarcoma cells.

  6. Expression of the hypoxia-inducible monocarboxylate transporter MCT4 is increased in triple negative breast cancer and correlates independently with clinical outcome

    SciTech Connect

    Doyen, J.; Trastour, C.; Ettore, F.; Peyrottes, I.; Toussant, N.; Gal, J.; Ilc, K.; Roux, D.; Parks, S.K.; Ferrero, J.M.; Pouysségur, J.

    2014-08-15

    Highlights: • Glycolytic markers are highly expressed in triple negative breast cancers. • Lactate/H{sup +} symporter MCT4 demonstrated the strongest deleterious impact on survival. • MCT4 should serve as a new prognostic factor in node-negative breast cancers. - Abstract: Background: {sup 18}Fluor-deoxy-glucose PET-scanning of glycolytic metabolism is being used for staging in many tumors however its impact on prognosis has never been studied in breast cancer. Methods: Glycolytic and hypoxic markers: glucose transporter (GLUT1), carbonic anhydrase IX (CAIX), monocarboxylate transporter 1 and 4 (MCT1, 4), MCT accessory protein basigin and lactate-dehydrogenase A (LDH-A) were assessed by immunohistochemistry in two cohorts of breast cancer comprising 643 node-negative and 127 triple negative breast cancers (TNBC) respectively. Results: In the 643 node-negative breast tumor cohort with a median follow-up of 124 months, TNBC were the most glycolytic (≈70%), followed by Her-2 (≈50%) and RH-positive cancers (≈30%). Tumoral MCT4 staining (without stromal staining) was a strong independent prognostic factor for metastasis-free survival (HR = 0.47, P = 0.02) and overall-survival (HR = 0.38, P = 0.002). These results were confirmed in the independent cohort of 127 cancer patients. Conclusion: Glycolytic markers are expressed in all breast tumors with highest expression occurring in TNBC. MCT4, the hypoxia-inducible lactate/H{sup +} symporter demonstrated the strongest deleterious impact on survival. We propose that MCT4 serves as a new prognostic factor in node-negative breast cancer and can perhaps act soon as a theranostic factor considering the current pharmacological development of MCT4 inhibitors.

  7. Characterization, bioinformatic analysis and dithiocarbamate inhibition studies of two new α-carbonic anhydrases, CAH1 and CAH2, from the fruit fly Drosophila melanogaster.

    PubMed

    Syrjänen, Leo; Tolvanen, Martti E E; Hilvo, Mika; Vullo, Daniela; Carta, Fabrizio; Supuran, Claudiu T; Parkkila, Seppo

    2013-03-15

    Carbonic anhydrases (CAs) are essential and ubiquitous enzymes. Thus far, there are no articles on characterization of Drosophila melanogaster α-CAs. Data from invertebrate CA studies may provide opportunities for anti-parasitic drug development because α-CAs are found in many parasite or parasite vector invertebrates. We have expressed and purified D. melanogaster CAH1 and CAH2 as proteins of molecular weights 30kDa and 28kDa. CAH1 is cytoplasmic whereas CAH2 is a membrane-attached protein. Both are highly active enzymes for the CO2 hydration reaction, being efficiently inhibited by acetazolamide. CAH2 in the eye of D. melanogaster may provide a new animal model for CA-related eye diseases. A series of dithiocarbamates were also screened as inhibitors of these enzymes, with some representatives showing inhibition in the low nanomolar range. PMID:22989910

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

    SciTech Connect

    Weiwei, Zhang; Hu, Renming

    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.

  9. Consumption of carbonyl sulphide (COS) by higher plant carbonic anhydrase (CA)

    NASA Astrophysics Data System (ADS)

    Protoschill-Krebs, G.; Wilhelm, C.; Kesselmeier, J.

    Carbonic anhydrase (CA), isolated from pea leaves, was found to consume carbonyl sulphide (COS), a climatic relevant trace gas in the atmosphere. The isolated enzyme, free of other carboxylases, showed a very high affinity towards this substrate. The experiments confirm that CA is the key enzyme for the consumption of COS in higher plants. Furthermore, the identification of this enzyme furthers our understanding of additional sinks for COS, which are needed to understand the balance of known global sources.

  10. Comparison in different species of biliary bilirubin-IX alpha conjugates with the activities of hepatic and renal bilirubin-IX alpha-uridine diphosphate glycosyltransferases.

    PubMed Central

    Fevery, J; Van de Vijver, M; Michiels, R; Heirwegh, K P

    1977-01-01

    The bilrubin-IXalpha conjugates in bile and the activities of bilirubin-IX alpha--UDP-glycosyltransferases in liver and kidney were determined for ten species of mammals and for the chicken. 1. In the mammalian species, bilirubin-IX alpha glucuronide was the predominant bile pigment. Excretion of neutral glycosides was unimportant, except in the cat, the mouse, the rabbit and the dog, where glucose and xylose represented 12--41% of total conjugating groups bound to bilirubin-IX alpha. In chicken bile, glucoside and glucuronide conjugates were of equal importance. They probably represent only a small fraction of the total bile pigment. 2. The transferase activities in liver showed pronounced species variation. This was also apparent with regard to activation by digitonin, pH optimum and relative activities of transferases acting on either UDP-glucuronic acid or neutral UDP-sugars. 3. Man, the dog, the cat and the rat excrete bilirubin-IX alpha largely as diconjugated derivatives. In general, diconjugated bilirubin-IX alpha could also be synthesized in vitro with liver homogenate, bilirubin-IX alpha and UDP-sugar. In contrast, for the other species examined, bilirubin pigments consisted predominantly of monoconjugated bilirubin-IX alpha. Synthesis in vitro with UDP-glucuronic acid, UDP-glucose or UDP-xylose as the sugar donor led exclusively to the formation of monoconjugated bilirubin-IX alpha. 4. The transferase activities in the kidney were restricted to the cortex and were important only for the rat and the dog. No activity at all could be detected for several species, including man. 5. Comparison of the transferase activities in liver with reported values of the maximal rate of excretion in bile suggests a close linkage between conjugation and biliary secretion of bilirubin-IX alpha. PMID:407905

  11. The distribution of carbonic anhydrase and ribulose diphosphate carboxylase in maize leaves.

    PubMed

    Poincelot, R P

    1972-09-01

    Extraction of maize (Zea mays) leaves by progressive grinding under suitably protective conditions yields total carbonic anhydrase activities (4800 units per milligram chlorophyll) comparable to the activity in spinach (Spinacia oleracea) leaves. The total ribulose diphosphate carboxylase activity was also equal to or greater than the best literature values for maize. Of the total leaf carbonic anhydrase, 72.5% on a chlorophyll basis was present in the mesophyll cells and 14.2% in the bundle-sheath cells. The distribution of the total leaf ribulose diphosphate carboxylase between the mesophyll and bundle-sheath cells was 42.0 and 48.7% respectively. There was three times as much total chlorophyll in extracts of the mesophyll cells compared with the bundle-sheath cells of maize. Similar results for the above distribution of the two enzymes were found using a differential grinding technique. The possible function of carbonic anhydrase in photosynthesis is discussed. The equal distribution of ribulose diphosphate carboxylase activity between the mesophyll and bundle-sheath cells casts doubt upon the hypothesis that a rigid biochemical compartmentation exists between these cell types in maize. PMID:16658170

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

    SciTech Connect

    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.

  13. Identification of Ectonucleotide Pyrophosphatase/Phosphodiesterase 3 (ENPP3) as a Regulator of N-Acetylglucosaminyltransferase GnT-IX (GnT-Vb)*

    PubMed Central

    Korekane, Hiroaki; Park, Jong Yi; Matsumoto, Akio; Nakajima, Kazuki; Takamatsu, Shinji; Ohtsubo, Kazuaki; Miyamoto, Yasuhide; Hanashima, Shinya; Kanekiyo, Kenji; Kitazume, Shinobu; Yamaguchi, Yoshiki; Matsuo, Ichiro; Taniguchi, Naoyuki

    2013-01-01

    Our previous studies on a β1,6-N-acetylglucosaminyltransferase, GnT-IX (GnT-Vb), a homolog of GnT-V, indicated that the enzyme has a broad GlcNAc transfer activity toward N-linked and O-mannosyl glycan core structures and that its brain-specific gene expression is regulated by epigenetic histone modifications. In this study, we demonstrate the existence of an endogenous inhibitory factor for GnT-IX that functions as a key regulator for GnT-IX enzymatic activity in Neuro2a (N2a) cells. We purified this factor from N2a cells and found that it is identical to ectonucleotide pyrophosphatase/phosphodiesterase 3 (ENPP3), as evidenced by mass spectrometry and by the knockdown and overexpression of ENPP3 in cultured cells. Kinetic analyses revealed that the mechanism responsible for the inhibition of GnT-IX caused by ENPP3 is the ENPP3-mediated hydrolysis of the nucleotide sugar donor substrate, UDP-GlcNAc, with the resulting generation of UMP, a potent and competitive inhibitor of GnT-IX. Indeed, ENPP3 knockdown cells had significantly increased levels of intracellular nucleotide sugars and displayed changes in the total cellular glycosylation profile. In addition to chaperones or other known regulators of glycosyltransferases, the ENPP3-mediated hydrolysis of nucleotide sugars would have widespread and significant impacts on glycosyltransferase activities and would be responsible for altering the total cellular glycosylation profile and modulating cellular functions. PMID:23960081

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

    PubMed

    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. PMID:19218391

  15. Carbonic anhydrase II binds to and increases the activity of the epithelial sodium-proton exchanger, NHE3.

    PubMed

    Krishnan, Devishree; Liu, Lei; Wiebe, Shane A; Casey, Joseph R; Cordat, Emmanuelle; Alexander, R Todd

    2015-08-15

    Two-thirds of sodium filtered by the renal glomerulus is reabsorbed from the proximal tubule via a sodium/proton exchanger isoform 3 (NHE3)-dependent mechanism. Since sodium and bicarbonate reabsorption are coupled, we postulated that the molecules involved in their reabsorption [NHE3 and carbonic anhydrase II (CAII)] might physically and functionally interact. Consistent with this, CAII and NHE3 were closely associated in a renal proximal tubular cell culture model as revealed by a proximity ligation assay. Direct physical interaction was confirmed in solid-phase binding assays with immobilized CAII and C-terminal NHE3 glutathione-S-transferase fusion constructs. To assess the effect of CAII on NHE3 function, we expressed NHE3 in a proximal tubule cell line and measured NHE3 activity as the rate of intracellular pH recovery, following an acid load. NHE3-expressing cells had a significantly greater rate of intracellular pH recovery than controls. Inhibition of endogenous CAII activity with acetazolamide significantly decreased NHE3 activity, indicating that CAII activates NHE3. To ascertain whether CAII binding per se activates NHE3, we expressed NHE3 with wild-type CAII, a catalytically inactive CAII mutant (CAII-V143Y), or a mutant unable to bind other transporters (CAII-HEX). NHE3 activity increased upon wild-type CAII coexpression, but not in the presence of the CAII V143Y or HEX mutant. Together these studies support an association between CAII and NHE3 that alters the transporter's activity. PMID:26041446

  16. Carbonic anhydrase II binds to and increases the activity of the epithelial sodium-proton exchanger, NHE3

    PubMed Central

    Krishnan, Devishree; Liu, Lei; Wiebe, Shane A.; Casey, Joseph R.; Cordat, Emmanuelle; Alexander, R. Todd

    2016-01-01

    Two-thirds of sodium filtered by the renal glomerulus is reabsorbed from the proximal tubule via a sodium/proton exchanger isoform 3 (NHE3)-dependent mechanism. Since sodium and bicarbonate reabsorption are coupled, we postulated that the molecules involved in their reabsorption [NHE3 and carbonic anhydrase II (CAII)] might physically and functionally interact. Consistent with this, CAII and NHE3 were closely associated in a renal proximal tubular cell culture model as revealed by a proximity ligation assay. Direct physical interaction was confirmed in solid-phase binding assays with immobilized CAII and C-terminal NHE3 glutathione-S-transferase fusion constructs. To assess the effect of CAII on NHE3 function, we expressed NHE3 in a proximal tubule cell line and measured NHE3 activity as the rate of intracellular pH recovery, following an acid load. NHE3-expressing cells had a significantly greater rate of intracellular pH recovery than controls. Inhibition of endogenous CAII activity with acetazolamide significantly decreased NHE3 activity, indicating that CAII activates NHE3. To ascertain whether CAII binding per se activates NHE3, we expressed NHE3 with wild-type CAII, a catalytically inactive CAII mutant (CAII-V143Y), or a mutant unable to bind other transporters (CAII-HEX). NHE3 activity increased upon wild-type CAII coexpression, but not in the presence of the CAII V143Y or HEX mutant. Together these studies support an association between CAII and NHE3 that alters the transporter’s activity. PMID:26041446

  17. Constellation's First Flight Test: Ares I-X

    NASA Technical Reports Server (NTRS)

    Davis, Stephan R.; Askins, Bruce R.

    2010-01-01

    On October 28, 2009, NASA launched Ares I-X, the first flight test of the Constellation Program that will send human beings to the Moon and beyond. This successful test is the culmination of a three-and-a-half-year, multi-center effort to design, build, and fly the first demonstration vehicle of the Ares I crew launch vehicle, the successor vehicle to the Space Shuttle. The suborbital mission was designed to evaluate the atmospheric flight characteristics of a vehicle dynamically similar to Ares I; perform a first stage separation and evaluate its effects; characterize and control roll torque; stack, fly, and recover a solid-motor first stage testing the Ares I parachutes; characterize ground, flight, and reentry environments; and develop and execute new ground hardware and procedures. Built from existing flight and new simulator hardware, Ares I-X integrated a Shuttle-heritage four-segment solid rocket booster for first stage propulsion, a spacer segment to simulate a five-segment booster, Peacekeeper axial engines for roll control, and Atlas V avionics, as well as simulators for the upper stage, crew module, and launch abort system. The mission leveraged existing logistical and ground support equipment while also developing new ones to accommodate the first in-line rocket for flying astronauts since the Saturn IB last flew from Kennedy Space Center (KSC) in 1975. This paper will describe the development and integration of the various vehicle and ground elements, from conception to stacking in KSC s Vehicle Assembly Building; hardware performance prior to, during, and after the launch; and preliminary lessons and data gathered from the flight. While the Constellation Program is currently under review, Ares I-X has and will continue to provide vital lessons for NASA personnel in taking a vehicle concept from design to flight.

  18. Oscillator strengths for Ar VII, Ca IX and Fe XV

    NASA Technical Reports Server (NTRS)

    Tayal, S. S.

    1986-01-01

    The excitation energies and oscillator strengths are calculated for electric-dipole-allowed and intercombination transitions between 3s2 1S, 3s3p(1,3)P0, 3p2 3P, 1D, 1S and 3s3d(1,3)D states in Ar VII, Ca IX, and Fe XV ions of the magnesium sequence. These states are represented by the fairly large configuration-interaction expansions. The calculations have been carried out in both LS and intermediate coupling schemes. The relativistic corrections have been included through the Breit-Pauli Hamiltonian. The results are compared with previous theoretical calculations and with measurements.

  19. Ares I-X Test Flight Reference Trajectory Development

    NASA Technical Reports Server (NTRS)

    Starr, Brett R.; Gumbert, Clyde R.; Tartabini, Paul V.

    2011-01-01

    Ares I-X was the first test flight of NASA's Constellation Program's Ares I crew launch vehicle. Ares I is a two stage to orbit launch vehicle that provides crew access to low Earth orbit for NASA's future manned exploration missions. The Ares I first stage consists of a Shuttle solid rocket motor (SRM) modified to include an additional propellant segment and a liquid propellant upper stage with an Apollo J2X engine modified to increase its thrust capability. The modified propulsion systems were not available for the first test flight, thus the test had to be conducted with an existing Shuttle 4 segment reusable solid rocket motor (RSRM) and an inert Upper Stage. The test flight's primary objective was to demonstrate controllability of an Ares I vehicle during first stage boost and the ability to perform a successful separation. In order to demonstrate controllability, the Ares I-X ascent control algorithms had to maintain stable flight throughout a flight environment equivalent to Ares I. The goal of the test flight reference trajectory development was to design a boost trajectory using the existing RSRM that results in a flight environment equivalent to Ares I. A trajectory similarity metric was defined as the integrated difference between the Ares I and Ares I-X Mach versus dynamic pressure relationships. Optimization analyses were performed that minimized the metric by adjusting the inert upper stage weight and the ascent steering profile. The sensitivity of the optimal upper stage weight and steering profile to launch month was also investigated. A response surface approach was used to verify the optimization results. The analyses successfully defined monthly ascent trajectories that matched the Ares I reference trajectory dynamic pressure versus Mach number relationship to within 10% through Mach 3.5. The upper stage weight required to achieve the match was found to be feasible and varied less than 5% throughout the year. The paper will discuss the flight

  20. 32 CFR 2003.9 - Reports to the President (Article IX).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 6 2013-07-01 2013-07-01 false Reports to the President (Article IX). 2003.9... PANEL (ISCAP) BYLAWS, RULES, AND APPEAL PROCEDURES Bylaws § 2003.9 Reports to the President (Article IX... President of the United States. The Panel also includes such information in any reports it may make to...

  1. Not Second-Class: Title IX, Equity, and Girls' High School Sports

    ERIC Educational Resources Information Center

    Stader, David L.; Surface, Jeanne L.

    2014-01-01

    Title IX is designed to protect students from discrimination based on sex in any educational institution that receives financial assistance. This article focuses on Title IX as it applies to high school athletic programs by considering the trial of a high school district in California. A federal court found considerable inequalities between boys…

  2. 46 CFR 57.02-2 - Adoption of section IX of the ASME Code.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Adoption of section IX of the ASME Code. 57.02-2 Section 57.02-2 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING WELDING... accordance with section IX of the ASME (American Society of Mechanical Engineers) Code, as limited,...

  3. 46 CFR 57.02-2 - Adoption of section IX of the ASME Code.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Adoption of section IX of the ASME Code. 57.02-2 Section 57.02-2 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING WELDING... accordance with section IX of the ASME (American Society of Mechanical Engineers) Code, as limited,...

  4. 46 CFR 57.02-2 - Adoption of section IX of the ASME Code.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Adoption of section IX of the ASME Code. 57.02-2 Section 57.02-2 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING WELDING... accordance with section IX of the ASME (American Society of Mechanical Engineers) Code, as limited,...

  5. Sex Discrimination Against Students: Implications of Title IX of the Education Amendments of 1972.

    ERIC Educational Resources Information Center

    Dunkle, Margaret C.; Sandler, Bernice

    Title IX of the Education Amendments of 1972 mandates that sex discrimination be eliminated in federally assisted education programs. Title IX has significant implications for a variety of issues including recruiting, admissions, financial aid, student rules and regulations, housing rules, health care and insurance benefits, student employment,…

  6. Almost As Fairly: The First Year of Title IX Implementation in Six Southern States. A Report.

    ERIC Educational Resources Information Center

    American Friends Service Committee, Columbia, SC. Southeastern Public Education Program.

    Volunteers from community organizations in six southern states monitored 21 school districts to find their districts' initial answer to Title IX, federal legislation barring sex discrimination. The actual monitoring of the 21 districts was completed in the late spring of 1976, with data covering the first year of Title IX implementation. The…

  7. "What Do I Think about Title IX?" Voices from a University Community

    ERIC Educational Resources Information Center

    Paule-Koba, Amanda L.; Harris, Othello; Freysinger, Valeria J.

    2013-01-01

    Despite the apparent benefits of Title IX, the implementation of the law remains controversial, and there are divergent beliefs regarding its impact on collegiate sport. The purpose of this study was to examine how members of a university community, whose intercollegiate sport programs have changed, perceive and make sense of Title IX and the…

  8. The Impact of Implementing Title IX in a Predominantly Black Public University.

    ERIC Educational Resources Information Center

    Simmons, Gertrude L.

    Information on the impact of implementing Title IX of the 1972 Education Amendments at Florida A and M University, a predominantly Black public university, is presented. Title IX assures everyone regardless of sex an equal opportunity to learn a skill, choose a course of study, advance in status, participate in a sport, receive a scholarship, or…

  9. Critical Issue Bibliography (CRIB) Sheet: Title IX of the Educational Amendments of 1972.

    ERIC Educational Resources Information Center

    ERIC Clearinghouse on Higher Education, Washington, DC.

    This CRitical Issue Bibliography (CRIB) Sheet cites resources that give an overview of Title IX legislation and offer information about compliance, litigation, and related issues. Title IX of the Education Amendments of 1972 protects individuals from gender-based discrimination in education programs or activities that receive federal financial…

  10. A Place on the Team: The Triumph and Tragedy of Title IX

    ERIC Educational Resources Information Center

    Suggs, Welch

    2006-01-01

    "A Place on the Team" is the inside story of how Title IX revolutionized American sports. The federal law guaranteeing women's rights in education, Title IX opened gymnasiums and playing fields to millions of young women previously locked out. Journalist Welch Suggs chronicles both the law's successes and failures-the exciting opportunities for…

  11. Derivation of a triple mosaic adenovirus based on modification of the minor capsid protein IX

    SciTech Connect

    Tang Yizhe; Le, Long P.; Matthews, Qiana L.; Han Tie; Wu Hongju; Curiel, David T.

    2008-08-01

    Adenoviral capsid protein IX (pIX) has been shown to be a potential locale to insert targeting, imaging-related and therapeutic modalities by genetic modification. Recent evidences suggested that capsid protein mosaicism could be a promising strategy for improving the utility of Ad vector. In this study, we explored a method to genetically generate triple pIX mosaic Ad serotype 5 (Ad5) displaying three types of pIX on a single virion. pIXs were modified at their carboxy termini with a Flag sequence, a hexahistidine sequence (His{sub 6}) or a monomeric red fluorescent protein (mRFP1), respectively. Western blotting analysis and fluorescence microscopy of the purified recombinant viruses indicated that all three modified pIXs were incorporated into the viral particles. Immuno-gold electron microscopy (EM) further confirmed that three types of pIX indeed co-existed on an individual virion. These results firstly validated a triple mosaic capsid configuration on pIX, and demonstrated the possibility of further radical design.

  12. Ongoing advances in quantitative PpIX fluorescence guided intracranial tumor resection (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Olson, Jonathan D.; Kanick, Stephen C.; Bravo, Jaime J.; Roberts, David W.; Paulsen, Keith D.

    2016-03-01

    Aminolevulinc-acid induced protoporphyrin IX (ALA-PpIX) is being investigated as a biomarker to guide neurosurgical resection of brain tumors. ALA-PpIX fluorescence can be observed visually in the surgical field; however, raw fluorescence emissions can be distorted by factors other than the fluorophore concentration. Specifically, fluorescence emissions are mixed with autofluorescence and attenuated by background absorption and scattering properties of the tissue. Recent work at Dartmouth has developed advanced fluorescence detection approaches that return quantitative assessments of PpIX concentration, which are independent of background optical properties. The quantitative fluorescence imaging (qFI) approach has increased sensitivity to residual disease within the resection cavity at the end of surgery that was not visible to the naked eye through the operating microscope. This presentation outlines clinical observations made during an ongoing investigation of ALA-PpIX based guidance of tumor resection. PpIX fluorescence measurements made in a wide-field hyperspectral imaging approach are co-registered with point-assessment using a fiber optic probe. Data show variations in the measured PpIX accumulation among different clinical tumor grades (i.e. high grade glioma, low grade glioma), types (i.e. primary tumors. metastases) and normal structures of interest (e.g. normal cortex, hippocampus). These results highlight the contrast enhancement and underscore the potential clinical benefit offered from quantitative measurements of PpIX concentration during resection of intracranial tumors.

  13. Plasma protoporphyrin IX following administration of 5-aminolevulinic acid as a potential tumor marker

    PubMed Central

    OTA, URARA; FUKUHARA, HIDEO; ISHIZUKA, MASAHIRO; ABE, FUMINORI; KAWADA, CHIAKI; TAMURA, KENJI; TANAKA, TOHRU; INOUE, KEIJI; OGURA, SHUN-ICHIRO; SHUIN, TARO

    2015-01-01

    Exogenously administered 5-aminolevulinic acid (ALA) is metabolized to protoporphyrin IX (PpIX), which specifically accumulates in cancer cells and emits red fluorescence by blue light irradiation. These phenomena are applied for the intraoperative diagnosis of cancer. Based on the fact that accumulated PpIX in cancer cells is exported extracellularly via the ATP-binding cassette transporter G2, we hypothesized that the measurement of plasma PpIX concentrations could be applied as a tumor marker for cancer screening. In the present study, the use of plasma samples from bladder cancer patients were evaluated as a tumor marker. ALA, 1.0 g, was orally administered to bladder cancer patients and healthy adults. The plasma concentration of PpIX was measured using a high-performance liquid chromatography system. The plasma PpIX concentration following ALA administration was significantly higher in bladder cancer patients than that in the healthy adults, suggesting the effectiveness of plasma PpIX analysis following ALA administration for cancer screening. Additionally, 4 h after ALA administration, plasma PpIX showed high sensitivity (94.4%) and high specificity (80.0%). PMID:26171183

  14. Perceptions of Women's Teams Coaches Regarding Gender Equity and Title IX Compliance in Community Colleges

    ERIC Educational Resources Information Center

    Kenney, Cynthia A.

    2013-01-01

    Title IX was enacted over 40 years ago, and although there have been marked increases in the number of girls and women participating in athletics at every level, gender equity in athletics continues to be a concern. This is especially evident at the community college level. Title IX requires equity in the areas of opportunities for participation,…

  15. Title IX Compliance at Two-Year Colleges: An Analysis of Perceived Barriers and Strategies

    ERIC Educational Resources Information Center

    Causby, Cory Scott

    2010-01-01

    Although Title IX legislation has been in effect since 1972 and has created unprecedented positive change on intercollegiate athletics, educational institutions have still had difficulty meeting the basic requirements set forth by Title IX and ensuring gender equity in their athletic programs. Additionally, specific research has been largely…

  16. Title IX and Employment Discrimination: A Wrong in Search of a Remedy.

    ERIC Educational Resources Information Center

    Salomone, Rosemary C.

    1980-01-01

    Focuses on the litigation challenging the authority of the Department of Health, Education, and Welfare to promulgate regulations governing employment discrimination pursuant to Title IX. Despite compelling challenges, interest in Title IX continues because its penalties are more extensive than those available under Title VII. (IRT)

  17. 40 CFR Appendix Ix to Part 266 - Methods Manual for Compliance With the BIF Regulations

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (CONTINUED) SOLID WASTES (CONTINUED) STANDARDS FOR THE MANAGEMENT OF SPECIFIC HAZARDOUS WASTES AND SPECIFIC TYPES OF HAZARDOUS WASTE MANAGEMENT FACILITIES Pt. 266, App. IX Appendix IX to Part 266—Methods Manual... Protection Agency regulations for boilers and industrial furnaces (BIFs) burning hazardous waste (see 40...

  18. 40 CFR Appendix Ix to Part 266 - Methods Manual for Compliance With the BIF Regulations

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... (CONTINUED) SOLID WASTES (CONTINUED) STANDARDS FOR THE MANAGEMENT OF SPECIFIC HAZARDOUS WASTES AND SPECIFIC TYPES OF HAZARDOUS WASTE MANAGEMENT FACILITIES Pt. 266, App. IX Appendix IX to Part 266—Methods Manual... Protection Agency regulations for boilers and industrial furnaces (BIFs) burning hazardous waste (see 40...

  19. Franklin v. Gwinnett County Public Schools and Its Impact on Title IX Enforcement.

    ERIC Educational Resources Information Center

    Vargyas, Ellen J.

    1993-01-01

    A court decision allowing monetary damages for intentional violations of Title IX of the Education Amendments of 1972 is seen as dramatically changing enforcement of the principal federal law against sex discrimination. Its treatment of sexual harassment is also considered. Implications for Title IX enforcement in colleges and universities are…

  20. Sexual Harassment and Student Rights: The Supreme Court Expands Title IX Remedies.

    ERIC Educational Resources Information Center

    Russo, Charles J.; And Others

    1992-01-01

    Ruling in "Franklin," the Supreme Court found in favor of a high school student who alleged that she had been subjected to sexual harassment in violation of Title IX of the Educational Amendments of 1972. Inquires about the nature and scope of damages available under Title IX. Concludes with policy considerations for administrators. (MLF)

  1. Atomic Data and Spectral Line Intensities for Ca IX

    NASA Technical Reports Server (NTRS)

    Landi, E.; Bhatia, A. K.

    2012-01-01

    Electron impact collision strengths, energy levels, oscillator strengths and spontaneous radiative decay rates are calculated for Ca IX. We include in the calculations the 33 lowest configurations in the n = 3, 4, 5 complexes, corresponding to 283 fine structure levels in the 3l3l ', 3l4l'' and 3l4l''' configurations, where l,l' = s, p, d, l '' = s, p, d, f and l''' = s, p, d, f, g. Collision strengths are calculated at five incident energies for all transitions: 5.8, 13.6, 24.2, 38.6 and 57.9 Ry above the threshold of each transition. An additional energy, very close to the transition threshold, has been added, whose value is between 0.0055 Ry and 0.23 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)/cubic cm range and at an electron temperature of log T(sub e)(K)=5.8, corresponding to the maximum abundance of Ca IX. Spectral line intensities are calculated, and their diagnostic relevance is discussed.

  2. Ares I-X Separation and Reentry Trajectory Analyses

    NASA Technical Reports Server (NTRS)

    Tartabini, Paul V.; Starr, Brett R.

    2011-01-01

    The Ares I-X Flight Test Vehicle was launched on October 28, 2009 and was the first and only test flight of NASA s two-stage Ares I launch vehicle design. The launch was successful and the flight test met all of its primary and secondary objectives. This paper discusses the stage separation and reentry trajectory analysis that was performed in support of the Ares I-X test flight. Pre-flight analyses were conducted to assess the risk of stage recontact during separation, to evaluate the first stage flight dynamics during reentry, and to define the range safety impact ellipses of both stages. The results of these pre-flight analyses were compared with available flight data. On-board video taken during flight showed that the flight test vehicle successfully separated without any recontact. Reconstructed trajectory data also showed that first stage flight dynamics were well characterized by pre-flight Monte Carlo results. In addition, comparisons with flight data indicated that the complex interference aerodynamic models employed in the reentry simulation were effective in capturing the flight dynamics during separation. Finally, the splash-down locations of both stages were well within predicted impact ellipses.

  3. Anisotropic cosmology and inflation from a tilted Bianchi IX model

    NASA Astrophysics Data System (ADS)

    Sundell, P.; Koivisto, T.

    2015-12-01

    The dynamics of the tilted axisymmetric Bianchi IX cosmological models are explored allowing energy flux in the source fluid. The Einstein equations and the continuity equation are presented treating the equation of state w and the tilt angle of the fluid λ as time-dependent functions, but when analyzing the phase space w and λ are considered free parameters and the shear, the vorticity and the curvature of the spacetime span a three-dimensional phase space that contains seven fixed points. One of them is an attractor that inflates the universe anisotropically, thus providing a counterexample to the cosmic no-hair conjecture. Also, examples of realistic though fine-tuned cosmologies are presented wherein the rotation can become significant towards the present epoch but the shear stays within the observational bounds. The examples suggest that the model used here can explain the parity-violating anomalies of the cosmic microwave background. The result significantly differs from an earlier study, where a nonaxisymmetric Bianchi IX type model with a tilted perfect dust source was found to induce too much shear for observationally significant vorticity.

  4. Ares I-X Upper Stage Simulator Residual Stress Analysis

    NASA Technical Reports Server (NTRS)

    Raju, Ivatury S.; Brust, Frederick W.; Phillips, Dawn R.; Cheston, Derrick

    2008-01-01

    The structural analyses described in the present report were performed in support of the NASA Engineering and Safety Center (NESC) Critical Initial Flaw Size (CIFS) assessment for the Ares I-X Upper Stage Simulator (USS) common shell segment. An independent assessment was conducted to determine the critical initial flaw size (CIFS) for the flange-to-skin weld in the Ares I-X Upper Stage Simulator (USS). The Ares system of space launch vehicles is the US National Aeronautics and Space Administration s plan for replacement of the aging space shuttle. The new Ares space launch system is somewhat of a combination of the space shuttle system and the Saturn launch vehicles used prior to the shuttle. Here, a series of weld analyses are performed to determine the residual stresses in a critical region of the USS. Weld residual stresses both increase constraint and mean stress thereby having an important effect on fatigue and fracture life. The results of this effort served as one of the critical load inputs required to perform a CIFS assessment of the same segment.

  5. "What do I think about Title IX?" Voices from a university community.

    PubMed

    Paule-Koba, Amanda L; Harris, Othello; Freysinger, Valeria J

    2013-03-01

    Despite the apparent benefits of Title IX, the implementation of the law remains controversial, and there are divergent beliefs regarding its impact on collegiate sport. The purpose of this study was to examine how members of a university community, whose intercollegiate sport programs have changed, perceive and make sense of Title IX and the changes it incurred. Using a gendered lens (Birrell, 2000) and qualitative interviews with 13 individuals connected to the university community, insight was gained into their perceptions of Title IX and women's and men's athletic opportunities. The theme of opportunity gained and lost was central to how these individuals perceive Title IX and resonates with the liberal (feminist) concerns out of which Title IX was born. PMID:23611015

  6. Ares I-X Flight Test Vehicle: Stack 5 Modal Test

    NASA Technical Reports Server (NTRS)

    Buehrle, Ralph D.; Templeton, Justin D.; Reaves, Mercedes C.; Horta, Lucas G.; Gaspar, James L.; Bartolotta, Paul A.; Parks, Russel A.; Lazor, Danel R.

    2010-01-01

    Ares I-X was the first flight test vehicle used in the development of NASA's Ares I crew launch vehicle. The Ares I-X used a 4-segment reusable solid rocket booster from the Space Shuttle heritage with mass simulators for the 5th segment, upper stage, crew module and launch abort system. Three modal tests were defined to verify the dynamic finite element model of the Ares I-X flight test vehicle. Test configurations included two partial stacks and the full Ares I-X flight test vehicle on the Mobile Launcher Platform. This report focuses on the first modal test that was performed on the top section of the vehicle referred to as Stack 5, which consisted of the spacecraft adapter, service module, crew module and launch abort system simulators. This report describes the test requirements, constraints, pre-test analysis, test operations and data analysis for the Ares I-X Stack 5 modal test.

  7. Evidence for a prevalent dimorphism in the activation peptide of human coagulation factor IX.

    PubMed Central

    McGraw, R A; Davis, L M; Noyes, C M; Lundblad, R L; Roberts, H R; Graham, J B; Stafford, D W

    1985-01-01

    We have independently isolated and characterized cDNA and genomic clones for the human coagulation factor IX. Sequence analysis in both cases indicates that threonine is encoded by the triplet ACT as the third residue of the activation peptide. This is in agreement with some earlier reports but in disagreement with others that show the alanine triplet GCT at this position. The discrepancy can thus be accounted for by natural variation of a single nucleotide in the normal population. Amino acid sequence analyses of activated factor IX from plasma samples of four individuals yielded two cases of alanine and two cases of threonine at the third position of the activation peptide. In factor IX from pooled plasma and in factor IX from a heterozygous individual, however, both alanine and threonine were found. Taken together, the findings show that a prevalent nondeleterious dimorphism exists in the activation peptide of human coagulation factor IX. PMID:3857619

  8. Collagen type IX from human cartilage: a structural profile of intermolecular cross-linking sites.

    PubMed Central

    Diab, M; Wu, J J; Eyre, D R

    1996-01-01

    Type IX collagen, a quantitatively minor collagenous component of cartilage, is known to be associated with and covalently cross-linked to type II collagen fibrils in chick and bovine cartilage. Type IX collagen molecules have also been shown to form covalent cross-links with each other in bovine cartilage. In the present study we demonstrate by structural analysis and location of cross-linking sites that, in human cartilage, type IX collagen is covalently cross-linked to type II collagen and to other molecules of type IX collagen. We also present evidence that, if the proteoglycan form of type IX collagen is present in human cartilage, it can only be a minor component of the matrix, similar to findings with bovine cartilage. PMID:8660302

  9. Ares I-X Flight Test Vehicle:Stack 1 Modal Test

    NASA Technical Reports Server (NTRS)

    Buehrle, Ralph D.; Templeton, Justin D.; Reaves, Mercedes C.; Horta, Lucas G.; Gaspar, James L.; Bartolotta, Paul A.; Parks, Russel A.; Lazor, Daniel R.

    2010-01-01

    Ares I-X was the first flight test vehicle used in the development of NASA s Ares I crew launch vehicle. The Ares I-X used a 4-segment reusable solid rocket booster from the Space Shuttle heritage with mass simulators for the 5th segment, upper stage, crew module and launch abort system. Three modal tests were defined to verify the dynamic finite element model of the Ares I-X flight test vehicle. Test configurations included two partial stacks and the full Ares I-X flight test vehicle on the Mobile Launcher Platform. This report focuses on the second modal test that was performed on the middle section of the vehicle referred to as Stack 1, which consisted of the subassembly from the 5th segment simulator through the interstage. This report describes the test requirements, constraints, pre-test analysis, test operations and data analysis for the Ares I-X Stack 1 modal test.

  10. Three functional β-carbonic anhydrases in Pseudomonas aeruginosa PAO1: role in survival in ambient air

    PubMed Central

    Lotlikar, Shalaka R.; Hnatusko, Shane; Dickenson, Nicholas E.; Choudhari, Shyamal P.; Picking, Wendy L.

    2013-01-01

    Bacterial β-class carbonic anhydrases (CAs) are zinc metalloenzymes catalysing reversible hydration of CO2. They maintain the intracellular balance of CO2/bicarbonate required for biosynthetic reactions and represent a new group of antimicrobial drug targets. Genome sequence analysis of Pseudomonas aeruginosa PAO1, an opportunistic human pathogen causing life threatening infections, identified three genes, PAO102, PA2053 and PA4676, encoding putative β-CAs that share 28–45 % amino acid sequence identity and belong to clades A and B. The genes are conserved among all sequenced pseudomonads. The CAs were cloned, heterologously expressed and purified. Metal and enzymic analyses confirmed that the proteins contain Zn2+ and catalyse hydration of CO2 to bicarbonate. PAO102 (psCA1) was 19–26-fold more active, and together with PA2053 (psCA2) showed CA activity at both pH 7.5 and 8.3, whereas PA4676 (psCA3) was active only at pH 8.3. Circular dichroism spectroscopy suggested that psCA2 and psCA3 undergo pH-dependent structural changes. Taken together, the data suggest that psCA1 may belong to type I and psCA3 to type II β-CAs. Immunoblot analysis showed that all three CAs are expressed in PAO1 cells when grown in ambient air and at 5 % CO2; psCA1 appeared more abundant under both conditions. Growth studies of transposon mutants showed that the disruption of psCA1 impaired PAO1 growth in ambient air and caused a minor defect at high CO2. Thus, psCA1 contributes to the adaptation of P. aeruginosa to low CO2 conditions and will be further studied for its role in virulence and as a potential antimicrobial drug target in this organism. PMID:23728627

  11. Effects of carbonic anhydrase-related protein VIII on human cells harbouring an A8344G mitochondrial DNA mutation.

    PubMed

    Wang, Tze-Kai; Cheng, Che-Kun; Chi, Tang-Hao; Ma, Yi-Shing; Wu, Shi-Bei; Wei, Yau-Huei; Hsieh, Mingli

    2014-04-01

    MERRF (myoclonus epilepsy associated with ragged-red fibres) is a maternally inherited mitochondrial encephalomyopathy with various syndromes involving both muscular and nervous systems. The most common mutation in MERRF syndrome, the A8344G mutation in mtDNA, has been associated with severe defects in the respiratory function of mitochondria. In the present study, we show that there is a significant decrease in CA8 (carbonic anhydrase-related protein VIII) in cybrids harbouring the MERRF A8344G mutation. CA8 deficiency and mutations were found to be associated with a distinctive lifelong gait disorder in wdl (Waddles) mice and novel syndromes characterized by cerebellar ataxia and mental retardation in humans. The results of the present study showed that overexpression of CA8 in MERRF cybrids significantly decreased cell death induced by STS (staurosporine) treatment, suggesting a protective function of CA8 in cells harbouring the A8344G mutation of mtDNA. Interestingly, an increase in the formation of LC3-II (microtubule-associated protein 1 light chain 3-II) was found in the cybrids with down-regulated CA8 expression, suggesting that reduced expression of CA8 leads to autophagy activation. Furthermore, cybrids exhibiting down-regulated CA8 showed increased cytosolic Ca2+ signals and reduced levels of phospho-Akt compared with those in the cybrids with overexpressed CA8, indicating that phospho-Akt is involved in the protection of cells by CA8. Our findings suggest that CA8 is involved in the autophagic pathway and may have a protective role in cultured cells from patients with MERRF. Targeting CA8 and the downstream autophagic pathway might help develop therapeutic agents for treatment of MERRF syndrome in the future. PMID:24476000

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

    PubMed

    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. PMID:24031050

  13. Importance of Post-Translational Modifications for Functionality of a Chloroplast-Localized Carbonic Anhydrase (CAH1) in Arabidopsis thaliana

    PubMed Central

    Burén, Stefan; Ortega-Villasante, Cristina; Blanco-Rivero, Amaya; Martínez-Bernardini, Andrea; Shutova, Tatiana; Shevela, Dmitriy; Messinger, Johannes; Bako, Laszlo; Villarejo, Arsenio; Samuelsson, Göran

    2011-01-01

    Background The Arabidopsis CAH1 alpha-type carbonic anhydrase is one of the few plant proteins known to be targeted to the chloroplast through the secretory pathway. CAH1 is post-translationally modified at several residues by the attachment of N-glycans, resulting in a mature protein harbouring complex-type glycans. The reason of why trafficking through this non-canonical pathway is beneficial for certain chloroplast resident proteins is not yet known. Therefore, to elucidate the significance of glycosylation in trafficking and the effect of glycosylation on the stability and function of the protein, epitope-labelled wild type and mutated versions of CAH1 were expressed in plant cells. Methodology/Principal Findings Transient expression of mutant CAH1 with disrupted glycosylation sites showed that the protein harbours four, or in certain cases five, N-glycans. While the wild type protein trafficked through the secretory pathway to the chloroplast, the non-glycosylated protein formed aggregates and associated with the ER chaperone BiP, indicating that glycosylation of CAH1 facilitates folding and ER-export. Using cysteine mutants we also assessed the role of disulphide bridge formation in the folding and stability of CAH1. We found that a disulphide bridge between cysteines at positions 27 and 191 in the mature protein was required for correct folding of the protein. Using a mass spectrometric approach we were able to measure the enzymatic activity of CAH1 protein. Under circumstances where protein N-glycosylation is blocked in vivo, the activity of CAH1 is completely inhibited. Conclusions/Significance We show for the first time the importance of post-translational modifications such as N-glycosylation and intramolecular disulphide bridge formation in folding and trafficking of a protein from the secretory pathway to the chloroplast in higher plants. Requirements for these post-translational modifications for a fully functional native protein explain the need for

  14. Immunocytochemical localization of V-H(+) -ATPase, Na(+) /K(+) -ATPase, and carbonic anhydrase in gill lamellae of adult freshwater euryhaline shrimp Macrobrachium acanthurus (Decapoda, Palaemonidae).

    PubMed

    Maraschi, Anieli Cristina; Freire, Carolina Arruda; Prodocimo, Viviane

    2015-08-01

    Physiological (organismal), biochemical, and molecular biological contributions to the knowledge of the osmoregulatory plasticity of palaemonid freshwater shrimps has provided a fairly complete model of transporter localization in their branchial epithelium. Direct immunological demonstration of the main enzymes in the gill epithelia of adult palaemonids is, however, still incipient. The diadromous freshwater shrimp Macrobrachium acanthurus was exposed to increased salinity (25‰ for 24 hr), and its responses at the systemic level were evaluated through the assays of hemolymph osmolality and muscle hydration, and at cellular and subcellular levels through the activity and localization of the V-H(+) -ATPase, the Na(+) /K(+) -ATPase, and the carbonic anhydrase. Results showed an increase in hemolymph osmolality (629 ± 5.3 mOsm/kg H2 O) and a decrease in muscle hydration (73.8 ± 0.5%), comparing values after 24 hr in 25‰ with control shrimps in freshwater (respectively 409.5 ± 15.8 mOsm/kg H2 O and 77.5 ± 0.4%). V-H(+) -ATPase was localized in pillar cells, whereas Na(+) /K(+) -ATPase in the septal cells. The main novelty of this study was that carbonic anhydrase was localized in the whole branchial tissue, in pillar and septal cells. Exposure to high salinity for 24 hr led to no detectable changes in their localization or in vitro activity. Immunolocalization data corroborated the literature and current models of palaemonid gill ion transport. The absence of changes reinforces the need for the constant expression of these enzymes to account for the euryhalinity of these shrimps. PMID:26036663

  15. 5-Aminolevulinic Acid-Induced Protoporphyrin IX Fluorescence in Meningioma: Qualitative and Quantitative Measurements In Vivo

    PubMed Central

    Valdes, Pablo A.; Bekelis, Kimon; Harris, Brent T.; Wilson, Brian C.; Leblond, Frederic; Kim, Anthony; Simmons, Nathan E.; Erkmen, Kadir; Paulsen, Keith D.; Roberts, David W.

    2014-01-01

    BACKGROUND The use of 5-aminolevulinic acid (ALA)-induced protoporphyrin IX (PpIX) fluorescence has shown promise as a surgical adjunct for maximizing the extent of surgical resection in gliomas. To date, the clinical utility of 5-ALA in meningiomas is not fully understood, with most descriptive studies using qualitative approaches to 5-ALA-PpIX. OBJECTIVE To assess the diagnostic performance of 5-ALA-PpIX fluorescence during surgical resection of meningioma. METHODS ALA was administered to 15 patients with meningioma undergoing PpIX fluorescence-guided surgery at our institution. At various points during the procedure, the surgeon performed qualitative, visual assessments of fluorescence by using the surgical microscope, followed by a quantitative fluorescence measurement by using an intra-operative probe. Specimens were collected at each point for subsequent neuropathological analysis. Clustered data analysis of variance was used to ascertain a difference between groups, and receiver operating characteristic analyses were performed to assess diagnostic capabilities. RESULTS Red-pink fluorescence was observed in 80% (12/15) of patients, with visible fluorescence generally demonstrating a strong, homogenous character. Quantitative fluorescence measured diagnostically significant PpIX concentrations (CPpIx) in both visibly and nonvisibly fluorescent tissues, with significantly higher CPpIx in both visibly fluorescent (P < .001) and tumor tissue (P = .002). Receiver operating characteristic analyses also showed diagnostic accuracies up to 90% for differentiating tumor from normal dura. CONCLUSION ALA-induced PpIX fluorescence guidance is a potential and promising adjunct in accurately detecting neoplastic tissue during meningioma resective surgery. These results suggest a broader reach for PpIX as a biomarker for meningiomas than was previously noted in the literature. PMID:23887194

  16. Supreme Court Says Title IX Covers Employment but Raises a Serious Question about the Future Impact of the Law.

    ERIC Educational Resources Information Center

    Flygare, Thomas J.

    1982-01-01

    The Supreme Court recently decided that Title IX covers employment practices in schools and colleges; however, portions of the Court's decision (whether Title IX provides "institutionwide" or "program-specific" coverage) raise serious questions about the future of Title IX as a force for sex equity in education. (Author/MLF)

  17. 12 CFR 900.3 - Terms relating to other entities and concepts used throughout 12 CFR chapter IX.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... used throughout 12 CFR chapter IX. 900.3 Section 900.3 Banks and Banking FEDERAL HOUSING FINANCE BOARD... to other entities and concepts used throughout 12 CFR chapter IX. As used throughout this chapter, the following terms relating to other entities and concepts used throughout 12 CFR chapter IX have...

  18. 12 CFR 900.3 - Terms relating to other entities and concepts used throughout 12 CFR chapter IX.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... used throughout 12 CFR chapter IX. 900.3 Section 900.3 Banks and Banking FEDERAL HOUSING FINANCE BOARD... to other entities and concepts used throughout 12 CFR chapter IX. As used throughout this chapter, the following terms relating to other entities and concepts used throughout 12 CFR chapter IX have...

  19. 12 CFR 900.3 - Terms relating to other entities and concepts used throughout 12 CFR chapter IX.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... used throughout 12 CFR chapter IX. 900.3 Section 900.3 Banks and Banking FEDERAL HOUSING FINANCE BOARD... to other entities and concepts used throughout 12 CFR chapter IX. As used throughout this chapter, the following terms relating to other entities and concepts used throughout 12 CFR chapter IX have...

  20. 12 CFR 900.3 - Terms relating to other entities and concepts used throughout 12 CFR chapter IX.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... used throughout 12 CFR chapter IX. 900.3 Section 900.3 Banks and Banking FEDERAL HOUSING FINANCE BOARD... to other entities and concepts used throughout 12 CFR chapter IX. As used throughout this chapter, the following terms relating to other entities and concepts used throughout 12 CFR chapter IX have...