LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 5 of total 5

Search options

  1. Article ; Online: Combining Active Carbonic Anhydrase with Nanogels: Enzyme Protection and Zinc Sensing.

    Si, Di / Nie, Guochao / Hurst, Tamiika K / Fierke, Carol A / Kopelman, Raoul

    International journal of nanomedicine

    2021  Volume 16, Page(s) 6645–6660

    Abstract: Background: Due to its excellent biocompatibility, the polyacrylamide (PAAm) hydrogel has shown great potential for the immobilization of enzymes used in biomedical applications. The major challenge involved is to preserve, during the immobilization ... ...

    Abstract Background: Due to its excellent biocompatibility, the polyacrylamide (PAAm) hydrogel has shown great potential for the immobilization of enzymes used in biomedical applications. The major challenge involved is to preserve, during the immobilization process, both the biological activity and the structural integrity of the enzymes. Here we report, for the first time, a proof-of-concept study for embedding active carbonic anhydrase (CA) into polyacrylamide (PAAm) nanogels. By immobilizing CA in these nanogels, we hope to provide important advantages, such as matrix protection of the CA as well as its targeted delivery, and also for potentially using these nanogels as zinc nano-biosensors, both in-vitro and in-vivo.
    Methods and results: Two methods are reported here for CA immobilization: encapsulation and surface conjugation. In the encapsulation method, the common process was improved, so as to best preserve the CA, by 1) using a novel biofriendly nonionic surfactant system (Span 80/Tween 80/Brij 30) and 2) using an Al
    Conclusion: This work demonstrates universal methods for immobilizing highly fragile bio-macromolecules inside nanoparticle carriers, while preserving their structural integrity and biological activity. The advantages and limitations are discussed, as well as the potential biomedical applications.
    MeSH term(s) Carbonic Anhydrases ; Enzymes, Immobilized ; Nanogels ; Nanoparticles ; Zinc
    Chemical Substances Enzymes, Immobilized ; Nanogels ; Carbonic Anhydrases (EC 4.2.1.1) ; Zinc (J41CSQ7QDS)
    Language English
    Publishing date 2021-09-27
    Publishing country New Zealand
    Document type Journal Article
    ZDB-ID 2364941-0
    ISSN 1178-2013 ; 1176-9114
    ISSN (online) 1178-2013
    ISSN 1176-9114
    DOI 10.2147/IJN.S321099
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    In stock of ZB MED Cologne/Königswinter

    Zs.A 6606: Show issues Location:
    Je nach Verfügbarkeit (siehe Angabe bei Bestand)
    bis Jg. 2021: Bestellungen von Artikeln über das Online-Bestellformular
    ab Jg. 2022: Lesesaal (EG)

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  2. Article ; Online: Genetically encoded ratiometric biosensors to measure intracellular exchangeable zinc in Escherichia coli.

    Wang, Da / Hurst, Tamiika K / Thompson, Richard B / Fierke, Carol A

    Journal of biomedical optics

    2011  Volume 16, Issue 8, Page(s) 87011

    Abstract: Zinc is an essential element for numerous cellular processes, therefore zinc homeostasis is regulated in living organisms. Fluorescent sensors have been developed as important tools to monitor the concentrations of readily exchangeable zinc in live cells. ...

    Abstract Zinc is an essential element for numerous cellular processes, therefore zinc homeostasis is regulated in living organisms. Fluorescent sensors have been developed as important tools to monitor the concentrations of readily exchangeable zinc in live cells. One type of biosensor uses carbonic anhydrase (CA) as the recognition element based on its tunable affinity, superior metal selectivity, and fluorescence signal from aryl sulfonamide ligands coupled to zinc binding. Here, we fuse carbonic anhydrase with a red fluorescent protein to create a series of genetically-encoded Förster resonance energy transfer-based excitation ratiometric zinc sensors that exhibit large signal increases in response to alterations in physiological-free zinc concentrations. These sensors were applied to the prokaryotic model organism Escherichia coli to quantify the readily exchangeable zinc concentration. In minimal media, E. coli BL21(DE3) cells expressing the CA sensor, exhibit a median intracellular readily exchangeable zinc concentration of 20 pM, much less than the total cellular zinc concentration of ∼0.2 mM. Furthermore, the intracellular readily exchangeable zinc concentration varies with the concentration of environmental zinc.
    MeSH term(s) Biosensing Techniques/instrumentation ; Biosensing Techniques/methods ; Carbonic Anhydrases/genetics ; Carbonic Anhydrases/metabolism ; Escherichia coli/chemistry ; Escherichia coli/genetics ; Escherichia coli/metabolism ; Fluorescence Resonance Energy Transfer/methods ; Luminescent Proteins/chemistry ; Luminescent Proteins/genetics ; Luminescent Proteins/metabolism ; Models, Biological ; Molecular Biology/methods ; Zinc/analysis ; Zinc/metabolism ; Red Fluorescent Protein
    Chemical Substances Luminescent Proteins ; Carbonic Anhydrases (EC 4.2.1.1) ; Zinc (J41CSQ7QDS)
    Language English
    Publishing date 2011-09-04
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 1309154-2
    ISSN 1560-2281 ; 1083-3668
    ISSN (online) 1560-2281
    ISSN 1083-3668
    DOI 10.1117/1.3613926
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    In stock of ZB MED Cologne/Königswinter

    Zs.A 4699: Show issues Location:
    Je nach Verfügbarkeit (siehe Angabe bei Bestand)
    bis Jg. 1994: Bestellungen von Artikeln über das Online-Bestellformular
    Jg. 1995 - 2021: Lesesall (2.OG)
    ab Jg. 2022: Lesesaal (EG)

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  3. Article: Carbonic anhydrase II-based metal ion sensing: Advances and new perspectives.

    Hurst, Tamiika K / Wang, Da / Thompson, Richard B / Fierke, Carol A

    Biochimica et biophysica acta

    2009  Volume 1804, Issue 2, Page(s) 393–403

    Abstract: Carbonic anhydrases are archetypical zinc metalloenzymes and as such, they have been developed as the recognition element of a family of fluorescent indicators (sensors) to detect metal ions, particularly Zn(2+) and Cu(2+). Subtle modification of the ... ...

    Abstract Carbonic anhydrases are archetypical zinc metalloenzymes and as such, they have been developed as the recognition element of a family of fluorescent indicators (sensors) to detect metal ions, particularly Zn(2+) and Cu(2+). Subtle modification of the structure of human carbonic anhydrase II isozyme (CAII) alters the selectivity, sensitivity, and response time for these sensors. Sensors using CAII variants coupled with zinc-dependent fluorescent ligands demonstrate picomolar sensitivity, unmatched selectivity, ratiometric fluorescence signal, and near diffusion-controlled response times. Recently, these sensors have been applied to measuring the readily exchangeable concentrations of zinc in the cytosol and nucleus of mammalian tissue culture cells and concentrations of free Cu(2+) in seawater.
    MeSH term(s) Carbonic Anhydrase II/chemistry ; Carbonic Anhydrase II/metabolism ; Humans ; Zinc/chemistry ; Zinc/metabolism
    Chemical Substances Carbonic Anhydrase II (EC 4.2.1.-) ; Zinc (J41CSQ7QDS)
    Language English
    Publishing date 2009-10-08
    Publishing country Netherlands
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Review
    ZDB-ID 60-7
    ISSN 1879-2596 ; 1879-260X ; 1872-8006 ; 1879-2642 ; 1879-2618 ; 1879-2650 ; 0006-3002 ; 0005-2728 ; 0005-2736 ; 0304-4165 ; 0167-4838 ; 1388-1981 ; 0167-4889 ; 0167-4781 ; 0304-419X ; 1570-9639 ; 0925-4439 ; 1874-9399
    ISSN (online) 1879-2596 ; 1879-260X ; 1872-8006 ; 1879-2642 ; 1879-2618 ; 1879-2650
    ISSN 0006-3002 ; 0005-2728 ; 0005-2736 ; 0304-4165 ; 0167-4838 ; 1388-1981 ; 0167-4889 ; 0167-4781 ; 0304-419X ; 1570-9639 ; 0925-4439 ; 1874-9399
    DOI 10.1016/j.bbapap.2009.09.031
    Database MEDical Literature Analysis and Retrieval System OnLINE

    Full text online

    More links

    Kategorien

    In stock of ZB MED Cologne/Königswinter

    Uc I Zs.247: Show issues Location:
    Je nach Verfügbarkeit (siehe Angabe bei Bestand)
    bis Jg. 2021: Bestellungen von Artikeln über das Online-Bestellformular
    ab Jg. 2022: Lesesaal (EG)

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  4. Article ; Online: Determination of zinc using carbonic anhydrase-based fluorescence biosensors.

    Bozym, Rebecca / Hurst, Tamiika K / Westerberg, Nissa / Stoddard, Andrea / Fierke, Carol A / Frederickson, Christopher J / Thompson, Richard B

    Methods in enzymology

    2009  Volume 450, Page(s) 287–309

    Abstract: This chapter summarizes the use of carbonic anhydrase (CA)-based fluorescent indicators to determine free zinc in solution, in cells, and in subcellular organelles. Expression (both in situ and in vitro) and preparation of CA-based indicators are ... ...

    Abstract This chapter summarizes the use of carbonic anhydrase (CA)-based fluorescent indicators to determine free zinc in solution, in cells, and in subcellular organelles. Expression (both in situ and in vitro) and preparation of CA-based indicators are described, together with techniques of their use, and procedures to minimize contamination. Recipes for zinc buffers are supplied.
    MeSH term(s) Biosensing Techniques ; Carbonic Anhydrases/chemistry ; Spectrometry, Fluorescence/methods ; Zinc/analysis
    Chemical Substances Carbonic Anhydrases (EC 4.2.1.1) ; Zinc (J41CSQ7QDS)
    Language English
    Publishing date 2009-01-06
    Publishing country United States
    Document type Journal Article
    ISSN 1557-7988
    ISSN (online) 1557-7988
    DOI 10.1016/S0076-6879(08)03414-9
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  5. Article: DsRed as a highly sensitive, selective, and reversible fluorescence-based biosensor for both Cu(+) and Cu(2+) ions.

    Sumner, James P / Westerberg, Nissa M / Stoddard, Andrea K / Hurst, Tamiika K / Cramer, Michele / Thompson, Richard B / Fierke, Carol A / Kopelman, Raoul

    Biosensors & bioelectronics

    2005  Volume 21, Issue 7, Page(s) 1302–1308

    Abstract: The wild type form of Red fluorescent protein (DsRed), an intrinsically fluorescent protein found in tropical corals, is found to be highly selective, reversible and sensitive for both Cu(+) and Cu(2+), with a nanomolar detection limit. The selectivity ... ...

    Abstract The wild type form of Red fluorescent protein (DsRed), an intrinsically fluorescent protein found in tropical corals, is found to be highly selective, reversible and sensitive for both Cu(+) and Cu(2+), with a nanomolar detection limit. The selectivity towards these ions is retained even in the presence of other heavy metal ions. The K(d) values for monovalent and divalent copper, based on single binding isotherms, are 450 and 540 nM, respectively. The wild type DsRed sensitivity to Cu(2+) (below 1 ppb) is seven orders of magnitude better than that of the related wild type Green Fluorescent protein (GFP), and it is even 40 times more sensitive than engineered mutants of GFP. Potential binding sites have been proposed, based on amino acid sequences for copper binding and the distance from the chromophore, with the aid of computer modeling.
    MeSH term(s) Biosensing Techniques/instrumentation ; Biosensing Techniques/methods ; Copper/analysis ; Copper/chemistry ; Ions ; Luminescent Proteins/analysis ; Luminescent Proteins/chemistry ; Spectrometry, Fluorescence/instrumentation ; Spectrometry, Fluorescence/methods
    Chemical Substances Ions ; Luminescent Proteins ; fluorescent protein 583 ; Copper (789U1901C5)
    Language English
    Publishing date 2005-07-18
    Publishing country England
    Document type Evaluation Study ; Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't ; Research Support, U.S. Gov't, Non-P.H.S.
    ZDB-ID 1011023-9
    ISSN 1873-4235 ; 0956-5663
    ISSN (online) 1873-4235
    ISSN 0956-5663
    DOI 10.1016/j.bios.2005.04.023
    Database MEDical Literature Analysis and Retrieval System OnLINE

    Full text online

    More links

    Kategorien

    In stock of ZB MED Cologne/Königswinter

    Zs.A 2275: Show issues Location:
    Je nach Verfügbarkeit (siehe Angabe bei Bestand)
    bis Jg. 1994: Bestellungen von Artikeln über das Online-Bestellformular
    Jg. 1995 - 2021: Lesesall (2.OG)
    ab Jg. 2022: Lesesaal (EG)

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

To top