Yazar "Canakci, Sabriye" seçeneğine göre listele

Listeleniyor 1 - 2 / 2
  • Küçük Resim Yok
    Öğe
    Cloning, expression and biochemical characterization of a beta-carbonic anhydrase from the soil bacterium Enterobacter sp B13
    (TAYLOR & FRANCIS LTD, 2016) Eminoglu, Aysenur; Vullo, Daniela; Asik, Aycan; Colak, Dilsat Nigar; Supuran, Claudiu T.; Canakci, Sabriye; Belduz, Ali Osman
    A recombinant carbonic anhydrase (CA, EC 4.2.1.1) from the soil-dwelling bacterium Enterobacter sp. B13 was cloned and purified by Co2+ affinity chromatography. Bioinformatic analysis showed that the new enzyme (denominated here B13-CA) belongs to the beta-class CAs and to possess 95% homology with the ortholog enzyme from Escherichia coli encoded by the can gene, whereas its sequence homology with the other such enzyme from E. coli (encoded by the cynT gene) was of 33%. B13-CA was characterized kinetically as a catalyst for carbon dioxide hydration to bicarbonate and protons. The enzyme shows a significant catalytic activity, with the following kinetic parameters at 20 degrees C and pH of 8.3: k(cat) of 4.8 x 10(5) s(-1) and k(cat)/K-m of 5.6 x 10(7) M-1 x s(-1). This activity was potently inhibited by acetazolamide which showed a K-l of 78.9 nM. Although only this compound was investigated for the moment as B13-CA inhibitor, further studies may reveal new classes of inhibitors/activators of this enzyme which may show biomedical or environmental applications, considering the posssible role of this enzyme in CaCO3 biomineralization processes.
  • Küçük Resim Yok
    Öğe
    Sulfonamide inhibition studies of the beta-carbonic anhydrase from the newly discovered bacterium Enterobacter sp B13
    (PERGAMON-ELSEVIER SCIENCE LTD, 2016) Eminoglu, Aysenur; Vullo, Daniela; Asik, Aycan; Colak, Dilsat Nigar; Canakci, Sabriye; Belduz, Ali Osman; Supuran, Claudiu T.
    The genome of the newly identified bacterium Enterobacter sp. B13 encodes for a beta-class carbonic anhydrases (CAs, EC 4.2.1.1), EspCA. This enzyme was recently cloned, and characterized kinetically by this group (J. Enzyme Inhib. Med. Chem. 2016, 31). Here we report an inhibition study with sulfonamides and sulfamates of this enzyme. The best EspCA inhibitors were some sulfanylated sulfonamides with elongated molecules, metanilamide, 4-aminoalkyl-benzenesulfonamides, acetazolamide, and deacetylated methazolamide (K(I)s in the range of 58.7-96.5 nM). Clinically used agents such as methazolamide, ethoxzolamide, dorzolamide, brinzolamide, benzolamide, zonisamide, sulthiame, sulpiride, topiramate and valdecoxib were slightly less effective inhibitors (K(I)s in the range of 103-138 nM). Saccharin, celecoxib, dichlorophenamide and many simple benzenesulfonamides were even less effective as EspCA inhibitors, with K(I)s in the range of 384-938 nM. Identification of effective inhibitors of this bacterial enzyme may lead to pharmacological tools useful for understanding the physiological role(s) of the beta-class CAs in bacterial pathogenicity/virulence. (C) 2016 Elsevier Ltd. All rights reserved.