scholarly journals Characterization of Carbonic Anhydrase 9 in the Alimentary Canal of Aedes aegypti and Its Relationship to Homologous Mosquito Carbonic Anhydrases

Author(s):  
Daniel Dixon ◽  
Leslie Van Ekeris ◽  
Paul Linser
2002 ◽  
Vol 205 (5) ◽  
pp. 591-602 ◽  
Author(s):  
Maria del Pilar Corena ◽  
Theresa J. Seron ◽  
Herm K. Lehman ◽  
Judith D. Ochrietor ◽  
Andrea Kohn ◽  
...  

SUMMARYThe larval mosquito midgut exhibits one of the highest pH values known in a biological system. While the pH inside the posterior midgut and gastric caeca ranges between 7.0 and 8.0, the pH inside the anterior midgut is close to 11.0. Alkalization is likely to involve bicarbonate/carbonate ions. These ions are produced in vivo by the enzymatic action of carbonic anhydrase. The purpose of this study was to investigate the role of this enzyme in the alkalization mechanism, to establish its presence and localization in the midgut of larval Aedes aegypti and to clone and characterize its cDNA. Here, we report the physiological demonstration of the involvement of carbonic anhydrase in midgut alkalization. Histochemistry and in situ hybridization showed that the enzyme appears to be localized throughout the midgut, although preferentially in the gastric caeca and posterior regions with specific cellular heterogeneity. Furthermore, we report the cloning and localization of the first carbonic anhydrase from mosquito larval midgut. A cDNA clone from Aedes aegypti larval midgut revealed sequence homology to α-carbonic anhydrases from vertebrates. Bioinformatics indicates the presence of at least six carbonic anhydrases or closely related genes in the genome of another dipteran, the fruit fly Drosophila melanogaster. Molecular analyses suggest that the larval mosquito may also possess multiple forms.


2006 ◽  
Vol 72 (8) ◽  
pp. 5500-5511 ◽  
Author(s):  
Amelia R. Soto ◽  
Hong Zheng ◽  
Dorinda Shoemaker ◽  
Jason Rodriguez ◽  
Betsy A. Read ◽  
...  

ABSTRACT Marine coccolithophorid algae are thought to play a significant role in carbon cycling due to their ability to incorporate dissolved inorganic carbon (DIC) into both calcite and photosynthetic products. Among coccolithophorids, Emiliania huxleyi is the most prolific, forming massive blooms that affect the global environment. In addition to its ecological importance, the elaborate calcite structures (coccoliths) are being investigated for the design of potential materials for science and biotechnological devices. To date, most of the research focus in this organism has involved the partitioning of DIC between calcification and photosynthesis, primarily using measurements of an external versus internal carbonic anhydrase (CA) activity under defined conditions. The actual genes, proteins, and pathways employed in these processes have not been identified and characterized (see the work of Quinn et al. in this issue [P. Quinn, R. M. Bowers, X. Zhang, T. M. Wahlund, M. A. Fanelli, D. Olszova, and B. A. Read, Appl. Environ. Microbiol. 72:5512-5526, 2006]). In this study, the cloning and preliminary characterization of two genetically distinct carbonic anhydrase cDNAs are described. Phylogenetic analysis indicated that these two genes belonged to the gamma (γ-EhCA2) and delta (δ-EhCA1) classes of carbonic anhydrases. The deduced amino acid sequence of δ-EhCA1 revealed that it encodes a protein of 702 amino acids (aa) (ca. 77.3 kDa), with a transmembrane N-terminal region of 373 aa and an in-frame C-terminal open reading frame of 329 aa that defines the CA region. The γ-EhCA2 protein was 235 aa in length (ca. 24.9 kDa) and was successfully expressed in Escherichia coli BL21(DE3) and purified as an active recombinant CA. The expression levels of each transcript from quantitative reverse transcription-PCR experiments under bicarbonate limitation and over a 24-h time course suggest that these isozymes perform different functions in E. huxleyi.


2020 ◽  
Vol 21 (7) ◽  
pp. 2442
Author(s):  
Jyoti Singh Tomar ◽  
Jun Shen

Carbonic anhydrase is a ubiquitous metalloenzyme that catalyzes the reversible interconversion of CO2/HCO3−. Equilibrium of these species is maintained by the action of carbonic anhydrase. Recent advances in magnetic resonance spectroscopy have allowed, for the first time, in vivo characterization of carbonic anhydrase in the human brain. In this article, we review the theories and techniques of in vivo 13C magnetization (saturation) transfer magnetic resonance spectroscopy as they are applied to measuring the rate of exchange between CO2 and HCO3− catalyzed by carbonic anhydrase. Inhibitors of carbonic anhydrase have a wide range of therapeutic applications. Role of carbonic anhydrases and their inhibitors in many diseases are also reviewed to illustrate future applications of in vivo carbonic anhydrase assessment by magnetic resonance spectroscopy.


2006 ◽  
Vol 1764 (8) ◽  
pp. 1413-1419 ◽  
Author(s):  
S. Zoë Fisher ◽  
Iyerus Tariku ◽  
Nicolette M. Case ◽  
Chingkuang Tu ◽  
Teri Seron ◽  
...  

Skull Base ◽  
2007 ◽  
Vol 17 (S 2) ◽  
Author(s):  
Heon Yoo ◽  
Gilson Baia ◽  
Justin Smith ◽  
Michael McDermott ◽  
Andrew Bollen ◽  
...  

2019 ◽  
Vol 25 (39) ◽  
pp. 5266-5278 ◽  
Author(s):  
Katia D'Ambrosio ◽  
Claudiu T. Supuran ◽  
Giuseppina De Simone

Protozoans belonging to Plasmodium, Leishmania and Trypanosoma genera provoke widespread parasitic diseases with few treatment options and many of the clinically used drugs experiencing an extensive drug resistance phenomenon. In the last several years, the metalloenzyme Carbonic Anhydrase (CA, EC 4.2.1.1) was cloned and characterized in the genome of these protozoa, with the aim to search for a new drug target for fighting malaria, leishmaniasis and Chagas disease. P. falciparum encodes for a CA (PfCA) belonging to a novel genetic family, the η-CA class, L. donovani chagasi for a β-CA (LdcCA), whereas T. cruzi genome contains an α-CA (TcCA). These three enzymes were characterized in detail and a number of in vitro potent and selective inhibitors belonging to the sulfonamide, thiol, dithiocarbamate and hydroxamate classes were discovered. Some of these inhibitors were also effective in cell cultures and animal models of protozoan infections, making them of considerable interest for the development of new antiprotozoan drugs with a novel mechanism of action.


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