Carbonic anhydrase isozymes

Topiramate inhibits carbonic anhydrase isozymes II and IV, which are present in the central nervous system. Respiratory alkalosis in a 15-year-old girl, who presented with hyperpnea, was not therefore surprising (16). The problem resolved within 24 hours of withdrawal. 

Carbonic Anhydrase Isozyme II Origin bovine erythrocytes Fluka... 

K. K. Kannan, M. Ramanadham and T. A. Jones, Structure, refinement, and function of carbonic anhydrase isozymes refinement of human carbonic anhydrase I, Ann. N.Y Acad. Sci, 1984, 429, 49-60 (pdb 2cab). 

N.m.r. has been used to study the active site of other zinc-containing enzymes. In bovine carbonic anhydrase there is a single zinc co-ordination site available for Cl interaction, and the latter can be inhibited by CN and acetazolamide. C1 Resonance has also been used to investigate the environmental diflFerences of the zinc in carbonic anhydrase isozymes and the activation of pyruvate kinase with zinc, and to determine the pJ values in cobalt(u)-carbonic anhydrase. It is suggested that, although the TpK of aquozinc is about 9, the environment of the zinc ion in carbonic anhydrase B greatly increases the tendency of a zinc-bound water molecule... 

Figure 10.11. The structures of the polymerizable lipids used in the liposomes for detection of carbonic anhydrase isozymes.

Human CAII (carbonic anhydrase isozyme II) ZnNsO 9.8 1 CP/QCPMG [53]... 

The same group further investigated human carbonic anhydrase isozyme II (hCAII), which is a 30 kDa protein [53]. The Zn ion is tetrahedraUy bound to the imidazole side chains of three histidines. The fourth Hgand can be either water or hydroxide. It was believed at the time that the nature of the fourth ligand would depend on pH value. If the argument were accepted, the Zn spectra of hCAII at pH 5 and 8.5 would look drastically different since the theoretical calculations of the EFG tensor based on the... 

It is generally accepted that a zinc(II) ion ligated to three imidazoles of histidines and a water molecule are essential for catalytic activity. An ionization with a pK of approximately 7.0 controls the activity of BCA. The basic form of the enzyme is active towards CO2 hydration, but the acidic form is active towards HCO3 dehydration. This ionization has been attributed by some authors to an equilibrium between a zinc-aquo and a zinc-hydroxo form of BCA. Others have assigned the activity linked ionization to a non-ligated active site histidine conserved in all carbonic anhydrase isozymes for which structures have been determined. 

Bayram, E. Senturk, M. Kufrevioglu, O.I. Supuran, CT. (2008). In vitro inhibition of salicylic acid derivatives on human cytosolic carbonic anhydrase isozymes I and II. Bioorganic and Medicinal Chemistry, 16,9101-9105. 

Ozensoy, O. Arslan, O. Sinan, O.S. (2004). A new method for the purification of carbonic anhydrase isozymes by affinity chromatography. Biochemistry (Moscow), 69, 216-219. 

Supuran, C.T. Scozzafava, A. (2000a). Activation of carbonic anhydrase isozymes. In The Carbonic Anhydrases - New Horizons Chegwidden, W.R. Carter, N. Edwards, Y. Eds. Birkhauser Verlag Basel, Switzerland, pp 197-219. 

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