Characterization and Anions Inhibition Studies of an α-carbonic Anhydrase From the Teleost Fish Dicentrarchus Labrax

Bioorg Med Chem. 2011 Jan 15;19(2):744-8. doi: 10.1016/j.bmc.2010.12.033. Epub 2010 Dec 16.

Abstract

Carbonic anhydrase (CA; EC 4.2.1.1) was purified from the gill of the teleost fish Dicentrarchus labrax (European seabass). The purification procedure consisted of a single step affinity chromatography on Sepharose 4B-tyrosine-sulfanilamide. The enzyme was purified 84.9-fold with a yield of 58%, and a specific activity of 838.9 U/mg proteins. It has an optimum pH at 8.0; an optimum temperature at 10°C. The kinetic parameters of this enzyme were determined for its esterase activity, with 4-nitrophenyl acetate (NPA) as substrate. The following anions, H₂NSO₃⁻, I⁻, SCN⁻, NO₃⁻, NO₂⁻, N₃⁻, Br⁻, Cl⁻, SO₄²⁻, and F⁻ showed inhibitory effects on the enzyme. Sulfamic acid, iodide, and thiocyanate exhibited the strongest inhibitory action, in the micromolar range (K(i)s of 87-187 μM). NO₃⁻, NO₂⁻ and N₃⁻ were moderate inhibitors, whereas other anions showed only weak actions. All tested anions inhibited the enzyme in a competitive manner. Our findings indicate that these anions inhibit the fish enzyme in a similar manner to other α-CAs from mammals investigated earlier, but the susceptibility to various anions differs significantly between the fish and mammalian CAs.

MeSH terms

  • Animals
  • Anions / chemistry*
  • Anions / pharmacology
  • Bass / metabolism*
  • Carbonic Anhydrase Inhibitors / chemical synthesis
  • Carbonic Anhydrase Inhibitors / chemistry*
  • Carbonic Anhydrase Inhibitors / pharmacology
  • Carbonic Anhydrases / chemistry*
  • Carbonic Anhydrases / metabolism
  • Kinetics
  • Sulfonic Acids / chemistry
  • Sulfonic Acids / pharmacology
  • Thiocyanates / chemistry
  • Thiocyanates / pharmacology

Substances

  • Anions
  • Carbonic Anhydrase Inhibitors
  • Sulfonic Acids
  • Thiocyanates
  • sulfamic acid
  • Carbonic Anhydrases
  • thiocyanate