Anion inhibition studies of an α-carbonic anhydrase from the living fossil Astrosclera willeyana

Bioorg Med Chem Lett. 2012 Feb 1;22(3):1314-6. doi: 10.1016/j.bmcl.2011.12.085. Epub 2011 Dec 23.


An α-carbonic anhydrase (CA, EC isolated from the living fossil sponge Astrosclera willeyana, Astrosclerin, was investigated for its inhibition profile with simple inorganic anions, complex anions and other small molecules known to interact with these zinc enzymes. Astrosclerin is a catalytically highly efficient enzyme, and is inhibited in the low micromolar range by sulfamide, sulfamic acid, phenylboronic acid and phenylarsonic acid, and in the submillimolar range by a variety of anions including fluoride, chloride, cyanate, thiocyanate, cyanide, hydrogen sulfide, bisulfate, stannate, perosmate, divanadate, perrhenate, perruthenate, selenocyanide, trithiocarbonate, diethyldithiocarbamate and iminodisulfonate. Less efficient Astrosclerin inhibitors were sulfate, bromide, iodide, azide, bicarbonate, carbonate, tetraborate and perchlorate (K(I)s of 5.11-30.6mM) whereas tetrafluoroborate was not at all inhibitory. Because Astrosclerin is involved in calcification processes in vivo, its anion inhibition profile may be important for future studies designed to shed light on the physiologic functions of α-CAs in marine organisms.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anions / antagonists & inhibitors*
  • Carbonic Anhydrase Inhibitors / chemistry
  • Carbonic Anhydrase Inhibitors / pharmacology
  • Carbonic Anhydrases / chemistry
  • Carbonic Anhydrases / genetics
  • Carbonic Anhydrases / metabolism*
  • Enzyme Activation / drug effects
  • Humans
  • Porifera / chemistry
  • Porifera / enzymology*
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism


  • Anions
  • Carbonic Anhydrase Inhibitors
  • Recombinant Proteins
  • Carbonic Anhydrases