A magnificent enzyme superfamily: carbonic anhydrases, their purification and characterization

Abstract

In this paper, we reviewed the purification and characterization methods of the a-carbonic anhydrase (CA, EC 4.2.1.1) class. Six genetic families (a-, b-, g-, d-, z-and Z-CAs) all know to date, all encoding such enzymes in organisms widely distributed over the phylogenetic tree. Starting from the manuscripts published in the 1930s on the isolation and purification of a-CAs from blood and other tissues, and ending with the recent discovery of the last genetic family in protozoa, the Z-CAs, considered for long time an a-CA, we present historically the numerous and different procedures which were employed for obtaining these catalysts in pure form. a-CAs possess important application in medicine (as many human a-CA isoforms are drug targets) as well as biotechnological processes, in which the enzymes are ultimately used for CO 2 capture in order to mitigate the global warming effects due to greenhouse gases. Recently, it was discovered an involvement of CAs in cancerogenesis as well as infection caused by pathogenic agents such as bacteria, fungi and protozoa. Inhibition studies of CAs identified in the genome of the aforementioned organisms might lead to the discovery of innovative drugs with a novel mechanism of action.

Major contribution of the type II beta carbonic anhydrase CanB (Cj0237) to the capnophilic growth phenotype of Campylobacter jejuni

“…These metalloenzymes are widely distributed in all kingdoms of life and catalyse the reversible hydration of CO 2 to bicarbonate and protons (Smith and Ferry, ). They play many metabolic roles in both prokaryotes and eukaryotes, and can be divided into at least six phylogenetic groups, designated as the α‐, β‐, γ‐, δ‐, ζ‐ and η‐classes (Smith and Ferry, ; Supuran, ; Ozensoy Guler et al ., ). The α‐class CAs are widely distributed in mammals, protozoa, fungi, algae, some prokaryotes and the plant cytoplasm, whereas the β‐class can be found in bacteria, fungi, algae and plant chloroplasts.…”

“…The different CA classes have arisen by convergent evolution and are distinct in their secondary, tertiary and quaternary structures; the enzymes belonging to the α‐class are usually monomeric, β‐CA enzymes are oligomeric with 2–8 monomers, and γ‐CA enzymes are homotrimers (Smith and Ferry, ). In addition, they exhibit differences in their active sites, as both α and β classes require a single Zn 2+ ion for their catalytic activity, whereas the γ‐class may require Zn 2+ , Fe 2+ or Co 2+ , and the ζ‐class may use Cd 2+ for catalytic activity (Ozensoy Guler et al ., ). Despite these differences, all CAs exhibit a similar mechanism based on divalent metal ion‐dependent deprotonation of water, resulting in formation of a hydroxide ion.…”

A new procedure for the cloning, expression and purification of the β-carbonic anhydrase from the pathogenic yeastMalassezia globosa, an anti-dandruff drug target

“…CO 2 is the final product of the respiration in all domains of life, from microorganisms to mammals [8][9][10] ; bicarbonate (HCO À 3 ) is a substrate for several carboxylating enzymes involved in biosynthetic pathways such as biosynthesis of fatty acids, amino acids and nucleotides [11][12][13][14] . The interconversion of CO 2 and HCO À 3 is spontaneously balanced to maintain the equilibrium between dissolved inorganic CO 2 , carbonic acid (H 2 CO 3 ), bicarbonate (HCO À 3 ) and carbonate (CO 2À 3 ).…”

“…The interconversion of CO 2 and HCO À 3 is spontaneously balanced to maintain the equilibrium between dissolved inorganic CO 2 , carbonic acid (H 2 CO 3 ), bicarbonate (HCO À 3 ) and carbonate (CO 2À 3 ). Almost, all life on earth depend on the production of sugars from sunlight and CO 2 (photosynthesis) and the metabolic breakdown (respiration) of those sugars to produce the energy needed for movement, growth and reproduction 8,9,14,15 . The uncatalyzed hydration-dehydration reaction CO 2 + H 2 O !…”

Comparison of the inhibitory potential towards carbonic anhydrase, acetylcholinesterase and butyrylcholinesterase of chalcone and chalcone epoxide

“…Carbonic anhydrases (CAs) are metalloenzymes found in all kingdoms of life and are essential components in numerous physiological and pathologic processes, including biosynthetic processes, photosynthesis, ion transport, electrolyte secretion in tissues and organs, respiration, acid‐base regulation, CO 2 homeostasis, bone resorption, calcification, tumorigenesis, and CO 2 fixation . Seven classes of CAs are known: alpha (α), beta (β), gamma (γ), delta (δ), zeta (ζ), eta (η), and theta (θ) CAs . The α‐CA family is found primarily in humans and is comprised of 16 isozymes.…”