CO2 Hydration Reaction Research Articles

Carbonic Anhydrases: New Perspectives on Protein Functional Role and Inhibition in Helicobacter pylori.

Our understanding of the function of bacterial carbonic anhydrases (CAs, EC 4.2.1.1) has increased significantly in the last years. CAs are metalloenzymes able to modulate CO2, HCO3– and H+ concentration through their crucial role in catalysis of reversible CO2 hydration (CO2 + H2O ⇄ HCO3– + H+). In all living organisms, CA activity is linked to physiological processes, such as those related to the transport and supply of CO2 or HCO3–, pH homeostasis, secretion of electrolytes, biosynthetic processes and photosynthesis. These important processes cannot be ensured by the very low rate of the non-catalyzed reaction of CO2 hydration. It has been recently shown that CAs are important biomolecules for many bacteria involved in human infections, such as Vibrio cholerae, Brucella suis, Salmonella enterica, Pseudomonas aeruginosa, and Helicobacter pylori. In these species, CA activity promotes microorganism growth and adaptation in the host, or modulates bacterial toxin production and virulence. In this review, recent literature in this research field and some of the above-mentioned issues are discussed, namely: (i) the implication of CAs from bacterial pathogens in determining the microorganism growth and virulence; (ii) the druggability of these enzymes using classical CA inhibitors (CAIs) of the sulfonamide-type as examples; (iii) the role played by Helicobacter pylori CAs in the acid tolerance/adaptation of the microbe within the human abdomen; (iv) the role of CAs played in the outer membrane vesicles spawned by H. pylori in its planktonic and biofilm phenotypes; (v) the possibility of using H. pylori CAIs in combination with probiotic strains as a novel anti-ulcer treatment approach. The latter approach may represent an innovative and successful strategy to fight gastric infections in the era of increasing resistance of pathogenic bacteria to classical antibiotics.

Tracking oxygen atoms in electrochemical CO oxidation – Part I: Oxygen exchange via [formula omitted] hydration

We report a new method to measure the kinetic rate constant of CO2 hydration using electrochemical oxidation of carbon monoxide (CO oxidation) in isotope-labeled electrolyte. CO oxidation is often used as a model reaction to investigate the surface of metallic electrocatalysts, most notably in CO stripping experiments. Using chip-based electrochemistry mass spectrometry with 18O-labeled electrolyte we show that: 1) For CO stripping experiments on Pt, one oxygen in the product CO2 comes from the reactant CO and the other comes from the electrolyte, consistent with the Langmuir-Hinshelwood mechanism involving the adsorbates *CO and *OH. 2) Some of the formed CO2 subsequently exchanges oxygen with the electrolyte via short-lived carbonic acid. We use the time-dependent isotopic ratios to calculate the kinetic reaction rate constant of the CO2 hydration reaction and compare it to literature. By doing this at two different temperatures we show that the method is robust and that 18O-labeled CO stripping experiments provide an accurate measurement of the rate constant for CO2 hydration. Chip-based electrochemistry mass spectrometry combined with isotopic labeling is thus shown to be a versatile and powerful tool for elucidating mechanistic aspects of homogeneous reactions as well as electrocatalytic reactions.

Effect of amino acids and amines on the activity of the recombinant ι-carbonic anhydrase from the Gram-negative bacterium Burkholderia territorii

We here report a study on the activation of the ι-class bacterial CA from Burkholderia territorii (BteCAι). This protein was recently characterised as a zinc-dependent enzyme that shows a significant catalytic activity (k cat 3.0 × 105 s−1) for the physiological reaction of CO2 hydration to bicarbonate and protons. Some amino acids and amines, among which some proteinogenic derivatives as well as histamine, dopamine and serotonin, showed efficient activating properties towards BteCAι, with activation constants in the range 3.9–13.3 µM. L-Phe, L-Asn, L-Glu, and some pyridyl-alkylamines, showed a weaker activating effect towards BteCAι, with KA values ranging between 18.4 µM and 45.6 µM. Nowadays, no information is available on active site architecture, metal ion coordination and catalytic mechanism of members of the ι-group of CAs, and this study represents another contribution towards a better understanding of this still uncharacterised class of enzymes.

Overexpression and Purification of Gracilariopsis chorda Carbonic Anhydrase (GcCAα3) in Nicotiana benthamiana, and Its Immobilization and Use in CO2 Hydration Reactions.

Carbonic anhydrase (CA; EC 4.2.2.1) is a Zn-binding metalloenzyme that catalyzes the reversible hydration of CO2. Recently, CAs have gained a great deal of attention as biocatalysts for capturing CO2 from industrial flue gases owing to their extremely fast reaction rates and simple reaction mechanism. However, their general application for this purpose requires improvements to stability at high temperature and under in vitro conditions, and reductions in production and scale-up costs. In the present study, we developed a strategy for producing GcCAα3, a CA isoform from the red alga Gracilariopsis chorda, in Nicotiana benthamiana. To achieve high-level expression and facile purification of GcCAα3, we designed various constructs by incorporating various domains such as translation-enhancing M domain, SUMO domain and cellulose-binding domain CBM3. Of these constructs, MC-GcCAα3 that had the M and CBM3 domains was expressed at high levels in N. benthamiana via agroinfiltration with a yield of 1.0 g/kg fresh weight. The recombinant protein was targeted to the endoplasmic reticulum (ER) for high-level accumulation in plants. Specific and tight CBM3-mediated binding of recombinant GcCAα3 proteins to microcrystalline cellulose beads served as a means for both protein purification from total plant extracts and protein immobilization to a solid surface for increased stability, facilitating multiple rounds of use in CO2 hydration reactions.

Equilibrium and kinetic isotopic fractionation in the CO2 hydration and hydroxylation reactions: Analysis of the role of hydrogen-bonding via quantum mechanical calculations

The formation of H2CO3 and HCO3− from CO2 is common in aqueous environmental systems and occurs via the CO2 hydration and hydroxylation reactions. The reactions are especially important in the context of CaCO3 mineral precipitation. The reactions carry with them equilibrium and kinetic isotope fractionations that impact paleoclimate proxy records. Herein, quantum mechanical calculations of dissolved inorganic carbon species embedded in H2O clusters are analyzed under a transition state theory framework to predict kinetic isotope fractionations associated with the reactions. Experimental measurements of reaction energetics and equilibrium isotope fractionations are well-reproduced by the models which suggests the computational methods are justified.The CO2 hydration reaction discriminates against 13C by 19–23‰ and against 18O by 14–15‰ at 25 °C. The CO2 hydroxylation reaction discriminates against 13C by 26–31‰ and against 18O by 27–30‰ at 25 °C. Our analyses of the model isotopic fractionations lead to the conclusion that hydrogen-bonds and C(CO2)-O(H2O or OH−) distances influence the calculated values. We infer that when the model H-bond patterns more realistically represent the aqueous species, the accuracy and precision of equilibrium fractionation factor prediction is improved.Implications for coral carbonate paleothermometry are discussed. Results indicate that hydration and hydroxylation δ13C-δ18O slopes bound the values of slopes form corals and abiotic precipitation experiments, albeit with key uncertainties related to precipitation fractionations. The process of regressing molecular model fractionation results against H-bond patterns as presented here is a promising way to improve isotope fractionation calculations in aqueous systems.

High-level production in a plant system of a thermostable carbonic anhydrase and its immobilization on microcrystalline cellulose beads for CO2 capture

Plant-produced SazCA and its application to CO2 capture. Technologies that rely on chemical absorption or physical adsorption have been developed to capture CO2 from industrial flue gases and sequester it at storage sites. Carbonic anhydrases (CAs), metalloenzymes, that catalyze the reversible hydration of CO2 have recently received attention as biocatalysts in the capture of CO2 from flue gases, but their cost presents a major obstacle for use at an industrial scale. This cost, however, can be reduced either by producing a long-lasting enzyme suitable for CO2 capture or by lowering production costs. High-level expression, easy purification, and immobilization of CAs from Sulfurihydrogenibium azorense (SazCA) were investigated in a plant system. Fusion of the 60-amino acid-long ectodomain (M-domain) of the human receptor-type tyrosine-protein phosphatase C increased the levels of SazCA accumulation. Fusion of the cellulose-binding module (CBM3) from Clostridium thermocellum resulted in tight binding of recombinant protein to microcrystalline cellulose beads, enabling easy purification. The chimeric fusion protein, BMC-SazCA, which consisted of SazCA with the M and CBM3 domains, was expressed in tobacco (Nicotiana benthamiana), giving a recombinant protein yield in leaf extracts of 350mg/kg fresh weight. BMC-SazCA produced in planta was active in the presence of various chemicals used in CO2 capture. Immobilization of BMC-SazCA on the surface of microcrystalline cellulose beads extended its heat stability, allowing its reuse in multiple rounds of the CO2 hydration reaction. These results suggest that production of SazCA in plants has great potential for CA-based CO2 sequestration and mineralization.

Enhanced enzyme-based CO2 capture in countercurrent packed-bed column reactors

An enhanced CO2 hydration process with human carbonic anhydrase II (hCA II) enzyme immobilized on packing surface and micro-particles dispersed in the liquid phase was proposed. This innovative hybrid enzymatic process was simulated in a countercurrent packed-bed column reactor via an unsteady-state, isothermal, 3-D model including continuity, momentum and species (including the biocatalytic micro-particles) balance equations in the liquid and gas phases, filtration equation describing the accumulation of biocatalytic micro-particles in packed bed, chemical reaction and diffusion in hCA II enzyme washcoat and liquid film. In the hybrid enhanced immobilized enzyme CO2 capture system, hCA II enzyme supported on the surface of micro-particles works as a free solution-phase enzyme, which instantaneously catalyzes CO2 hydration reaction and upgrades significantly CO2 conversion, particularly in the region where the enzymatic process with immobilized hCA II enzyme on the packing surface is strongly limited by the diffusion. The impact of hCA II enzyme immobilized on the micro-particles surface is more important when the foremost amount of hCA II enzyme is immobilized on the packing via larger washcoat layers with enhanced mass transfer resistance, at larger feed buffer concentration and lower thermodynamic dissociation constant of the protonated acid form of buffer. Enhanced CO2 hydration process provide a reasonable CO2 conversion at a much lower liquid velocity and permits to significantly downgrade the height of the packed bed. These immobilized enzyme CO2 capture systems intend to maximize the mass transfer in packed-bed column reactors to expand the degree of utilization of the large hydration turnover of hCA II enzyme.

Sulfonamide Inhibition Studies of an α-Carbonic Anhydrase from Schistosoma mansoni, a Platyhelminth Parasite Responsible for Schistosomiasis.

Schistosomiasis is a debilitating infection provoked by parasitic flatworms called schistosomes. The species Schistosoma mansoni is endemic in Africa, where it causes intestinal schistosomiasis. Recently, an α-carbonic anhydrase (CA, EC 4.2.1.1) was cloned and characterized from this organism and designated as SmCA. The protein is expressed in the tegument (skin) of S. mansoni at the host–parasite interface. Recombinant SmCA possesses high catalytic activity in the CO2 hydration reaction, similar to that of human CA isoform II with a kcat of 1.2 × 106 s−1 and a kcat/KM of 1.3 × 108 M−1·s−1. It has been found that schistosomes whose SmCA gene is suppressed using RNA interference are unable to establish a robust infection in mice, suggesting that the chemicals that inhibit SmCA function should have the same debilitating effect on the parasites. In this study, a collection of aromatic/heterocyclic sulfonamides were investigated as possible SmCA inhibitors. Several sulfonamides inhibited SmCA with medium to weak potency (KI values of 737.2 nM−9.25 μM), whereas some heterocyclic compounds inhibited the enzyme with KI values in the range of 124−325 nM. The α-CA from S. mansoni, SmCA, is proposed as a new anti-schistosomiasis drug target.

Anion Inhibition Studies of the β-Class Carbonic Anhydrase CAS3 from the Filamentous Ascomycete Sordaria macrospora.

CAS3 is a newly cloned cytosolic β-class carbonic anhydrase (CA, EC 4.2.1.1) from the filamentous ascomycete Sordaria macrospora. This enzyme has a high catalytic activity for the physiological CO2 hydration reaction and herein, we report the inhibition profile of CAS3 with anions and small molecules. The most effective CAS3 anions/small molecule inhibitors were diethyl-dithiocarbamate, sulfamide, sulfamate, phenyl boronic and phenyl arsonic acids, with KIs in the range of 0.89 mM–97 µM. Anions such as iodide, the pseudohalides, bicarbonate, carbonate, nitrate, nitrite, hydrogensulfide, stannate, selenate, tellurate, tetraborate, perrhenate, perruthenate, selenocyanide and trithiocarbonate were low millimolar CAS3 inhibitors. The light halides, sulfate, hydrogensulfite, peroxydisulfate, diphosphate, divanadate, perchlorate, tetrafluoroborate, fluorosulfonate and iminodisulfonate did not significantly inhibit this enzyme. These data may be useful for developing antifungals based on CA inhibition, considering the fact that many of the inhibitors reported here may be used as lead molecules and, by incorporating the appropriate organic scaffolds, potent nanomolar inhibitors could be developed.

Sulfonamide Inhibition Profile of the β-Carbonic Anhydrase from Malassezia restricta, An Opportunistic Pathogen Triggering Scalp Conditions.

The critical CO2 hydration reaction to bicarbonate and protons is catalyzed by carbonic anhydrases (CAs, EC 4.2.1.1). Their physiological role is to assist the transport of the CO2 and HCO3− at the cellular level, which will not be ensured by the low velocity of the uncatalyzed reaction. CA inhibition may impair the growth of microorganisms. In the yeasts, Candida albicans and Malassezia globosa, the activity of the unique β-CA identified in their genomes was demonstrated to be essential for growth of the pathogen. Here, we decided to investigate the sulfonamide inhibition profile of the homologous β-CA (MreCA) identified in the genome of Malassezia restricta, an opportunistic pathogen triggering dandruff and seborrheic dermatitis. Among 40 investigated derivatives, the best MreCA sulfonamide inhibitors were dorzolamide, brinzolamide, indisulam, valdecoxib, sulthiam, and acetazolamide (KI < 1.0 μM). The MreCA inhibition profile was different from those of the homologous enzyme from Malassezia globosa (MgCA) and the human isoenzymes (hCA I and hCA II). These results might be useful to for designing CA inhibitor scaffolds that may selectively inhibit the dandruff-producing fungi.

Escherichia coli γ-carbonic anhydrase: characterisation and effects of simple aromatic/heterocyclic sulphonamide inhibitors

Carbonic anhydrases (CAs, EC 4.2.1.1) are ubiquitous metalloenzymes involved in biosynthetic processes, transport, supply, and balance of CO2/HCO3 - into the cell. In Bacteria, CAs avoid the depletion of the dissolved CO2/HCO3 - from the cell, providing them to the central metabolism that is compromised without the CA activity. The involvement of CAs in the survival, pathogenicity, and virulence of several bacterial pathogenic species is recent. Here, we report the kinetic properties of the recombinant γ-CA (EcoCAγ) encoded in the genome of Escherichia coli. EcoCAγ is an excellent catalyst for the physiological CO2 hydration reaction to bicarbonate and protons, with a kcat of 5.7 × 105 s−1 and kcat/KM of 6.9 × 106 M−1 s−1. The EcoCAγ inhibition profile with a broad series of known CA inhibitors, the substituted benzene-sulphonamides, and clinically licenced drugs was explored. Benzolamide showed a KI lower than 100 nM. Our study reinforces the hypothesis that the synthesis of new drugs capable of interfering selectively with the bacterial CA activity, avoiding the inhibition of the human α -CAs, is achievable and may lead to novel antibacterials.

Effect of Carbonic Anhydrase on CO2 Separation Performance of Thin Poly(amidoamine) Dendrimer/Poly(ethylene glycol) Hybrid Membranes.

The effect of carbonic anhydrase (CA) on the separation performance of thin poly(amidoamine) (PAMAM) dendrimer/poly(ethylene glycol) (PEG) hybrid membranes was investigated. CA, a type of enzyme, was used to promote CO2 hydration and dehydration reactions and to assess whether these reactions were the rate-limiting step in CO2 permeation through the membrane. The relationship between the membrane thickness and the CO2 permeance was evaluated in CO2/H2 or CO2/He separation using PAMAM/PEG hybrid membranes (thickness: 10–100 μm) with and without CA. Without CA, the CO2 permeance of PAMAM/PEG hybrid membranes was not inversely proportional to the membrane thickness. On the other hand, with CA, the CO2 permeance was inversely proportional to the membrane thickness. It was implied that, without CA, the rate-limiting step of CO2 transport was either the CO2 hydration reaction at the feed side or the CO2 dehydration reaction at the permeate side. On the other hand, with CA addition, the rate-limiting step of CO2 transport was diffusion, and CO2 permeance could be increased without sacrificing the selectivity by reducing membrane thickness. The effect of the position of CA (i.e., on the surface and/or reverse surface) on CO2 separation performance was investigated to evaluate which reaction was the rate-limiting step of CO2 permeation through the membrane. It was suggested that the rate-limiting step of CO2 permeation was CO2 dehydration reaction at the permeate side.

Proton shuttle efficiency of bicarbonate: A theoretical study on tautomerization and CO2 hydration

The efficiency of bicarbonate molecule (HCO3−) as a proton shuttle in the tautomerization and (non)enzymatic CO2 hydration reactions has been investigated with the aid of computational chemistry methods (DFT and ab initio). The results revealed that bicarbonate can decrease the barrier height of tautomerization (keto-enol, azo-hydrazo and imine-amine) more than 70%. This value is around 45% for water molecules. Also, HCO3− can catalyze the CO2 hydration both inside (enzymatic) and outside (nonenzymatic) the active site of human carbonic anhydrases II (HCA II). In the absence of enzyme, bicarbonate molecule can lower the CO2 hydration from ∼50 kcal mol−1 in the gas phase to ∼14 kcal mol−1 in the aqueous media. This reaction maintains its barrier (∼15 kcal mol−1) for bicarbonate-Zn complex in the active site of enzyme; it has been observed that amino acid residues, mainly Thr199 and Glu106, are actively involved in the proton transfer network and facilitate CO2 hydration ability of bicarbonate.

Extending the Inhibition Profiles of Coumarin-Based Compounds Against Human Carbonic Anhydrases: Synthesis, Biological, and In Silico Evaluation.

Carbonic anhydrases (CAs, EC 4.2.1.1) catalyze the fundamental reaction of CO2 hydration in all living organisms and are actively involved in the regulation of a plethora of pathological and physiological conditions. A set of new coumarin/ dihydrocoumarin derivatives was here synthesized, characterized, and tested as human CA inhibitors. Their inhibitory activity was evaluated against the cytosolic human isoforms hCA I and II and the transmembrane hCA IX and hCA XII. Two compounds showed potent inhibitory activity against hCA IX, being more active or equipotent with the reference drug acetazolamide. Computational procedures were used to investigate the binding mode of this class of compounds within the active site of hCA IX and XII that are validated as anti-tumor targets.

Kinetic Study of CO2 Hydration by Small-Molecule Catalysts with A Second Coordination Sphere that Mimic the Effect of the Thr-199 Residue of Carbonic Anhydrase.

Zinc complexes were synthesized as catalysts that mimic the ability of carbonic anhydrase (CA) for the CO2 hydration reaction (H2O + CO2 → H+ + HCO3−). For these complexes, a tris(2-pyridylmethyl)amine (TPA) ligand mimicking only the active site, and a 6-((bis(pyridin-2-ylmethyl)amino)methyl)pyridin-2-ol (TPA-OH) ligand mimicking the hydrogen-bonding network of the secondary coordination sphere of CA were used. Potentiometric pH titration was used to determine the deprotonation ability of the Zn complexes, and their pKa values were found to be 8.0 and 6.8, respectively. Stopped-flow spectrophotometry was used to confirm the CO2 hydration rate. The rate constants were measured to be 648.4 and 730.6 M−1s−1, respectively. The low pKa value was attributed to the hydrogen-bonding network of the secondary coordination sphere of the catalyst that mimics the behavior of CA, and this was found to increase the CO2 hydration rate of the catalyst.

State of the Art on Carbonic Anhydrase Modulators for Biomedical Purposes

The current review is intended to highlight recent advances in the search of new and effective modulators of the metalloenzymes Carbonic Anhydrases (CAs, EC 4.2.1.1) expressed in humans (h). CAs reversibly catalyze the CO2 hydration reaction, which is of crucial importance in the regulation of a plethora of fundamental processes at cellular level as well as in complex organisms. The first section of this review will be dedicated to compounds acting as activators of the hCAs (CAAs) and their promising effects on central nervous system affecting pathologies mainly characterized from memory and learning impairments. The second part will focus on the emerging chemical classes acting as hCA inhibitors (CAIs) and their potential use for the treatment of diseases.

Thermostability enhancement of the α-carbonic anhydrase from Sulfurihydrogenibium yellowstonense by using the anchoring-and-self-labelling-protein-tag system (ASLtag)

Carbonic anhydrases (CAs, EC 4.2.1.1) are a superfamily of ubiquitous metalloenzymes present in all living organisms on the planet. They are classified into seven genetically distinct families and catalyse the hydration reaction of carbon dioxide to bicarbonate and protons, as well as the opposite reaction. CAs were proposed to be used for biotechnological applications, such as the post-combustion carbon capture processes. In this context, there is a great interest in searching CAs with robust chemical and physical properties. Here, we describe the enhancement of thermostability of the α-CA from Sulfurihydrogenibium yellowstonense (SspCA) by using the anchoring-and-self-labelling-protein-tag system (ASLtag). The anchored chimeric H5-SspCA was active for the CO2 hydration reaction and its thermostability increased when the cells were heated for a prolonged period at high temperatures (e.g. 70 °C). The ASLtag can be considered as a useful method for enhancing the thermostability of a protein useful for biotechnological applications, which often need harsh operating conditions.

Sulfonamide Inhibition Studies of a New β-Carbonic Anhydrase from the Pathogenic Protozoan Entamoeba histolytica.

A newly described β-carbonic anhydrase (CA, EC 4.2.1.1) from the pathogenic protozoan Entamoeba histolytica, EhiCA, was recently shown to possess a significant catalytic activity for the physiologic CO2 hydration reaction (kcat of 6.7 × 105 s−1 and a kcat/Km of 8.9 × 107 M−1 s−1). A panel of sulfonamides and one sulfamate, some of which are clinically used drugs, were investigated for their inhibitory properties against EhiCA. The best inhibitors detected in the study were 4-hydroxymethyl/ethyl-benzenesulfonamide (KIs of 36–89 nM), whereas some sulfanilyl-sulfonamides showed activities in the range of 285–331 nM. Acetazolamide, methazolamide, ethoxzolamide, and dichlorophenamide were less effective inhibitors (KIs of 509–845 nM) compared to other sulfonamides investigated here. As β-CAs are not present in vertebrates, the present study may be useful for detecting lead compounds for the design of more effective inhibitors with potential to develop anti-infectives with alternative mechanisms of action.

Cloning, Characterization and Anion Inhibition Studies of a β-Carbonic Anhydrase from the Pathogenic Protozoan Entamoeba histolytica.

We report the cloning and catalytic activity of a β-carbonic anhydrase (CA, EC 4.2.1.1), isolated from the pathogenic protozoan Entamoeba histolytica, EhiCA. This enzyme has a high catalytic activity for the physiologic CO2 hydration reaction, with a kcat of 6.7 × 105 s−1 and a kcat/Km of 8.9 × 107 M−1 × s−1. An anion inhibition study of EhiCA with inorganic/organic anions and small molecules revealed that fluoride, chloride, cyanide, azide, pyrodiphosphate, perchlorate, tetrafluoroborate and sulfamic acid did not inhibit the enzyme activity, whereas pseudohalides (cyanate and thiocyanate), bicarbonate, nitrate, nitrite, diethyldithiocarbamate, and many complex inorganic anions showed inhibition in the millimolar range (KIs of 0.51–8.4 mM). The best EhiCA inhibitors were fluorosulfonate, sulfamide, phenylboronic acid and phenylarsonic acid (KIs in the range of 28–86 μM). Since β-CAs are not present in vertebrates, the present study may be useful for detecting lead compounds for the design of effective enzyme inhibitors, with potential to develop anti-infectives with alternative mechanisms of action.

Modelling of Enzymatic Reactive CO 2 Absorption

Post-combustion CO2 capture strategy asks for novel effective processes avoiding the use of polluting solvents and oriented towards CO2 utilization. Recent research efforts are focused on the development of CO2 absorption processes promoted by the activity of the enzyme carbonic anhydrase (EC - 4.2.1.1) (Leimbrik et al., 2017; Russo et al., 2013). This ubiquitous enzyme is able to catalyse the CO2 hydration reaction and can be used to enhance CO2 absorption rate into aqueous alkaline solvents such as carbonate solutions. The adoption of the biomimetic strategy for post-combustion CO2 capture is based on the use of environmental friendly solvents. Recent studies on the development of carbonic anhydrase biocatalysts for CO2 capture through enzymatic reactive absorption focused on different enzyme immobilization techniques. Moreover, theoretical studies showed the potential use of immobilized enzymes in typical gas-liquid contactors. The present contribution concerns the rational design of absorption columns through the use of kinetic parameters assessed for carbonic anhydrase immobilized on fine particles. The kinetics of CA immobilized on magnetic nanoparticles have been previously characterized under conditions relevant for the industrial application (K2CO3 solutions at 25-40°C and at different carbonate conversion degrees) (Peirce et al., 2017; Peirce, 2017). The model simulations provided information on the performances of the technical grade CA and of the biocatalyst made with nanoparticles (NPs) coated with covalently immobilized CA. The results showed that effective intensification of the capture process can be achieved using the fine slurry biocatalyst.