Chemically modified carbonic anhydrases useful in carbon capture systems

A homogenous liquid formulation comprising an aqueous solution of a CO2 absorption mediating compound and a soluble composition having carbonic anhydrase activity comprising an α-class carbonic anhydrase polypeptide chemically modified by treatment with a cross-linking agent, wherein the chemically modified carbonic anhydrase has increased carbonic anhydrase activity in the presence of the CO2 absorption mediating compound relative to the activity of the same carbonic anhydrase polypeptide that is not chemically modified.

A method for preparing a chemically modified α-class carbonic anhydrase comprising contacting in a solution:

• (i) a recombinant carbonic anhydrase polypeptide derived from an α-class carbonic anhydrase comprising an amino acid sequence selected from the group consisting of SEQ ID NO:
• 1298, 1300, 1302, 1304, 1306, and 1308;
• and (ii) a cross-linking agent selected from the group consisting of a dialdehyde, a bis-imidate ester, a bis(N-hydroxysuccinimide) ester, a diacid chloride, and mixtures thereof.