Design of a Superpositively Charged Enzyme: Human Carbonic Anhydrase II Variant with Ferritin Encapsulation and Immobilization

• DOI: 10.1021/acs.biochem.1c00515
• Publication Date: 2021-11-10T20:50:14Z
• Authors: Joshua A. Bulos; Rui Guo; Zhiheng Wang; Maegan A. DeLessio; Jeffery G. Saven; Ivan J. Dmochowski
• Keywords: Carbonic anhydrase II

Supercharged proteins exhibit high solubility and other desirable properties, but no engineered superpositively charged enzymes have previously been made. Superpositively variants of such as green fluorescent protein efficiently encapsulated within Archaeoglobus fulgidus thermophilic ferritin (AfFtn). Encapsulation by supramolecular can yield systems with a variety sequestered cargo. To advance applications in enzymology chemistry, we sought general method for supercharging an enzyme that retains activity is compatible AfFtn encapsulation. The zinc metalloenzyme human carbonic anhydrase II (hCAII) attractive encapsulation target based on its hydrolytic physiologic conversion carbon dioxide to bicarbonate. A computationally designed variant hCAII contains positively residues substituted at 19 sites the protein's surface, resulting shift putative net charge from -1 +21. This hCAII(+21) exhibits without need fusion partners or additional reagents. esterase comparable wild type spontaneously templates assembly 24mers around itself. AfFtn-hCAII(+21) host-guest complex both greater thermal stability when compared hCAII(+21). Upon immobilization solid support, enzymatic enhancement elevated temperatures.