Genetic design of co-expressed Mesorhizobium loti carbonic anhydrase and chaperone GroELS to enhancing carbon dioxide sequestration

• Published in: International journal of biological macromolecules Vol. 167; pp. 326 - 334
• Main Authors: Effendi, Sefli Sri Wahyu, Tan, Shih-I, Ting, Wan-Wen, Ng, I-Son
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 15.01.2021
• Subjects: Biomineralization; Calorimetry, Differential Scanning; Carbon Dioxide - metabolism; Carbonic anhydrase; Carbonic Anhydrases - genetics; Carbonic Anhydrases - metabolism; Chaperone GroELS; Chaperonin 60; Escherichia coli - genetics; Escherichia coli - metabolism; Gene Expression; Inclusion bodies; Isothermal titration calorimetry; Kinetics; Mesorhizobium - enzymology; Mesorhizobium - genetics; Mesorhizobium loti; Molecular Chaperones - genetics; Molecular Chaperones - metabolism; Protein Binding; Protein Engineering - methods; Protein Folding; Recombinant Proteins; Thermodynamics; Biomineralization; Mesorhizobium loti; Chaperone GroELS; Isothermal titration calorimetry; Carbonic anhydrase; Inclusion bodies
• ISSN: 0141-8130; 1879-0003
• DOI: 10.1016/j.ijbiomac.2020.11.189

Mesorhizobium loti carbonic anhydrase (MlCA), an intrinsically high catalytic enzyme, has been employed for carbon dioxide capture and sequestration. However, recombinant expression of MlCA in Escherichia coli often forms inclusion bodies. Hence, protein partners such as fusion-tags and molecular chaperones are involved in regarding reduce the harshness of protein folding. TrxA-tag and GroELS have been chosen to co-express with MlCA in E. coli under an inducible T7 promoter or a constitutive J23100 promoter to compare productivity and activity. The results possessed that coupling protein partners effectively increased soluble MlCA up to 2.9-folds under T7 promoter, thus enhancing the CA activity by 120% and achieving a 5.2-folds turnover rate. Besides, it has also shifted the optimum temperature from 40 °C to 50 °C, promoted stability in the broad pH range (4.5 to 9.5) and the presence of various metal ions. Based on the in vitro assay and isothermal titration calorimetry (ITC) analysis, GroELS enhancing CA activity was due to change the intrinsic thermodynamic properties of the enzyme from endothermic to exothermic reaction (i.e., ∆H = 89.8 to −121.8 kJ/mol). Therefore, the collaboration of TrxA-MlCA with GroELS successfully augmented CO2 biomineralization. •The first study exploited a constitutive promoter for Mesorhizobium loti CA (MlCA).•TrxA-tag and GroELS have assisted more soluble protein and activity of MlCA.•Thermostability and ion tolerance of MlCA are improved due to GroELS presence.•MlCA with GroELS co-expression accelerates carbon dioxide biomineralization rate.•Thermodynamic variables revealed the influence of GroELS on MlCA binding ability.