Additionally, we preserved the crystal waters during all simulation. We chose the ff19SB forcefield for the protein molecule, with missing hydrogens were added by the LEAP module of AMBER20. The forcefield parameters for CO2 and HCO3 -were generated by the inbuilt antechamber module of AMBER20. Similarly, partial atomic charges on them were assigned by employing the standard RESP (restrained electrostatic potential) charge fitting method, calculated at the B3LYP/6-31G* level of theory with the gaussian09 packages. An appropriate number of positively charged Na + ions were added to the system in order to obtain electrical neutrality. Thereafter, the resulting complex system was solvated with an octahedral TIP3P water box extended up to 10 Å from the protein surface.