A carbonic anhydrase with high stability and catalytic efficiency | Research

Background

Carbonic anhydrases (CA) are a family of enzymes that are found in virtually all organisms on earth. They catalyze the conversion of carbon dioxide and water into carbonic acid, protons and bicarbonate ions. The CA enzyme plays a fundamental role in diverse biological-related mechanisms such as CO2 transport, pH homeostasis, cell respiration and photosynthesis. These enzymes are renowned for their rapid kinetics, with the potential to process up to a million CO2 molecules per second, however like most enzymes they suffer from poor thermostability.

Every year, over 9 billion metric tons of CO2 are emitted globally by various industries, including coal-fired power plants. Traditional carbon capture and sequestration (CCS) methods often rely on solvents like amines for rapid absorption, but this process is hindered by high desorption temperatures. Incorporating natural carbonic anhydrases into large-scale carbon capture systems could expedite CO2 capture in alkaline solvents with slower absorption rates. However, the effectiveness of CA as a catalyst has been constrained by enzyme inactivation in harsh alkaline environments and the elevated desorption temperatures required for CO2 release

Description of the invention

Researchers at the University of Waterloo have engineered a new carbonic anhydrase enzyme with exceptional thermostability and enhanced catalytic efficiency, surpassing that of the most active known carbonic anhydrases. It has also demonstrated the ability to refold after thermal denaturation.

Advantages

The UW engineered carbonic anhydrase boasts exceptional thermostability at >100°C, functions in a broad pH range of 5-10, and can refold into a stable monomer after denaturing from heat. This allows it to act effectively as a catalyst in both medical and industrial processes. The use of CAs offers a greener solution for reducing CO2 emission and the high efficiency of the catalyst would enable improved CO2 capture.