Carbonic Anhydrases and Their Biotechnological Applications

Abstract

The carbonic anhydrases (CAs) are mostly zinc-containing metalloenzymes which catalyze the reversible hydration/dehydration of carbon dioxide/bicarbonate. The CAs have been extensively studied because of their broad physiological importance in all kingdoms of life and clinical relevance as drug targets. In particular, human CA isoform II (HCA II) has a catalytic efficiency of 108 M−1 s−1, approaching the diffusion limit. The high catalytic rate, relatively simple procedure of expression and purification, relative stability and extensive biophysical studies of HCA II has made it an exciting candidate to be incorporated into various biomedical applications such as artificial lungs, biosensors and CO2 sequestration systems, among others. This review highlights the current state of these applications, lists their advantages and limitations, and discusses their future development.

Structural and biophysical characterization of the α-carbonic anhydrase from the gammaproteobacteriumThiomicrospira crunogenaXCL-2: insights into engineering thermostable enzymes for CO2sequestration

“…The reduction of the disulfide bond in NgCA led to decreased conformational stability, making it more sensitive to denaturation/inactivation by GdnHCl. It was inferred in subsequent papers regarding other -CAs that the presence of this disulfide bond accounted for increased conformational stability, including the incorporation of the same disulfide bond into an hCA II variant (Boone, Habibzadegan, Gill et al, 2013). Therefore, previous studies as well as our data strongly suggest that this disulfide bond is a major contributor to the increase in thermal and conformational stability of TcruCA.…”

“…# 2015 International Union of Crystallography sequestration has shown promise owing to its efficiency in catalyzing CO 2 removal and its ability to be produced in large quantities (Favre et al, 2009;Boron, 2010;Pierre, 2012;Boone, Habibzadegan, Gill et al, 2013). However, CA must maintain its characteristic high catalytic efficiency in extreme conditions, such as high temperature, pressure and extreme pHs, in order to be a viable CO 2 -sequestration agent (Savile & Lalonde, 2011;Boone, Habibzadegan, Gill et al, 2013).…”

“…However, CA must maintain its characteristic high catalytic efficiency in extreme conditions, such as high temperature, pressure and extreme pHs, in order to be a viable CO 2 -sequestration agent (Savile & Lalonde, 2011;Boone, Habibzadegan, Gill et al, 2013). To this end, there has been a large effort to characterize CAs from organisms that thrive in extreme environments (Alvizo et al, 2014) and to engineer thermostable and pH-stable variants (Mirjafari et al, 2007;Boron, 2010;Yu et al, 2012;Boone, Habibzadegan, Tu et al, 2013).…”

“…One of the most abundant of the GHG is CO 2 , the atmospheric accumulation of which has been correlated with a rise in global temperatures (Boone, Gill et al, 2013). The burning of fossil fuels, such as coal, oil and natural gas, has sharply increased the concentration of atmospheric CO 2 and has been correlated with increased global temperatures over the past century (Intergovernmental Panel on Climate Change, 2005;Canadell et al, 2007).…”

“…However, the removal of CO 2 from industrial flue gases requires harsh chemical processes and extreme temperatures and is often cost-inefficient (Intergovernmental Panel on Climate Change, 2005;Pierre, 2012). The need for a more efficient CO 2 -sequestration process has promoted developments in enzymatic CO 2 sequestration (Boone, Gill et al, 2013). The use of carbonic anhydrase (CA) for CO 2…”