Encapsulation of carbonic anhydrase in metal-organic frameworks to facilitate CO2 capture

Abstract

Global warming is a growing problem because of increasing temperatures and green house gases. Therefore, to reduce the amount of CO2 in the atmosphere this project explores the encapsulation of the protein SazCA into the Metal organic framework ZIF-8. Because SazCA is a protein that can transform CO2 into bicarbonate which in later stages can form into a solid material to be used for long term storage or other applications. The activity of SazCA have been measured with Wilbur-Anderson units. Previous work on this project have shown some problems with the encapsulation of SazCA, namely low activity at 3 % of the free SazCA and low protein coverage. Results found that the reducing of free zinc did not improve the activity of the SazCA@ZIF-8. However it was found that with increasing amount of BSA mixed with SazCA in the ZIF-8 synthesis, the BSA protected the SazCA and increased the activity to about 32 % of the free SazCA. The activity of SazCA@ZIF-8 did not recover completely in long term storage after 8 weeks, but is persistently getting better than that of free SazCA in the same condition. In activity measurements in 50, 60 and 70 ◦C the SazCA@ZIF-8 did not show better activity at higher temper atures but further experiments will have to be performed. It was noted that in the ZIF-8 synthesis the protein coverage reduced with about 50 % and was traced to the 2-MIM being responsible. It was concluded that the 2-MIM did not degrade the protein and it was concluded that the 2-MIM affect the protein measurement in the Bradford protein measurement.