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Published on: November 8, 2019
Protein purification with vapor-phase carbon dioxide
M A Winters1, D Z Frankel, P G Debenedetti
1Department of Chemical Engineering, Princeton University, Princeton, New Jersey 08544-5263, USA.
Biotechnology and Bioengineering
|April 1, 1999
Summary
Gaseous carbon dioxide (CO2) effectively precipitates proteins from dimethylsulfoxide (DMSO). This method allows for selective protein separation and purification, with most recovered proteins retaining biological activity.
Area of Science:
- Biochemistry
- Chemical Engineering
- Protein Chemistry
Background:
- Dimethylsulfoxide (DMSO) is a common solvent for proteins, but its use in separation processes can be challenging.
- Selective precipitation is a key technique for protein purification and recovery.
Purpose of the Study:
- To investigate the use of gaseous carbon dioxide (CO2) as an antisolvent for fractional protein precipitation from DMSO.
- To evaluate the potential for selective separation and purification of various proteins using this method.
Main Methods:
- Proteins (alkaline phosphatase, insulin, lysozyme, ribonuclease, trypsin) were dissolved in DMSO.
- Compressed CO2 was introduced as a gaseous antisolvent (GAS) under isothermal conditions.
- Protein precipitation pressures were determined, and separation was analyzed using SDS-PAGE and biological activity assays.
Main Results:
- CO2 addition caused DMSO expansion and reduced solvent strength, inducing protein precipitation.
- Different proteins exhibited distinct solubilities in CO2-expanded DMSO, enabling selective precipitation.
- SDS-PAGE confirmed successful separation of protein mixtures, and activity assays showed high recovery for most proteins (except alkaline phosphatase).
Conclusions:
- Gaseous antisolvent precipitation is a viable and effective method for selective protein separation and purification from DMSO.
- Control of CO2 pressure allows for precise management of precipitate composition and purity.
- Vapor-phase antisolvents offer easy separation and recovery, preserving protein biological activity.
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