Precipitation of porcine insulin with carbon dioxide.
Recent works have pointed to the use of volatile electrolytes such as carbon dioxide (CO2) dissolved in aqueous solutions as a promising alternative to the precipitating agents conventionally used for protein recovery in the food and pharmaceutical industries. In this work we investigated experimental and theoretical aspects of the precipitation of porcine insulin, a biomolecule of pharmaceutical interest, using CO2 as an acid-precipitating agent. The solubility of porcine insulin in NaHCO3 solutions in pressurized CO2 was determined as a function of temperature and pressure, with a minimum being observed close to the protein isoelectric point. A thermodynamic model was developed and successfully utilized to correlate the experimental data. Insulin was considered a polyelectrolyte in the model and its self-association reactions were also taken into account. The biological activity of insulin was maintained after precipitation with CO2, although some activity can be lost if foam is formed in the depressurization step.
Faculdade de Engenharia Química, Universidade Estadual de Campinas-UNICAMP, Campinas-SP, Brazil.
Alexandre Keiji
AK
Tashima
Marcel
M
Ottens
Luuk A M
LA
Van der Wielen
Dennys E
DE
Cintra
José R
JR
Pauli
Pedro de Alcântara Pessôa
Pde A
Filho
Everson Alves
EA
Miranda
D002245:Carbon Dioxide / Q000378:metabolism*; D002254:Carbonates / Q000378:metabolism; D005591:Chemical Fractionation / Q000379:methods*; D011232:Chemical Precipitation; D007328:Insulin / Q000302:isolation & purification*; D007526:Isoelectric Point
D002254:Carbonates; D007328:Insulin; D002245:Carbon Dioxide; C005686:sodium carbonate