On the solubility of proteins as a function of pH: Mathematical development and application

Autor(es)

Mercier Franco, Luis Fernando ^[1] ; Pessoa Filho, Pedro de Alcantara ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Biochem Engn Lab, Dept Chem Engn, Sch Engn, BR-05424970 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Fluid Phase Equilibria; v. 306, n. 2, p. 242-250, JUL 25 2011.
• Citações Web of Science: 8

Resumo

Thermodynamic relations between the solubility of a protein and the solution pH are presented in this work. The hypotheses behind the development are that the protein chemical potential in liquid phase can be described by Henry's law and that the solid-liquid equilibrium is established only between neutral molecules. The mathematical development results in an analytical expression of the solubility curve, as a function of the ionization equilibrium constants, the pH and the solubility at the isoelectric point. It is shown that the same equation can be obtained either by directly calculating the fraction of neutral protein molecules or by integrating the curve of the protein average charge. The methodology was successfully applied to the description of the solubility of porcine insulin as a function of pH at three different temperatures and of bovine beta-lactoglobulin at four different ionic strengths. (C) 2011 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 09/06575-0 - Modelagem termodinâmica do equilíbrio sólido-líquido em sistemas contendo proteínas: efeito do pH
• Beneficiário: Luís Fernando Mercier Franco
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica
• Processo FAPESP: 08/11232-1 - Estudo sobre a influência de co-solventes em propriedades termodinâmicas de proteínas em solução
• Beneficiário: Pedro de Alcântara Pessôa Filho
• Modalidade de apoio: Auxílio à Pesquisa - Regular