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Thermodynamic studies of partitioning behavior of lysozyme and conalbumin in aqueous two-phase systems

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Resumo:The objective of this study was to determine the thermodynamic parameters (ΔtrG, ΔtrH and ΔtrS) associated with lysozyme and conalbumin partitioning in aqueous two-phases systems (ATPS). Influence of salt type and polyethylene glycol (PEG) concentrations on the partition coefficient of lysozyme and conalbumin from egg white was studied. The evaluated ATPS were composed of PEG 1500 and inorganic salts (sodium citrate and sodium sulfate) at a temperature of 25 °C and pH 7.0, with PEG 1500 g mol−1 concentrations of 14%, 16% and 18% (mass basis). Partitioning of lysozyme in PEG–citrate ATPS was enthalpically driven, however the PEG–sulfate ATPS was entropically driven. The tested systems can be employed for the separation of these two proteins in egg white, due to the fact that lysozyme migrates toward the polymeric phase and conalbumin to the saline phase in both ATPS. A high recovery of conalbumin in the saline phase of the PEG–sulfate ATPS was determined to be enthalpically driven.
Autores principais:Sousa, Rita de Cássia Superbi de
Outros Autores:Coimbra, Jane Sélia dos Reis; Silva, Luis Henrique Mendes da; Silva, Maria do Carmo Hespanhol da; Rojas, Edwin Elard Garcia; Vicente, A. A.
Assunto:Aqueous two-phase systems Egg white protein Conalbumin Lysozyme Thermodynamic parameters
Ano:2009
País:Portugal
Tipo de documento:artigo
Tipo de acesso:acesso aberto
Instituição associada:Universidade do Minho
Idioma:inglês
Origem:RepositóriUM - Universidade do Minho
Descrição
Resumo:The objective of this study was to determine the thermodynamic parameters (ΔtrG, ΔtrH and ΔtrS) associated with lysozyme and conalbumin partitioning in aqueous two-phases systems (ATPS). Influence of salt type and polyethylene glycol (PEG) concentrations on the partition coefficient of lysozyme and conalbumin from egg white was studied. The evaluated ATPS were composed of PEG 1500 and inorganic salts (sodium citrate and sodium sulfate) at a temperature of 25 °C and pH 7.0, with PEG 1500 g mol−1 concentrations of 14%, 16% and 18% (mass basis). Partitioning of lysozyme in PEG–citrate ATPS was enthalpically driven, however the PEG–sulfate ATPS was entropically driven. The tested systems can be employed for the separation of these two proteins in egg white, due to the fact that lysozyme migrates toward the polymeric phase and conalbumin to the saline phase in both ATPS. A high recovery of conalbumin in the saline phase of the PEG–sulfate ATPS was determined to be enthalpically driven.