title: Role of pH-induced structural change in protein aggregation in foam fractionation of bovine serum albumin.
abstract: For reducing protein aggregation in foam fractionation, the role of pH-induced structural change in the interface-induced protein aggregation was analyzed using bovine serum albumin (BSA) as a model protein. The results show that the decrease in pH from 7.0 to 3.0 gradually unfolded the BSA structure to increase the molecular size and the relative content of β-sheet and thus reduced the stability of BSA in the aqueous solution. At the isoelectric point (pH 4.7), BSA suffered the lowest level in protein aggregation induced by the gas-liquid interface. In the pH range from 7.0 to 4.7, most BSA aggregates were formed in the defoaming process while in the pH range from 4.7 to 3.0, the BSA aggregates were formed at the gas-liquid interface due to the unfolded BSA structure and they further aggregated to form insoluble ones in the desorption process.
authors.affiliation: School of Chemical Engineering and Technology, Hebei University of Technology, No.8 Guangrong Road, Dingzi Gu, Hongqiao District, Tianjin, 300130, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Li
authors.affiliation: School of Chemical Engineering and Technology, Hebei University of Technology, No.8 Guangrong Road, Dingzi Gu, Hongqiao District, Tianjin, 300130, China.
authors.forename: Zhaoliang
authors.initials: Z
authors.lastname: Wu
authors.affiliation: Key Laboratory of Green Chemical Technology & High Efficient Energy Saving, Hebei University of Technology, No. 8 Guangrong Road, Dingzi Gu, Hongqiao District, Tianjin, 300130, China.
authors.forename: Yanji
authors.initials: Y
authors.lastname: Wangb
authors.affiliation: School of Chemical Engineering and Technology, Hebei University of Technology, No.8 Guangrong Road, Dingzi Gu, Hongqiao District, Tianjin, 300130, China.
authors.forename: Linlin
authors.initials: L
authors.lastname: Ding
authors.affiliation: Lianyungang TCM Branch of Jiangsu Union Technical Institute, Jiangsu Lianyungang 222006, China.
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Wang
keywords: BSA; Foam fractionation; Molecular structure; Protein aggregation; pH