Purification of amyloid beta peptide and mechanistic study of its interaction with biflavonoid inhibitors

Abstract

Proteins and peptides expressed in the prokaryotic system often form inclusion body. Solubilization and refolding processes are required for their recovery but remain a tough task. In this study, an efficient plasmid vector system was constructed to purify those proteins and peptides in soluble form. The targets were expressed as a part of fusion protein and were cut off by cleavage at a specific site. To select a suitable fusion partner capable of solubilizing the aggregation-prone (inclusion-body forming) proteins and peptides, Escherichia coli thermostable proteins were screened and identified. Among them, trigger factor protein was selected for the following experiments because of its high expression and stability. Utilizing this system, Aβ and other selected protein and peptides that otherwise form inclusion body were expressed in soluble state and purified like other soluble proteins. Proteins and peptides expressed in the prokaryotic system often form inclusion body. Solubilization and refolding processes are required for their recovery but remain a tough task. In this study, an efficient plasmid vector system was constructed to purify those proteins and peptides in soluble form. The targets were expressed as a part of fusion protein and were cut off by cleavage at a specific site. To select a suitable fusion partner capable of solubilizing the aggregation-prone (inclusion-body forming) proteins and peptides, Escherichia coli thermostable proteins were screened and identified. Among them, trigger factor protein was selected for the following experiments because of its high expression and stability. Utilizing this system, Aβ and other selected protein and peptides that otherwise form inclusion body were expressed in soluble state and purified like other soluble proteins.