Improved Non-chromatographic Purification of a Recombinant Protein by Cationic Elastin-like Polypeptides

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• 作者：Dong Woo Lim ; Kimberly Trabbic-Carlson ; J. Andrew MacKay ; Ashutosh Chilkoti
• 刊名：Biomacromolecules
• 出版年：2007
• 出版时间：May 2007
• 年：2007
• 卷：8
• 期：5
• 页码：1417 - 1424
• 全文大小：289K
• 年卷期：v.8,no.5(May 2007)
• ISSN：1526-4602

文摘

This paper reports an improvement in the purification of thioredoxin (Trx) expressed from E. coli by inversetransition cycling (ITC) using cationic elastin-like polypeptides (ELPs). Two ELP libraries having 2% and 5%lysine residues and molecular weights ranging from 4 to 61.1 kDa showed greater salt sensitivity in their inversetransition behavior than purely aliphatic ELPs. Expression yield of Trx-ELP fusions was an unpredictable functionof guest residue composition, but reducing the molecular weight of the ELP tag generally increased Trx yield. Acationic 4.3 kDa ELP is the shortest ELP used to purify any protein by ITC to date. A 15.9 kDa ELP with a guestresidue composition of K:V:F of 1:7:1 was found to be the optimal cationic tag to purify Trx, as it provided 50%greater Trx yield and only required one-fifth the added NaCl for purification of Trx as compared to previouslyused aliphatic ELP tags.