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Affinity‐tagged green fluorescent protein (GFP) extraction from a clarified E. coli cell lysate using a two‐phase aqueous micellar system
Author(s) -
Mazzola Priscila G.,
Lam Henry,
Kavoosi Mojgan,
Haynes Charles A.,
Pessoa Adalberto,
Penna Thereza Christina Vessoni,
Wang Daniel I.C.,
Blankschtein Daniel
Publication year - 2006
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.20806
Subject(s) - lysis , green fluorescent protein , chromatography , chemistry , downstream processing , escherichia coli , affinity chromatography , micelle , dilution , extraction (chemistry) , aqueous two phase system , fluorescence , cell disruption , aqueous solution , biochemistry , enzyme , organic chemistry , gene , physics , quantum mechanics , thermodynamics
Green fluorescent protein (GFP) has been proposed as an ideal choice for a protein‐based biological indicator for use in the validation of decontamination or disinfection treatments. In this article, we present a potentially scalable and cost‐effective way to purify recombinant GFP, produced by fermentation in Escherichia coli , by affinity‐enhanced extraction in a two‐phase aqueous micellar system. Affinity‐enhanced partitioning, which improves the specificity and yield of the target protein by specific bioaffinity interactions, has been demonstrated. A novel affinity tag, family 9 carbohydrate‐binding module (CBM9) is fused to GFP, and the resulting fusion protein is affinity‐extracted in a decyl β‐ D ‐glucopyranoside (C 10 G 1 ) two‐phase aqueous micellar system. In this system, C 10 G 1 acts as phase forming and as affinity surfactant. We will further demonstrate the implementation of this concept to attain partial recovery of affinity‐tagged GFP from a clarified E. coli cell lysate, including the simultaneous removal of other contaminating proteins. The cell lysate was partitioned at three levels of dilution (5×, 10×, and 40×). Irrespective of the dilution level, CBM9‐GFP was found to partition preferentially to the micelle‐rich phase, with the same partition coefficient value as that found in the absence of the cell lysate. The host cell proteins from the cell lysate were found to partition preferentially to the micelle‐poor phase, where they experience less excluded‐volume interactions. The demonstration of proof‐of‐principle of the direct affinity‐enhanced extraction of CBM9‐GFP from the cell lysate represents an important first step towards developing a cost‐effective separation method for GFP, and more generally, for other proteins of interest. © 2006 Wiley Periodicals, Inc.