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BioMed Research International
Volume 2014, Article ID 483596, 10 pages
Research Article

Quantitative Evaluation of E1 Endoglucanase Recovery from Tobacco Leaves Using the Vacuum Infiltration-Centrifugation Method

Department of Chemical Engineering and Materials Science, University of California at Davis, 1 Shields Avenue, Davis, CA 95616, USA

Received 28 November 2013; Revised 4 April 2014; Accepted 29 April 2014; Published 26 May 2014

Academic Editor: Qiang “Shawn” Chen

Copyright © 2014 Nathaniel J. Kingsbury and Karen A. McDonald. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


As a production platform for recombinant proteins, plant leaf tissue has many advantages, but commercialization of this technology has been hindered by high recovery and purification costs. Vacuum infiltration-centrifugation (VI-C) is a technique to obtain extracellularly-targeted products from the apoplast wash fluid (AWF). Because of its selective recovery of secreted proteins without homogenizing the whole tissue, VI-C can potentially reduce downstream production costs. Lab scale experiments were conducted to quantitatively evaluate the VI-C method and compared to homogenization techniques in terms of product purity, concentration, and other desirable characteristics. From agroinfiltrated Nicotiana benthamiana leaves, up to 81% of a truncated version of E1 endoglucanase from Acidothermus cellulolyticus was recovered with VI-C versus homogenate extraction, and average purity and concentration increases of 4.2-fold and 3.1-fold, respectively, were observed. Formulas were developed to predict recovery yields of secreted protein obtained by performing multiple rounds of VI-C on the same leaf tissue. From this, it was determined that three rounds of VI-C recovered 97% of the total active recombinant protein accessible to the VI-C procedure. The results suggest that AWF recovery is an efficient process that could reduce downstream processing steps and costs for plant-made recombinant proteins.