Expression in Escherichia coli, refolding and crystallization of Aspergillus niger feruloyl esterase A using a serial factorial approach

TY - JOUR

T1 - Expression in Escherichia coli, refolding and crystallization of Aspergillus niger feruloyl esterase A using a serial factorial approach

AU - Benoit, Isabelle

AU - Coutard, Bruno

AU - Oubelaid, Rachid

AU - Asther, Marcel

AU - Bignon, Christophe

PY - 2007/9

Y1 - 2007/9

N2 - Hydrolysis of plant biomass is achieved by the combined action of enzymes secreted by microorganisms and directed against the backbone and the side chains of plant cell wall polysaccharides. Among side chains degrading enzymes, the feruloyl esterase A (FAEA) specifically removes feruloyl residues. Thus, FAEA has potential applications in a wide range of industrial processes such as paper bleaching or bio-ethanol production. To gain insight into FAEA hydrolysis activity, we solved its crystal structure. In this paper, we report how the use of four consecutive factorial approaches (two incomplete factorials, one sparse matrix, and one full factorial) allowed expressing in Escherichia coli, refolding and then crystallizing Aspergillus niger FAEA in 6 weeks. Culture conditions providing the highest expression level were determined using an incomplete factorial approach made of 12 combinations of four E. coli strains, three culture media and three temperatures (full factorial: 36 combinations). Aspergillus niger FAEA was expressed in the form of inclusion bodies. These were dissolved using a chaotropic agent, and the protein was purified by affinity chromatography on Ni column under denaturing conditions. A suitable buffer for refolding the protein eluted from the Ni column was found using a second incomplete factorial approach made of 96 buffers (full factorial: 3840 combinations). After refolding, the enzyme was further purified by gel filtration, and then crystallized following a standard protocol: initial crystallization conditions were found using commercial crystallization screens based on a sparse matrix. Crystals were then optimized using a full factorial screen.

AB - Hydrolysis of plant biomass is achieved by the combined action of enzymes secreted by microorganisms and directed against the backbone and the side chains of plant cell wall polysaccharides. Among side chains degrading enzymes, the feruloyl esterase A (FAEA) specifically removes feruloyl residues. Thus, FAEA has potential applications in a wide range of industrial processes such as paper bleaching or bio-ethanol production. To gain insight into FAEA hydrolysis activity, we solved its crystal structure. In this paper, we report how the use of four consecutive factorial approaches (two incomplete factorials, one sparse matrix, and one full factorial) allowed expressing in Escherichia coli, refolding and then crystallizing Aspergillus niger FAEA in 6 weeks. Culture conditions providing the highest expression level were determined using an incomplete factorial approach made of 12 combinations of four E. coli strains, three culture media and three temperatures (full factorial: 36 combinations). Aspergillus niger FAEA was expressed in the form of inclusion bodies. These were dissolved using a chaotropic agent, and the protein was purified by affinity chromatography on Ni column under denaturing conditions. A suitable buffer for refolding the protein eluted from the Ni column was found using a second incomplete factorial approach made of 96 buffers (full factorial: 3840 combinations). After refolding, the enzyme was further purified by gel filtration, and then crystallized following a standard protocol: initial crystallization conditions were found using commercial crystallization screens based on a sparse matrix. Crystals were then optimized using a full factorial screen.

KW - Aspergillus niger

KW - Carboxylic Ester Hydrolases

KW - Crystallization

KW - Escherichia coli

KW - Fungal Proteins

KW - Protein Folding

KW - Recombinant Proteins

U2 - 10.1016/j.pep.2007.04.001

DO - 10.1016/j.pep.2007.04.001

M3 - Article

C2 - 17533138

SN - 1046-5928

VL - 55

SP - 166

EP - 174

JO - Protein Expression and Purification

JF - Protein Expression and Purification

IS - 1

ER -