title: Predicting enzyme adsorption to lignin films by calculating enzyme surface hydrophobicity.
abstract: The inhibitory action of lignin on cellulase cocktails is a major challenge to the biological saccharification of plant cell wall polysaccharides. Although the mechanism remains unclear, hydrophobic interactions between enzymes and lignin are hypothesized to drive adsorption. Here we evaluate the role of hydrophobic interactions in enzyme-lignin binding. The hydrophobicity of the enzyme surface was quantified using an estimation of the clustering of nonpolar atoms, identifying potential interaction sites. The adsorption of enzymes to lignin surfaces, measured using the quartz crystal microbalance, correlates to the hydrophobic cluster scores. Further, these results suggest a minimum hydrophobic cluster size for a protein to preferentially adsorb to lignin. The impact of electrostatic contribution was ruled out by comparing the isoelectric point (pI) values to the adsorption of proteins to lignin surfaces. These results demonstrate the ability to predict enzyme-lignin adsorption and could potentially be used to design improved cellulase cocktails, thus lowering the overall cost of biofuel production.
authors.affiliation: From the Biosciences Center and.
authors.forename: Deanne W
authors.initials: DW
authors.lastname: Sammond
authors.affiliation: From the Biosciences Center and.
authors.forename: John M
authors.initials: JM
authors.lastname: Yarbrough
authors.affiliation: the Applied Chemicals and Materials Division, National Institute for Standards and Technology, Boulder, Colorado 80305, and.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Mansfield
authors.affiliation: From the Biosciences Center and.
authors.forename: Yannick J
authors.initials: YJ
authors.lastname: Bomble
authors.affiliation: From the Biosciences Center and.
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Hobdey
authors.affiliation: From the Biosciences Center and.
authors.forename: Stephen R
authors.initials: SR
authors.lastname: Decker
authors.affiliation: From the Biosciences Center and.
authors.forename: Larry E
authors.initials: LE
authors.lastname: Taylor
authors.affiliation: From the Biosciences Center and National Bioenergy Center, National Renewable Energy Laboratory, Golden, Colorado 80401.
authors.forename: Michael G
authors.initials: MG
authors.lastname: Resch
authors.affiliation: the Center for Renewable Carbon, Center for the Catalytic Conversion of Biomass (C3Bio), University of Tennessee, Knoxville, Tennessee 37917.
authors.forename: Joseph J
authors.initials: JJ
authors.lastname: Bozell
authors.affiliation: From the Biosciences Center and.
authors.forename: Michael E
authors.initials: ME
authors.lastname: Himmel
authors.affiliation: From the Biosciences Center and.
authors.forename: Todd B
authors.initials: TB
authors.lastname: Vinzant
authors.affiliation: From the Biosciences Center and Michael.Crowley@nrel.gov.
authors.forename: Michael F
authors.initials: MF
authors.lastname: Crowley
mesh_terms: D000327:Adsorption; D001230:Aspergillus / Q000201:enzymology*; D005656:Fungal Proteins / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D008031:Lignin / Q000737:chemistry*; D010105:Oxygenases / Q000737:chemistry*; D058525:Quartz Crystal Microbalance Techniques
chemical_list: D005656:Fungal Proteins; D008031:Lignin; D010105:Oxygenases; C044391:ligninase
keywords: Cellulase; Enzyme Inhibitor; Glycoside Hydrolase; Hydrophobic Interaction; Lignin; Protein Chemistry; Protein Engineering