DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Substitution of distal and active site residues reduces product inhibition of E1 from Acidothermus Cellulolyticus

Journal Article · · Protein Engineering, Design and Selection

Abstract Cellulases are largely afflicted by inhibition from their reaction products, especially at high-substrate loading, which represents a major challenge for biomass processing. This challenge was overcome for endoglucanase 1 (E1) from Acidothermus cellulolyticus by identifying a large conformational change involving distal residues upon binding cellobiose. Having introduced alanine substitutions at each of these residues, we identified several mutations that reduced cellobiose inhibition of E1, including W212A, W213A, Q247A, W249A and F250A. One of the mutations (W212A) resulted in a 47-fold decrease in binding affinity of cellobiose as well as a 5-fold increase in the kcat. The mutation further increased E1 activity on Avicel and dilute-acid treated corn stover and enhanced its productivity at high-substrate loadings. These findings were corroborated by funnel metadynamics, which showed that the W212A substitution led to reduced affinity for cellobiose in the +1 and +2 binding sites due to rearrangement of key cellobiose-binding residues.

Research Organization:
National Renewable Energy Laboratory (NREL), Golden, CO (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Office of Workforce Development for Teachers & Scientists (WDTS); USDOE Office of Science (SC), Workforce Development for Teachers and Scientists (WDTS)
Grant/Contract Number:
AC36-08GO28308; SC0014664
OSTI ID:
1837094
Report Number(s):
NREL/JA--2700-81872; gzab031
Journal Information:
Protein Engineering, Design and Selection, Journal Name: Protein Engineering, Design and Selection Vol. 34; ISSN 1741-0126
Publisher:
Oxford University PressCopyright Statement
Country of Publication:
United Kingdom
Language:
English

References (38)

LINCS: A linear constraint solver for molecular simulations journal September 1997
The challenge of enzyme cost in the production of lignocellulosic biofuels journal November 2011
Charge engineering of cellulases improves ionic liquid tolerance and reduces lignin inhibition: Impact of Charge on Cellulase Activity in ILs journal March 2014
Alleviating product inhibition in cellulase enzyme Cel7A: Alleviating Product Inhibition in Cel7A journal September 2015
Inhibition ofTrichoderma reesei cellulase by sugars and solvents journal July 1990
GLYCAM06: A generalizable biomolecular force field. Carbohydrates: GLYCAM06 journal September 2007
Strategies to reduce end-product inhibition in family 48 glycoside hydrolases: Reducing Product Inhibition in Glycoside Hydrolases journal February 2016
The Crystal Structure of a Family 5 Endoglucanase Mutant in Complexed and Uncomplexed Forms Reveals an Induced Fit Activation Mechanism journal April 1996
Insights into ligand-induced conformational change in Cel5A from Bacillus agaradhaerens revealed by a catalytically active crystal form journal March 2000
Cellulase recycling in biorefineries—is it possible? journal March 2015
Enhanced enzymatic cellulose degradation by cellobiohydrolases via product removal journal October 2012
Cellulose Hydrolysis by Cellobiohydrolase Cel7A Shows Mixed Hyperbolic Product Inhibition journal April 2011
Nonphysical sampling distributions in Monte Carlo free-energy estimation: Umbrella sampling journal February 1977
Engineering the Exo-loop of Trichoderma reesei Cellobiohydrolase, Cel7A. A comparison with Phanerochaete chrysosporium Cel7D journal October 2003
Design and operation of an integrated membrane reactor for enzymatic cellulose hydrolysis journal December 2002
Enzymatic hydrolysis of biomass at high-solids loadings – A review journal September 2013
Reactor design for minimizing product inhibition during enzymatic lignocellulose hydrolysis: I. Significance and mechanism of cellobiose and glucose inhibition on cellulolytic enzymes journal May 2010
Reactor design for minimizing product inhibition during enzymatic lignocellulose hydrolysis journal May 2010
PLUMED: A portable plugin for free-energy calculations with molecular dynamics journal October 2009
Carbohydrate – Protein aromatic ring interactions beyond CH/π interactions: A Protein Data Bank survey and quantum chemical calculations journal August 2020
GROMACS: High performance molecular simulations through multi-level parallelism from laptops to supercomputers journal September 2015
ff14SB: Improving the Accuracy of Protein Side Chain and Backbone Parameters from ff99SB journal July 2015
Mechanism of Competitive Inhibition and Destabilization of Acidothermus cellulolyticus Endoglucanase 1 by Ionic Liquids journal November 2017
Enhanced Activity and Stability of Acidothermus cellulolyticus Endoglucanase 1 in Ionic Liquids via Engineering Active Site Residues and Non-Native Disulfide Bridges journal July 2020
Crystal Structure of Thermostable Family 5 Endocellulase E1 from Acidothermus cellulolyticus in Complex with Cellotetraose , journal January 1996
Snapshots along an Enzymatic Reaction Coordinate:  Analysis of a Retaining β-Glycoside Hydrolase , journal August 1998
Fungal Cellulases journal January 2015
Molecular Dynamics Simulations of Family 7 Cellobiohydrolase Mutants Aimed at Reducing Product Inhibition journal September 2014
Promoting transparency and reproducibility in enhanced molecular simulations journal July 2019
Ligand binding free-energy calculations with funnel metadynamics journal August 2020
Canonical sampling through velocity rescaling journal January 2007
Polymorphic transitions in single crystals: A new molecular dynamics method journal December 1981
Funnel metadynamics as accurate binding free-energy method journal April 2013
Probing Carbohydrate Product Expulsion from a Processive Cellulase with Multiple Absolute Binding Free Energy Methods journal March 2011
Three-dimensional structure of cellobiohydrolase II from Trichoderma reesei journal July 1990
Production of glucose by enzymatic hydrolysis of cellulose journal February 1968
Characterization and genomic analysis of kraft lignin biodegradation by the beta-proteobacterium Cupriavidus basilensis B-8 journal January 2013
Catalytically Enhanced Endocellulase Cel5A from Acidothermus cellulolyticus journal January 2005