TY - JOUR
T1 - Evolving a lipase for hydrolysis of natural triglycerides along with enhanced tolerance towards a protease and surfactants
AU - Alfaro-Chávez, Ana L.
AU - Liu, Jian Wei
AU - Stevenson, Bradley J.
AU - Goldman, Adrian
AU - Ollis, David L.
N1 - Publisher Copyright:
© The Author(s) 2019. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: [email protected].
PY - 2019/12/13
Y1 - 2019/12/13
N2 - In the accompanying paper, we described evolving a lipase to the point where variants were soluble, stable and capable of degrading C8 TAG and C8 esters. These variants were tested for their ability to survive in an environment that might be encountered in a washing machine. Unfortunately, they were inactivated both by treatment with a protease used in laundry detergents and by very low concentrations of sodium dodecyl sulfate (SDS). In addition, all the variants had very low levels of activity with triglycerides with long aliphatic chains and with naturally occurring oils, like olive oil. Directed evolution was used to select variants with enhanced properties. In the first 10 rounds of evolution, the primary screen was selected for variants capable of hydrolyzing olive oil whereas the secondary screen was selected for enhanced tolerance towards a protease and SDS. In the final six rounds of evolution, the primary and secondary screens identified variants that retained activity after treatment with SDS. Sixteen cycles of evolution gave variants with greatly enhanced lipolytic activity on substrates that had both long (C16 and C18) as well as short (C3 and C8) chains. We found variants that were stable for more than 3 hours in protease concentrations that rapidly degrade the wild-type enzyme. Enhanced tolerance towards SDS was found in variants that could break down naturally occurring lipid and resist protease attack. The amino acid changes that gave enhanced properties were concentrated in the cap domain responsible for substrate binding.
AB - In the accompanying paper, we described evolving a lipase to the point where variants were soluble, stable and capable of degrading C8 TAG and C8 esters. These variants were tested for their ability to survive in an environment that might be encountered in a washing machine. Unfortunately, they were inactivated both by treatment with a protease used in laundry detergents and by very low concentrations of sodium dodecyl sulfate (SDS). In addition, all the variants had very low levels of activity with triglycerides with long aliphatic chains and with naturally occurring oils, like olive oil. Directed evolution was used to select variants with enhanced properties. In the first 10 rounds of evolution, the primary screen was selected for variants capable of hydrolyzing olive oil whereas the secondary screen was selected for enhanced tolerance towards a protease and SDS. In the final six rounds of evolution, the primary and secondary screens identified variants that retained activity after treatment with SDS. Sixteen cycles of evolution gave variants with greatly enhanced lipolytic activity on substrates that had both long (C16 and C18) as well as short (C3 and C8) chains. We found variants that were stable for more than 3 hours in protease concentrations that rapidly degrade the wild-type enzyme. Enhanced tolerance towards SDS was found in variants that could break down naturally occurring lipid and resist protease attack. The amino acid changes that gave enhanced properties were concentrated in the cap domain responsible for substrate binding.
KW - Lip3
KW - directed evolution
KW - lipase
KW - protease tolerance
KW - surfactant tolerance
UR - http://www.scopus.com/inward/record.url?scp=85076446908&partnerID=8YFLogxK
U2 - 10.1093/protein/gzz023
DO - 10.1093/protein/gzz023
M3 - Article
SN - 1741-0126
VL - 32
SP - 129
EP - 143
JO - Protein Engineering, Design and Selection
JF - Protein Engineering, Design and Selection
IS - 3
ER -