The effect of thermodynamic properties of solvent mixtures explains the difference between methanol and ethanol in C.antarctica lipase B catalyzed alcoholysis
Kinetic modelling, molecular modelling, and experimental determination of the initial reaction velocity of lipase-catalyzed alcoholysis were combined to study the effect of the alcohol substrate to catalytic activity. The model system consisted of methanol or ethanol at varying concentrations, vinyl...
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ftunivmilanobic:oai:boa.unimib.it:10281/89369 2024-04-14T08:04:38+00:00 The effect of thermodynamic properties of solvent mixtures explains the difference between methanol and ethanol in C.antarctica lipase B catalyzed alcoholysis SASSO, FRANCESCO Kulschewski T Secundo F LOTTI, MARINA Pleiss J. Sasso, F Kulschewski, T Secundo, F Lotti, M Pleiss, J 2015 STAMPA http://hdl.handle.net/10281/89369 https://doi.org/10.1016/j.jbiotec.2015.08.023 eng eng Elsevier info:eu-repo/semantics/altIdentifier/pmid/26325200 info:eu-repo/semantics/altIdentifier/wos/WOS:000365364900001 volume:214 firstpage:1 lastpage:8 numberofpages:8 journal:JOURNAL OF BIOTECHNOLOGY http://hdl.handle.net/10281/89369 doi:10.1016/j.jbiotec.2015.08.023 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-84941280266 Model Thermodynamic activity Toluene Vinyl acetate BIO/10 - BIOCHIMICA info:eu-repo/semantics/article 2015 ftunivmilanobic https://doi.org/10.1016/j.jbiotec.2015.08.023 2024-03-21T17:18:19Z Kinetic modelling, molecular modelling, and experimental determination of the initial reaction velocity of lipase-catalyzed alcoholysis were combined to study the effect of the alcohol substrate to catalytic activity. The model system consisted of methanol or ethanol at varying concentrations, vinyl acetate as ester substrate 15.2% (v/v), toluene as organic solvent, water at a controlled thermodynamic activity of 0.09, and C. antarctica lipase B as enzyme. For both alcohol substrates, the initial reaction velocity increased sharply at low concentrations and reached a maximum at 0.7% (v/v) for methanol and 2% (v/v) for ethanol. For higher concentrations, the reaction rate decreased to a level of 74% and 60% of the peak value, respectively, due to substrate inhibition. The concentration dependency was described by a kinetic model, including a ping-pong bi-bi mechanism and competitive inhibition by the alcohol, and confirmed previous observations that methanol is more efficiently inhibiting the enzyme than ethanol. However, if the initial reaction velocity was expressed in terms of thermodynamic activity of the two alcohol substrates, the maximum of initial reaction velocity was similar for methanol (aMeOHmax=0.19) and ethanol (aEtOHmax=0.21). This was confirmed by molecular modelling which resulted in similar KM (0.22 and 0.19) and Ki values (0.44 and 0.49) for methanol and ethanol, respectively, if expressed in thermodynamic activities. Thus, the experimentally observed difference between methanol and ethanol is not due to differences in interaction with the enzyme but is a consequence of the thermodynamics of the substrate-solvent mixture. For low concentrations in toluene, the activity coefficient of methanol is 40% higher than the activity coefficient of ethanol (γMeOH=8.5, γEtOH=6.1). Article in Journal/Newspaper Antarc* Antarctica Università degli Studi di Milano-Bicocca: BOA (Bicocca Open Archive) Journal of Biotechnology 214 1 8 |
institution |
Open Polar |
collection |
Università degli Studi di Milano-Bicocca: BOA (Bicocca Open Archive) |
op_collection_id |
ftunivmilanobic |
language |
English |
topic |
Model Thermodynamic activity Toluene Vinyl acetate BIO/10 - BIOCHIMICA |
spellingShingle |
Model Thermodynamic activity Toluene Vinyl acetate BIO/10 - BIOCHIMICA SASSO, FRANCESCO Kulschewski T Secundo F LOTTI, MARINA Pleiss J. The effect of thermodynamic properties of solvent mixtures explains the difference between methanol and ethanol in C.antarctica lipase B catalyzed alcoholysis |
topic_facet |
Model Thermodynamic activity Toluene Vinyl acetate BIO/10 - BIOCHIMICA |
description |
Kinetic modelling, molecular modelling, and experimental determination of the initial reaction velocity of lipase-catalyzed alcoholysis were combined to study the effect of the alcohol substrate to catalytic activity. The model system consisted of methanol or ethanol at varying concentrations, vinyl acetate as ester substrate 15.2% (v/v), toluene as organic solvent, water at a controlled thermodynamic activity of 0.09, and C. antarctica lipase B as enzyme. For both alcohol substrates, the initial reaction velocity increased sharply at low concentrations and reached a maximum at 0.7% (v/v) for methanol and 2% (v/v) for ethanol. For higher concentrations, the reaction rate decreased to a level of 74% and 60% of the peak value, respectively, due to substrate inhibition. The concentration dependency was described by a kinetic model, including a ping-pong bi-bi mechanism and competitive inhibition by the alcohol, and confirmed previous observations that methanol is more efficiently inhibiting the enzyme than ethanol. However, if the initial reaction velocity was expressed in terms of thermodynamic activity of the two alcohol substrates, the maximum of initial reaction velocity was similar for methanol (aMeOHmax=0.19) and ethanol (aEtOHmax=0.21). This was confirmed by molecular modelling which resulted in similar KM (0.22 and 0.19) and Ki values (0.44 and 0.49) for methanol and ethanol, respectively, if expressed in thermodynamic activities. Thus, the experimentally observed difference between methanol and ethanol is not due to differences in interaction with the enzyme but is a consequence of the thermodynamics of the substrate-solvent mixture. For low concentrations in toluene, the activity coefficient of methanol is 40% higher than the activity coefficient of ethanol (γMeOH=8.5, γEtOH=6.1). |
author2 |
Sasso, F Kulschewski, T Secundo, F Lotti, M Pleiss, J |
format |
Article in Journal/Newspaper |
author |
SASSO, FRANCESCO Kulschewski T Secundo F LOTTI, MARINA Pleiss J. |
author_facet |
SASSO, FRANCESCO Kulschewski T Secundo F LOTTI, MARINA Pleiss J. |
author_sort |
SASSO, FRANCESCO |
title |
The effect of thermodynamic properties of solvent mixtures explains the difference between methanol and ethanol in C.antarctica lipase B catalyzed alcoholysis |
title_short |
The effect of thermodynamic properties of solvent mixtures explains the difference between methanol and ethanol in C.antarctica lipase B catalyzed alcoholysis |
title_full |
The effect of thermodynamic properties of solvent mixtures explains the difference between methanol and ethanol in C.antarctica lipase B catalyzed alcoholysis |
title_fullStr |
The effect of thermodynamic properties of solvent mixtures explains the difference between methanol and ethanol in C.antarctica lipase B catalyzed alcoholysis |
title_full_unstemmed |
The effect of thermodynamic properties of solvent mixtures explains the difference between methanol and ethanol in C.antarctica lipase B catalyzed alcoholysis |
title_sort |
effect of thermodynamic properties of solvent mixtures explains the difference between methanol and ethanol in c.antarctica lipase b catalyzed alcoholysis |
publisher |
Elsevier |
publishDate |
2015 |
url |
http://hdl.handle.net/10281/89369 https://doi.org/10.1016/j.jbiotec.2015.08.023 |
genre |
Antarc* Antarctica |
genre_facet |
Antarc* Antarctica |
op_relation |
info:eu-repo/semantics/altIdentifier/pmid/26325200 info:eu-repo/semantics/altIdentifier/wos/WOS:000365364900001 volume:214 firstpage:1 lastpage:8 numberofpages:8 journal:JOURNAL OF BIOTECHNOLOGY http://hdl.handle.net/10281/89369 doi:10.1016/j.jbiotec.2015.08.023 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-84941280266 |
op_doi |
https://doi.org/10.1016/j.jbiotec.2015.08.023 |
container_title |
Journal of Biotechnology |
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214 |
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1 |
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8 |
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1796301296608739328 |