Change search
Link to record
Permanent link

Direct link
BETA
Alternative names
Publications (7 of 7) Show all publications
Finnveden, M., Semlitsch, S., He, O. & Martinelle, M. (2019). Mono-substitution of symmetric diesters: selectivity of Mycobacterium smegmatis acyltransferase variants. Catalysis Science & Technology
Open this publication in new window or tab >>Mono-substitution of symmetric diesters: selectivity of Mycobacterium smegmatis acyltransferase variants
2019 (English)In: Catalysis Science & Technology, ISSN 2044-4753, E-ISSN 2044-4761Article in journal (Refereed) Published
Abstract [en]

A method for selectively reacting one, out of two identical carboxylic esters in a symmetric diester has been developed. An esterase from Mycobacterium smegmatis (MsAcT) has a restricted active site resulting in a narrow acyl donor specificity. This constraint was used to develop a selective synthesis route from divinyl adipate (a symmetric diester) towards mixed vinyl adipate esters. To find a suitable catalyst, the wild type (wt) MsAcT and two MsAcT variants: a single point mutant (L12A) and a double point mutant (T93A/F154A), were immobilized and studied under solvent-free conditions. Out of the tested catalysts, MsAcT L12A was the most selective for mono-transesterification of divinyl adipate. When divinyl adipate was reacted with 1.5 equivalents of a hydroxyl vinyl ether full conversion of DVA was observed yielding over 95% mixed diester. Furthermore, the limitations for longer dicarboxylic esters were studied, showing that MsAcT T93A/F154A tolerated up to at least dimethyl sebacate.

Place, publisher, year, edition, pages
Royal Society of Chemistry, 2019
National Category
Other Biological Topics
Identifiers
urn:nbn:se:kth:diva-256565 (URN)10.1039/C9CY01181A (DOI)000487788800006 ()2-s2.0-85072780268 (Scopus ID)
Funder
Swedish Research Council Formas, 211-2013-70
Note

QC 20190903

Available from: 2019-08-28 Created: 2019-08-28 Last updated: 2019-10-28Bibliographically approved
Nameer, S., Semlitsch, S., Martinelle, M. & Johansson, M. (2017). One-pot enzyme-catalyzed synthesis of dual-functional polyester macromers towards surface-active hydrophobic films. RSC Advances, 7(79), 50294-50299
Open this publication in new window or tab >>One-pot enzyme-catalyzed synthesis of dual-functional polyester macromers towards surface-active hydrophobic films
2017 (English)In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 7, no 79, p. 50294-50299Article in journal (Refereed) Published
Abstract [en]

Selective enzyme catalysis is a valuable tool for the processing of monomers into value-added materials. In the present study natural resources were used to retrieve an omega-hydroxy fatty acid monomer containing an epoxide functionality. A procedure was developed for the synthesis of dual-functional oligomers by utilizing lipase catalysis in a one-pot synthesis route. The chemoselectivity of the enzyme allowed addition of thiol monomers to the retrieved epoxy monomers, without harming the epoxides, achieving a thiol-epoxy functional polyester resin. The synthesis reached full conversion (> 99%) after 8 h. It was possible to selectively crosslink the resin through UV-initiated cationic polymerization of the epoxides into thiol-functional thermosets. The curing performance was followed in situ by real-time FTIR. The thiol groups on the surface of the film were accessible for post-modification.

Place, publisher, year, edition, pages
ROYAL SOC CHEMISTRY, 2017
National Category
Chemical Sciences
Identifiers
urn:nbn:se:kth:diva-217462 (URN)10.1039/c7ra09828f (DOI)000413944200060 ()2-s2.0-85032902830 (Scopus ID)
Note

QC 20171117

Available from: 2017-11-17 Created: 2017-11-17 Last updated: 2019-05-02Bibliographically approved
Torron, S., Semlitsch, S., Martinell, M. & Johansson, M. (2016). Biocatalytic Synthesis of Epoxy Resins from Fatty Acids as a Versatile Route for the Formation of Polymer Thermosets with Tunable Properties. Biomacromolecules, 17(12), 4003-4010
Open this publication in new window or tab >>Biocatalytic Synthesis of Epoxy Resins from Fatty Acids as a Versatile Route for the Formation of Polymer Thermosets with Tunable Properties
2016 (English)In: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 17, no 12, p. 4003-4010Article in journal (Refereed) Published
Abstract [en]

The work herein presented describes the synthesis and polymerization of series of bio-based epoxy resins prepared through lipase catalyzed transesterification. The epoxy-functional polyester resins with various architectures (linear, hi branched, and tetra-branched) were synthesized through condensation of fatty acids derived from epoxidized soybean oil and linseed oil with three different hydroxyl cores under bulk conditions. The selectivity of the lipases toward esterification/transesterification reactions allowed the formation of macromers with up to 12 epoxides in the backbone. The high degree of functionality of the resins resulted in polymer thermosets with T-g values ranging from 25 to over 100 degrees C prepared through cationic polymerization. The determining parameters of the synthesis and the mechanism for the formation of the species were determined through kinetic studies by H-1 NMR, SEC, and molecular modeling studies. The correlation between macromer structure and thermoset properties was studied through real-time FTIR measurements, DSC, and DMA.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2016
National Category
Biochemistry and Molecular Biology Polymer Technologies
Identifiers
urn:nbn:se:kth:diva-199493 (URN)10.1021/acs.biomac.6b01383 (DOI)000389787200017 ()2-s2.0-85006106040 (Scopus ID)
Note

QC 20170118

Available from: 2017-01-18 Created: 2017-01-09 Last updated: 2018-06-14Bibliographically approved
Semlitsch, S., Torron, S., Johansson, M. & Martinelle, M. (2016). Enzymatic catalysis as a versatile tool for the synthesis of multifunctional, bio-based oligoester resins. Green Chemistry, 18(7), 1923-1929
Open this publication in new window or tab >>Enzymatic catalysis as a versatile tool for the synthesis of multifunctional, bio-based oligoester resins
2016 (English)In: Green Chemistry, ISSN 1463-9262, E-ISSN 1463-9270, Vol. 18, no 7, p. 1923-1929Article in journal (Refereed) Published
Abstract [en]

The use of enzymes as selective catalysts for processing renewable monomers into added value polymers and materials has received increased attention during the last decade. In the present work Candida antarctica lipase B (CalB) was used as catalyst in one-pot routes to synthesise multifunctional oligoester resins based on an epoxy-functional omega-hydroxy-fatty acid (EFA) extracted from birch bark. The chemoselective enzymatic process resulted in three different EFA-based telechelic oligomers with targeted molecular weights; containing maleimide, methacrylate or oxetane as end-groups, respectively. The enzyme catalysed synthesis of the maleimide and the oxetane telechelic oligomers reached full conversion of monomers (>95%) after 2 h. In the case of methacrylate functional oligomer the EFA monomer reached full conversion (>98%) after 2 h but the integration of the methacrylate moiety took more than 10 h. This was due to a rate limiting reaction path using ethylene glycol dimethacrylate as substrate. The oligomer products were characterised by NMR, MALDI-TOF-MS and SEC.

Place, publisher, year, edition, pages
Royal Society of Chemistry, 2016
Keywords
Ring-Opening Polymerization, Suberin Monomer, Lipase, Polyesters, Route, Chemistry, Polymers, Acids, Bark
National Category
Polymer Chemistry
Identifiers
urn:nbn:se:kth:diva-185665 (URN)10.1039/c5gc02597d (DOI)000372981400012 ()2-s2.0-84962377189 (Scopus ID)
Funder
EU, FP7, Seventh Framework Programme, 289253
Note

QC 20160426

Available from: 2016-04-26 Created: 2016-04-25 Last updated: 2018-04-11Bibliographically approved
Torron, S., Semlitsch, S., Martinelle, M. & Johansson, M. (2014). Polymer Thermosets from Multifunctional Polyester Resins Based on Renewable Monomers. Macromolecular Chemistry and Physics, 215(22), 2198-2206
Open this publication in new window or tab >>Polymer Thermosets from Multifunctional Polyester Resins Based on Renewable Monomers
2014 (English)In: Macromolecular Chemistry and Physics, ISSN 1022-1352, E-ISSN 1521-3935, Vol. 215, no 22, p. 2198-2206Article in journal (Refereed) Published
Abstract [en]

The use of monomers based on natural materials as a future supply of raw materials has gained more interest in the last decade. Sources ranging from wood to plant oils and algae are exploited as alternatives to traditional fossil-based resources for the synthesis of polymeric materials. The use of these raw materials is not only of interest because of its abundance, but also in terms of price, durability, and/or biodegradability. In the present study, a series of resins utilizing a monomer derived from birch bark is prepared. The thermoset resins are formed by reacting an epoxy-functional omega-hydroxy fatty acid with methacrylate monomers using enzyme catalysis to form multifunctional resins via a one-pot synthesis. The derived oligomers are crosslinked through different polymerization routes to produce thermosets with different properties and/or functionalities. This approach allows natural-based resins with tuned functionalities and mechanical and thermal properties to be obtained.

Keywords
dual curing, enzymatic catalysis, renewable monomers, suberin
National Category
Polymer Technologies
Identifiers
urn:nbn:se:kth:diva-158419 (URN)10.1002/macp.201400192 (DOI)000345444200006 ()2-s2.0-84913620344 (Scopus ID)
Note

QC 20150107

Available from: 2015-01-07 Created: 2015-01-07 Last updated: 2017-12-05Bibliographically approved
Hendil-Forssell, P., Semlitsch, S. & Martinelle, M.Engineering the esterase/acyltransferase from Mycobacterium smegmatis: extended substrate scope for amide synthesis in water.
Open this publication in new window or tab >>Engineering the esterase/acyltransferase from Mycobacterium smegmatis: extended substrate scope for amide synthesis in water
(English)Manuscript (preprint) (Other academic)
Abstract [en]

Some esterases/lipases display high acyl transfer activity, favoring alcoholysis over hydrolysis, which make them valuable catalysts for synthesis reactions in aqueous media. An esterase from Mycobacterium smegmatis, MsAcT, has been characterized as an efficient catalyst for ester synthesis in water. The acyl donor specificity for MsAcT was however found to be very narrow and the enzyme displayed no activity towards esters with larger acyl group than butyrate. With rational engineering, the narrow acyl donor specificity of wild type MsAcT enzyme was altered and variants displaying extended substrate scope were generated. A double mutant, T93A/F154A, could accommodate methyl nonanoate as substrate, i.e. five carbons longer acyl group as compared to wild type, without compromising the acyl transfer capabilities. With similar selectivity towards a broad range of acyl donors (propionate to nonanoate) this is a more applicable catalyst than the wild type. Furthermore, the T93A/F154A variant was an efficient catalyst for synthesis of N-benzylhexanamide in water using methyl hexanoate as acyl donor, which is not a substrate for the wild type enzyme. The conversion reached 81% and the enzyme variant could potentially be used to produce amides in water with a wide variety of acyl donors.

National Category
Biocatalysis and Enzyme Technology
Research subject
Biotechnology
Identifiers
urn:nbn:se:kth:diva-196890 (URN)
Note

QC 20161129

Available from: 2016-11-24 Created: 2016-11-24 Last updated: 2017-08-23Bibliographically approved
Hendil-Forssell, P., Semlitsch, S. & Martinelle, M.Rational engineering of an esterase/acyltransferase for improved amidase specificity in amide synthesis and hydrolysis.
Open this publication in new window or tab >>Rational engineering of an esterase/acyltransferase for improved amidase specificity in amide synthesis and hydrolysis
(English)Manuscript (preprint) (Other academic)
Abstract [en]

The esterase/acyltransferase from Mycobacterium smegmatis, MsAcT, display high acyltransfer capacity in water media with demonstrations found for both ester and amide syntheses. However, it has recently been discovered that esterases in contrast to amidases lack a key hydrogen bond in the transition state, donated by the scissile NH-group of the substrate. Esterases with improved amidase performance have been achieved with the introduction of amino-acid side chains or water network as hydrogen bond acceptors. Using the esterase from Mycobacterium smegmatis, MsAcT, the influence of this hydrogen bond was studied in both amide hydrolysis and synthesis, using a rational engineering approach. Two positions were selected for mutagenesis and enzyme variants with improved performance in amide synthesis and hydrolysis were generated. Compared to the wild-type, variant F154A had the highest absolute increase in amidase specificity (11-fold) and I194Q had the greatest change in relative amidase versus esterase reaction specificity (160-fold). The relative reaction specificities for amide over ester synthesis followed a similar trend as that of hydrolysis and the best variant was I194Q with a 32-fold increase compared to wt. Based on MD-simulations water seems to play an important role in the transition state as a hydrogen bond bridge between the NH-group of the amide substrate and the enzyme.

National Category
Biocatalysis and Enzyme Technology
Research subject
Biotechnology
Identifiers
urn:nbn:se:kth:diva-196891 (URN)
Note

QC 20161129

Available from: 2016-11-24 Created: 2016-11-24 Last updated: 2016-11-29Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-2644-0752

Search in DiVA

Show all publications