Michel Eppink | Wageningen University (original) (raw)

Papers by Michel Eppink

Research paper thumbnail of Efficient Fractionation of Lipids in a Multiproduct Microalgal Biorefinery by Polymers and Ionic Liquid-Based Aqueous Two-Phase Systems

ACS Sustainable Chemistry & Engineering, 2021

Research paper thumbnail of High-throughput process development of chromatography steps : Advantages and limitations of different formats

Research Article Strategic Assay Selection for analytics in high-throughput process development: ... more Research Article Strategic Assay Selection for analytics in high-throughput process development: Case studies for downstream processing of monoclonal antibodies Spyridon Konstantinidis, Simyee Kong, Sunil Chhatre, Ajoy Velayudhan, Eva Heldin and Nigel Titchener-Hooker http://dx.doi.org/10.1002/biot.201100476 Technical Report Self-packed filter plates: A good alternative for pre-packed filter plates for developing purification processes for therapeutic proteins Xiaonan Li, Guy de Roo, Kim Burgers, Marcel Ottens and Michel Eppink http://dx.doi.org/10.1002/biot.201200045

Research paper thumbnail of Automation and miniaturization: enabling tools for fast, high‐throughput process development in integrated continuous biomanufacturing

Journal of Chemical Technology & Biotechnology, 2021

Research paper thumbnail of Multiproduct Microalgae Biorefineries Mediated by Ionic Liquids

Trends in Biotechnology, 2021

Research paper thumbnail of Selective fractionation of free glucose and starch from microalgae using aqueous two-phase systems

Research paper thumbnail of Flow cytometry to estimate the cell disruption yield and biomass release of Chlorella sp. during bead milling

Research paper thumbnail of Pulsed Electric Field for protein release of the microalgae Chlorella vulgaris and Neochloris oleoabundans

Research paper thumbnail of Influence of nitrogen depletion in the growth of N. oleoabundans on the release of cellular components after beadmilling

Bioresource technology, Jan 19, 2016

Cell disruption by bead milling of Neochloris oleoabundans grown under nitrogen repleted (NR) and... more Cell disruption by bead milling of Neochloris oleoabundans grown under nitrogen repleted (NR) and nitrogen depleted (ND) conditions was evaluated based on the release of biochemicals and biomass to the supernatant. Additionally, energy consumption for cell disruption was calculated per kg of released component. Bead milling of NR cells resulted on average in 34% (w/w) release of biochemicals into the supernatant, with a similar composition as the untreated microalgal biomass. With ND cells, the release was higher and more selective, i.e. 57%, 59%, 68% and 56% (w/w) of respectively biomass, proteins, carbohydrates and lipids whereof 92%, 57% and 46% (w/w) respectively of phospho-, glyco- and neutral lipids.

Research paper thumbnail of Label-Free Glycoprofiling with Multiplex Surface Plasmon Resonance: A Tool To Quantify Sialylation of Erythropoietin

Analytical Chemistry, 2015

Protein glycosylation is among the most common and well-defined post-translational modifications ... more Protein glycosylation is among the most common and well-defined post-translational modifications due to its vital role in protein function. Monitoring variation in glycosylation is necessary for producing more effective therapeutic proteins. Glycans attached to glycoproteins interact highly specific with lectins, natural carbohydrate-binding proteins, which property is used in the current label-free methodology. We have established a lectin microarray for label-free detection of lectin-carbohydrate interactions allowing us to study protein glycosylation directly on unmodified glycoproteins. The method enables simultaneous measurement of up to 96 lectin-carbohydrate interactions on a multiplex surface plasmon resonance imaging platform within 20 min. Specificity determination of lectins succeeded by analysis of neoglycoproteins and enzymatically remodeled glycoproteins to verify carbohydrate binding. We demonstrated the possibilities for glycosylation fingerprinting by comparing different Erythropoietin sources without the need for any sample pretreatment and we were able to accurately quantify relative sialylation levels of Erythropoietin.

Research paper thumbnail of Abstract 2651: Impressive efficacy and safety profile of a novel generation duocarmycin-based HER2-targeting ADC

Cancer Research, 2014

We have built a linker-drug platform based on a cleavable linker-duocarmycin payload for the deve... more We have built a linker-drug platform based on a cleavable linker-duocarmycin payload for the development of novel generation antibody-drug conjugates. SYD983, a lead ADC originating from that platform, is a cysteine-coupled HER2-targeting ADC based on trastuzumab. SYD983 is a heterogeneous product that consists of a mixture of naked Ab and ADCs with a drug-to-antibody ratio (DAR) of 2, 4, 6, the mean DAR being 2.0. We have shown that SYD983 binds to HER2, induces antibody-dependent cell-mediated cytotoxicity, and is efficiently internalized into HER2-expressing cells. SYD983 very potently kills HER2-expressing cells in vitro and is inactive in cells that don't express HER2. SYD983 is stable in human and cynomolgus monkey (CM) plasma in vitro but has relatively poor stability in mouse plasma. The latter is due to mouse-specific carboxylesterase (CES1c) since stability of SYD983 in plasma of CES1c knockout mice is similar to that in human and CM plasma. SYD983 could be dosed up to...

Research paper thumbnail of Identification of a novel conserved sequence motif in flavoprotein hydroxylases with a putative dual function in FAD/NAD(P)H binding

Research paper thumbnail of Selective cysteine ← serine replacements in p -hydroxybenzoate hydroxylase from Pseudomonas fluorescens allow the unambiguous assignment of Cys211 as the site of modification by spin-labeled p -chloromercuribenzoate

"Protein Engineering, Design and Selection", 1994

p-Hydroxybenzoate hydroxylase from Pseudomonas fluorescens contains five sulfhydryl groups per su... more p-Hydroxybenzoate hydroxylase from Pseudomonas fluorescens contains five sulfhydryl groups per subunit. Cysteine-->serine replacements show that the thiols are not essential for catalysis. The increased dissociation constant for FAD in mutant Cys158Ser suggests that Cys158 is important for the solvation of the pyrophosphate moiety of the prosthetic group. Wild-type p-hydroxybenzoate hydroxylase is rapidly inactivated by mercurial compounds. Inactivation by a spin-labeled derivative of p-chloromercuribenzoate is fully abolished in mutant Cys211Ser. Incorporation of the spin label in the other Cys-->Ser mutants strongly impairs substrate binding without affecting the catalytic properties of the FAD. The results are discussed with respect to previous tentative assignments from chemical modification studies and in light of the 3-D structure of the enzyme-substrate complex.

Research paper thumbnail of Crystal structure of p-hydroxybenzoate hydroxylase complexed with its reaction product 3,4-dihydroxybenzoate

Journal of Molecular Biology, 1988

Research paper thumbnail of Omics tools in accelerated purification process development: Multidimensional fractionation and characterization of crude protein mixtures

Journal of Bioscience and Bioengineering, 2009

Research paper thumbnail of Stereoselective Carveol Dehydrogenase from Rhodococcus erythropolis DCL14

Journal of Biological Chemistry, 1999

Research paper thumbnail of Seven new mutations in the nicotinamide adenine dinucleotide reduced–cytochrome b5 reductase gene leading to methemoglobinemia type I

Blood, 2001

Cytochrome b5 reductase (b5R) deficiency manifests itself in 2 distinct ways. In methemoglobinemi... more Cytochrome b5 reductase (b5R) deficiency manifests itself in 2 distinct ways. In methemoglobinemia type I, the patients only suffer from cyanosis, whereas in type II, the patients suffer in addition from severe mental retardation and neurologic impairment. Biochemical data indicate that this may be due to a difference in mutations, causing enzyme instability in type I and complete enzyme deficiency or enzyme inactivation in type II. We have investigated 7 families with methemoglobulinemia type I and found 7 novel mutations in the b5R gene. Six of these mutations predicted amino acid substitutions at sites not involved in reduced nicotinamide adenine dinucleotide (NADH) or flavin adenine dinucleotide (FAD) binding, as deduced from a 3-dimensional model of human b5R. This model was constructed from comparison with the known 3-dimensional structure of pig b5R. The seventh mutation was a splice site mutation leading to skipping of exon 5 in messenger RNA, present in heterozygous form in...

Research paper thumbnail of Multi-dimensional fractionation and characterization of crude protein mixtures: Toward establishment of a database of protein purification process development parameters

Biotechnology and Bioengineering, 2012

A multi-dimensional fractionation and characterization scheme was developed for fast acquisition ... more A multi-dimensional fractionation and characterization scheme was developed for fast acquisition of the relevant molecular properties for protein separation from crude biological feedstocks by ion-exchange chromatography (IEX), hydrophobic interaction chromatography (HIC), and size-exclusion chromatography. In this approach, the linear IEX isotherm parameters were estimated from multiple linear salt-gradient IEX data, while the nonlinear IEX parameters as well as the HIC isotherm parameters were obtained by the inverse method under column overloading conditions. Collected chromatographic fractions were analyzed by gel electrophoresis for estimation of molecular mass, followed by mass spectrometry for protein identification. The usefulness of the generated molecular properties data for rational decision-making during downstream process development was equally demonstrated. Monoclonal antibody purification from crude hybridoma cell culture supernatant was used as case study. The obtained chromatographic parameters only apply to the employed stationary phases and operating conditions, hence prior high throughput screening of different chromatographic resins and mobile phase conditions is still a prerequisite. Nevertheless, it provides a quick, knowledge-based approach for rationally synthesizing purification cascades prior to more detailed process optimization and evaluation.

Research paper thumbnail of High-throughput and multiplexed regeneration buffer scouting for affinity-based interactions

Analytical Biochemistry, 2014

Research paper thumbnail of Cell disruption for microalgae biorefineries

Biotechnology advances

Microalgae are a potential source for various valuable chemicals for commercial applications rang... more Microalgae are a potential source for various valuable chemicals for commercial applications ranging from nutraceuticals to fuels. Objective in a biorefinery is to utilize biomass ingredients efficiently similarly to petroleum refineries in which oil is fractionated in fuels and a variety of products with higher value. Downstream processes in microalgae biorefineries consist of different steps whereof cell disruption is the most crucial part. To maintain the functionality of algae biochemicals during cell disruption while obtaining high disruption yields is an important challenge. Despite this need, studies on mild disruption of microalgae cells are limited. This review article focuses on the evaluation of conventional and emerging cell disruption technologies, and a comparison thereof with respect to their potential for the future microalgae biorefineries. The discussed techniques are bead milling, high pressure homogenization, high speed homogenization, ultrasonication, microwave ...

Research paper thumbnail of Combined bead milling and enzymatic hydrolysis for efficient fractionation of lipids, proteins, and carbohydrates of Chlorella vulgaris microalgae

Research paper thumbnail of Efficient Fractionation of Lipids in a Multiproduct Microalgal Biorefinery by Polymers and Ionic Liquid-Based Aqueous Two-Phase Systems

ACS Sustainable Chemistry & Engineering, 2021

Research paper thumbnail of High-throughput process development of chromatography steps : Advantages and limitations of different formats

Research Article Strategic Assay Selection for analytics in high-throughput process development: ... more Research Article Strategic Assay Selection for analytics in high-throughput process development: Case studies for downstream processing of monoclonal antibodies Spyridon Konstantinidis, Simyee Kong, Sunil Chhatre, Ajoy Velayudhan, Eva Heldin and Nigel Titchener-Hooker http://dx.doi.org/10.1002/biot.201100476 Technical Report Self-packed filter plates: A good alternative for pre-packed filter plates for developing purification processes for therapeutic proteins Xiaonan Li, Guy de Roo, Kim Burgers, Marcel Ottens and Michel Eppink http://dx.doi.org/10.1002/biot.201200045

Research paper thumbnail of Automation and miniaturization: enabling tools for fast, high‐throughput process development in integrated continuous biomanufacturing

Journal of Chemical Technology & Biotechnology, 2021

Research paper thumbnail of Multiproduct Microalgae Biorefineries Mediated by Ionic Liquids

Trends in Biotechnology, 2021

Research paper thumbnail of Selective fractionation of free glucose and starch from microalgae using aqueous two-phase systems

Research paper thumbnail of Flow cytometry to estimate the cell disruption yield and biomass release of Chlorella sp. during bead milling

Research paper thumbnail of Pulsed Electric Field for protein release of the microalgae Chlorella vulgaris and Neochloris oleoabundans

Research paper thumbnail of Influence of nitrogen depletion in the growth of N. oleoabundans on the release of cellular components after beadmilling

Bioresource technology, Jan 19, 2016

Cell disruption by bead milling of Neochloris oleoabundans grown under nitrogen repleted (NR) and... more Cell disruption by bead milling of Neochloris oleoabundans grown under nitrogen repleted (NR) and nitrogen depleted (ND) conditions was evaluated based on the release of biochemicals and biomass to the supernatant. Additionally, energy consumption for cell disruption was calculated per kg of released component. Bead milling of NR cells resulted on average in 34% (w/w) release of biochemicals into the supernatant, with a similar composition as the untreated microalgal biomass. With ND cells, the release was higher and more selective, i.e. 57%, 59%, 68% and 56% (w/w) of respectively biomass, proteins, carbohydrates and lipids whereof 92%, 57% and 46% (w/w) respectively of phospho-, glyco- and neutral lipids.

Research paper thumbnail of Label-Free Glycoprofiling with Multiplex Surface Plasmon Resonance: A Tool To Quantify Sialylation of Erythropoietin

Analytical Chemistry, 2015

Protein glycosylation is among the most common and well-defined post-translational modifications ... more Protein glycosylation is among the most common and well-defined post-translational modifications due to its vital role in protein function. Monitoring variation in glycosylation is necessary for producing more effective therapeutic proteins. Glycans attached to glycoproteins interact highly specific with lectins, natural carbohydrate-binding proteins, which property is used in the current label-free methodology. We have established a lectin microarray for label-free detection of lectin-carbohydrate interactions allowing us to study protein glycosylation directly on unmodified glycoproteins. The method enables simultaneous measurement of up to 96 lectin-carbohydrate interactions on a multiplex surface plasmon resonance imaging platform within 20 min. Specificity determination of lectins succeeded by analysis of neoglycoproteins and enzymatically remodeled glycoproteins to verify carbohydrate binding. We demonstrated the possibilities for glycosylation fingerprinting by comparing different Erythropoietin sources without the need for any sample pretreatment and we were able to accurately quantify relative sialylation levels of Erythropoietin.

Research paper thumbnail of Abstract 2651: Impressive efficacy and safety profile of a novel generation duocarmycin-based HER2-targeting ADC

Cancer Research, 2014

We have built a linker-drug platform based on a cleavable linker-duocarmycin payload for the deve... more We have built a linker-drug platform based on a cleavable linker-duocarmycin payload for the development of novel generation antibody-drug conjugates. SYD983, a lead ADC originating from that platform, is a cysteine-coupled HER2-targeting ADC based on trastuzumab. SYD983 is a heterogeneous product that consists of a mixture of naked Ab and ADCs with a drug-to-antibody ratio (DAR) of 2, 4, 6, the mean DAR being 2.0. We have shown that SYD983 binds to HER2, induces antibody-dependent cell-mediated cytotoxicity, and is efficiently internalized into HER2-expressing cells. SYD983 very potently kills HER2-expressing cells in vitro and is inactive in cells that don't express HER2. SYD983 is stable in human and cynomolgus monkey (CM) plasma in vitro but has relatively poor stability in mouse plasma. The latter is due to mouse-specific carboxylesterase (CES1c) since stability of SYD983 in plasma of CES1c knockout mice is similar to that in human and CM plasma. SYD983 could be dosed up to...

Research paper thumbnail of Identification of a novel conserved sequence motif in flavoprotein hydroxylases with a putative dual function in FAD/NAD(P)H binding

Research paper thumbnail of Selective cysteine ← serine replacements in p -hydroxybenzoate hydroxylase from Pseudomonas fluorescens allow the unambiguous assignment of Cys211 as the site of modification by spin-labeled p -chloromercuribenzoate

"Protein Engineering, Design and Selection", 1994

p-Hydroxybenzoate hydroxylase from Pseudomonas fluorescens contains five sulfhydryl groups per su... more p-Hydroxybenzoate hydroxylase from Pseudomonas fluorescens contains five sulfhydryl groups per subunit. Cysteine-->serine replacements show that the thiols are not essential for catalysis. The increased dissociation constant for FAD in mutant Cys158Ser suggests that Cys158 is important for the solvation of the pyrophosphate moiety of the prosthetic group. Wild-type p-hydroxybenzoate hydroxylase is rapidly inactivated by mercurial compounds. Inactivation by a spin-labeled derivative of p-chloromercuribenzoate is fully abolished in mutant Cys211Ser. Incorporation of the spin label in the other Cys-->Ser mutants strongly impairs substrate binding without affecting the catalytic properties of the FAD. The results are discussed with respect to previous tentative assignments from chemical modification studies and in light of the 3-D structure of the enzyme-substrate complex.

Research paper thumbnail of Crystal structure of p-hydroxybenzoate hydroxylase complexed with its reaction product 3,4-dihydroxybenzoate

Journal of Molecular Biology, 1988

Research paper thumbnail of Omics tools in accelerated purification process development: Multidimensional fractionation and characterization of crude protein mixtures

Journal of Bioscience and Bioengineering, 2009

Research paper thumbnail of Stereoselective Carveol Dehydrogenase from Rhodococcus erythropolis DCL14

Journal of Biological Chemistry, 1999

Research paper thumbnail of Seven new mutations in the nicotinamide adenine dinucleotide reduced–cytochrome b5 reductase gene leading to methemoglobinemia type I

Blood, 2001

Cytochrome b5 reductase (b5R) deficiency manifests itself in 2 distinct ways. In methemoglobinemi... more Cytochrome b5 reductase (b5R) deficiency manifests itself in 2 distinct ways. In methemoglobinemia type I, the patients only suffer from cyanosis, whereas in type II, the patients suffer in addition from severe mental retardation and neurologic impairment. Biochemical data indicate that this may be due to a difference in mutations, causing enzyme instability in type I and complete enzyme deficiency or enzyme inactivation in type II. We have investigated 7 families with methemoglobulinemia type I and found 7 novel mutations in the b5R gene. Six of these mutations predicted amino acid substitutions at sites not involved in reduced nicotinamide adenine dinucleotide (NADH) or flavin adenine dinucleotide (FAD) binding, as deduced from a 3-dimensional model of human b5R. This model was constructed from comparison with the known 3-dimensional structure of pig b5R. The seventh mutation was a splice site mutation leading to skipping of exon 5 in messenger RNA, present in heterozygous form in...

Research paper thumbnail of Multi-dimensional fractionation and characterization of crude protein mixtures: Toward establishment of a database of protein purification process development parameters

Biotechnology and Bioengineering, 2012

A multi-dimensional fractionation and characterization scheme was developed for fast acquisition ... more A multi-dimensional fractionation and characterization scheme was developed for fast acquisition of the relevant molecular properties for protein separation from crude biological feedstocks by ion-exchange chromatography (IEX), hydrophobic interaction chromatography (HIC), and size-exclusion chromatography. In this approach, the linear IEX isotherm parameters were estimated from multiple linear salt-gradient IEX data, while the nonlinear IEX parameters as well as the HIC isotherm parameters were obtained by the inverse method under column overloading conditions. Collected chromatographic fractions were analyzed by gel electrophoresis for estimation of molecular mass, followed by mass spectrometry for protein identification. The usefulness of the generated molecular properties data for rational decision-making during downstream process development was equally demonstrated. Monoclonal antibody purification from crude hybridoma cell culture supernatant was used as case study. The obtained chromatographic parameters only apply to the employed stationary phases and operating conditions, hence prior high throughput screening of different chromatographic resins and mobile phase conditions is still a prerequisite. Nevertheless, it provides a quick, knowledge-based approach for rationally synthesizing purification cascades prior to more detailed process optimization and evaluation.

Research paper thumbnail of High-throughput and multiplexed regeneration buffer scouting for affinity-based interactions

Analytical Biochemistry, 2014

Research paper thumbnail of Cell disruption for microalgae biorefineries

Biotechnology advances

Microalgae are a potential source for various valuable chemicals for commercial applications rang... more Microalgae are a potential source for various valuable chemicals for commercial applications ranging from nutraceuticals to fuels. Objective in a biorefinery is to utilize biomass ingredients efficiently similarly to petroleum refineries in which oil is fractionated in fuels and a variety of products with higher value. Downstream processes in microalgae biorefineries consist of different steps whereof cell disruption is the most crucial part. To maintain the functionality of algae biochemicals during cell disruption while obtaining high disruption yields is an important challenge. Despite this need, studies on mild disruption of microalgae cells are limited. This review article focuses on the evaluation of conventional and emerging cell disruption technologies, and a comparison thereof with respect to their potential for the future microalgae biorefineries. The discussed techniques are bead milling, high pressure homogenization, high speed homogenization, ultrasonication, microwave ...

Research paper thumbnail of Combined bead milling and enzymatic hydrolysis for efficient fractionation of lipids, proteins, and carbohydrates of Chlorella vulgaris microalgae