Christoph Metzner - Academia.edu (original) (raw)

Papers by Christoph Metzner

Research paper thumbnail of Real-time analysis of protein and protein mixture interaction with lipid bilayers

Biochimica et Biophysica Acta (BBA) - Biomembranes

Research paper thumbnail of Immune Protection of Retroviral Vectors Upon Molecular Painting with the Complement Regulatory Protein CD59

Molecular Biotechnology

Glycosylphosphatidylinositol anchoring is a type of post-translational modification that allows p... more Glycosylphosphatidylinositol anchoring is a type of post-translational modification that allows proteins to be presented on the exterior side of the cell membrane. Purified glycosylphosphatidylinositol-anchored protein can spontaneously re-insert into lipid bilayer membranes in a process termed Molecular Painting. Here, we demonstrate the possibility of inserting purified, recombinant CD59 into virus particles produced from a murine retroviral producer cell line. CD59 is a regulator of the complement system that helps protect healthy cells from the lytic activity of the complement cascade. In this study, we could show that Molecular Painting confers protection from complement activity upon murine retroviral vector particles. Indeed, increased infectivity of CD59-modified virus particles was observed upon challenge with human serum, indicating that Molecular Painting is suitable for modulating the immune system in gene therapy or vaccination applications.

Research paper thumbnail of Integrated Method for Purification and Single-Particle Characterization of Lentiviral Vector Systems by Size Exclusion Chromatography and Tunable Resistive Pulse Sensing

Molecular Biotechnology

Elements derived from lentiviral particles such as viral vectors or virus-like particles are comm... more Elements derived from lentiviral particles such as viral vectors or virus-like particles are commonly used for biotechnological and biomedical applications, for example in mammalian protein expression, gene delivery or therapy, and vaccine development. Preparations of high purity are necessary in most cases, especially for clinical applications. For purification, a wide range of methods are available, from density gradient centrifugation to affinity chromatography. In this study we have employed size exclusion columns specifically designed for the easy purification of extracellular vesicles including exosomes. In addition to viral marker protein and total protein analysis, a well-established single-particle characterization technology, termed tunable resistive pulse sensing, was employed to analyze fractions of highest particle load and purity and characterize the preparations by size and surface charge/electrophoretic mobility. With this study, we propose an integrated platform combining size exclusion chromatography and tunable resistive pulse sensing for monitoring production and purification of viral particles. Keywords Viral vectors Á Virus-like particles Á Lentivirus Á Extracellular vesicles Á Gene therapy Á Vaccine development Á Size exclusion chromatography Á Tunable resistive pulse sensing Á Single particle analysis Abbreviations FV Flow virometry LV Lentivirus NTA Nanoparticle tracking analysis PERT Product-enhanced reverse transcriptase assay RPS Resistive pulse sensing SEC Size exclusion chromatography SPA Single-particle analysis TRPS Tunable resistive pulse sensing Electronic supplementary material The online version of this article (

Research paper thumbnail of Biomedical applications of glycosylphosphatidylinositol-anchored proteins

Journal of Lipid Research

as well as carbohydrate side chains. Proteins are singled out for GPI anchoring due to the presen... more as well as carbohydrate side chains. Proteins are singled out for GPI anchoring due to the presence of a GPI signaling sequence (GSS). The GSS contains the later site of GPI attachment (the amino acid in the  position) and a series of hydrophobic amino acids, essentially forming a membraneassociating domain linking the pre-GPI protein to the luminal side of the endoplasmic reticulum. Biosynthesis of the anchor occurs separately and consists of a complex series of enzymatic reactions involving more than 11 enzymes (3). Synthesis starts at the cytosolic side of the endoplasmic reticulum with phosphoinositol, flips to the lumenal side, and sequentially adds the carbohydrate core elements. The transamidase enzyme complex replaces the GSS with the preformed GPI anchor by amide bond formation to the amino acid in the  position. The GPI-APs are then transported to their final destination via the Golgi system. During transport, further modification of the anchor lipids occurs in a process termed lipid remodeling (4). GPI-APs may be lost from the membrane either with their anchors intact, in a process termed shedding, or upon enzymatic cleavage, i.e., by phosphoinositol-specific phospholipases B and C (5) (see Fig. 1). Biosynthesis, biochemistry and cell biology, trafficking, organization, and dynamics at the cell surface and the release of GPI-APs have all been reviewed recently in greater detail (4, 6-11). To these detailed insights into the topic, we would like to add information about the applications of GPI-APs in biotechnology, and more specifically, in biomedicine (12-14). These applications are mainly based on the membranetargeting properties of GPI-APs and directed at modifying or Abstract Glycosylphosphatidylinositol (GPI)-anchored proteins (GPI-APs) use a unique posttranslational modification to link proteins to lipid bilayer membranes. The anchoring structure consists of both a lipid and carbohydrate portion and is highly conserved in eukaryotic organisms regarding its basic characteristics, yet highly variable in its molecular details. The strong membrane targeting property has made the anchors an interesting tool for biotechnological modification of lipid membrane-covered entities from cells through extracellular vesicles to enveloped virus particles. In this review, we will take a closer look at the mechanisms and fields of application for GPI-APs in lipid bilayer membrane engineering and discuss their advantages and disadvantages for biomedicine.-Heider, S., J. A. Dangerfield, and C. Metzner. Biomedical applications of glycosylphosphatidylinositol-anchored proteins.

Research paper thumbnail of GPI Membrane Anchors-The Much Needed Link

Research paper thumbnail of Post Release Modification of Viral Envelopes

Research paper thumbnail of A modular system for transduction targeting of viral vectors for gene therapy

Research paper thumbnail of Modification of lentiviral vector surfaces using Molecular Painting

http://online.liebertpub.com/doi/pdf/10.1089/hum.2013.2513

Research paper thumbnail of Comment on Patel et al.; “Protein transfer-mediated surface engineering to adjuvantate virus-like nanoparticles for enhanced anti-viral immune responses” Nanomedicine, 2015. 11(5): p. 1097-107

Nanomedicine: Nanotechnology, Biology and Medicine, 2015

Research paper thumbnail of Surface Modification of Retroviral Vectors for Gene Therapy

Research paper thumbnail of Surface Engineering of Biomembranes with GPI-anchored Proteins and its Applications

Research paper thumbnail of Recent advances in the basic biology of mouse mammary tumour virus

Biological research

The existence of a negative trans-acting factor (Naf) in MMTV has been known for some time; howev... more The existence of a negative trans-acting factor (Naf) in MMTV has been known for some time; however, efforts to clearly identify a role for the factor have been unsuccessful. Recently, we could show that Naf is responsible for the differential expression of at least 10 different cellular factors, some of which it seems may be linked to the reproducible down regulation of gene expression and reduced growth rates that characterise Naf positive cells. Despite the advances made with the trans-acting Rev-like protein mechanisms of lentiviruses and the cis-acting RNA transport elements (CTEs) of beta retroviruses, little was known about the mechanisms that promote nuclear export of incompletely spliced MMTV mRNA. We have shown that HIV-1 Rev can trans-regulate expression of MMTV containing genes and also specifically interact with MMTV RNA. More recently, we have identified a novel karyophilic viral protein encoded by a multiple spliced transcript and additionally shown that export of non...

Research paper thumbnail of A modular system for transduction targeting of viral vectors for gene therapy

Research paper thumbnail of Quantitative real-time single particle analysis of virions

Virology, 2014

Providing information about single virus particles has for a long time been mainly the domain of ... more Providing information about single virus particles has for a long time been mainly the domain of electron microscopy. More recently, technologies have been developed-or adapted from other fields, such as nanotechnology-to allow for the real-time quantification of physical virion particles, while supplying additional information such as particle diameter concomitantly. These technologies have progressed to the stage of commercialization increasing the speed of viral titer measurements from hours to minutes, thus providing a significant advantage for many aspects of virology research and biotechnology applications. Additional advantages lie in the broad spectrum of virus species that may be measured and the possibility to determine the ratio of infectious to total particles. A series of disadvantages remain associated with these technologies, such as a low specificity for viral particles. In this review we will discuss these technologies by comparing four systems for real-time single ...

Research paper thumbnail of Postexit surface engineering of retroviral/lentiviral vectors

BioMed research international, 2013

Gene delivery vectors based on retroviral or lentiviral particles are considered powerful tools f... more Gene delivery vectors based on retroviral or lentiviral particles are considered powerful tools for biomedicine and biotechnology applications. Such vectors require modification at the genomic level in the form of rearrangements to allow introduction of desired genes and regulatory elements (genotypic modification) as well as engineering of the physical virus particle (phenotypic modification) in order to mediate efficient and safe delivery of the genetic information to the target cell nucleus. Phenotypic modifications are typically introduced at the genomic level through genetic manipulation of the virus producing cells. However, this paper focuses on methods which allow modification of viral particle surfaces after they have exited the cell, that is, directly on the viral particles in suspension. These methods fall into three categories: (i) direct covalent chemical modification, (ii) membrane-topic reagents, and (iii) adaptor systems. Current applications of such techniques will ...

Research paper thumbnail of MMTV accessory factor Naf affects cellular gene expression

Virology, 2006

Mouse mammary tumour virus (MMTV) encodes a viral superantigen (Sag) and a negative acting factor... more Mouse mammary tumour virus (MMTV) encodes a viral superantigen (Sag) and a negative acting factor (Naf) which share parts of their coding sequence. Using 2-dimensional gel electrophoresis (2D-DIGE), we could show that at least 10 different cellular proteins were differentially expressed in Naf positive cells. Also, luciferase reporter expression was down-regulated in Naf expressing cells independent of the promoter used and further experiments suggested that this effect was due in part to a decrease in cellular growth rates. Although in Naf positive cells expression of the major sag containing transcript was strongly induced by the synthetic glucocorticoid dexamethasone, the hormone analogue neither influenced luciferase expression nor mRNA expression of selected cellular proteins identified by 2D-DIGE. Taken together, these data support the previous finding that Naf and Sag have separable activities and suggest that Naf may play a role in modulating host cell gene expression during...

Research paper thumbnail of Rafts, anchors and viruses — A role for glycosylphosphatidylinositol anchored proteins in the modification of enveloped viruses and viral vectors

Virology, 2008

Lipid rafts have been proposed as sites for the assembly of a number of viruses and are considere... more Lipid rafts have been proposed as sites for the assembly of a number of viruses and are considered to play a major role in pseudotyping events. As a consequence, host glycosylphosphatidylinositol (GPI) anchored proteins commonly associated with lipid rafts can be found being incorporated into viral lipid envelopes with beneficial consequences for viral replication. In this review we will look at the link between lipid rafts, GPIanchored proteins and retroviral particles and how these relationships can be exploited for the modification of enveloped viruses.

Research paper thumbnail of Association of glycosylphosphatidylinositol-anchored protein with retroviral particles

The FASEB Journal, 2008

We describe for the first time the association of glycosylphosphatidylinositol (GPI) -anchored pr... more We describe for the first time the association of glycosylphosphatidylinositol (GPI) -anchored proteins with retroviral and lentiviral particles, similar to a process well established for cells, termed "painting." The aim of the study was to assess the feasibility of modification of retroviral vectors by exogenous addition of recombinant protein, removing the need for genetic engineering of virus producer cell lines. The recombinant GPI protein CD59his was purified via fast protein liquid chromatography and associated with concentrated virus stock in a controlled incubation procedure. Reaction mixtures were purified in order to remove nonassociated GPI protein and endogenous protein. Analysis of samples by immunoblotting revealed that CD59his was only detectable in the presence of viral particles. From this, we conclude that CD59his could be stably associated with retroviral particles. In addition, we demonstrated by flow cytometry that virus particles remain infectious after these procedures. As well as suggesting a novel possibility for interaction between enveloped virus and host, we believe that the stable association of recombinant GPI proteins to retroviral particles can be developed into an important tool for both research and clinical applications, especially in the fields of gene therapy and vaccine development.-Metzner, C., Mostegl, M. M., Günzburg, W. H., Salmons, B., Dangerfield, J. A. Association of glycosylphosphatidylinositol-anchored protein with retroviral particles. FASEB J. 22, 2734 -2739 (2008)

Research paper thumbnail of Investigating retroviral envelope proteome plasticity

Retrovirology, 2013

ABSTRACT http://www.retrovirology.com/content/10/S1/P60

Research paper thumbnail of Fluorescence Molecular Painting of Enveloped Viruses

Molecular Biotechnology, 2013

In this study, we describe a versatile, flexible, and quick method to label different families of... more In this study, we describe a versatile, flexible, and quick method to label different families of enveloped viruses with glycosylphosphatidylinositol-modified green fluorescent protein, termed fluorescence molecular painting (FMP). As an example for a potential application, we investigated virus attachment by means of flow cytometry to determine if viral binding behavior may be analyzed after FMP of enveloped viruses. Virus attachment was inhibited by using either dextran sulfate or by blocking attachment sites with virus pre-treatment. Results from the FMP-flow cytometry approach were verified by immunoblotting and enzyme-linked immunosorbent assay. Since the modification strategy is applicable to a broad range of proteins and viruses, variations of this method may be useful in a range of research and applied applications from bio-distribution studies to vaccine development and targeted infection for gene delivery.

Research paper thumbnail of Real-time analysis of protein and protein mixture interaction with lipid bilayers

Biochimica et Biophysica Acta (BBA) - Biomembranes

Research paper thumbnail of Immune Protection of Retroviral Vectors Upon Molecular Painting with the Complement Regulatory Protein CD59

Molecular Biotechnology

Glycosylphosphatidylinositol anchoring is a type of post-translational modification that allows p... more Glycosylphosphatidylinositol anchoring is a type of post-translational modification that allows proteins to be presented on the exterior side of the cell membrane. Purified glycosylphosphatidylinositol-anchored protein can spontaneously re-insert into lipid bilayer membranes in a process termed Molecular Painting. Here, we demonstrate the possibility of inserting purified, recombinant CD59 into virus particles produced from a murine retroviral producer cell line. CD59 is a regulator of the complement system that helps protect healthy cells from the lytic activity of the complement cascade. In this study, we could show that Molecular Painting confers protection from complement activity upon murine retroviral vector particles. Indeed, increased infectivity of CD59-modified virus particles was observed upon challenge with human serum, indicating that Molecular Painting is suitable for modulating the immune system in gene therapy or vaccination applications.

Research paper thumbnail of Integrated Method for Purification and Single-Particle Characterization of Lentiviral Vector Systems by Size Exclusion Chromatography and Tunable Resistive Pulse Sensing

Molecular Biotechnology

Elements derived from lentiviral particles such as viral vectors or virus-like particles are comm... more Elements derived from lentiviral particles such as viral vectors or virus-like particles are commonly used for biotechnological and biomedical applications, for example in mammalian protein expression, gene delivery or therapy, and vaccine development. Preparations of high purity are necessary in most cases, especially for clinical applications. For purification, a wide range of methods are available, from density gradient centrifugation to affinity chromatography. In this study we have employed size exclusion columns specifically designed for the easy purification of extracellular vesicles including exosomes. In addition to viral marker protein and total protein analysis, a well-established single-particle characterization technology, termed tunable resistive pulse sensing, was employed to analyze fractions of highest particle load and purity and characterize the preparations by size and surface charge/electrophoretic mobility. With this study, we propose an integrated platform combining size exclusion chromatography and tunable resistive pulse sensing for monitoring production and purification of viral particles. Keywords Viral vectors Á Virus-like particles Á Lentivirus Á Extracellular vesicles Á Gene therapy Á Vaccine development Á Size exclusion chromatography Á Tunable resistive pulse sensing Á Single particle analysis Abbreviations FV Flow virometry LV Lentivirus NTA Nanoparticle tracking analysis PERT Product-enhanced reverse transcriptase assay RPS Resistive pulse sensing SEC Size exclusion chromatography SPA Single-particle analysis TRPS Tunable resistive pulse sensing Electronic supplementary material The online version of this article (

Research paper thumbnail of Biomedical applications of glycosylphosphatidylinositol-anchored proteins

Journal of Lipid Research

as well as carbohydrate side chains. Proteins are singled out for GPI anchoring due to the presen... more as well as carbohydrate side chains. Proteins are singled out for GPI anchoring due to the presence of a GPI signaling sequence (GSS). The GSS contains the later site of GPI attachment (the amino acid in the  position) and a series of hydrophobic amino acids, essentially forming a membraneassociating domain linking the pre-GPI protein to the luminal side of the endoplasmic reticulum. Biosynthesis of the anchor occurs separately and consists of a complex series of enzymatic reactions involving more than 11 enzymes (3). Synthesis starts at the cytosolic side of the endoplasmic reticulum with phosphoinositol, flips to the lumenal side, and sequentially adds the carbohydrate core elements. The transamidase enzyme complex replaces the GSS with the preformed GPI anchor by amide bond formation to the amino acid in the  position. The GPI-APs are then transported to their final destination via the Golgi system. During transport, further modification of the anchor lipids occurs in a process termed lipid remodeling (4). GPI-APs may be lost from the membrane either with their anchors intact, in a process termed shedding, or upon enzymatic cleavage, i.e., by phosphoinositol-specific phospholipases B and C (5) (see Fig. 1). Biosynthesis, biochemistry and cell biology, trafficking, organization, and dynamics at the cell surface and the release of GPI-APs have all been reviewed recently in greater detail (4, 6-11). To these detailed insights into the topic, we would like to add information about the applications of GPI-APs in biotechnology, and more specifically, in biomedicine (12-14). These applications are mainly based on the membranetargeting properties of GPI-APs and directed at modifying or Abstract Glycosylphosphatidylinositol (GPI)-anchored proteins (GPI-APs) use a unique posttranslational modification to link proteins to lipid bilayer membranes. The anchoring structure consists of both a lipid and carbohydrate portion and is highly conserved in eukaryotic organisms regarding its basic characteristics, yet highly variable in its molecular details. The strong membrane targeting property has made the anchors an interesting tool for biotechnological modification of lipid membrane-covered entities from cells through extracellular vesicles to enveloped virus particles. In this review, we will take a closer look at the mechanisms and fields of application for GPI-APs in lipid bilayer membrane engineering and discuss their advantages and disadvantages for biomedicine.-Heider, S., J. A. Dangerfield, and C. Metzner. Biomedical applications of glycosylphosphatidylinositol-anchored proteins.

Research paper thumbnail of GPI Membrane Anchors-The Much Needed Link

Research paper thumbnail of Post Release Modification of Viral Envelopes

Research paper thumbnail of A modular system for transduction targeting of viral vectors for gene therapy

Research paper thumbnail of Modification of lentiviral vector surfaces using Molecular Painting

http://online.liebertpub.com/doi/pdf/10.1089/hum.2013.2513

Research paper thumbnail of Comment on Patel et al.; “Protein transfer-mediated surface engineering to adjuvantate virus-like nanoparticles for enhanced anti-viral immune responses” Nanomedicine, 2015. 11(5): p. 1097-107

Nanomedicine: Nanotechnology, Biology and Medicine, 2015

Research paper thumbnail of Surface Modification of Retroviral Vectors for Gene Therapy

Research paper thumbnail of Surface Engineering of Biomembranes with GPI-anchored Proteins and its Applications

Research paper thumbnail of Recent advances in the basic biology of mouse mammary tumour virus

Biological research

The existence of a negative trans-acting factor (Naf) in MMTV has been known for some time; howev... more The existence of a negative trans-acting factor (Naf) in MMTV has been known for some time; however, efforts to clearly identify a role for the factor have been unsuccessful. Recently, we could show that Naf is responsible for the differential expression of at least 10 different cellular factors, some of which it seems may be linked to the reproducible down regulation of gene expression and reduced growth rates that characterise Naf positive cells. Despite the advances made with the trans-acting Rev-like protein mechanisms of lentiviruses and the cis-acting RNA transport elements (CTEs) of beta retroviruses, little was known about the mechanisms that promote nuclear export of incompletely spliced MMTV mRNA. We have shown that HIV-1 Rev can trans-regulate expression of MMTV containing genes and also specifically interact with MMTV RNA. More recently, we have identified a novel karyophilic viral protein encoded by a multiple spliced transcript and additionally shown that export of non...

Research paper thumbnail of A modular system for transduction targeting of viral vectors for gene therapy

Research paper thumbnail of Quantitative real-time single particle analysis of virions

Virology, 2014

Providing information about single virus particles has for a long time been mainly the domain of ... more Providing information about single virus particles has for a long time been mainly the domain of electron microscopy. More recently, technologies have been developed-or adapted from other fields, such as nanotechnology-to allow for the real-time quantification of physical virion particles, while supplying additional information such as particle diameter concomitantly. These technologies have progressed to the stage of commercialization increasing the speed of viral titer measurements from hours to minutes, thus providing a significant advantage for many aspects of virology research and biotechnology applications. Additional advantages lie in the broad spectrum of virus species that may be measured and the possibility to determine the ratio of infectious to total particles. A series of disadvantages remain associated with these technologies, such as a low specificity for viral particles. In this review we will discuss these technologies by comparing four systems for real-time single ...

Research paper thumbnail of Postexit surface engineering of retroviral/lentiviral vectors

BioMed research international, 2013

Gene delivery vectors based on retroviral or lentiviral particles are considered powerful tools f... more Gene delivery vectors based on retroviral or lentiviral particles are considered powerful tools for biomedicine and biotechnology applications. Such vectors require modification at the genomic level in the form of rearrangements to allow introduction of desired genes and regulatory elements (genotypic modification) as well as engineering of the physical virus particle (phenotypic modification) in order to mediate efficient and safe delivery of the genetic information to the target cell nucleus. Phenotypic modifications are typically introduced at the genomic level through genetic manipulation of the virus producing cells. However, this paper focuses on methods which allow modification of viral particle surfaces after they have exited the cell, that is, directly on the viral particles in suspension. These methods fall into three categories: (i) direct covalent chemical modification, (ii) membrane-topic reagents, and (iii) adaptor systems. Current applications of such techniques will ...

Research paper thumbnail of MMTV accessory factor Naf affects cellular gene expression

Virology, 2006

Mouse mammary tumour virus (MMTV) encodes a viral superantigen (Sag) and a negative acting factor... more Mouse mammary tumour virus (MMTV) encodes a viral superantigen (Sag) and a negative acting factor (Naf) which share parts of their coding sequence. Using 2-dimensional gel electrophoresis (2D-DIGE), we could show that at least 10 different cellular proteins were differentially expressed in Naf positive cells. Also, luciferase reporter expression was down-regulated in Naf expressing cells independent of the promoter used and further experiments suggested that this effect was due in part to a decrease in cellular growth rates. Although in Naf positive cells expression of the major sag containing transcript was strongly induced by the synthetic glucocorticoid dexamethasone, the hormone analogue neither influenced luciferase expression nor mRNA expression of selected cellular proteins identified by 2D-DIGE. Taken together, these data support the previous finding that Naf and Sag have separable activities and suggest that Naf may play a role in modulating host cell gene expression during...

Research paper thumbnail of Rafts, anchors and viruses — A role for glycosylphosphatidylinositol anchored proteins in the modification of enveloped viruses and viral vectors

Virology, 2008

Lipid rafts have been proposed as sites for the assembly of a number of viruses and are considere... more Lipid rafts have been proposed as sites for the assembly of a number of viruses and are considered to play a major role in pseudotyping events. As a consequence, host glycosylphosphatidylinositol (GPI) anchored proteins commonly associated with lipid rafts can be found being incorporated into viral lipid envelopes with beneficial consequences for viral replication. In this review we will look at the link between lipid rafts, GPIanchored proteins and retroviral particles and how these relationships can be exploited for the modification of enveloped viruses.

Research paper thumbnail of Association of glycosylphosphatidylinositol-anchored protein with retroviral particles

The FASEB Journal, 2008

We describe for the first time the association of glycosylphosphatidylinositol (GPI) -anchored pr... more We describe for the first time the association of glycosylphosphatidylinositol (GPI) -anchored proteins with retroviral and lentiviral particles, similar to a process well established for cells, termed "painting." The aim of the study was to assess the feasibility of modification of retroviral vectors by exogenous addition of recombinant protein, removing the need for genetic engineering of virus producer cell lines. The recombinant GPI protein CD59his was purified via fast protein liquid chromatography and associated with concentrated virus stock in a controlled incubation procedure. Reaction mixtures were purified in order to remove nonassociated GPI protein and endogenous protein. Analysis of samples by immunoblotting revealed that CD59his was only detectable in the presence of viral particles. From this, we conclude that CD59his could be stably associated with retroviral particles. In addition, we demonstrated by flow cytometry that virus particles remain infectious after these procedures. As well as suggesting a novel possibility for interaction between enveloped virus and host, we believe that the stable association of recombinant GPI proteins to retroviral particles can be developed into an important tool for both research and clinical applications, especially in the fields of gene therapy and vaccine development.-Metzner, C., Mostegl, M. M., Günzburg, W. H., Salmons, B., Dangerfield, J. A. Association of glycosylphosphatidylinositol-anchored protein with retroviral particles. FASEB J. 22, 2734 -2739 (2008)

Research paper thumbnail of Investigating retroviral envelope proteome plasticity

Retrovirology, 2013

ABSTRACT http://www.retrovirology.com/content/10/S1/P60

Research paper thumbnail of Fluorescence Molecular Painting of Enveloped Viruses

Molecular Biotechnology, 2013

In this study, we describe a versatile, flexible, and quick method to label different families of... more In this study, we describe a versatile, flexible, and quick method to label different families of enveloped viruses with glycosylphosphatidylinositol-modified green fluorescent protein, termed fluorescence molecular painting (FMP). As an example for a potential application, we investigated virus attachment by means of flow cytometry to determine if viral binding behavior may be analyzed after FMP of enveloped viruses. Virus attachment was inhibited by using either dextran sulfate or by blocking attachment sites with virus pre-treatment. Results from the FMP-flow cytometry approach were verified by immunoblotting and enzyme-linked immunosorbent assay. Since the modification strategy is applicable to a broad range of proteins and viruses, variations of this method may be useful in a range of research and applied applications from bio-distribution studies to vaccine development and targeted infection for gene delivery.