Publications de Horst Arthur Vogel

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The human estrogen receptor alpha (ER!) mediates the proliferative action of hormones in breast cancer cells by regulating the expression of target genes to control cellular functions. Current methodologies do not permit a real-time assessment of these pro ...

Our recently solved high-resolution structure of the serotonin 5-HT3 receptor (5-HT3R) delivered the first detailed structural insights for a mammalian pentameric ligand-gated ion channel. Based on this structure, we here performed a total of 2.8-μs all-at ...

A reporter assay was developed to detect and quantify nonsense codon suppression by chem. aminoacylated tRNAs in mammalian cells. It is based on the cellular expression of the enhanced green fluorescent protein (EGFP) as a reporter for the site-specific amino acid incorporation in its sequence using an orthogonal suppressor tRNA derived from Escherichia coli. Suppression of an engineered amber codon at position 64 in the EGFP run-off transcript could be achieved by the incorporation of a leucine via an in v

We combined biophys., biochem., and pharmacol. approaches to investigate the ability of the a1a- and a1b-adrenergic receptor (AR) subtypes to form homo- and hetero-oligomers. Receptors tagged with different epitopes (hemagglutinin and Myc) or fluorescent proteins (cyan and green fluorescent proteins) were transiently expressed in HEK-293 cells either individually or in different combinations. Fluorescence resonance energy transfer measurements provided evidence that both the a1a- and a1b-AR can form homo-ol

We describe the fabrication and application of a bioanalytical chip, made of SU-8 photoresist, comprising integrated, high aspect-ratio microfluidic channels, suitable to manipulate and investigate vesicles, cell fragments and biological cells. A central m ...

With the reversible sequential (ReSeq) binding assay, we present a novel approach for the ultrasensitive profiling of receptor function in single living cells. This assay is based on the repetitive application of fluorescent ligands that have fast assocn.- ...

Two types of ligand-gated ion channels were expressed with the Semliki Forest virus (SFV) expression system. The cDNAs for mouse serotonin 5-HT3 receptor and rat and human purinoreceptor P2x subtypes were introduced into the pSFV1 vector. In vitro transcribed RNAs were coelectroporated with pSFV-Helper2 RNA into BHK cells, where in vivo packaging resulted in high titer SFV-5-HT3 and SFV-P2x virus stocks. Infection of BHK, CHO, and RIN cells resulted in high-level expression of recombinant receptors. Satn. b

A direct immunosensor has been developed using an acoustic wave device as a transducer. The device is based on an acoustic waveguide geometry that supports a Love wave. The biorecognition surface, formed on a gold layer, consisted of a biotinylated supported lipid layer which specifically bound streptavidin and, subsequently, biotinylated goat IgG. The modified surface was used as a model immunosensor and successfully detected rabbit anti-goat IgG in the concn. range 3*10-8-10-6 M. Using the anti-goat IgG b

In a recent paper, a new class of synthetic lipids, which self-assemble to form monolayers on gold surfaces, was introduced. The addn. of a monolayer of phospholipids to these layers results in robust supported lipid bilayers designed to reconstitute transmembrane proteins. This paper presents a detailed characterization of the monolayers and bilayers formed by these lipids and assesses their ability for the incorporation of membrane-spanning proteins. Film balance methods, electron microscopy, surface plas

The attachment of a tetradecyl chain to the ionophore 18-crown-6 leads to a stronger interaction with a supported lipid monolayer. Some C14-18-crown-6 mols. introduced in the aq. phase are incorporated in the phospholipid membrane. This process is used to produce ionophore contg. lipid monolayers of detd. compn. at the surface of an electrode. The ionophore content and the sensitivity to K+ of these layers are detd. by capacitance measurements. [on SciFinder (R)]

We report here the generation of mutants of the human O6-alkylguanine-DNA alkyltransferase (hAGT) for the efficient in vivo labeling of fusion proteins with synthetic reporter mols. Libraries of hAGT were displayed on phage, and mutants capable of efficiently reacting with the inhibitor O6-benzylguanine were selected based on their ability to irreversibly transfer the benzyl group to a reactive cysteine residue. Using synthetic O6-benzylguanine derivs., the selected mutant proteins allow for a highly effici

A simple approach to the in situ measurement of IR spectra of self-assembled monolayers (SAMs) on gold in an aq. environment is described. A thin gold film (3-5 nm) on the surface of a germanium internal reflection element is used as a substrate for the self-assembly of a monolayer of a chelating thioalkane. High signal-to-noise spectra are obtained, allowing identification of the chem. groups present in the SAM. Complexation of ions by the SAM can be monitored, and the secondary conformation of His-tagged

The invention concerns an assembly comprising: (a) means for determining the intensity of a plurality of electromagnetic signals, (b) a correlator for correlating or autocorrelating said signals, (c) means for continuously calculating the variance and/or the standard deviation of said signals. It also concerns a method for analysing the intensity of a plurality of electromagnetic radiations scattered and/or emitted from solid, fluid or gaseous samples.

A general method for the specific and covalent labeling of fusion proteins in vivo is described. The approach is based on the unusual mechanism of the human DNA repair protein O6-alkylguanine-DNA alkyl-transferase, which irreversibly transfers an alkyl group from O6-alkylguanine-DNA to one of its cysteine residues. Labeling is possible in bacterial as well as eukaryotic cells and is independent of the nature of the label, thereby opening up new ways to study proteins in vivo. [on SciFinder (R)]

Understanding cellular signaling mediated by cell surface receptors is key to modern biomedical research and drug development. The discovery of a growing no. of potential mol. targets and therapeutic compds. requires downscaling and accelerated functional ...

A serotonin 5-HT3 receptor was functionally expressed to high levels and on a large scale in mammalian cells with the Semliki Forest virus system. Conditions were optimized to maximize detergent solubilization of the receptor, while preserving ligand binding activity. An efficient one-step purifn. yielding .apprx.50% of the histidine-tagged 5-HT3 receptor was achieved with immobilized metal ion chromatog. The expressed receptor, in both membranes and purified prepns., exhibited wild-type ligand binding prop

High signal-to-noise Fourier transform IR (FTIR) spectra of the 5-hydroxytryptamine (serotonin) receptor (5-HT3R) and the nicotinic acetylcholine receptor (nAChR) were obtained by microscope FTIR spectroscopy using micrometer-sized, fully hydrated protein films. Because this novel procedure requires only nanogram quantities of membrane proteins, which is 4-5 orders of magnitude less than the amt. of protein typically used for conventional FTIR spectroscopy, it opens the possibility to access the structure a

A new method was presented to investigate the interactions between membrane receptors and their ligands in an artificial, reconstituted membrane system. Lipid bilayers were anchored via covalently attached thiolipids to TiO2/SiO2 waveguide surfaces to produce mech. stable, long-lasting, and reusable membranes. The coupling scheme was designed to keep the membrane at a distance from the surface, thus maintaining a certain membrane flexibility and allowing for an aq. phase between the surface and bilayer. The

The method analyzes biological fluids collected from patients, and uses attenuated total reflecting (ATR) sensors and spectral analysis by Fourier transform infrared spectroscopy (FTIR) to form a spectral fingerprint of extracellular vesicles (EVs) isolate ...

G protein-coupled receptors (GPCRs) are vital for diverse biological functions, including vision, smell, and aging. They are involved in a wide range of diseases, and are among the most important targets of medicinal drugs. Tools that facilitate GPCR studi ...

Horst Arthur Vogel

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Monitoring proliferative activities of hormone-like odorants in human breast cancer cells by gene transcription profiling and electrical impedance spectroscopy

A Gating Mechanism of the Serotonin 5-HT3 Receptor

Monitoring mis-acylated tRNA suppression efficiency in mammalian cells via EGFP fluorescence recovery

Oligomerization of the alpha 1a- and alpha 1b-Adrenergic Receptor Subtypes: Potential Implications in Receptor Internalization

Micropositioning and microscopic observation of individual picoliter-sized containers within SU-8 microchannels

Reversible sequential-binding probe receptor-ligand interactions in single cells

Expression of ligand-gated ion channels with the Semliki Forest virus expression system

Antibody Binding to a Functionalized Supported Lipid Layer: A Direct Acoustic Immunosensor

Sulfur-bearing lipids for the covalent attachment of supported lipid bilayers to gold surfaces: a detailed characterization and analysis

Determination of the surface concentration of crown ethers in supported lipid membranes by capacitance measurements

Directed Evolution of O6-Alkylguanine-DNA Alkyltransferase for Efficient Labeling of Fusion Proteins with Small Molecules In Vivo

Direct Observation of Self-Assembled Monolayers, Ion Complexation, and Protein Conformation at the Gold/Water Interface: An FTIR Spectroscopic Approach

Assembly and method for a correlator structure

Covalent labeling of fusion proteins with chemical probes in living cells

Investigating cellular signaling reactions in single attoliter vesicles

Characterization of a mouse serotonin 5-HT3 receptor purified from mammalian cells

Downscaling Fourier Transform Infrared Spectroscopy to the Micrometer and Nanogram Scale: Secondary Structure of Serotonin and Acetylcholine Receptors

Covalently attached lipid bilayers on planar waveguides for measuring protein binding to functionalized membranes

Use of fourier transform infrared spectroscopy analysis of extracellular vesicles isolated from body fluids for diagnosing, prognosing and monitoring pathophysiological states and method therfor

The G protein coupled receptor CXCR4 designed by the QTY code becomes more hydrophilic and retains cell signaling activity