Hans-Georg A. Breitinger

German University in Cairo

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George P. Hess

Smithsonian Conservation Biology Institute

Kyle R. Gee

Thermo Fisher Scientific (United States)

Barry K. Carpenter

Cardiff University

Armanda Gameiro

Binghamton University

Ulrike Breitinger

German University in Cairo

Raymond Wieboldt

University of Basel

Robert Aarhus

University of Minnesota

Jürgen Jäger

Friedrich-Alexander-Universität Erlangen-Nürnberg

Christof Grewer

Binghamton University

Mary E. Gurnack

University of Minnesota

Cooperative Institutions

Cornell University

Friedrich-Alexander-Universität Erlangen-Nürnberg

University of Minnesota

Yale University

German University in Cairo

Twin Cities Orthopedics

University of Minnesota Medical Center

Binghamton University

University of Miami

RTI International

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Toward the Development of New Photolabile Protecting Groups That Can Rapidly Release Bioactive Compounds upon Photolysis with Visible Light

The Journal of Organic Chemistry (2003)

Anamitro Banerjee Christof Grewer Latha Ramakrishnan Jürgen Jäger Armanda Gameiro

The synthesis and characterization of a new photolabile protecting group (caging group) for carboxylic acids, the 2-(dimethylamino)-5-nitrophenyl (DANP) group, is described. This compound has a major absorption band in the visible wavelength region with a maximum near 400 nm (epsilon400 = 9077 M(-1) cm(-1) at pH 7.4 and 21 degrees C). The caging group is attached through an ester linkage to the carboxyl functionality of beta-alanine, which activates the inhibitory glycine receptor in the mammalian central nervous system. Such caged compounds play an important role in transient kinetic investigations of fast cellular processes. Upon photolysis of DANP-caged beta-alanine, the caging group is released within 5 micros. Quantum yields of 0.03 and 0.002 were obtained in the UV region (308 and 360 nm) and the visible region (450 nm), respectively. Laser-pulse photolysis experiments, using 337 or 360 nm light, were performed with the caged compound equilibrated with HEK 293 cells transiently transfected with cDNA encoding the alpha1 homomeric, wild-type glycine receptor. The experiments demonstrated that neither DANP-caged beta-alanine nor its byproducts inhibit or activate the glycine receptors on the cell surface. Under physiological conditions, the DANP-caged beta-alanine is water-soluble and stable and can be used for transient kinetic measurements.

Alanine

Homomeric

Quantum yield

10.1021/jo0300643

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Inhibition of the Serotonin 5-HT₃ Receptor by Nicotine, Cocaine, and Fluoxetine Investigated by Rapid Chemical Kinetic Techniques,

Biochemistry (2002)

Hans-Georg A. Breitinger Natarajan Geetha George P. Hess

ADVERTISEMENT RETURN TO ISSUEPREVAddition/CorrectionORIGINAL ARTICLEThis notice is a correctionInhibition of the Serotonin 5-HT3 Receptor by Nicotine, Cocaine, and Fluoxetine Investigated by Rapid Chemical Kinetic Techniques,Hans-Georg A. Breitinger, Natarajan Geetha, and George P. HessCite this: Biochemistry 2002, 41, 27, 8784Publication Date (Web):June 12, 2002Publication History Published online12 June 2002Published inissue 1 July 2002https://pubs.acs.org/doi/10.1021/bi025162hhttps://doi.org/10.1021/bi025162hcorrectionACS PublicationsCopyright © 2002 American Chemical Society. This publication is available under these Terms of Use. Request reuse permissions This publication is free to access through this site. Learn MoreArticle Views274Altmetric-Citations-LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail PDF (4 KB) Get e-Alertsclose Get e-Alerts

10.1021/bi025162h

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Patch-Clamp Study of Hepatitis C p7 Channels Reveals Genotype-Specific Sensitivity to Inhibitors

Biophysical Journal (2016)

Ulrike Breitinger Noha S. Farag Nourhan K. M. Ali Hans-Georg A. Breitinger

Amantadine

Rimantadine

IC50

hERG

10.1016/j.bpj.2016.04.018

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Citations (23)

Inhibition of the Serotonin 5-HT₃ Receptor by Nicotine, Cocaine, and Fluoxetine Investigated by Rapid Chemical Kinetic Techniques

Biochemistry (2001)

Hans-Georg A. Breitinger Natarajan Geetha George P. Hess

The 5-HT3 serotonin receptor plays an important role in regulating communication between cells in the central and peripheral nervous systems. It is the target of many different therapeutic agents and abused drugs. A rapid chemical kinetic method with a time resolution of 10 ms in combination with the whole-cell current-recording technique was employed to study the receptor in NIE-115 mouse neuroblastoma cells. The mechanism of the channel-opening process, receptor desensitization, and receptor inhibition by nicotine, cocaine, and fluoxetine were investigated. Two different forms of the 5-HT3 serotonin receptor, each with a different desensitization rate, were observed. The inhibition of the receptor by nicotine has not previously been reported. Both nicotine and cocaine compete with serotonin for the receptor site that controls channel opening, with observed dissociation constants of 25 and 7 μM, respectively. Fluoxetine (Prozac), a widely used antidepressant, occupies a different regulatory site on the receptor with an apparent Ki value of 244 μM.

Mechanism of Action

10.1021/bi0106890

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Synthesis and Characterization of Photolabile Derivatives of Serotonin for Chemical Kinetic Investigations of the Serotonin 5-HT₃ Receptor

Biochemistry (2000)

Hans-Georg A. Breitinger Raymond Wieboldt Doraiswamy Ramesh Barry K. Carpenter George P. Hess

A series of photolabile o-nitrobenzyl derivatives of serotonin (caged serotonin) were synthesized: the amine-linked serotonin derivatives N-(2-nitrobenzyl) serotonin (Bz-5HT) and N-(alpha-carboxy-2-nitrobenzyl) serotonin (N-CNB-5HT), and O-alpha-carboxy-2-nitrobenzyl) serotonin (O-CNB-5HT), which has the caging group attached to the phenolic OH group. All the derivatives released free serotonin when excited by 308-nm or 337-nm laser pulses. The time constant of serotonin release from N-CNB-5HT was 1. 2 ms, with a quantum yield of 0.08. This is too slow for rapid chemical kinetic measurements. O-CNB-5HT is suitable for transient kinetic investigations of the serotonin 5-HT(3) receptor. It released serotonin with a time constant of 16 micros and a quantum yield of 0.03. The biological properties of O-CNB-5HT were evaluated, and the applicability of the compound for kinetic studies of the 5-HT(3) receptor was demonstrated. O-CNB-5HT does not activate the 5-HT(3) receptor by itself, nor does it modulate the response of a cell when co-applied with serotonin. When irradiated with a 337-nm laser pulse, O-CNB-5HT released free serotonin that evoked 5-HT(3) receptor-mediated whole-cell currents in NIE-115 mouse neuroblastoma cells.

Serotonin Antagonists

10.1021/bi992781q

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Citations (54)

[27] Preparation of cyclic ADP-ribose antagonists and caged cyclic ADP-ribose

Methods in enzymology on CD-ROM/Methods in enzymology (1997)

Timothy F. Walseth Robert Aarhus Mary E. Gurnack Long Wong Hans-Georg A. Breitinger

Photoaffinity labeling

Cyclic ADP-Ribose

Ribose

10.1016/s0076-6879(97)80121-8

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Citations (27)