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Cumberbatch D, Mori T, Yang J, Mi D, Vinson P, Weaver CD, Johnson CH. A BRET Ca 2+ sensor enables high-throughput screening in the presence of background fluorescence. Sci Signal 2022; 15:eabq7618. [PMID: 35973028 PMCID: PMC9930640 DOI: 10.1126/scisignal.abq7618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The intrinsic fluorescence of samples confounds the use of fluorescence-based sensors. This is of particular concern in high-throughput screening (HTS) applications using large chemical libraries containing intrinsically fluorescent compounds. To overcome this problem, we developed a bioluminescence resonance energy transfer (BRET) Ca2+ sensor, CalfluxCTN. We demonstrated that it reliably reported changes in intracellular Ca2+ concentrations evoked by an agonist and an antagonist of the human muscarinic acetylcholine receptor M1 (hM1R) even in the presence of the fluorescent compound fluorescein, which interfered with a standard fluorescent HTS sensor (Fluo-8). In an HTS using a chemical library containing fluorescent compounds, CalfluxCTN accurately identified agonists and antagonists that were missed or miscategorized using Fluo-8. Moreover, we showed that a luciferase substrate that becomes activated only when inside cells generated long-lasting BRET signals in HTS, enabling results to be reliably compared among replicate samples for hours. Thus, the use of a self-luminescent sensor instead of a fluorescent sensor could facilitate the complete screening of chemical libraries in a high-throughput context and enable analysis of autofluorescent samples in many different applications.
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Affiliation(s)
- Derrick Cumberbatch
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, USA
| | - Tetsuya Mori
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, USA
| | - Jie Yang
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, USA
| | - Dehui Mi
- Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN, USA
| | | | - C. David Weaver
- Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN, USA
- Department of Pharmacology, Vanderbilt University, Nashville, TN, USA
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Gómez S, Giovannini T, Cappelli C. Absorption spectra of xanthines in aqueous solution: a computational study. Phys Chem Chem Phys 2020; 22:5929-5941. [PMID: 32115599 DOI: 10.1039/c9cp05420k] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
We present a detailed computational analysis of the UV/Vis spectra of caffeine, paraxanthine and theophylline in aqueous solution. A hierarchy of solvation approaches for modeling the aqueous environment have been tested, ranging from the continuum model to the non-polarizable and polarizable quantum mechanical (QM)/molecular mechanics (MM) models, with and without the explicit inclusion of water molecules in the QM portion. The computed results are directly compared with the experimental data, thus highlighting the role of electrostatic, polarization and hydrogen boding solute-solvent interactions.
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Affiliation(s)
- Sara Gómez
- Scuola Normale Superiore, Classe di Scienze, Piazza dei Cavalieri 7, 56126 Pisa, Italy.
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3
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Beri A, Banipal PK, Banipal TS. Effect of potassium chloride on the solvation behavior of caffeine, theophylline and theobromine: Volumetric, viscometric, calorimetry and spectroscopic approach. Food Chem 2018; 266:110-118. [DOI: 10.1016/j.foodchem.2018.05.112] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2017] [Revised: 05/23/2018] [Accepted: 05/24/2018] [Indexed: 12/07/2022]
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Rao F, Chen Z, Zhou D, Kang Y, Guo L, Xue Y. DFT investigation on the metabolic mechanisms of theophylline by cytochrome P450 monooxygenase. J Mol Graph Model 2018; 84:109-117. [PMID: 29957347 DOI: 10.1016/j.jmgm.2018.06.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2017] [Revised: 06/11/2018] [Accepted: 06/12/2018] [Indexed: 11/16/2022]
Abstract
Theophylline, one of the most commonly used bronchodilators and respiratory stimulators for the treatment of acute and chronic asthmatic conditions, can cause permanent neurological damage through chronic or excessive ingestion. In this work, DFT calculation was performed to identify the metabolic mechanisms of theophylline by cytochrome P450 (CYP450) monooxygenase. Two main metabolic pathways were investigated, namely, N1- (path A) and N3- (path B) demethylations, which proceeded through N-methyl hydroxylation followed by the decomposition of the generated carbinolamine species. N-methyl hydroxylation involved a hydrogen atom transfer (HAT) mechanism, which can be generalized as the N-demethylation mechanism of xanthine derivatives. The energy gap between the low-spin double state (LS) and the high-spin quartet state (HS) was low (<1 kcal mol-1), indicating a two-state reactivity (TSR) mechanism. The generated carbinolamine species preferred to decompose through the adjacent heteroatom (O6 for path A and O2 for path B) mediated mechanism. Path B was kinetically more feasible than path A attributed to its relatively lower activation energy. 1-Methylxanthine therefore was the energetically favorable metabolite of theophylline. The observations obtained in the work were in agreement with the experimental observation, which can offer important implications for further pharmacological and clinic studies.
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Affiliation(s)
- Fan Rao
- College of Chemistry and Chemical Engineering, Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province, China West Normal University, Nanchong, 637002, China
| | - Zeqin Chen
- College of Chemistry and Chemical Engineering, Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province, China West Normal University, Nanchong, 637002, China; College of Materials and Chemistry and Chemical Engineering, Chengdu University of Technology, Chengdu, 610059, China.
| | - Dagang Zhou
- College of Chemistry and Chemical Engineering, Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province, China West Normal University, Nanchong, 637002, China.
| | - Yuan Kang
- College of Chemistry and Chemical Engineering, Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province, China West Normal University, Nanchong, 637002, China
| | - Linfeng Guo
- College of Chemistry and Chemical Engineering, Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province, China West Normal University, Nanchong, 637002, China
| | - Ying Xue
- College of Chemistry, Key Laboratory of Green Chemistry and Technology in Ministry of Education, Sichuan University, Chengdu, 610064, China
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El Hamdani H, El Amane M, Duhayon C. Crystal structure of tetra-aqua-bis-(1,3-dimethyl-2,6-dioxo-7 H-purin-7-ido-κ N7)cobalt(II). Acta Crystallogr E Crystallogr Commun 2017; 73:1302-1304. [PMID: 28932460 PMCID: PMC5588566 DOI: 10.1107/s2056989017011379] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Accepted: 08/02/2017] [Indexed: 11/10/2022]
Abstract
The title complex, [Co(C7H7N4O2)2(H2O)4], comprises mononuclear mol-ecules consisting of a CoII ion, two deprotonated theophylline ligands (systematic name: 1,3-dimethyl-7H-purine-2,6-dione) and four coordinating water mol-ecules. The CoII atom lies on an inversion centre and has a slightly distorted octa-hedral coordination environment, with two N atoms of two trans-oriented theophylline ligands and the O atoms of four water mol-ecules. An intra-molecular hydrogen bond stabilizes this conformation. A three-dimensional supra-molecular network structure is formed by inter-molecular O-H⋯O and O-H⋯N hydrogen bonds.
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Affiliation(s)
- Hicham El Hamdani
- Equipe Metallation, Complexes Moleculaires et Applications, Universite Moulay, Ismail, Faculte des Sciences, Meknes, BP 11201 Zitoune, 50000 Meknes, Morocco
| | - Mohammed El Amane
- Equipe Metallation, Complexes Moleculaires et Applications, Universite Moulay, Ismail, Faculte des Sciences, Meknes, BP 11201 Zitoune, 50000 Meknes, Morocco
| | - Carine Duhayon
- Laboratoire de Chimie de Coordination du CNRS, 205, route de Narbonne, BP 44099, F-31077 Toulouse Cedex 4, France
- Université de Toulouse, UPS, INPT, F-31077 Toulouse Cedex 4, France
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Mary Novena L, Suresh Kumar S, Athimoolam S, Saminathan K, Sridhar B. Single crystal, vibrational and computational studies of Theophylline (a bronchodilator drug) and its chloride salt. J Mol Struct 2017. [DOI: 10.1016/j.molstruc.2016.11.087] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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7
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Ultrafast Electronic Deactivation Dynamics of Xanthosine Monophosphate. Molecules 2017; 22:molecules22010160. [PMID: 28106804 PMCID: PMC6155666 DOI: 10.3390/molecules22010160] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 01/12/2017] [Accepted: 01/13/2017] [Indexed: 11/30/2022] Open
Abstract
Ultrafast energy dissipation is a crucial factor for the photostability of DNA and RNA, but even some of the key electronic deactivation pathways in monomeric nucleic acid building stones are still controversial. Here, we report on the excited-state dynamics of the rare nucleotide xanthosine monophosphate as a function of deprotonation state (XMP vs. XMP−) and excitation wavelength (λpump= 278–243 nm) by femtosecond time-resolved fluorescence and absorption spectroscopy. We show that the predominating relaxation channel leads to a return of the photo-excited molecules to the electronic ground state in τ∼1 ps. The mechanism likely involves an out-of-plane deformation of the five-membered ring, different from the main electronic deactivation pathways in the canonical purine bases adenine and guanine. The results are discussed in terms of the structural and electronic differences of XMP compared to the canonical nucleotides.
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Xanthines Studied via Femtosecond Fluorescence Spectroscopy. Molecules 2016; 21:molecules21121668. [PMID: 27918492 PMCID: PMC6274292 DOI: 10.3390/molecules21121668] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Revised: 11/25/2016] [Accepted: 11/29/2016] [Indexed: 11/30/2022] Open
Abstract
Xanthines represent a wide class of compounds closely related to the DNA bases adenine and guanine. Ubiquitous in the human body, they are capable of replacing natural bases in double helices and give rise to four-stranded structures. Although the use of their fluorescence for analytical purposes was proposed, their fluorescence properties have not been properly characterized so far. The present paper reports the first fluorescence study of xanthine solutions relying on femtosecond spectroscopy. Initially, we focus on 3-methylxanthine, showing that this compound exhibits non-exponential fluorescence decays with no significant dependence on the emission wavelength. The fluorescence quantum yield (3 × 10−4) and average decay time (0.9 ps) are slightly larger than those found for the DNA bases. Subsequently, we compare the dynamical fluorescence properties of seven mono-, di- and tri-methylated derivatives. Both the fluorescence decays and fluorescence anisotropies vary only weakly with the site and the degree of methylation. These findings are in line with theoretical predictions suggesting the involvement of several conical intersections in the relaxation of the lowest singlet excited state.
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Singh VB. Spectroscopic signatures and structural motifs in isolated and hydrated caffeine: a computational study. RSC Adv 2014. [DOI: 10.1039/c4ra09749a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Blue and red shift of the VEE of the S1 (1ππ*) state of caffeine after forming complex with water at isolated and conjugated carbonyl site.
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Srivastava SK, Singh VB. Ab initio and DFT studies of the structure and vibrational spectra of anhydrous caffeine. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2013; 115:45-50. [PMID: 23831977 DOI: 10.1016/j.saa.2013.06.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2012] [Revised: 05/29/2013] [Accepted: 06/04/2013] [Indexed: 06/02/2023]
Abstract
Vibrational spectra and molecular structure of anhydrous caffeine have been systematically investigated by second order Moller-Plesset (MP2) perturbation theory and density functional theory (DFT) calculations. Vibrational assignments have been made and many previous ambiguous assignments in IR and Raman spectra are amended. The calculated DFT frequencies and intensities at B3LYP/6-311++G(2d,2p) level, were found to be in better agreement with the experimental values. It was found that DFT with B3LYP functional predicts harmonic vibrational wave numbers more close to experimentally observed value when it was performed on MP2 optimized geometry rather than DFT geometry. The calculated TD-DFT vertical excitation electronic energies of the valence excited states of anhydrous caffeine are found to be in consonance to the experimental absorption peaks.
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Yamazaki S, Sobolewski AL, Domcke W. Photophysics of xanthine: computational study of the radiationless decay mechanisms. Phys Chem Chem Phys 2009; 11:10165-74. [DOI: 10.1039/b913131k] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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12
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Mburu E, Matsika S. An Ab Initio Study of Substituent Effects on the Excited States of Purine Derivatives. J Phys Chem A 2008; 112:12485-91. [DOI: 10.1021/jp807145c] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Elizabeth Mburu
- Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122
| | - Spiridoula Matsika
- Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122
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Shukla MK, Leszczynski J. A Theoretical Study of Excited State Properties of Adenine−Thymine and Guanine−Cytosine Base Pairs. J Phys Chem A 2002. [DOI: 10.1021/jp014516w] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- M. K. Shukla
- Computational Center for Molecular Structure and Interactions, Department of Chemistry, Jackson State University, 1400 J. R. Lynch Street, Jackson, Mississippi 39217
| | - Jerzy Leszczynski
- Computational Center for Molecular Structure and Interactions, Department of Chemistry, Jackson State University, 1400 J. R. Lynch Street, Jackson, Mississippi 39217
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Shukla MK, Leszczynski J. A Theoretical Investigation of Excited-State Properties of the Adenine−Uracil Base Pair. J Phys Chem A 2002. [DOI: 10.1021/jp004551n] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- M. K. Shukla
- Computational Center for Molecular Structure and Interactions, Department of Chemistry, Jackson State University, 1400 J.R. Lynch Street, Jackson, Mississippi 39217
| | - Jerzy Leszczynski
- Computational Center for Molecular Structure and Interactions, Department of Chemistry, Jackson State University, 1400 J.R. Lynch Street, Jackson, Mississippi 39217
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Shukla M, Leszczynski J. A DFT investigation on effects of hydration on the tautomeric equilibria of hypoxanthine. ACTA ACUST UNITED AC 2000. [DOI: 10.1016/s0166-1280(00)00536-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Shukla MK, Leszczynski J. Theoretical Study of Proton Transfer in Hypoxanthine Tautomers: Effects of Hydration. J Phys Chem A 2000. [DOI: 10.1021/jp9940912] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- M. K. Shukla
- Computational Center for Molecular Structure and Interactions, Department of Chemistry, Jackson State University, 1400 J.R. Lynch Street, Jackson, Mississippi 39217 and Department of Physics, Banaras Hindu University, Varanasi-221005, India
| | - Jerzy Leszczynski
- Computational Center for Molecular Structure and Interactions, Department of Chemistry, Jackson State University, 1400 J.R. Lynch Street, Jackson, Mississippi 39217 and Department of Physics, Banaras Hindu University, Varanasi-221005, India
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Shukla M, Mishra P. Electronic structures and spectra of two antioxidants: uric acid and ascorbic acid. ACTA ACUST UNITED AC 1996. [DOI: 10.1016/s0166-1280(96)90992-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Shukla M, Mishra P. Structure-activity relationship for some xanthines as adenosine A1 receptor antagonists, bronchodilators and phosphodiesterase inhibitors: an electric field mapping approach. ACTA ACUST UNITED AC 1995. [DOI: 10.1016/0166-1280(95)04186-a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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