scholarly journals Non-Covalent Binding of Tripeptides-Containing Tryptophan to Polynucleotides and Photochemical Deamination of Modified Tyrosine to Quinone Methide Leading to Covalent Attachment

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4315
Author(s):  
Antonija Erben ◽  
Igor Sviben ◽  
Branka Mihaljević ◽  
Ivo Piantanida ◽  
Nikola Basarić
Keyword(s):  
Quantum Yield ◽  
Photophysical Properties ◽  
Covalent Binding ◽  
Quinone Methide ◽  
Covalent Attachment ◽  
Dna And Rna ◽  
Pair Composition ◽  
Aqueous Solvent ◽  
Fluorometric Study ◽  
Spectral Responses

A series of tripeptides TrpTrpPhe (1), TrpTrpTyr (2), and TrpTrpTyr[CH2N(CH3)2] (3) were synthesized, and their photophysical properties and non-covalent binding to polynucleotides were investigated. Fluorescent Trp residues (quantum yield in aqueous solvent ΦF = 0.03–0.06), allowed for the fluorometric study of non-covalent binding to DNA and RNA. Moreover, high and similar affinities of 2×HCl and 3×HCl to all studied double stranded (ds)-polynucleotides were found (logKa = 6.0–6.8). However, the fluorescence spectral responses were strongly dependent on base pair composition: the GC-containing polynucleotides efficiently quenched Trp emission, at variance to AT- or AU-polynucleotides, which induced bisignate response. Namely, addition of AT(U) polynucleotides at excess over studied peptide induced the quenching (attributed to aggregation in the grooves of polynucleotides), whereas at excess of DNA/RNA over peptide the fluorescence increase of Trp was observed. The thermal denaturation and circular dichroism (CD) experiments supported peptides binding within the grooves of polynucleotides. The photogenerated quinone methide (QM) reacts with nucleophiles giving adducts, as demonstrated by the photomethanolysis (quantum yield ΦR = 0.11–0.13). Furthermore, we have demonstrated photoalkylation of AT oligonucleotides by QM, at variance to previous reports describing the highest reactivity of QMs with the GC reach regions of polynucleotides. Our investigations show a proof of principle that QM precursor can be imbedded into a peptide and used as a photochemical switch to enable alkylation of polynucleotides, enabling further applications in chemistry and biology.

scholarly journals Getting DNA and RNA out of the dark with 2CNqA: a bright adenine analogue and interbase FRET donor

2020 ◽  
Vol 48 (14) ◽  
pp. 7640-7652 ◽  
Author(s):  
Anna Wypijewska del Nogal ◽  
Anders F Füchtbauer ◽  
Mattias Bood ◽  
Jesper R Nilsson ◽  
Moa S Wranne ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Nucleic Acids ◽  
Photophysical Properties ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Molar Absorptivity ◽  
Dna And Rna ◽  
Double Stranded Dna ◽  
Rna Duplexes

Abstract With the central role of nucleic acids there is a need for development of fluorophores that facilitate the visualization of processes involving nucleic acids without perturbing their natural properties and behaviour. Here, we incorporate a new analogue of adenine, 2CNqA, into both DNA and RNA, and evaluate its nucleobase-mimicking and internal fluorophore capacities. We find that 2CNqA displays excellent photophysical properties in both nucleic acids, is highly specific for thymine/uracil, and maintains and slightly stabilises the canonical conformations of DNA and RNA duplexes. Moreover, the 2CNqA fluorophore has a quantum yield in single-stranded and duplex DNA ranging from 10% to 44% and 22% to 32%, respectively, and a slightly lower one (average 12%) inside duplex RNA. In combination with a comparatively strong molar absorptivity for this class of compounds, the resulting brightness of 2CNqA inside double-stranded DNA is the highest reported for a fluorescent base analogue. The high, relatively sequence-independent quantum yield in duplexes makes 2CNqA promising as a nucleic acid label and as an interbase Förster resonance energy transfer (FRET) donor. Finally, we report its excellent spectral overlap with the interbase FRET acceptors qAnitro and tCnitro, and demonstrate that these FRET pairs enable conformation studies of DNA and RNA.

scholarly journals A Sustainable Biomineralization Approach for the Synthesis of Highly Fluorescent Ultra-Small Pt Nanoclusters

Biosensors ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 128 ◽  
Author(s):  
Rajkamal Balu ◽  
Robert Knott ◽  
Christopher M. Elvin ◽  
Anita J. Hill ◽  
Namita R. Choudhury ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Photoelectron Spectroscopy ◽  
Photophysical Properties ◽  
Conformational Dynamics ◽  
Aqueous Media ◽  
Intrinsically Disordered Protein ◽  
X Ray ◽  
Pt Nanoclusters ◽  
Intrinsically Disordered ◽  
Green Fluorescent

Herein we report the first example of a facile biomineralization process to produce ultra-small-sized highly fluorescent aqueous dispersions of platinum noble metal quantum clusters (Pt-NMQCs) using a multi-stimulus responsive, biomimetic intrinsically disordered protein (IDP), Rec1-resilin. We demonstrate that Rec1-resilin acts concurrently as the host, reducing agent, and stabilizer of the blue-green fluorescent Pt-NMQCs once they are being formed. The photophysical properties, quantum yield, and fluorescence lifetime measurements of the synthesized Pt-NMQCs were examined using UV-Vis and fluorescence spectroscopy. The oxidation state of the Pt-NMQCs was quantitatively analyzed using X-ray photoelectron spectroscopy. Both a small angle X-ray scattering technique and a modeling approach have been attempted to present a detailed understanding of the structure and conformational dynamics of Rec1-resilin as an IDP during the formation of the Pt-NMQCs. It has been demonstrated that the green fluorescent Pt-NMQCs exhibit a high quantum yield of ~7.0% and a lifetime of ~9.5 ns in aqueous media. The change in photoluminescence properties due to the inter-dot interactions between proximal dots and aggregation of the Pt-NMQCs by evaporation was also measured spectroscopically and discussed.

scholarly journals Photochemical Reactivity of Naphthol-Naphthalimide Conjugates and Their Biological Activity

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3355
Author(s):  
Matija Sambol ◽  
Patricia Benčić ◽  
Antonija Erben ◽  
Marija Matković ◽  
Branka Mihaljević ◽  
...  
Keyword(s):  
Biological Activity ◽  
Rational Design ◽  
Human Cancer ◽  
Photophysical Properties ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Quinone Methide ◽  
Quantum Yields ◽  
Photochemical Reactivity ◽  
Human Cancer Cell Lines

Quinone methide precursors 1a–e, with different alkyl linkers between the naphthol and the naphthalimide chromophore, were synthesized. Their photophysical properties and photochemical reactivity were investigated and connected with biological activity. Upon excitation of the naphthol, Förster resonance energy transfer (FRET) to the naphthalimide takes place and the quantum yields of fluorescence are low (ΦF ≈ 10−2). Due to FRET, photodehydration of naphthols to QMs takes place inefficiently (ΦR ≈ 10−5). However, the formation of QMs can also be initiated upon excitation of naphthalimide, the lower energy chromophore, in a process that involves photoinduced electron transfer (PET) from the naphthol to the naphthalimide. Fluorescence titrations revealed that 1a and 1e form complexes with ct-DNA with moderate association constants Ka ≈ 105–106 M−1, as well as with bovine serum albumin (BSA) Ka ≈ 105 M−1 (1:1 complex). The irradiation of the complex 1e@BSA resulted in the alkylation of the protein, probably via QM. The antiproliferative activity of 1a–e against two human cancer cell lines (H460 and MCF 7) was investigated with the cells kept in the dark or irradiated at 350 nm, whereupon cytotoxicity increased, particularly for 1e (>100 times). Although the enhancement of this activity upon UV irradiation has no imminent therapeutic application, the results presented have importance in the rational design of new generations of anticancer phototherapeutics that absorb visible light.

Effects of electron-withdrawing groups in imidazole-phenanthroline ligands and their influence on the photophysical properties of EuIII complexes for white light-emitting diodes

2017 ◽  
Vol 41 (18) ◽  
pp. 9826-9839 ◽  
Author(s):  
Boddula Rajamouli ◽  
Rachna Devi ◽  
Abhijeet Mohanty ◽  
Venkata Krishnan ◽  
Sivakumar Vaidyanathan
Keyword(s):  
Thin Film ◽  
Quantum Yield ◽  
White Light ◽  
Light Emitting Diode ◽  
Photophysical Properties ◽  
Red Light ◽  
Europium Complexes ◽  
Light Emitting ◽  
White Light Emitting Diodes ◽  
Phenanthroline Ligands

The red light emitting diode (LED) was fabricated by using europium complexes with InGaN LED (395 nm) and shown digital images, corresponding CIE color coordinates (red region) as well as obtained highest quantum yield of the thin film (78.7%).

scholarly journals Clickable azide-functionalized bromoarylaldehydes – synthesis and photophysical characterization

2020 ◽  
Vol 16 ◽  
pp. 1683-1692 ◽  
Author(s):  
Dominik Göbel ◽  
Marius Friedrich ◽  
Enno Lork ◽  
Boris J Nachtsheim
Keyword(s):  
High Efficiency ◽  
Photophysical Properties ◽  
Covalent Attachment ◽  
Terminal Alkynes ◽  
Facile Synthesis ◽  
Triazole Derivatives ◽  
Emission Behavior ◽  
Substituted Benzaldehydes ◽  
Covalently Linked

Herein, we present a facile synthesis of three azide-functionalized fluorophores and their covalent attachment as triazoles in Huisgen-type cycloadditions with model alkynes. Besides two ortho- and para-bromo-substituted benzaldehydes, the azide functionalization of a fluorene-based structure will be presented. The copper(I)-catalyzed azide–alkyne cycloaddition (CuAAC) of the so-synthesized azide-functionalized bromocarbaldehydes with terminal alkynes, exhibiting different degrees of steric demand, was performed in high efficiency. Finally, we investigated the photophysical properties of the azide-functionalized arenes and their covalently linked triazole derivatives to gain deeper insight towards the effect of these covalent linkers on the emission behavior.

scholarly journals The binding of o-aminoazotoluene to deoxyribonucleic acid, ribonucleic acid and protein in the C57 mouse

1968 ◽  
Vol 109 (5) ◽  
pp. 917-920 ◽  
Author(s):  
T A Lawson
Keyword(s):  
Single Dose ◽  
Solvent Extraction ◽  
Ribonucleic Acid ◽  
Mouse Liver ◽  
Deoxyribonucleic Acid ◽  
Covalent Binding ◽  
Male Mice ◽  
Micro Scale ◽  
Female Mice ◽  
Dna And Rna

1. 3H-labelled o-aminoazotoluene was synthesized from [G−3H]o-toluidine on a semi-micro scale. 2. An association of 3H with DNA, RNA and protein from the liver, kidney and spleen of female C57b mice was demonstrated after the administration of a single dose of [3H]o-aminoazotoluene. 3. This association is judged to represent covalent binding as a result of experiments involving solvent extraction, examination of the acid hydrolysates of the DNA and RNA and administration of [3H]water with unlabelled o-aminoazotoluene. 4. Examination of the extents of binding at various times after the administration of a single dose of [3H]o-aminoazotoluene showed that there was a peak of binding to liver DNA in the female mice at about 16hr. that was not present in the male mice. 5. The extent of binding to DNA, RNA and protein at 16hr. in the female C57b mouse liver was greater than that in the spleen and kidney.

scholarly journals Luminescent Tetranuclear Gold(I) Dibenzo[g,p]chrysene Derivatives: Effect of the Environment on Photophysical Properties

Molecules ◽  
2020 ◽  
Vol 25 (4) ◽  
pp. 949 ◽  
Author(s):  
Francisco J. Caparrós ◽  
Mani Outis ◽  
Yongsik Jung ◽  
Hyeonho Choi ◽  
João Carlos Lima ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
High Resolution ◽  
Quantum Yield ◽  
31P Nmr ◽  
High Resolution Mass Spectrometry ◽  
Photophysical Properties ◽  
Emission Spectra ◽  
Intermolecular Contacts ◽  
Supramolecular Aggregation ◽  
Resolution Mass

A new 2,7,10,15-tetraethynyldibenzo[g,p]chrysene ligand (1) and two tetranuclear gold(I) derivatives containing PPh3 (3) and PMe3 (4) phosphines were synthesized and characterized by 1H and 31P NMR, IR spectroscopy, and high-resolution mass spectrometry. The compounds were studied in order to analyze the effect of the introduction of gold(I) on the supramolecular aggregation and photophysical properties. Absorption and emission spectra displayed broad bands due to the establishment of π π interactions as an indication of intermolecular contacts and the formation of aggregates. A decrease of the recorded quantum yield (QY) of the gold(I) derivatives was observed compared to the uncomplexed ligand. The introduction of the complexes into poly methyl methacrylate (PMMA) and Zeonex 480R matrixes was analyzed, and an increase of the measured QY of 4 in Zeonex was observed. No phosphorescent emission was detected.

Synthesis, photophysical properties and photocatalytic activity of tungsten porphyrin (TPPWCl4)

2013 ◽  
Vol 17 (06n07) ◽  
pp. 460-472 ◽  
Author(s):  
Rodica-Mariana Ion
Keyword(s):  
Mass Spectrometry ◽  
Photocatalytic Activity ◽  
Quantum Yield ◽  
Photophysical Properties ◽  
Chemical Properties ◽  
Analytical Techniques ◽  
Solid Substrates ◽  
Reaction Processes ◽  
Photooxidation Reaction

Although tungsten porphyrins are known as mimicking models in biology, only a few papers about its chemical properties have been reported, the rarity of studies being attributed to the difficulties encountered in their synthesis due to their low stability. In this paper 5,10,15,20-tetra-p-phenyl-porphyrin tungsten(VI) chlorine (TPPWCl4) was studied, this metallo-porphyrin characterized by different analytical techniques: UV-vis, FTIR, ESR, mass spectrometry, including photophysical determination of its singlet oxygen quantum yield, too. Its photodegradation reaction with the mechanism and species involved into this destruction reaction processes is discussed, too. Also, in order to maintain its photostability, TPPWCl4has been incorporated into solid substrates, such as ZnO and TiO2, and these composites were subsequently tested in the photooxidation reaction of isoamylenes (2-methyl-2-butene and 2-methyl-1-butene mixture).

Photophysical properties of microencapsulated phthalocyanines

2010 ◽  
Vol 14 (03) ◽  
pp. 278-283 ◽  
Author(s):  
Virginia E. Diz ◽  
Gabriela A. Gauna ◽  
Cristian A. Strassert ◽  
Josefina Awruch ◽  
Lelia E. Dicelio
Keyword(s):  
Differential Scanning Calorimetry ◽  
Light Scattering ◽  
Quantum Yield ◽  
Fluorescence Quantum Yield ◽  
Photophysical Properties ◽  
Oxygen Production ◽  
Electronic Microscopy ◽  
Scanning Calorimetry ◽  
Singlet Molecular Oxygen ◽  
Photophysical Parameters

Lipophilic substituted zinc(II) phthalocyanines: 2,3,9,10,16,17,23,24-octakis[(N,N-dimethylaminoethylsulfanyl)]phthalocyaninatozinc(II) (S1) and tetrakis(N,N-dibutylaminoethoxy)phthalocyaninatozinc(II) (3) were incorporated into soybean L-α-phosphatidylcholine (SPC) liposomes of 100 nm diameter. Liposomes were characterized by static light scattering (SLS), transmission electronic microscopy (TEM), and differential scanning calorimetry. The fluorescence quantum yield and singlet molecular oxygen production of 3 are Φ F = 0.15 and ΦΔ = 0.24, respectively, whereas the same photophysical parameters for S1 are Φ F = 0.13 and ΦΔ = 0.51. Higher values of Φ F and ΦΔ are obtained in organic solvent for both dyes. Synthesis of compound 3 has also been reported.

Photophysical Properties of Supported Dyes. Quantum Yield Calculations in Scattering Media

2001 ◽  
Vol 26 (2-3) ◽  
pp. 159-177 ◽  
Author(s):  
Sandra Amore ◽  
M. Gabriela Lagorio ◽  
Lelia E. Dicelio ◽  
Enrique San Román
Keyword(s):  
Quantum Yield ◽  
Photophysical Properties ◽  
Scattering Media
Sign in / Sign up

Export Citation Format

Share Document