Study on Interaction of Cationic Porphyrazine with Synthetic Polynucleotides

Interactions of cationic tetrakis (N, N′, N″, N‴- tetramethyltetra-3, 4-pyridinoporphyrazinatozinc (II) (Zn (tmtppa)) with synthetic polynucleotides, poly (G-C) and poly (A-T), and calf thymus DNA have been characterized in 7.5 mM phosphate buffer of pH 7.2 by UV-Vis absorption and fluorescence spectroscopy. The appearance of hypochromicity more than 30% in UV-Vis spectra of porphyrazine due to interaction of both poly (G-C) and poly (A-T) indicates interaction similar to that of porphyrazine with DNA.The binding constants were determined from the changes in the Q-band maximum of the porphyrazine spectra at various poly (G-C) and DNA concentrations. The values of K were 2.5 × 106M−1, 2.5 × 106M−1and 2.5 × 105M−1for poly (G-C), poly (A-T) and DNA, respectively, at 25°C. The thermodynamic parameters (ΔG°, ΔH°, ΔS°) were calculated using the van't Hoff equation at various temperatures. The enthalpy and entropy changes were determined to be 41.14 kJ mol−1and 260.50 J mol−1·K−1for poly (G-C) and 53.59 kJ mol−1and 285.46 J mol−1·K−1for DNA at 25°C. The positive and large values of the entropy and enthalpy suggest that both hydrophobic and electrostatic interactions may play an important role in the stabilization of the complex formation. The binding of polynucleotides to porphyrazine quenches fluorescence emission of ethidium bromide (EB), and the quenching process obeys linear Stern-Volmer relationship. The results reviled groove-binding mode of porphyrazine for both AT- and GC-rich polynucleotides of DNA.

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Thermodynamic investigation of manganese(III) 5-(1-(4-carboxybutyl)pyridinium-4-yl) 10,15,20-tris-(1-methylpyridinium-4-yl)porphyrin with calf thymus DNA

Journal of Porphyrins and Phthalocyanines ◽

10.1142/s1088424609001224 ◽

2009 ◽

Vol 13 (08n09) ◽

pp. 964-972 ◽

Cited By ~ 2

Author(s):

Hamid Dezhampanah ◽

Abdol-Khalegh Bordbar ◽

Shahram Tangestaninejad

Keyword(s):

Fluorescence Emission ◽

Resonance Light Scattering ◽

Water Soluble ◽

Calf Thymus Dna ◽

External Mode ◽

Calf Thymus ◽

Enthalpy And Entropy Changes ◽

Enthalpy And Entropy ◽

Hoff Equation ◽

Ct Dna

Binding properties of two water-soluble porphyrins, manganese(III) 5-(1-(4-carboxybutyl)pyridinium-4-yl) 10,15,20-tris(1-methylpyridinium-4-yl)porphyrin ( Mn(III)5-CBPyP ) and manganese(III) 5,10,15,20-tetrakis(1-methylpyridinium-4-yl)porphyrin ( Mn(III)TMPyP ), in the presence of various concentration of calf thymus DNA (ct-DNA), has been studied in 7.5 mM phosphate buffer, pH = 7.2 and at various temperatures by UV-vis absorption, resonance light scattering (RLS) and fluorescence spectroscopy and viscosity measurement. Optical absorption and RLS measurements have demonstrated three different species of both porphyrins form in DNA solution. The thermodynamic parameters were calculated by van't Hoff equation at various temperatures. The values of -4.89 kJ.mol-1 and +65.98 J.mol-1.K-1 for Mn(III)5-CBPyP and -14.92 kJ.mol-1 and +15.46 J mol-1.K-1 for TMPyP were estimated for enthalpy and entropy changes of interaction, respectively. The data indicate that the process is exothermic and enthalpy- and entropy-driven, suggesting that electrostatic forces play a considerable role in the interaction process. The binding of both porphyins to DNA quenches fluorescence emission of ethidium bromide (EB) and the quenching process obeys linear Stern-Volmer relationship, indicating the quenching of electron transfer of EB from its binding sites by these porphyrins. The results of using these techniques indicate the external mode of binding for both porphyrins and a higher binding affinity of Mn(III)5-CBPyP with respect to Mn(III)TMPyP .

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Thermodynamic characterization of phthalocyanine–human serum albumin interaction

Spectroscopy An International Journal ◽

10.1155/2011/549403 ◽

2011 ◽

Vol 25 (5) ◽

pp. 235-242 ◽

Cited By ~ 2

Author(s):

Hamid Dezhampanah ◽

Abdol Khalegh Bordbar ◽

Shamim Farshad

Keyword(s):

Human Serum Albumin ◽

Optical Absorption ◽

Serum Albumin ◽

Human Serum ◽

Optical Absorption Spectroscopy ◽

Thermodynamic Characterization ◽

Enthalpy And Entropy Changes ◽

Enthalpy And Entropy ◽

Hoff Equation

The thermodynamic of the binding of nickel (II) tetrasulfonated phthalocyanine anion [Ni(tspc)4–], to human serum albumin (HSA) was investigated in 5 mM aqueous phosphate buffer of pH 7.40 at 25°C using optical absorption spectroscopy. The results show that [Ni(tspc)4–] does not have any affinity for aggregation due to increasing of salt concentration and exists as monomers even in homogeneous aqueous solutions of high ionic strengths (more than 2 M NaCl). The binding constant (K) was obtained by analysis of optical absorption spectra of mentioned complex at various HSA concentrations using SQUAD software. The value ofKwas estimated to be 4.89×105±0.03 (M–1) at 25°C. The thermodynamic parameters were calculated by van’t Hoff equation. The enthalpy and entropy changes were 28.08 kJ/mol and 203.09 J/(mol?·?K) at 25°C, respectively. The results indicate that the binding is mainly entropy driven and the enthalpy is unfavorable for it, the hydrophobic forces thus playing a major role in the binding process.

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N-Methylpyridylporphyrin tailed with folate conjugate as a potential lysosomal-targeted photosensitizer: Synthesis, DNA interaction, singlet oxygen and subcellular localization

Journal of Porphyrins and Phthalocyanines ◽

10.1142/s1088424619500445 ◽

2019 ◽

Vol 23 (06) ◽

pp. 679-684

Author(s):

Yi-Mei Zhao ◽

Qian-Qian Lu ◽

Si Yao ◽

Hui-Fang Su ◽

Hong-Jian Liu ◽

...

Keyword(s):

Photodynamic Therapy ◽

Singlet Oxygen ◽

Fluorescence Spectra ◽

Binding Constants ◽

Binding Mode ◽

Dna Interaction ◽

H Nmr ◽

Calf Thymus ◽

Folate Conjugate ◽

Tumor Drugs

In recent years, great interest has been focused on the use of photosensitizers (PS) for photodynamic therapy (PDT) as safe and effective anti-tumor drugs. As a good lysosomal-targeted drug, folic acid (FA) is highly interesting as well. [Formula: see text]-methylpyridylporphyrin tailed with folate conjugate (Me-Por-FA) was newly designed and synthesized and the structure was confirmed by UV-vis, IR, 1H NMR, MS and elemental analysis. The interaction of this porphyrin with calf thymus DNA was the intercalative binding mode, which was confirmed by ultraviolet and fluorescence spectra, and the binding constants [Formula: see text] was 6.24 × 104 L/mol. The singlet oxygen (1O[Formula: see text] generated by Me-Por-FA was determined by 1, 3-diphenylisobenzofuran (DPBF) method using tetrapyridylporphyrin (H[Formula: see text]TMPyP) as a comparison with the following order: H2TMPyP > Me-Por-FA. Stained with LysoTracker[Formula: see text] Green DND-26, Me-Por-FA was mainly distributed over the lysosomes during 4 h, but H[Formula: see text]TMPyP was not. This suggests that Me-Por-FA could be developed as a targeted photosensitizer for precise photodynamic therapy.

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DNA AND BSA INTERACTIONS OF COPPER(II) AND ZINC(II) COMPLEXES WITH ANTIFUNGAL AGENT FLUCONAZOLE

10.46793/iccbi21.399s ◽

2021 ◽

Author(s):

Nevena Lj. Stevanović ◽

Mia Stanković ◽

Tina P. Andrejević ◽

Darko P. Ašanin ◽

Ivana M. Stanojević ◽

...

Keyword(s):

Cyclic Voltammetry ◽

Bovine Serum Albumin ◽

Emission Spectroscopy ◽

Antitumor Agents ◽

Fungal Infections ◽

Fluorescence Emission ◽

Binding Constants ◽

Special Importance ◽

Calf Thymus ◽

Ct Dna

Aromatic nitrogen-containing heterocycles (N-heterocycles) have attracted a considerable attention as scaffolds for compounds, which have an application in different pharmacological areas, ranging from vitamins to different antimicrobial and antitumor agents. In this respect, azoles are of special importance as potent and broad-spectrum agents used for the treatment of many invasive fungal infections. In the present study, the interaction of the clinically used antifungal drug fluconazole (fcz) and its copper(II) and zinc(II) complexes, {[CuCl2(fcz)2].5H2O}n (1) and {[ZnCl2(fcz)2]·2C2H5OH}n (2), with calf thymus DNA (ct- DNA) and bovine serum albumin (BSA) has been investigated. Fluorescence emission spectroscopy was applied for the binding study of complexes 1 and 2 and fcz with ct-DNA and BSA, while cyclic voltammetry was additionally used for investigation of their interactions with ct-DNA. The values of calculated binding constants (KA) of the investigated compounds towards ct-DNA and BSA follow the order fcz < 1 < 2 and 2 < fcz < 1, respectively.

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Interaction of an abiraterone with calf thymus DNA: Investigation with spectroscopic technique and modeling studies

10.1101/2019.12.19.883033 ◽

2019 ◽

Author(s):

Tanveer A. Wani ◽

Nawaf Alsaif ◽

Ahmed H. Bakheit ◽

Seema Zargar ◽

Abdurrahman A. Al-Mehizia ◽

...

Keyword(s):

Binding Energy ◽

Experimental Studies ◽

Binding Constants ◽

Binding Mode ◽

Docking Studies ◽

Spectroscopic Technique ◽

Calf Thymus Dna ◽

Quenching Effect ◽

Mechanisms Of Toxicity ◽

Calf Thymus

AbstractBinding of toxic ligands to DNA could result in undesirable biological processes, such as carcinogenesis or mutagenesis. Binding mode of Abiraterone (ABR), a steroid drug and ctDNA(calf thymus DNA was investigated in this study using fluorescence and ultraviolet–visible spectroscopy. The probable prediction of binding and the type of interaction forces involved in the arrangement between ABR and ctDNA were explored through spectroscopic and molecular docking studies. The results indicated the binding of ABR to ctDNA in the minor groove. The binding constants were in the range of 1.35 × 106 – 0.36× 106 L mol-1 at the studied temperatures. Fluorescence and spectrophotometric data suggested static quenching between ctDNA and ABR The endothermic values of thermodynamic parameters ΔH = -82.8 kJ mol−1; ΔS = - 161 J mol−1 K−1 suggested that hydrogen bonding is the main force involved in binding ctDNA and ABR. In experimental studies the free binding energy at 298K was −34.9 kJ mol−1 with the relative binding energy ≈ −29.65 kJ mol−1 of docked structure. The Ksv obtained for ABR-KI was similar to that for ABR-ctDNA -KI demonstrating no protection by ctDNA against quenching effect of KI. Thus, suggesting involvement of groove binding between ABR and ctDNA. No change in the fluorescence intensity of ABR-ctDNA was observed in presence of NaCl. Thus, ruling out the involvement of electrostatic interaction. These studies could serve as new insights in understanding the mechanisms of toxicity, resistance and side effects of ABR.

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Molecular Modeling and Spectroscopic Studies on the Interaction of Transresveratrol with Bovine Serum Albumin

Journal of Chemistry ◽

10.1155/2013/494706 ◽

2013 ◽

Vol 2013 ◽

pp. 1-7 ◽

Cited By ~ 1

Author(s):

Xiaoli Liu ◽

Yonghui Shang ◽

Xudong Ren ◽

Hua Li

Keyword(s):

Molecular Modeling ◽

Bovine Serum Albumin ◽

Serum Albumin ◽

Conformational Changes ◽

Binding Sites ◽

Bovine Serum ◽

Electrostatic Interactions ◽

Binding Constants ◽

Binding Mode ◽

Spectroscopic Studies

The interaction of transresveratrol (TRES) with bovine serum albumin (BSA) has been investigated by ultraviolet-visible, fluorescence, Fourier transform infrared spectroscopic methods and molecular modeling techniques. The fluorescence results show that the intrinsic fluorescence of BSA is quenched by TRES through a static quenching procedure. The binding constants of TRES with BSA at 292, 297 and 302 K are calculated as10.22×104,8.71×104, and7.59×104 L mol−1, respectively, and corresponding numbers of binding sites are approximately equal to unity. The thermodynamic parameters ΔHand ΔSare estimated to be −21.82 kJ mol−1and +21.15 J mol−1 K−1, which indicates that the interaction of TRES with BSA is driven mainly by hydrophobic forces and there are also hydrogen bonds and electrostatic interactions. The competitive experiments suggest that the binding site of TRES to BSA is probably located on site II. The results of infrared spectra show that the binding of TRES with BSA leads to conformational changes of BSA, and the binding stabilizes theα-helix andβ-sheet at the cost of a corresponding loss in theβ-turn structure of BSA. The results of molecular modeling calculation clarify the binding mode and the binding sites which are in good accordance with the experiment results.

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DNA Binding of Some Chiral Metallointercalators Derived From 9,10-Phenanthrenediamine

Metal-Based Drugs ◽

10.1155/mbd.1998.225 ◽

1998 ◽

Vol 5 (4) ◽

pp. 225-231 ◽

Cited By ~ 3

Author(s):

Susan F. Murphy-Poulton ◽

Robert S. Vagg ◽

Kymberley A. Vickery ◽

Peter A. Williams

Keyword(s):

Nucleic Acid ◽

Ternary Complex ◽

Thermal Denaturation ◽

Binding Constants ◽

Binding Mode ◽

Induced Circular Dichroism ◽

Supportive Evidence ◽

Equilibrium Binding ◽

Calf Thymus ◽

Dna Thermal Denaturation

A study of the interaction with calf thymus DNA is described of a novel set of chiral ternary complex cations of general form [Ru(N4-tet)(phdi)]2+ (where N4-tet is the chiral linear tetradentate R*R*-picchxn or R*R*-picchxnMe2). Individual equilibrium binding constants (KB) have been determined from spectroscopic titrations employing the hypochromism induced in the visible absorbance of the cations on interaction with the nucleic acid. These demonstrate both stereo- and enantioselectivity in the binding interactions. These KB data, together with induced circular dichroism and DNA thermal denaturation results, are all indicative of selective intercalation of the bidentate components of the cations into the nucleobase stack of the duplex. Supportive evidence for a secondary binding mode for the picchxn complexes is provided by the different mutagenicity profiles obtained for related cations.

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Synthesis, singlet oxygen generation and DNA photocleavage of β,β′-conjugated polycationic porphyrins

Journal of Porphyrins and Phthalocyanines ◽

10.1142/s1088424619500378 ◽

2019 ◽

Vol 23 (06) ◽

pp. 655-663 ◽

Cited By ~ 9

Author(s):

Li Chen ◽

Yimei Zhao ◽

Xinyu Sun ◽

Jun Jiang ◽

Fengshou Wu ◽

...

Keyword(s):

Singlet Oxygen ◽

Fluorescence Emission ◽

Binding Constants ◽

Binding Mode ◽

Binding Modes ◽

Cleavage Rate ◽

Oxygen Generation ◽

Vis Spectroscopy ◽

Pbr322 Plasmid ◽

Ct Dna

In this paper, three [Formula: see text],[Formula: see text]-conjugated cationic porphyrin compounds were designed and synthesized. The structure of the intermediates and desired porphyrins were confirmed by UV, IR, 1H NMR, MS and elemental analysis. The interaction modes between these porphyrins and ct-DNA were studied by UV-vis spectroscopy and fluorescence emission spectroscopy. The results showed that PCP 1 had an external binding mode with DNA at low DNA concentration and could intercalate DNA with the increase of concentration. PCP 2 interacted with DNA through an external binding mode, and PCP 3 could insert into DNA. The binding constants ([Formula: see text] between PCP1[Formula: see text]PCP3 and ct-DNA were calculated to be 8.41 × 104, 7.33 × 104 and 4.14 × 104 M[Formula: see text], respectively. The singlet oxygen (1O[Formula: see text] generation of PCP1[Formula: see text]PCP3 was determined by the 1,3-diphenylisobenzofuran (DPBF) method using tetrapyridylporphyrin (H2TMPyP) as a reference. The 1O2 generation rate of PCP1[Formula: see text]PCP3 followed the order of PCP2 >PCP1>H2TMPyP >PCP3. Subsequently, the photocleavage effect of porphyrins on pBR322 plasmid DNA was studied by gel electrophoresis. At 10.0 [Formula: see text]M, PCP1 and PCP2 could cleave DNA completely. At 2.0 [Formula: see text]M, the cleavage rate of DNA by PCP3 was 57.5%, which was significantly higher than that of H2TMPyP (38.8%). These results verified that the amount of cationic ions in the porphyrin structure could affect the binding modes of porphyrins with DNA and their cleavage ability of DNA.

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ComparativeIn VitroBinding Studies of TiCl2(dpme)2, Ti(ada)2(bzac)2, and TiCl2(bzac)(bpme) Titanium Complexes with Calf-Thymus DNA

Biochemistry Research International ◽

10.1155/2015/836928 ◽

2015 ◽

Vol 2015 ◽

pp. 1-7 ◽

Cited By ~ 3

Author(s):

Pamita Awasthi ◽

Nitesh Kumar ◽

Raj Kaushal ◽

Mohan Kumar ◽

Shrikant Kukreti

Keyword(s):

Circular Dichroism ◽

Binding Constants ◽

Blue Shift ◽

Binding Mode ◽

Visible Absorption ◽

Calf Thymus ◽

Absorption Studies ◽

Uv Visible ◽

Ct Dna ◽

Circular Dichroïsm

The binding of TiCl2(dpme)2(1), (dpme = 6,6′-dimethyl-2,2′-bipyridine), Ti(ada)2(bzac)2(2), (ada = adamantylamine; bzac = benzoylacetone), and TiCl2(bzac)(bpme) (3), (bpme = 4,4′-dimethyl-2,2′-bipyrdine) with calf thymus (ct) DNA has been studied by UV-visible spectroscopy, thermal denaturation, and circular dichroism spectroscopy. In UV-visible study complexes1,2, and3showed red, blue, and red shifts, respectively, upon the addition of ct-DNA along with a significant hyperchromism. The intrinsic binding constants (Kb) calculated from UV-visible absorption studies were 2.3 × 103 M−1, 3.3 × 103 M−1and, 7.1 × 103 M−1for complexes1,2, and3, respectively. The change in melting temperature (ΔTm) was calculated to be 2-3°C for each complex. Circular dichroism (CD) study showed blue shift for complex2and red shift for complexes1and3along with rise in molecular ellipticity upon the addition of complexes. Results suggest a binding mode of complex2different than1and3.

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The magnetic properties, DNA/HSA binding and nuclease activity of manganese N-confused porphyrin

Journal of Porphyrins and Phthalocyanines ◽

10.1142/s1088424616500449 ◽

2016 ◽

Vol 20 (05) ◽

pp. 624-638 ◽

Cited By ~ 8

Author(s):

Su-Hong Peng ◽

Biao-Biao Lv ◽

Atif Ali ◽

Jia-Min Wang ◽

Xiao Ying ◽

...

Keyword(s):

Nuclease Activity ◽

Binding Mode ◽

Active Species ◽

Zero Field ◽

Zero Field Splitting ◽

Groove Binding ◽

Binding Properties ◽

Calf Thymus ◽

Ct Dna ◽

Groove Binding Mode

The first oxidative cleavage of DNA by manganese [Formula: see text]-confused porphyrin [chloro(2-aza-2-methyl-5,10,15,20-tetrakis([Formula: see text]-chlorophenyl)-21-carbaporphyrin)manganese(III), 1] using H2O2 as oxidant agent and its magnetic, calf thymus DNA(ct-DNA)- and human serum albumin (HSA) binding properties were investigated. The magnitude of the axial (D) zero-field splitting for the mononuclear Mn(III) center in 1 was determined to be approximately 2.71 cm[Formula: see text] by paramagnetic susceptibility measurements. The DNA- and HSA binding experimental results showed that 1 bound to ct-DNA via an outside groove binding mode and the hydrophobic cavity located in subdomain IIA of HSA with the binding constant of 4.144 × 105 M[Formula: see text] and [Formula: see text] 106 M[Formula: see text], respectively. Thermodynamic parameters revealed that both DNA- and HSA binding were spontaneous process. The main driven forces were the hydrogen bond and van der Waals for the former, but hydrophobic interaction for the latter, which were further confirmed by molecular docking modeling. Manganese [Formula: see text]-confused porphyrin 1 could cleave the supercoiled plasmid DNA efficiently in the presence of hydrogen peroxide. Hydroxyl radical ([Formula: see text]OH) was found the active species for oxidative damage of DNA.

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