For example, square planar complexes penetrate deeper into the dna. Studies on dna binding to metal complexes of sal 2trien zhou chengyong1,2. Synthesis, crystal structure, and dnabinding studies of a. Electronic absorption spectroscopy is universally employed to determine the binding characteristics of metal complexes with dna 3032. Metal complexes with extensive aromatic ligands could bind gq with high specificity and demonstrate unique features in biomedicine, biotechnology and nanotechnology. In this thesis, several series of metal complexes were developed as bindersstabilizers to target specific gq topology in various cancerous cell lines. Research online is the open access institutional repository for the university of. A terpyridine ligand was conjugated to the n2atoms of 2amino2deoxyuridine and its locked counterpart 2aminolna, and these metalcomplexing monomers were incorporated into oligodeoxyribonucleotides. Find, read and cite all the research you need on researchgate.
Dnabinding studies of mixed ligand cobaltiii complexes. The joining of two ruthenium centres with intercalating. Furthermore, there are an increasing number of studies highlighting the biological applications of a broad range of nucleic acid binding metal complexes. Synthesis, characterisation and dna binding studies of. Synthesis, characterization, dna binding interaction. Dna binding and recognition by binuclear transition metal. The dna binding experiment of the complexes 1, 3 and 4 by uvvis absorption, and eb dna displacement by fluorescence spectroscopy, reveal an intercalative mode of binding between ct dna calf. Both the complexes bind to calfthymus dna ctdna through. The interaction of an analog of distamycin, a dna minor groove binding agent, with the short triplex dag. The mobility of the bands decreased as the concentration of the complex was increased, indicating that there was increase in the interaction between the metal. First, the effects of intervening mismatches on dna structure, dynamics and dna charge transport reactivity is examined.
Dna interaction studies of a new platinumii complex. Structural intermediates of a dnaligase complex illuminate. The dna cleavage studies of metal complexes presented more protruding activity in the attendance of h 2 o 2 associated to that in the absence of h 2 o 2. Ir, uvvis, powdered xrd and esr spectral studies, that established mla type of composition for the metal complexes. Ml, ma, and mla account for the metalbinding by cysgly and hisgly, the formation of protonated. The main aim of our research work is to synthesize transitionmetal complexes using. Biophysical investigation of the dna interaction of a new binuclear ruthenium complex yubo wang department of chemical and biological engineering chalmers university of technology abstract 50 years since the structure of dna was proposed, dnainteractive agents are still an intense field of study. These aromatic side arms introduce new modes of dna binding, involving mutual interactions of functional groups held in close proximity. The use of a supramolecular design allows components of the assembly to be varied to enhance device function and light absorbing properties. Binding of the complex to dna lead to perturbation in their ligand centered band. Due to cationic character, threedimensional structural profiles, and propensity for performing hydrolysis, redox, or photoreactions of metal ions and complexes, have a natural ability for interacting with dna. To identify the metal binding site in a productive ligasedna complex that includes both 5. This work studies the synthesis and characterization of new metal complexes of two schiff base ligands derived from the condensation reaction of cefotaxime with 1hindole2, 3dione isatin l i and pdimethylaminobenzaldehyde n,ndmab l ii scheme 1 and studies the coordi.
Jayabalakrishnan2 1department of chemistry, kumaraguru college of technology, coimbatore, tn, india 2department of chemistry, sri ramakrishna mission vidyalaya college of arts and science, coimbatore,tn, india. Dna binding by psylig mutants was measured by emsa using the 18mer singlynicked substrate described previously or a 40mer linear substrate prepared as described above and listed in supplementary table s1. Establishing correlations among structure, dynamics and reactivity is a fundamental problem in biological chemistry. Octahedral transition metal complexes containing three bipyridine or phenanthroline ligands have been shown to be groove binders or possible partial intercalators 8, 9. All the metal complexes were screened for antibacterial activities. The relative binding efficacy of the complexes to dna was much higher than the binding of ligands, especially the complex of cu l1 l2 cl 2 had the highest binding ability to dna. Design, syntheses and functional studies of dna binding metal complexes final seminar april 10, 1998 antitumor activity of many anticancer drugs is based on their interaction with dna five basic interaction types are observed. Structural data of dna binding and molecular docking studies. The interaction of vanadiummorin complex with calfthymus dna was monitored by uvvisible spectroscopy. Synthesis of two mononuclear schiff base metal m fe, cu. Aspects of our molecular design process and results on the dna binding properties for a number of these mixedmetal complexes will be discussed.
Three dimensional representations of various metal complex geometries. Interactions of metal complexes with dna jihan talib university of wollongong talib, jihan, interactions of metal complexes with dna, phd thesis, school of chemistry. Synthesis and characterization of schiff base metal complexes. Electronic absorption spectroscopy serves as the most common means to study the interactions between metal complexes and dna barton et al. Transition metal complexes that cleave dna under physiological. Tuned structure and dna binding properties of metal complexes. The % fluorescence decrease is directly related to the extent of dna binding.
On slow evaporation of the reaction mixture, brown crystals of complex. The dna binding studies of the cobalt complex containing the ligand smbtu is reported. Competitive dnabinding studies between metal complexes, cuphendionphenclcl 1, cuphendionebpyclcl 2, cudppt2h2opf6 3, nidppt2cl2 4, zndppt2cl2 5, and k3fecn6 6 where phen. From the spectral studies an octahedral geometry was proposed for the copper complex. The absorption spectra of complex in aqueous solutions were compared in the absence and in the presence of ctdna are shown in the fig 1. Metal complexes as dna intercalators accounts of chemical. Synthesis, characterization, antimicrobial, dna binding and cleavage studies of mixed ligand cuii, coii complexes. From all the spectral data a distorted octahedral geometry has proposed for both the complexes. In continuance of our ongoing research on dna binding and cleavage happenings of transition metal complexes, in this paper we obtainable the synthesis, characterization and dna cleavage. Doublehelical dna can bend,6 form loops and cruciforms,7 and fold. The results of these studies showed that dna binding strengthened as the size of the unique ligand was increased. The schiff base ligands and the corresponding metal complexes have the.
The results showed that the metal complexes are biologically active. Interaction of ruii complexes and dna photobiology. Synthesis, characterization, dna binding and cleavage. Studies on the interaction of transition metal com. The focus of this work is introduction of gelred gr as a stable, sensitive and environmentally safe fluorescent dna dye instead of the highly toxic ethidium bromide eb. Ii complexes to dna, competitive binding experiments were carried out.
In addition, dna binding properties of the ligand and its metal complexes. Over the last 30 years there has been increasing interest in utilizing kinetically inert transitionmetal complexes as noncovalent dna and rnabinding agents. Nuclease digestion studies have suggested that hu binding alters the helical pitch 9, and circularization assays are indicative of dna bending upon hu binding 10, 11. The dna binding ability of inert chiral transition metal complexes has attracted considerable interest. In previous studies of hu binding to linear dna, multiple complexes were detected in. Dna binding studies performed on the 4acylpyrazolone ligand and its three. Pdf synthesis, characterization, dna binding properties. Synthesis, characterization, antimicrobial and dna binding. The electronic absorption spectral data of the complexes suggest an octahedral geometry around the central. Reactivity and structural studies of metal complexes bound. Prepared complexes showed enhanced dna binding tendency than the parent drug that might be of interest for future research. Dna cleavage, binding and intercalation studies of drugbased oxovanadiumiv. From the results, it can be concluded that both the complexes show intercalative binding mode with dna rather than groove binding. Synthesis, characterization and dna binding study of mixed.
Materials and methods all the reagents and solvents used for the synthesis of ligand and the metal complexes were analar grade of. Investigation on new rutheniumii 68 synthesis of the rucl. There are two wellresolved bands at about 272, 278 nm for the. Herein we describe the reversible changing of dna duplex thermal stability by exploiting transition metal complexation phenomena. Significant attention has centered upon metal complexes capable of binding. The path for metal complexes to a dna target ncbi nih. Synthesis, characterization, dna binding and cleavage studies. Design, syntheses and functional studies of dna binding metal.
The ligand and their metal complexes were screened for their antimicrobial activity against bacteria. Mar 30, 2009 metal ions and metal complexes have long been recognized as critically important components of nucleic acid chemistry, both in regulation of gene expression and as promising therapeutic agents. Metal complexes can bind to dna through a series of interactions like coordination by the dna bases, intercalation and noncovalent interaction including hydrogen bonding between the coordinated ligands and phosphate oxygen atoms of the sugarphosphate group10,11. Mar 30, 2010 in addition, dna binding properties of the ligand and its metal complexes have been investigated by electronic absorption spectroscopy, fluorescence spectra, ethidium bromide displacement experiments, iodide quenching experiments, salt effect and viscosity measurements. Here, this problem is explored in the context of the design and reactivity of different metallointercalators bound to dna. Evaluation of dna binding and cytotoxic activity of a new.
Effective modulation of dna duplex stability by reversible. Competitive dnabinding studies between metal complexes and. Results indicate the dna binding affinities of complexes follow the order 3 4 1 2 5 6. Metal complexes can interact with nucleic acids through a variety of different modes, with the particular mode of binding being predictably governed by the metal complex structure. The absorption spectra of the niii complex in the absence and presence of ctdna are given in figure 2. Aqueous solutions of the complexes fesal 2trien no 3 and cusal 2trien were prepared by dissolving in water at a concentration of 1. Further dna was isolated from yeast cells and checked for purity, dna binding ability of both the complexes was studied by uv absorption titration technique. Stability, energetics and dna binding studies of zinc complexes. In addition, dna binding properties of the ligand and its metal complexes have been investigated by electronic absorption spectroscopy, fluorescence spectra, ethidium bromide displacement experiments, iodide quenching experiments, salt effect and viscosity measurements. Mono and bimetallic transition metal complexes that bind to dna.
Three modes of association between metal complexes and dna are generally distingished. Synthesis, characterization, antimicrobial and dna binding studies on mnii and zni i metal complexes containing mixed ligands b. Understanding how metal complexes interact with dna has become an active research area at the interface between chemistry, molecular biology and medicine. Dnabinding metallointercalators are positively charged, planar, polycyclic, aromatic compounds that unwind the dna double helix and insert themselves between dna base pairs. Synthesis, characterization and dna binding study of ruthentumii thiosemicarbazone complexes k. Transition metal complexes have attracted considerable attention as catalytic systems for use in the oxidation of organic compounds 2, probes in electrontransfer reactions involving metalloproteins 3. Reactivity and structural studies of metal complexes bound to dna.
In absorption titration experiments, the spectra of ct dna in the presence and absence of each compound have. Dna binding and cleavage activity of a structurally. Pdf metal complex interactions with dna researchgate. Synthesis, characterisation and dna binding studies of metal. An overview is presented of the key role for heavy metal compounds in medicine with a focus on dna binding, and on pt compounds used in treatment of cancer.
Concerning the noncovalent interactions between transition metal complexes and dna, they can occur by intercalation, groove binding, or external electrostatic binding. Thus through a series of experiments in this thesis, attempts have been made to correlate the structure and dynamics of metal complexes bound to dna. Dec 14, 2011 in general, metal complexes upon binding to dna are stabilized through a series of weak interactions such as the. Structural data of dna binding and molecular docking. To compare quantitatively the dna binding strengths of these complexes, the intrinsic dna binding constants kb are determined from the decay of the absorbance at 263 nm for complex 1 and complex 2 with increasing concentrations of dna by using equation 1 given in our previous article11,18.
Dna binding, dna cleavage and bsa interaction of vanadium. Here we describe recent results on a variety of transition metal complexes. The dna binding experiment of the complexes 1, 3 and 4 by uvvis absorption, and ebdna displacement by fluorescence spectroscopy, reveal an intercalative mode of binding between ctdna calf. Section d biological activities of ligands and their metal complexes synthesis and characterization of some transition metal complexes 232 4. Biophysical investigation of the dna interaction of a new.
This arrangement allows two metal ions to stay close to each other and consequently these. The interaction of transition metal complexes contain ing multidentate ligands with. Dna cleavage, binding and intercalation studies of drugbased. Metallointercalators insert themselves between two intact base pairs without expelling or replacing the original nitrogenous bases.
Synthesis, characterization, dna binding properties. Metallointercalators with different metal centers, oxidation states, coordination geometries, and overall sizes will exhibit varying depths of insertion. Binding studies of small molecules to dna are very important in the development of dna molecular probes and new therapeutic reagents. Interaction of ruii complexes and dna reproduced from n. Metallointercalation is a dna binding mode that has been extensively studied. The protonated and positively charged ligands can strengthen the dna binding and recognition by these binuclear metal complexes. Competitive dnabinding studies between metal complexes. Synthesis, characterization, antimicrobial, dna binding. Synthesis and characterization of schiff base metal.
Metal ions and metal complexes have long been recognized as critically important components of nucleic acid chemistry, both in regulation of gene expression and as promising therapeutic agents. In this thesis, several series of metal complexes were developed as bindersstabilizers to target. Truly, metal complexes bound to dna provide an interesting system to study structure, function and dynamics in a single package. The necessity for cellular regulation of dna led to the development of metallonucleases to catalyze and repair dna strand breaks. Dna binding studies were carried out by viscosity method. Investigation of dna binding mechanism, photoinduced cleavage. Dna binding to metal complexes of sal 2trien 39 biochemistry moscow vol. Synthesis, characterization, dna binding interaction studies. Even less defined structurally are other conformations of dna, some of which are illustrated schematically in figure 8. Biological activities of ligands and their metal complexes. Transition metal complexes can bind to dna through covalent bonding via replacement of a labile ligand of the complex by a nitrogen base of dna such as guanine n7 or noncovalent interactions such as intercalation, electrostatic, or groove binding.
Importantly, combining either of these techniques with icpms or aas can give. Stability, energetics and dna binding studies of zinc. Binding of metallointercalators to dna is reversible and depends on the properties of the intercalating molecule. Design, syntheses and functional studies of dna binding.
Synthesis, structure, dna binding and anticancer activity of a new. Synthesis, characterization, antimicrobial, dna binding and. Recent studies have shown that a variety of transition metal complexes have significant potential as probes for sequence and structurespecific dna binding 2. Jun 20, 2016 the method is based on the decrease of fluorescence derived from the displacement of gelred from dna by metal complexes. Synthesis, characterization and dna binding study of. In general, transition metal complexes act as dna binding agents, and their biological activity is diverse. Investigation on new rutheniumii hydrazone complexes as. In order to investigate the possible binding modes of the ligand and complexes with ct dna uvvisible titration method has been used. In previous studies of hu binding to linear dna, multiple complexes were detected in gel mobility shift assays gmsa. Synthesis, characterization, antimicrobial and dna. Studies on dna binding to metal complexes of sal2trien. Molecular modelling studies were also performed to confirm the geometries of the complexes.
635 1358 756 1155 1205 114 642 262 1071 642 250 235 552 764 616 61 1194 76 465 132 496 1047 1017 1324 409 1118 1059 321 1366 76 713 730 698 890 98 686 1026 513 588