Association of antitumor antibiotics, mithramycin and chromomycin, with Zn(II)

Devi, Pukhrambam Grihanjali; Pal, Sudipta; Banerjee, Raja; Dasgupta, Dipak

doi:10.1016/j.jinorgbio.2006.08.018

Cited by 21 publications

(32 citation statements)

References 24 publications

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“…are a result of the complex formation between them. The appearance of a new absorbance band around 440 nm is a signature of metal complexation by CHR (Aich et al 1992a;Devi et al 2007). Presence of an isosbestic point at 423 nm for CHR indicates the presence of a single type of [CHR:Cu 2? ]…”

Section: Resultsmentioning

confidence: 99%

“…We also observe the emergence of new positive bands around 242 nm and 322 nm. The appearance of these new CD (Aich et al 1992a;Devi et al 2007). Spectra in the visible region are characterized by quenching of intensity at 420 nm.…”

Section: Stoichiometry Of the (Chr): Cu 2? Complexmentioning

confidence: 99%

“…, etc. (Aich et al 1992a;Devi et al 2007;Gochin 1998;Reyzer et al 2001). Previous studies from our laboratory have shown that CHR forms complexes with Mg 2?…”

Section: Introductionmentioning

confidence: 98%

“…and Zn 2? (Aich et al 1992a;Devi et al 2007). The antibiotic forms two different types of complexes (1:1 and 1:2) with Mg 2?…”

Section: Introductionmentioning

confidence: 99%

“…In contrast, it forms only a single type of complex with Zn 2? (Devi et al 2007). Renewed studies to explore alternative therapeutic potential of generic drugs like CHR/MTR have led us to suggest alternate probable targets of the antibiotics within the cell (Chakraborty et al 2008;Sleiman et al 2011).…”

Section: Introductionmentioning

confidence: 99%

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Association of aureolic acid antibiotic, chromomycin A3 with Cu2+ and its negative effect upon DNA binding property of the antibiotic

et al. 2011

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Here we have examined the association of an aureolic acid antibiotic, chromomycin A3 (CHR), with Cu(2+). CHR forms a high affinity 2:1 (CHR:Cu(2+)) complex with dissociation constant of 0.08 × 10(-10) M(2) at 25°C, pH 8.0. The affinity of CHR for Cu(2+) is higher than those for Mg(2+) and Zn(2+) reported earlier from our laboratory. CHR binds preferentially to Cu(2+) in presence of equimolar amount of Zn(2+). Complex formation between CHR and Cu(2+) is an entropy driven endothermic process. Difference between calorimetric and van't Hoff enthalpies indicate the presence of multiple equilibria, supported from biphasic nature of the kinetics of association. Circular dichroism spectroscopy show that [(CHR)(2):Cu(2+)] complex assumes a structure different from either of the Mg(2+) and Zn(2+) complex reported earlier. Both [(CHR)(2):Mg(2+)] and [(CHR)(2):Zn(2+)] complexes are known to bind DNA. In contrast, [(CHR)(2):Cu(2+)] complex does not interact with double helical DNA, verified by means of Isothermal Titration Calorimetry of its association with calf thymus DNA and the double stranded decamer (5'-CCGGCGCCGG-3'). In order to interact with double helical DNA, the (antibiotic)(2) : metal (Mg(2+) and Zn(2+)) complexes require a isohelical conformation. Nuclear Magnetic Resonance spectroscopy shows that the Cu(2+) complex adopts a distorted octahedral structure, which cannot assume the required conformation to bind to the DNA. This report demonstrates the negative effect of a bivalent metal upon the DNA binding property of CHR, which otherwise binds to DNA in presence of metals like Mg(2+) and Zn(2+). The results also indicate that CHR has a potential for chelation therapy in Cu(2+) accumulation diseases. However cytotoxicity of the antibiotic might restrict the use.

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Section: Resultsmentioning

confidence: 99%

Section: Stoichiometry Of the (Chr): Cu 2? Complexmentioning

confidence: 99%

“…, etc. (Aich et al 1992a;Devi et al 2007;Gochin 1998;Reyzer et al 2001). Previous studies from our laboratory have shown that CHR forms complexes with Mg 2?…”

Section: Introductionmentioning

confidence: 98%

“…and Zn 2? (Aich et al 1992a;Devi et al 2007). The antibiotic forms two different types of complexes (1:1 and 1:2) with Mg 2?…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Association of aureolic acid antibiotic, chromomycin A3 with Cu2+ and its negative effect upon DNA binding property of the antibiotic

et al. 2011

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Biological and Biomedical Aspects of Metal Phenolates

Ming

2014

Patai's Chemistry of Functional Groups

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The phenol functionality is involved in diverse biological processes and functions, serving as a proton donor and as a metal‐binding ligand. It is commonly found in many biochemicals (such as siderophores and the amino acids tyrosine and tryptophan), pharmaceuticals (including antibiotics, metal‐chelating agents, and diagnostic agents), and natural products (such as polyphenols, flavonoids, and salicylic acid). In association with other functional groups, the phenol moiety forms various types of metal‐binding sites of diverse structures and functions, for example, for iron binding and transport, in enzymes for oxygenation of substrates, and for biotransformation of aromatic compounds. Many environmentally hazardous aromatic compounds such as bisphenol A, PCB, and DDT can be degraded by tyrosinate(phenolate)‐containing metalloenzymes from microorganisms, which provides a clue for bioremediation of these toxic substances. Moreover, the phenol‐containing wet‐adhesive byssal proteins from some clams and mussels has stimulated further development of adhesive materials for medical and other applications; and the study of binding of transferrin with nanoparticles affords better understanding of protein–mineral interfacial interactions. In addition to these naturally occurring metal‐phenolate centers, there are many metal complexes of phenol and derivatives that exhibit various catalytic activities and serve as structural and/or functional model systems for tyrosinate‐containing metalloproteins.

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