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1.
The thermodynamic parameters enthalpy and entropy of the interaction between calcium(II) or copper(II) with 5′-UMP, 5′-CMP,
5′-AMP, 5′-GMP or 5′-IMP in aqueous solution were determined calorimetrically (ionic strength adjusted to 0.1 with tetramethylammonium
bromide) at 25 °C and pH 7 for Ca(II) or pH 3–5 for Cu(II). The experimental conditions were carefully selected to avoid polynuclear
complex formation and nucleotide self-stacking. The calorimetric data confirm the tendency toward macrochelation which was
indicated by Sigel after very precise potentiometric studies, and which follows the order Cu(II)>Ca(II) for the metal ions
and GMP>IMP>AMP>CMP=UMP for the nucleotides. Macrochelate formation for these metal-nucleoside monophosphate complexes is
energetically favorable and entropically unfavorable.
Received: 13 August 1999 / Accepted: 1 February 2000 相似文献
2.
A. Zenker M. Galanski T. L. Bereuter B. K. Keppler W. Lindner 《Journal of biological inorganic chemistry》2000,5(4):498-504
The binding behaviour as well as the time-dependent reaction of five platinum(II) complexes with 5′-GMP have been investigated
by capillary electrophoresis under simulated physiological conditions referred to chloride concentration, pH and temperature.
Different amine ligands influenced the binding properties towards 5′-GMP and resulted in different half-times of the overall
reaction. Complexes with bidentate ligands reacted faster with the monophosphate compared to complexes with monodentate ligands.
Complexes consisting of two monodentate hydroxyethylamine ligands reacted very slowly owing to a competitive intramolecular
reaction of the hydroxyethyl residues, which was proven by NMR investigations. Reducing the number of hydroxyethyl residues
increased the half-times of the reactions. Moreover, the major adducts formed with 5′-GMP were identified by MALDI-MS analysis.
Received: 29 December 1999 / Accepted: 19 April 2000 相似文献
3.
Complexes of copper(II) dipeptides with hexacyanoferrate(III). Magnetic and spectroscopic properties
Alessandro Desideri Luigi Sportelli Rosa Bartucci Silvia Morante 《Inorganica chimica acta》1985,106(2):85-87
The interaction between hexacyanoferrate(III) and two copper(II) dipeptide complexes, such as Cu(II)- glycylhistidine and Cu(II)-glycylphenylalanine, has been investigated by electronic and EPR spectroscopy and by magnetic susceptibility measurements. In both cases the magnetic susceptibility values sum to those corresponding to the patent complexes. However, the electronic relaxation time of the copper(II) ion in the mixed complexes is modified so much that the copper(II) EPR signal disappears suggesting the existence of a specific metal—metal interaction probably through a cyanide bridge. This hypothesis is also supported by the appearance of an hypsochromic shift of the Cu(II) electronic band after addition of hexacyanoferrate(III). 相似文献
4.
Brij Bhushan Uma Shanker Kamaluddin 《Origins of life and evolution of the biosphere》2011,41(5):469-482
Manganese exists in different oxidation states under different environmental conditions with respect to redox potential. Various
forms of manganese oxides, namely, Manganosite (MnO), Bixbyite (Mn2O3), Hausmannite (Mn3O4) and Pyrolusite (MnO2) were synthesized and their possible role in chemical evolution studied. Adsorption studies of ribose nucleotides (5′-AMP,
5′-GMP, 5′-CMP and 5′-UMP) on these manganese oxides at neutral pH, revealed a higher binding affinity to manganosite (MnO)
compared to the other manganese oxides. That manganese oxides having a lower Mn-O ratio show higher binding affinity for the
ribonucleotides indirectly implies that such oxides may have provided a surface onto which biomonomers could have been concentrated
through selective adsorption. Purine nucleotides were adsorbed to a greater extent compared to the pyrimidine nucleotides.
Adsorption data followed Langmuir adsorption isotherms, and X
m
and K
L
values were calculated. The nature of the interaction and mechanism was elucidated by infrared spectral studies conducted
on the metal-oxide and ribonucleotide-metal-oxide adducts. 相似文献
5.
Molecular aggregation of nucleotides and carbohydrates—their implication to prebiotic polymerization
Hydrogen bonding pattern of nucleotides and carbohydrates has been analysed using Cambridge database. An analysis on ribonucleotides
shows the 3′ …5′ hydrogen bond mediated aggregation to be the most common alignment. The 2′ …5′ alignment, which occurs under
special circumstances in nature, is found to be the second choice. An analysis on carbohydrates suggests that self assembly
of these molecules is not conducive to the formation of polysaccharides of the type which are found in present day living
organisms. Further, the role of water molecules in the polymerization of three important biomolecules, namely nucleotides,
carbohydrates and amino acids, has been analysed. Implication of these results to prebiotic polymerization is discussed
DCB contribution No. 804. 相似文献
6.
Maria Grazia Santangelo Alfredo Medina-Molner Arthur Schweiger George Mitrikas Bernhard Spingler 《Journal of biological inorganic chemistry》2007,12(6):767-775
Simple copper salts are known to denature poly d(GC). On the other hand, copper complexes of substituted 1,4,7,10,13-pentaazacyclohexadecane-14,16-dione
are able to convert the right-handed B form of the same DNA sequence to the corresponding left-handed Z form. A research program
was started in order to understand why Cu(II) as an aquated ion melts DNA and induces the conformational change to Z-DNA in
the form of an azamacrocyclic complex. In this paper, we present a continuous wave and pulse electron paramagnetic resonance
study of the mononucleotide model system Cu(II)–guanosine 5′-monophosphate . Pulse EPR methods like electron–nuclear double
resonance and hyperfine sublevel correlation spectroscopy provide unique information about the electronic and geometric structure
of this model system through an elaborate mapping of the hyperfine and nuclear quadrupole interactions between the unpaired
electron of the Cu(II) ion and the magnetic nuclei of the nucleotide ligand. It was found that the Cu(II) ion is directly
bound to N7 of guanosine 5′-monophosphate and indirectly bound via a water of hydration to a phosphate group. This set of
experiments opens the way to more detailed structural characterization of specifically bound metal ions in a variety of nucleic
acids of biological interest, in particular to understand the role of the metal–(poly)nucleotide interaction.
Arthur Schweiger died on 4 January 2006. 相似文献
7.
5-Hydroperoxymethyl-2′-deoxyuridine (HPMdU) is formed in DNA by ionizing radiation. Although relatively stable, HPMdU eventually
decomposes to two products 5-hydroxymethyl-2′-deoxyuridine (HMdU) and 5-formyl-2′-deoxyuridine (FdU). We show that a number
of transition metal ions and metalloproteins accelerate this process. Of the metal ions tested, Sn(II) and Fe(II) were the
most active, with the former producing exclusively HMdU, and the latter, a mixture of both. Cu(I), Cu(II), Co(II), and Ni(II)
induced a predominant generation of FdU, with copper ions being more effective than Co and Ni. FdU was also preferentially
formed in the presence of the iron-containing proteins transferrin and ferritin, whereas HMdU was the major product in the
presence of apotransferrin as well as in the presence of ceruloplasmin, a copper-containing protein. 相似文献
8.
H A Tajmir-Riahi 《Biopolymers》1991,31(1):101-108
The interaction of guanosine-5'-monophosphoric acid (H2-GMP) with the alkaline earth metal ions has been studied in aqueous solution at neutral pH. The crystalline salts of the type Mg-GMP.5H2O, Ca-GMP.6H2O, Sr-GMP.7H2O, and Ba-GMP.7H2O were isolated and characterized by Fourier transform ir, 1H-nmr and x-ray powder diffraction measurements. Two types of macrochelate complexes have been identified: (a) The direct metalbase and indirect metal-phosphate bindings (inner and outer sphere interaction) for the Mg(II), Ca(II), and Sr(II), ions; and (b) the indirect metal-base and direct metal-phosphate bindings (outer and inner sphere interaction) for the Ba(II) ion. In aqueous solution, an equilibrium exists between the base-metal-H2O...PO3 and base...H2O-M-PO3 interactions. The ribose moiety shows C3'-endo/anti conformation in the free acid; C2'-endo/anti in the Na2-GMP salt; C3'-endo/anti in the Mg(II)-, Ca(II)-, and Sr(II)-GMP salts; and C2'-endo/anti, in the Ba(II)-GMP salt. 相似文献
9.
Kamaluddin Mala Nath Sushama W. Deopujari Archana Sharma 《Origins of life and evolution of the biosphere》1990,20(3-4):259-268
Due to ease of formation of cyanide under prebiotic conditions, cyanide ion might have formed stable complexes with transition metal ions on the primitive earth. In the course of chemical evolution insoluble metal cyano complexes, which settled at the bottom of primeval sea could have formed peptide and metal amino acid complexes through adsorption processes of amino acids onto these metal cyano complexes.Adsorption of amino acids such as glycine, aspartic acid, and histidine on copper ferrocyanide and zinc ferrocyanide have been studied over a wide pH range of 3.6 – 8.5. Amino acids were adsorbed on the metal ferrocyanide complexes for different time periods. The progress of the adsorption was followed spectro-photometrically using ninhydrin reagent. Histidine was found to show maximum adsorption on both the adsorbents at neutral pH. Zinc ferrocyanide exhibits good sorption behaviour for all the three amino acids used in these investigations. 相似文献
10.
Annegret Hille Ingo Ott Ana Kitanovic Igor Kitanovic Hamed Alborzinia Elke Lederer Stefan Wölfl Nils Metzler-Nolte Sven Schäfer William S. Sheldrick Caroline Bischof Ulrich Schatzschneider Ronald Gust 《Journal of biological inorganic chemistry》2009,14(5):711-725
We developed N,N′-bis(salicylidene)-1,2-phenylenediamine (salophene, 1) as a chelating agent for metal ions such as Mn(II/III), Fe(II/III), Co(II), Ni(II), Cu(II), and Zn(II). The resulting complexes,
from which owing to the carrier ligand a selective mode of action is assumed, were tested for antiproliferative effects on
the MCF-7 breast cancer cell line. The cytotoxicity in this assay depended on the nature of the transition metal used. Iron
complexes in oxidation states +II and +III (3, 4) strongly reduced cell proliferation in a concentration-dependent manner, whereas, e.g., the manganese analogues 5 and 6 were only marginally active. Therefore, the [N,N′-bis(salicylidene)-1,2-phenylenediamine]iron(II/III) complexes 3 and 4 were selected for studies on the mode of action. Both complexes possessed high activity against various tumor cells, for
instance, MDA-MB-231 mammary carcinoma cells as well as HT-29 colon carcinoma cells. They were able to generate reactive oxygen
species, showed DNA binding, and induced apoptosis. Exchange of 1 by N,N′-bis(salicylidene)-1,2-cyclohexanediamine (saldach, 2) yielding complexes 7 and 8 reduced the in vitro effects drastically. An unequivocal mode of action cannot be deduced from these results, but it seems
to be very likely that cell death is caused by interference with more than one intracellular target.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
11.
J. Štěpánek Jozef Kowalewski J. Lang Peter Mojzeš 《Journal of biological inorganic chemistry》1998,3(5):543-556
The interaction of Ni(II) ions with adenine mononucleotides (5′-AMP, 3′-AMP, 2′-AMP, 2′,3′-cAMP, 3′,5′-cAMP) was studied
in aqueous solution using Raman spectroscopy and 13C and 31P NMR paramagnetic relaxation measurements. Macrochelate structures were observed to form for all non-cyclic AMPs, with increasing
stability in the series: 3′-AMP < 2′-AMP < 5′-AMP. N7 of adenine was found to be the key site of the Ni(II)-adenine interaction
for all non-cyclic AMPs. For 2′-AMP, an alternative binding to the pyrimidine ring may also exist. The dependence of Raman
spectra on AMP and Ni(II) concentration confirmed the existence of a stable 1 : 2 Ni(II)-(5′-AMP) complex, besides the 1 : 1
complexes. In this complex, the adenine moieties of both 5′-AMP molecules are situated close to Ni(II), and their relative
orientations with respect to the cation are very similar. The paramagnetic relaxation enhancements of the carbons indicate
that the nickel ion is not located in the plane of the adenine units, but that the line connecting Ni(II) and N7 deviates
strongly from the adenine planes. Phosphates are outer-sphere coordinated by the cation. Findings from both methods have led
us to propose possible global architectures of the complex.
Received: 26 June 1998 / Accepted: 22 July 1998 相似文献
12.
The chief motive behind this research is the interest provoked by the presence of metal ions as necessary stabilizers of the negative charges of phosphate groups in nucleic acids. The effect that the presence of different metal ions produces on the band principally assigned to the nu(s) PO(3)(2-) mode has been studied using FT-IR and FT-Raman spectroscopy. The results obtained reveal the diagnostic capacity of these techniques in determining the type of metal ion interaction with respect to the mononucleotides that form DNA and RNA, providing a tool for improving the knowledge of the stabilizing or destabilizing effects of these ions on such macromolecules. The metal complexes of the ribonucleotides 5'-CMP and 5'-GMP with Mg(II), Ca(II), Sr(II), Ba(II), Cr(III), Co(II), Cu(II), Zn(II), Cd(II), Al(III) and Ga(III) were obtained in this study. After studying and analyzing the IR and Raman spectra of all these complexes and comparing them with the spectra of the corresponding disodium salts, it was verified that, independently of the type of nucleotide involved, the presence of the metal in the vicinity of the phosphate group produces an alteration in the aforementioned nu(s) PO(3)(2-) band. This effect is related to the type of interaction that the phosphate group has with the metal. Three components are observed: (1) one near 983-975 cm(-1) (detectable in IR and Raman), associated with phosphate groups in an electrostatic type of interaction with the metal ion, separated by two or more water molecules; (2) another near 989-985 cm(-1) (only in IR), associated with phosphate groups in indirect interaction through the water molecules of the coordination sphere of the metal ions; and (3) the IR and Raman bands near 1014-1001 cm(-1), which represent phosphate groups directly bonded to the metal ion. These results are supported by the behavior of 5'-CMP in aqueous solution in the presence of Mg(II) ions. 相似文献
13.
1. Human lactoferrin and transferrin are capable of binding two iron or copper ions into specific binding sites in the presence of bicarbonate. 2. Urea and several alkyl ureas have been effective in unfolding these metal-protein complexes. 3.Biphasic transitions are observed for the unfolding of each of the metal complexes of these proteins as determined by direct visible spectroscopy suggesting the release of iron(III) and Cu(II) ions from both of these metal-binding proteins during the unfolding process. 4. Greater stabilization and increased resistance to protein unfolding is observed for all iron(III) complexes compared to Cu(II) complexes of lactoferrin and transferrin as determined by isothermal unfolding and thermal denaturation. 5. Relative stabilization of the different metal-protein complexes investigated within this study were determined to be as follows: Lf-Fe(III) greater than Lf-Cu(II); Tf-Fe(III) greater than Tf-Cu(II), and Lf-Fe(III) greater than Tf-Fe(III); Lf-Cu(II) greater than Tf-Cu(II). 相似文献
14.
H A Tajmir-Riahi 《Biopolymers》1991,31(9):1065-1075
The interaction of the La (III) and Tb (III) ions with adenosine-5'-monophosphate (5'-AMP), guanosine-5'-monophosphate (5'-GMP), and 2'-deoxyguanosine-5'-monophosphate (5'-dGMP) anions with metal/nucleotide ratios of 1 and 2 has been studied in aqueous solution in acidic and neutral pHs. The solid complexes were isolated and characterized by Fourier transform ir and 1H-nmr spectroscopy. The lanthanide (III)-nucleotide complexes are polymeric in nature both in the solid and aqueous solutions. In the metal-nucleotide complexes isolated from acidic solution, the nucleotide binding is via the phosphate group (inner sphere) and an indirect metal-N-7 interaction (outer-sphere) with the adenine N-1 site protonated. In the complexes obtained from neutral solution, metal chelation through the N-7 and the PO3(2-) group is prevailing. In aqueous solution, an equilibrium between the inner and outer sphere metal-nucleotide interaction has been observed. The ribose moiety shows C2'-endo/anti pucker in the free AMP anion and in the lanthanide (III)-AMP complexes, whereas the GMP anion with C2'-endo/anti sugar conformation exhibits a mixture of the C2'-endo/anti and C3'-endo/anti sugar puckers in the lanthanide (III)-GMP salts. The deoxyribose has O4'-endo/anti sugar pucker in the free dGMP anion and a C3'-endo/anti, in the lanthanide (III)-dGMP complexes. 相似文献
15.
We have proposed that double metal cyanide compounds (DMCs) might have played vital roles as catalysts in chemical evolution and the origin of life. We have synthesized a series of metal octacyanomolybdates (MOCMos) and studied their interactions with ribose nucleotides. MOCMos have been shown to be effective adsorbents for 5′-ribonucleotides. The maximum adsorption level was found to be about 50 % at neutral pH under the conditions studied. The zinc(II) octacyanomolybdate(IV) showed larger adsorption compared to other MOCMos. The surface area seems to important parameter for the adsorption of nucleotides. The adsorption followed a Langmuir adsorption isotherms with an overall adsorption trends of the order of 5′-GMP > 5′-AMP > 5′-CMP > 5′-UMP. Purine nucleotides were adsorbed more strongly than pyrimidine nucleotides on all MOCMos possibly because of the additional binding afforded by the imidazole ring in purines. Infrared spectral studies of adsorption adducts indicate that adsorption takes place through interaction between adsorbate molecules and outer divalent ions of MOCMos. 相似文献
16.
Sze-Tin Von Hoi-Ling Seng Hong-Boon Lee Seik-Weng Ng Yusuke Kitamura Makoto Chikira Chew-Hee Ng 《Journal of biological inorganic chemistry》2012,17(1):57-69
Abstract
By inhibiting only two or three of 12 restriction enzymes, the series of [M(phen)(edda)] complexes [M(II) is Cu, Co, Zn; phen is 1,10-phenanthroline; edda is N,N′-ethylenediaminediacetate] exhibit DNA binding specificity. The Cu(II) and Zn(II) complexes could differentiate the palindromic sequences 5′-CATATG-3′ and 5′-GTATAC-3′, whereas the Co(II) analogue could not. This and other differences in their biological properties may arise from distinct differences in their octahedral structures. The complexes could inhibit topoisomerase I, stabilize or destabilize G-quadruplex, and lower the mitochondrial membrane potential of MCF7 breast cells. The pronounced stabilization of G-quadruplex by the Zn(II) complex may account for the additional ability of only the Zn(II) complex to induce cell cycle arrest in S phase. On the basis of the known action of anticancer compounds against the above-mentioned individual targets, we suggest the mode of action of the present complexes could involve multiple targets. Cytotoxicity studies with MCF10A and cisplatin-resistant MCF7 suggest that these complexes exhibit selectivity towards breast cancer cells over normal ones. 相似文献17.
Summary Nine representativeDl-amino acids were resolved using ligand-exchange chromatography whose mobile phase containe Cu (II) and ribonucleic acids. It was also found that deoxyribonucleic acids could be substituted for RNAs. In the presence of 5-GMP, 4XMP, (a mixture of 5-GMP,-AMP,-CMP, and-UMP), and oligomer of RNA,L-amino acids, which seemed to give more stable complexes, were eluted more slowly than the opposite isomers. 相似文献
18.
Nelson R. Tirone Bethanea C. Peghini Ana Cristina M. Barcelos Eddie F. C. Murta Marcia A. Michelin 《Cancer immunology, immunotherapy : CII》2009,58(12):2003-2010
Purpose
The present study evaluated mRNA expression of interferon-alpha (IFN-α), IFN-α receptor subunits (IFNAR-1 and IFNAR-2) and an IFN-stimulated gene encoding the enzyme 2′,5′-oligoadenylate synthetase (2′5′OAS) in biopsies on patients with varying grades of cervical intraepithelial neoplasia (CIN I, II and III). 相似文献19.
Spanevello RM Mazzanti CM Kaizer R Zanin R Cargnelutti D Hannel L Côrrea M Mazzanti A Festugatto R Graça D Schetinger MR Morsch VM 《Neurochemical research》2006,31(4):455-462
Apyrase and 5′-nucleotidase activities were analyzed in an ethidium bromide (EB) demyelinating model associated with interferon-β (IFN-β). The animals were divided in groups: I, control (saline); II, saline and IFN-β; III, EB and IV, EB and IFN-β. After 7, 15 and 30 days the animals (n=5) were sacrificed and the cerebral cortex was removed for synaptosome preparation and enzymatic assays. Apyrase activity using ATP as substrate increased in groups II, III and IV (P<0.001) after 7 days and in groups III and IV (P<0.001) after 15 days. Using ADP as substrate, an activation of this enzyme was observed in group III (P<0.05) after seven and 15 days. The 5′-nucleotidase activity increased in group III (P<0.05) after 7 days and in groups II, III and IV (P<0.001) after 15 days. After 30 days treatment, no significant alteration was observed in enzyme activities. Results showed that apyrase and 5′-nucleotidase activities are altered in demyelination events and that IFN-β was able to regulate the adenine nucleotide hydrolysis. 相似文献
20.
The hammerhead ribozyme is able to cleave RNA in a sequence-specific manner. These ribozymes are usually designed with four
basepairs in helix II, and with equal numbers of nucleotides in the 5′ and 3′ hybridizing arms that bind the RNA substrate
on either side of the cleavage site. Here guidelines are given for redesigning the ribozyme so that it is small, but retains
efficient cleavage activity. First, the ribozyme may be reduced in size by shortening the 5′ arm of the ribozyme to five or
six nucleotides; for these ribozymes, cleavage of short substrates is maximal. Second, the internal double-helix of the ribozyme
(helix II) may be shortened to one or no basepairs, forming a miniribozyme or minizyme, respectively. The sequence of the
shortened helix+loop II greatly affects cleavage rates. With eight or more nucleotides in both the 5′ and the 3′ arms of a
miniribozyme containing an optimized sequence for helix+loop II, cleavage rates of short substrates are greater than for analogous
ribozymes possessing a longer helix II. Cleavage of genelength RNA substrates may be best achieved by miniribozymes. 相似文献