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1.
Zavitsanos K Nunes AM Malandrinos G Hadjiliadis N 《Journal of inorganic biochemistry》2011,105(10):1329-1337
In the present study we used the plasmid relaxation assay, a very sensitive method for detection of DNA strand breaks in vitro, in order to evaluate the role of peptide fragments of histone H2B in DNA strand breakage induced by copper and nickel. We have found that in the presence of peptides modeling the histone fold domain (H2B32-62 and H2B63-93) as well as the N-terminal tail (H2B1-31) of histone H2B there is an increased DNA damage by Cu2+/H2O2 and Ni2+/H2O2 reaction mixtures. On the contrary, the C-terminal tail (H2B94-125) seems to have a protective role on the attack of ROS species to DNA. We have rendered our findings to the interactions of the peptides with DNA, as well as with the metal. 相似文献
2.
3.
Kowalik-Jankowska T Biega L Kuczer M Konopińska D 《Journal of inorganic biochemistry》2008,102(8):1615-1622
The stoichiometry, stability constants and solution structure of the complexes formed in the reaction of copper(II) with hexapeptide NPTNLH, i.e. the Neobelliera Bullata Trypsin Modulating Oostatic Factor (Neb-TMOF), and its analogues DPTNLH, Ac-NPTNLH and Ac-DPTNLH have been determined by potentiometric, UV-visible, CD and EPR spectroscopic methods. Upon raising pH for Ac-NPTNLH and Ac-DPTNLH peptides, copper(II) coordination starts from the imidazole nitrogen of the His6; afterwards three deprotonated amide nitrogens are progressively involved in metal ions coordination. In a wide pH range of 4.5-8.5 for the NPTNLH and DPTNLH ligands the CuL complex dominates with the imidazole nitrogen of His6 coordinated to form a macrochelate. The N-terminal amino group of the NPTNLH and DPTNLH peptides takes part in the coordination of the metal ion in the CuL, CuH−1L and CuH−2L complexes. However, at pH above 9 the CuH−3L complex with the {NIm, 3N−} coordination mode is formed. For the CuH−2L complex the spectroscopic data clearly indicate the 4N {NH2, CO or COO−, 2N−, NIm} bonding mode with the axial coordination of the N-terminal amine group to the metal ion. 相似文献
4.
Maria Antonietta Zoroddu Serenella Medici Massimiliano Peana 《Journal of inorganic biochemistry》2009,103(9):1214-1220
Multi-histidinic peptides have been investigated for Cu(II) and Ni(II) binding. We present spectroscopic evidence that, at low pH and from sub-stoichiometric to stoichiometric amounts of metals, macrochelate and multi-histidinic Cu(II) and Ni(II) complexes form; but, from neutral pH and above, both copper and nickel bind to individual histidine residues. NMR, EPR, UV–Visible (UV–Vis) and UV–Visible CD spectroscopy were used to understand about the variety of complexes obtained at low pHs, where amide deprotonation and coordination is unfavoured. A structural transition between two coordination geometries, as the pH is raised, was observed. Metal binds to Nδ of histidine imidazole when main-chain coordination is involved and coordinates via Nε under mildly acidic conditions and sub-stoichiometric amounts of metals. From EPR results a distortion from planarity has been evidenced for the Cu(II) multi-histidinic macrochelate systems, which may be relevant to biological activity. The behaviour of our peptides was comparable to the pH dependent effect on Cu(II) coordination observed in octapeptide repeat domain in prion proteins and in amyloid precursor peptides involved in Alzheimer’s disease. Changes in pH and levels of metal affect coordination mode and can have implications for the affinity, folding and redox properties of proteins and peptide fragments. 相似文献
5.
Alexandra Myari Gerasimos Malandrinos John Plakatouras Nick Hadjiliadis Imre Sóvágó 《Bioinorganic Chemistry and Applications》2003,1(1):99-112
His-Val-His and His-Val-Gly-Asp are two naturally occurring peptide sequences, present at the active site
of Cu,Zn-superoxide dismutase (Cu,Zn-SOD). We have already studied the interaction of His-Val-His=A
(copper binding site) with Cu(II) and of His-Val-Gly-Asp=B (zinc binding site) with Zn(II). As a
continuation of this work and for comparison purposes we have also studied the interaction of Zn(II) with
His-Val-His and Cu(II) with His-Val-Gly-Asp using both potentiometric and spectroscopic methods (visible,
EPR, NMR). The stoichiometry, stability constants and solution structure of the complexes formed have been
determined. Histamine type of coordination is observed for/ZnAH/2+, /ZnA/+, /ZnA2H/+ and/ZnA2/ in acidic pH while deprotonation of coordinated water molecules is observed at higher pH. /CUB/ species is
characterized by the formation of a macrochelate and histamine type coordination. Its stability results in the
suppression of amide deprotonation which occurs at high pH resulting in the formation of the highly distorted
from square planar geometry 4N complex/CuBH-3/3. 相似文献
6.
Tomasz Frączyk 《化学与生物多样性》2021,18(4):e2100043
Proteins anchor copper(II) ions mainly by imidazole from histidine residues located in different positions in the primary protein structures. However, the motifs with histidine in the first three N-terminal positions (His1, His2, and His3) show unique Cu(II)-binding properties, such as availability from the surface of the protein, high flexibility, and high Cu(II) exchangeability with other ligands. It makes such sequences beneficial for the fast exchange of Cu(II) between ligands. Furthermore, sequences with His1 and His2, thus, non-saturating the Cu(II) coordination sphere, are redox-active and may play a role in Cu(II) reduction to Cu(I). All human protein sequences deposited in UniProt Knowledgebase were browsed for those containing His1, His2, or His3. Proteolytically modified sequences (with the removal of a propeptide or Met residue) were taken for the analysis. Finally, the sequences were sorted out according to the subcellular localization of the proteins to match the respective sequences with the probability of interaction with divalent copper. 相似文献
7.
Czapor H Bielińska S Kamysz W Szyrwiel Ł Brasuń J 《Journal of inorganic biochemistry》2011,105(2):297-302
The coordination properties of cyclic octapeptides with multi-His motif: c(His-Gly-His-Xaa-His-Gly-His-Xaa) where Xaa = Asp or Lys, were investigated. The binding abilities of this peptides towards Cu(II) ions were studied by using different analytic methods as: potentiometry, spectroscopy and mass spectrometry. The obtained results show that the studied peptides in physiological related pH prefer formation of the species with the {4NIm} binding mode. The efficiency of Cu(II) binding depends on additional side chain groups Asp or Lys. Additionally the analysis of results for His containing cyclopeptides with different numbers of amino acid residues in cyclopeptide ring e.g. four, eight shows that in higher pH in both cases the binding by four amide nitrogens is not observed in the case of α-amino acid peptides. 相似文献
8.
Gnana S. Siluvai Michiko Nakano Mary Mayfield Ninian J. Blackburn 《Journal of biological inorganic chemistry》2011,16(2):285-297
Sco is a red copper protein that plays an essential yet poorly understood role in the metalation of the CuA center of cytochrome oxidase, and is stable in both the Cu(I) and Cu(II) forms. To determine which oxidation state is important
for function, we constructed His135 to Met or selenomethionine (SeM) variants that were designed to stabilize the Cu(I) over
the Cu(II) state. H135M was unable to complement a scoΔ strain of Bacillus subtilis, indicating that the His to Met substitution abrogated cytochrome oxidase maturation. The Cu(I) binding affinities of H135M
and H135SeM were comparable to that of the WT and 100-fold tighter than that of the H135A variant. The coordination chemistry
of the H135M and H135SeM variants was studied by UV/vis, EPR, and XAS spectroscopy in both the Cu(I) and the Cu(II) forms.
Both oxidation states bound copper via the S atoms of C45, C49 and M135. In particular, EXAFS data collected at both the Cu
and the Se edges of the H135SeM derivative provided unambiguous evidence for selenomethionine coordination. Whereas the coordination
chemistry and copper binding affinity of the Cu(I) state closely resembled that of the WT protein, the Cu(II) state was unstable,
undergoing autoreduction to Cu(I). H135M also reacted faster with H2O2 than WT Sco. These data, when coupled with the complete elimination of function in the H135M variant, imply that the Cu(I)
state cannot be the sole determinant of function; the Cu(II) state must be involved in function at some stage of the reaction
cycle. 相似文献
9.
Ildikó Turi Dorina Szikszai Giuseppe Di Natale Enrico Rizzarelli Imre Sóvágó 《Journal of inorganic biochemistry》2010,104(8):885-4348
Nickel(II) complexes of the peptide fragments of human prion protein containing histidyl residues both inside and outside the octarepeat domain have been studied by the combined application of potentiometric, UV-visible and circular dichroism spectroscopic methods. The imidazole-N donor atoms of histidyl residues are the exclusive metal binding sites below pH 7.5, but the formation of stable macrochelates was characteristic only for the peptide HuPrP(76-114) containing four histidyl residues. Yellow colored square planar complexes were obtained above pH 7.5-8 with the cooperative deprotonation of three amide nitrogens in the [Nim,N−,N−,N−] coordination mode. It was found that the peptides can bind as many nickel(II) ions as the number of independent histidyl residues. All data supported that the complex formation processes of nickel(II) are very similar to those of copper(II), but with a significantly reduced stability for nickel(II), which shifts the complex formation reactions into the slightly alkaline pH range. The formation of coordination isomers was characteristic of the mononuclear complexes with a significant preference for the nickel(II) binding at the histidyl sites outside the octarepeat domain. The results obtained for the two-histidine fragments of the protein, HuPrP(91-115), HuPrP(76-114)H85A and HuPrP(84-114)H96A, made it possible to compare the binding ability of the His96 and His111 sites. These data reveal a significant difference in the nickel(II) and copper(II) binding sites of the peptides: His96 was found to predominate almost completely for nickel(II) ions, while the opposite order, but with comparable concentrations, was reported for copper(II). 相似文献
10.
Teresa Kowalik-Jankowska El?bieta Jankowska Franciszek Kasprzykowski 《Journal of inorganic biochemistry》2010,104(8):831-7499
The classical tachykinins, substance P, neurokinin A and neurokinin B are predominantly found in the nervous system where they act as neurotransmitters and neuromodulators. Significantly reduced levels of these peptides were observed in neurodegenerative diseases and it may be suggested that this reduction may also result from the copper(II)-catalyzed oxidation. The studies of the interaction of copper(II) with neurokinin A and the copper(II)-catalyzed oxidation were performed. Copper(II) complexes of the neurokinin A (His-Lys-Thr-Asp-Ser-Phe-Val-Gly-Leu-Met-NH2) and acetyl-neurokinin A (Ac-His-Lys-Thr-Asp-Ser-Phe-Val-Gly-Leu-Met-NH2) were studied by potentiometric, UV-Vis (UV-visible), CD (circular dichroism) and EPR spectroscopic methods to determine the stoichiometry, stability constants and coordination modes in the complexes formed. The histidine residue in first position of the peptide chain of neurokinin A coordinates strongly to Cu(II) ion with histamine-like {NH2, NIm} coordination mode. With increasing of pH, the formation of a dimeric complex Cu2H2L2 was found but this dimeric species does not prevent the deprotonation and coordination of the amide nitrogens. In the Ac-neurokinin A case copper(II) coordination starts from the imidazole nitrogen of the His; afterwards three deprotonated amide nitrogens are progressively involved in copper coordination. To elucidate the products of the copper(II)-catalyzed oxidation of the neurokinin A and Ac-neurokinin A, liquid chromatography-mass spectrometry (LC-MS) method and Cu(II)/hydrogen peroxide as a model oxidizing system were employed.Oxidation target for both studied peptides is the histidine residue coordinated to the metal ions. Both peptides contain Met and His residues and are very susceptible on the copper(II)-catalyzed oxidation. 相似文献
11.
A series of peptide ligands containing the sequence -Cys-Xaa-His- (CXH; Xaa=Gly or Lys) has been prepared and the coordination chemistry of these peptides with nickel(II) investigated. Selective protection of either the N-terminal cysteine thiol or amine group gave complexes with amino or thiolato coordination, respectively, to nickel(II). Insertion of CGH into a pentapeptide, N-acetyl-Ala-Cys-Gly-His-Ala-CONH2, allowed the formation of a square-planar thiolato Cys-Gly-His complex with nickel(II) in an internal position of the peptide. Inclusion of an N-terminal cysteine residue with a free amino terminus gave rise to pH- and dioxygen-dependent coordination behavior. Solutions of CGH-CONH2 with nickel(II) at neutral pH yielded a red nickel-thiolate complex, but at higher pH (8.5 or above) or with exposure to dioxygen, yellow nickel complexes with N-terminal amino coordination were observed. The disulfide-bridged dimers formed from Ni(CGH-CONH2) in the presence of air were characterized and found to have the typical coordination found in the amino-terminal binding motif of the serum albumins. Nickel(II) coordination and thiol reactivity were also studied by determination of rates of thiol alkylation and by monitoring air oxidation in the presence of various metals. Zinc(II) effectively inhibits thiol alkylation and oxidation (disulfide formation) in all the peptides studied. Nickel(II) inhibits aerobic oxidation and alkylation of N-terminal protected peptides such as N-acetyl-Cys-Gly-His, but does not inhibit air oxidation of free amino terminal peptides such as Cys-Gly-His. Instead, nickel(II) mediates the formation an additional product under aerobic conditions, a cysteinesulfinic acid.Electronic Supplementary Material Supplementary material is available for this article if you access the article at . A link in the frame on the left on that page takes you directly to the supplementary material.Abbreviations CGH
cysteinylglycylhistidine
- GGH
glycylglycylhistidine
- Xaa
any amino acid 相似文献
12.
Minhui He 《Inorganica chimica acta》2010,363(13):3619-3623
A tetranuclear copper(II) complex [Cu4L2(CH3COO)2(OH)2]·6H2O, in which L stands for the dianion of N-(3-carboxylsalicylidene)-4-(2-iminoethyl)morpholine, was synthesized and characterized by elemental analysis, IR, UV-Vis, TGA and X-ray single crystal diffraction. The crystal structure shows that the coordination unit is centrosymmetric with all the Cu(II) ions in square pyramidal coordination geometry. The coordination unit consists of two equivalent parts [Cu2L(CH3COO)(OH)], each containing two Cu(II) ions, a tetradentate N2O2 Schiff base dianion L2−, a CH3COO−, and a OH− anion. In [Cu2L(CH3COO)(OH)], the six coordination atoms (N2O4) are nearly coplanar, with Cu(1) and Cu(2) enchased in between; the phenolate oxygen and the OH− oxygen as bridging atoms bind the two Cu(II) ions in close proximity; both O4 around Cu(1) and N2O2 around Cu(2) form the basal plane of the coordination square pyramids. The two parts are connected by sharing two μ3-OH− oxygens and two μ2-CH3COO− oxygens from each other, forming four edge-sharing coordination square pyramids around the four Cu(II) ions. A 3D network is formed through hydrogen bonding along a and c axis, and π-π interaction along b axis. 相似文献
13.
Spectroscopy (UV-Vis, 1H NMR, ESR) and electrochemistry revealed details of the structure of the Cu(II)-TRH (pyroglutamyl-histidyl-prolyl amide) complex. The 1H NMR spectrum of TRH has been assigned. NMR spectra of TRH in the presence of Cu(II) showed that Cu(II) initially binds TRH through the imidazole. TRH analogs, pGlu-His-Pro-OH, pGlu-(1-Me)His-Pro-amide, pGlu-His-(3,4-dehydro)Pro-amide, pGlu-His-OH, pGlu-Glu-Pro-amide, and pGlu-Phe-Pro-amide provided comparison data. The stoichiometry of the major Cu(II)-TRH complex at pH 7.45 and greater is 1:1. The conditional formation constant (in pH 9.84 borate with 12.0 mM tartrate) for the formation of the complex is above 105 M−1. The coordination starts from the 1-N of the histidyl imidazole, and then proceeds along the backbone involving the deprotonated pGlu-His amide and the lactam nitrogen of the pGlu residue. The fourth equatorial donor is an oxygen donor from water. Hydroxide begins to replace the water before the pH reaches 11. Minority species with stoichiometry of Cu-(TRH)x (x = 2-4) probably exist at pH lower than 8.0. In non-buffered aqueous solutions, TRH acts as a monodentate ligand and forms a Cu(II)-(TRH)4 complex through imidazole nitrogens. All the His-containing analogs behave like TRH in terms of the above properties. 相似文献
14.
Christelle Hureau Christelle Mathé Peter Faller Tony A. Mattioli Pierre Dorlet 《Journal of biological inorganic chemistry》2008,13(7):1055-1064
The GGGTHSQW sequence in the amyloidogenic part of the prion protein is a potential binding site for Cu(II). We have previously
studied the binding of copper to the shorter GGGTH peptide and showed that it is highly pH dependent (Hureau et al. in J. Biol. Inorg. Chem. 11:735–744, 2006). Two predominant complexes could be characterized at pH 6.7 and 9.0 with equatorial binding modes of 3N1O and 4N for the
metal ion, respectively. In this work, we have further investigated the coordination of Cu(II) to the GGGTH peptide as well
as the longer GGGTHSQW peptide in order to identify the oxygen donor ligand at neutral pH and to study the proximity and redox
activity of the tryptophan residue of the latter. The results for both peptides show that, at pH 6.7, Cu(II) is coordinated
by a carbonyl peptide backbone. At higher pH values, the carbonyl ligand dissociates and the coordination changes to a 4N
binding mode, inducing a structural rearrangement that brings the GGGTHSQW peptide’s tryptophan residue into the vicinity
of the copper ion, thus affecting their respective redox properties. 相似文献
15.
N. Sharath H. S. Bhojya Naik B. Vinay Kumar 《Nucleosides, nucleotides & nucleic acids》2013,32(11):813-829
The DNA-binding and photonuclease activity of newly synthesized tetra-azamacrocyclic ligand L (C32H32N8O4) and its complexes of type [MLCl2] and [ML]Cl2 (where M = Co(II), Fe(II) and Cu(II); L = N,N′-[3-(4-{5-[(2-amino-ethylamino)-methyl]-isoxazol-3yl}-phenyl)-isoxazol-5-yl methyl-ethane-1,2-diamine] are specified. An octahedral geometry has been proposed for Fe(II) and Co(II) complexes, while the Cu(II) complex has a square planar environment. The absorption spectral results indicate that the complexes bind with the base pairs of DNA, with an intrinsic binding constant Kb of Fe(II), Co(II), and Cu(II) complexes found to be 3.2 × 104 M?1, 5.3 × 104 M?1, and 4.2 × 104 M?1, respectively, in 5 mM Tris-HCl/50 mM NaCl buffer at pH 7.2. The large enhancement in the relative viscosity of DNA on binding to the complexes supports the proposed DNA binding modes. The viscosity and thermal denaturation studies sustain the effective intercalation with DNA. The DNA photocleavage studies demonstrated that compounds exhibit significant photonuclease activity by a concentration dependent on singlet oxygen mediated mechanism. 相似文献
16.
Shigeru Negi Yoshiyuki Umeda Saeko Masuyama Koji Kano Yukio Sugiura 《Bioorganic & medicinal chemistry letters》2009,19(10):2789-2791
To improve the DNA hydrolytic activity of the zinc finger nuclease, we have created a new artificial zinc finger nuclease (ZWH4) by connecting two distinct zinc finger domains possessing different types of Zn(II) binding sites (Cys2His2- and His4-types). The overall fold of ZWH4 is similar to that of the wild-type Sp1 zinc finger (Sp1(zf123)) as revealed by circular dichroism spectroscopy. The gel mobility shift assay demonstrated that ZWH4 binds to the GC box DNA, although the DNA-binding affinity is lower than that of Sp1(zf123). Evidently, ZWH4 hydrolyzes the covalently closed circular plasmid DNA (form I) containing the GC box (pBSGC) to the linear duplex DNA (form III) in the presence of a higher concentration (50 times) of the protein than DNA for a 24-h reaction. Of special interest is the fact that the novel mixed zinc finger protein containing the Cys2His2- and His4-type domains was first created. The present results provide the useful information for the redesign strategy of an artificial nuclease based on the zinc finger motif. 相似文献
17.
The complexes between copper(II) and the synthetic octapeptide fragments of the prion protein Ac-GWGQPHGG-NH2 (1), Ac-PHGGGWGQ-NH2 (3) and the cyclic analogue c-(GWGQPHGG) (2) have been comparatively investigated by circular dichroism (CD), absorption (UV-Vis), and electron paramagnetic resonance (EPR) spectroscopic methods.The results suggest a similar copper(II) coordination behaviour of the two linear peptides. In both cases two major complex species were spectroscopically detected. The first one, existing in the range of pH 7-9, showed spectroscopic parameters attributable to a 3N complex species, while the 4N complex was the main species at strongly alkaline pH values. Copper(II) binding appears to be confined within the aminoacid sequence HGG.Cyclisation of the main chain, as in the peptide 2, was found to have remarkable effects on the copper(II) complex speciation especially at pH 7-8 where the 3N species predominated in the linear counterparts. By contrast the spectroscopic data obtained at pH 11 provided evidence of the restoration of the same set of donor atoms as in the linear peptides. 相似文献
18.
Ishikawa T Chatake T Morimoto Y Maeda M Kurihara K Tanaka I Niimura N 《Biochemical and biophysical research communications》2008,376(1):32-35
Insulin is stored in pancreatic β-cell as hexameric form with Zn2+ ions, while the hormonally active form is monomer. The hexamer requires the coordination of Zn2+ ions to the HisB10. In order to reveal the mechanism of the hexamerization of insulin, we investigated the Zn2+ free insulin at pD6.6 and pD9 by neutron crystallographic analyses. HisB10 is doubly protonated not only at pD6.6 but also at pD9, indicating an abnormal pKa of this histidine. It is suggested that HisB10 acts on a strong cation capture and contributes to the high stability of the hexameric form in pancreas. 相似文献
19.
Bal Wojciech Dyba Marcin Szewczuk Zbigniew Jeżowska‐Bojczuk Małgorzata Lukszo Jan Ramakrishna Gayatri Kasprzak Kazimierz S. 《Molecular and cellular biochemistry》2001,222(1-2):97-106
The Zn(II) binding by partial peptides of human protamine HP2: HP21–15; HP21–25, HP226–40, HP237–47, and HP243–57 was studied by circular dichroism (CD). Precipitation of a 20mer DNA by these partial peptides and the effects of Zn(II) thereon were investigated using polyacrylamide gel electrophoresis (GE). The results of this study suggest that reduced HP2 (thiol groups intact) can bind Zn(II) at various parts of the molecule. In the absence of DNA, the primary Zn(II) binding site in reduced HP2 is located in the 37–47 sequence (involving Cys37, His39, His43, and Cys47), while in the presence of DNA, the strongest Zn(II) binding is provided by sequences 12–22 (by His12, Cys13, His19, and His22) and 43–57 (His43, Cys47, Cys53, and His57). In its oxidized form, HP2 can bind zinc through His residues of the 7–22 sequence. Zn(II) markedly enhances DNA binding by all partial peptides. These findings suggest that Zn(II) ions may be a regulatory factor for sperm chromatin condensation processes. 相似文献
20.
Aleksandra Marciniak Marek Cebrat Justyna Brasuń 《International journal of peptide research and therapeutics》2017,23(1):135-143
Two new somatostatin analogs with a characteristic part of the sequence -c(Cys-Phe-Trp-Lys-Thr-Cys)- and with two histidine and two aspartic acid moieties in their structures were synthesized and analyzed in terms of their coordination abilities with copper (II) ions. Both peptides bind Cu(II) effectively. Ligands form 4N complexes with \(\left\{ {{\text{N}}_{\text{Im}} ,{ 3} {\text{N}}_{\text{amide}}^{ - } } \right\}\) binding mode in a basic range of pH. But in spite of very similar sequences of the two peptides a significant difference in the effectiveness of the binding of copper (II) ions was observed. 相似文献