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001-es BibID:	BIBFORM097685
035-os BibID:	(cikkazonosító)30394
Első szerző:	Kállay Csilla (vegyész)
Cím:	Thermodynamic and structural characterization of the Copper(II) complexes of peptides containing both histidyl and aspartyl residues / Csilla Kállay, Zoltán Nagy, Katalin Várnagy, Gerasimos Malandrinos, Nick Hadjiliadis, Imre Sóvágó
Dátum:	2007
ISSN:	1565-3633
Megjegyzések:	Terminally protected pentapeptides with 2 histidines (Ac-HHVGD-NH2 and Ac-HVGDH-NH2) and the terminally free peptides containing both internal aspartyl and C-terminal histidyl residues (FDAH and VIDAH) have been synthesized, and copper(II) complexes studied by potentiometric, UV-Vis, CD, and EPR spectroscopic techniques in solution. Both thermodynamic and spectroscopic data reveal that side chain donor atoms of aspartyl and histidyl residues have a significant contribution to the metal binding affinity of peptide molecules. In the case of terminally protected peptides, the role of the imidazole-N donor functions is reflected in the enhanced stability of the 3N and 4N coordinated copper(II) complexes. The amino and ?-carboxylate groups of FDAH and VIDAH create a very effective metal binding site with the (NH2, N?, ?-COO?) and (NH2, N?, N?, ?-COO?) coordination modes including the N-termini, while the histidine sites are available for the formation of the (Nim, N?, N?) binding mode resulting in the preference of dinuclear complex formation.
Tárgyszavak:	Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk
Megjelenés:	Bioinorganic Chemistry And Applications. - 2007 (2007), p. 1-9. -
További szerzők:	Nagy Zoltán (1974-) (vegyész) Várnagy Katalin (1961-) (vegyész) Malandrinos, Gerasimos Hadjiliadis, Nick Sóvágó Imre (1946-) (vegyész)
Pályázati támogatás:	T048352 OTKA T042722 OTKA
Internet cím:	Szerző által megadott URL DOI Intézményi repozitóriumban (DEA) tárolt változat
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001-es BibID:	BIBFORM095291
Első szerző:	Kállay Csilla (vegyész)
Cím:	Copper(II) complexes of terminally protected pentapeptides containing three histidyl residues in alternating positions, Ac-His-Xaa-His-Yaa-His-NH2 / Csilla Kállay, Katalin Várnagy, Gerasimos Malandrinos, Nick Hadjiliadis, Daniele Sanna, Imre Sóvágó
Dátum:	2006
ISSN:	1477-9226
Megjegyzések:	Copper(II) complexes of the pentapeptides Ac-HisAlaHisValHis-NH2, Ac-HisValHisAlaHis-NH2, Ac-HisProHisAlaHis-NH2, Ac-HisAlaHisProHis-NH2, Ac-HisGlyHisValHis-NH2 and Ac-HisValHisGlyHis-NH2 have been studied by potentiometric, UV-Vis, CD and EPR spectroscopic methods. It has been found that the pentapeptides are efficient ligands for the complexation with copper( II) and exhibit an outstanding versatility in the co-ordination geometry of complexes. The presence of three histidyl residues provides a high possibility for the formation of macrochelates via the exclusive binding of imidazole-N donor atoms. The macrochelation suppresses, but cannot preclude the deprotonation and metal ion co-ordination of amide functions and the species [CuH-2L] and [Cu2H-4L] predominate at physiological pH in equimolar solutions and in the presence of excess metal ions, respectively. It is also clear from the data that both C-terminal and internal histidyl residues can work as the anchoring sites for metal binding and subsequent amide deprotonation resulting in the formation of co-ordination isomers and dinuclear species in equimolar solutions and in the presence of excess metal ions, respectively. In more alkaline solutions ( pH similar to 10) a third amide function can be deprotonated and co-ordinated in the species [CuH-3L](-) with (N-, N-, N-, N-im) co-ordination. The dinuclear species [Cu2H-5L](-) and [Cu2H-6L](2-) containing hydroxide ions and/or imidazolato bridges are formed at high pH in the presence of excess of metal ions. The insertion of one proline into the sequence preceding histidyl residues hinders the deprotonation of amide functions at that site and the formation of only mononuclear complexes was observed with these peptides.
Tárgyszavak:	Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk
Megjelenés:	Dalton Transactions. - 2006 : 38 (2006), p. 4545-4552. -
További szerzők:	Várnagy Katalin (1961-) (vegyész) Malandrinos, Gerasimos Hadjiliadis, Nick Sanna, Daniele (1956-) (vegyész) Sóvágó Imre (1946-) (vegyész)
Pályázati támogatás:	T 048352 OTKA T 042722 OTKA
Internet cím:	Szerző által megadott URL DOI Intézményi repozitóriumban (DEA) tárolt változat
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001-es BibID:	BIBFORM010522
Első szerző:	Kállay Csilla (vegyész)
Cím:	Thermodynamic and structural characterization of the macrochelates formed in the reactions of copper(II) and zinc(II) ions with peptides of histidine / Csilla Kállay, Katalin Várnagy, Gerasimos Malandrinos, Nick Hadjiliadis, Daniele Sanna, Imre Sóvágó
Dátum:	2009
ISSN:	0020-1693
Megjegyzések:	Copper(II) complexes of the peptides Ac-HisSarHis-NH2, Ac-HisSarHisSarHis-NH2 and Ac-HisSarHisSarHisSarHis-NH2 have been studied by potentiometric, UV-Vis, CD and EPR spectroscopic methods. Stability constants for the corresponding zinc(II) complexes have also been reported. The formation of M(II)-2N(im), M(II)-3N(im) and M(II)-4N(im) bonded macrochelates was suggested in the pH range 5-7. The macrochelates were, however, not stable enough to prevent metal ion hydrolysis in slightly alkaline solutions. In the case of copper(II) complexes, the metal ion promoted deprotonation and coordination of the amide groups of histidyl residues were also suggested. The stability constants of macrochelate complexes were compared to the literature data reported for the macrochelates of the other peptides of histidine. It was found that the thermodynamic stability of macrochelate species is largely influenced by the number and location of histidyl residues in the peptide backbone. The highest stability was obtained for the HXHYH-type sequences, while the distant arrangement of histidyl residues resulted in a significant reduction of the stability constants. (C) 2008 Elsevier B. V. All rights reserved.
Tárgyszavak:	Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:	Inorganica Chimica Acta. - 362 : 3 (2009), p. 935-945. -
További szerzők:	Várnagy Katalin (1961-) (vegyész) Malandrinos, Gerasimos Hadjiliadis, Nick Sanna, Daniele (1956-) (vegyész) Sóvágó Imre (1946-) (vegyész)
Internet cím:	DOI Intézményi repozitóriumban (DEA) tárolt változat
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001-es BibID:	BIBFORM089119
Első szerző:	Várnagy Katalin (vegyész)
Cím:	Equilibrium and structural studies on copper(II) complexes of tetra-, penta- and hexa-peptides containing histidyl residues at the C-termini / Katalin Várnagy, Julianna Szabó, Imre Sóvágó, Gerasimos Malandrinos, Nick Hadjiliadis, Daniele Sanna, Giovanni Micera
Dátum:	2000
ISSN:	0300-9246 1364-5447
Megjegyzések:	The stoichiometry, stability constants and solution structure of the complexes formed in the reaction of copper(II) with oligopeptides containing histidyl residues at the C-termini (Gly(3)His, Gly(4)His and Gly(5)His) have been determined by potentiometric, UV-VIS and EPR spectroscopic methods. The formation of the species [CuHL](2+), [CuL](+), [CuH-1L], [CuH-2L](-) and [CuH-3L](2-) was detected in all cases. Binding modes of the species [CuL](+), [CuH-1L] and [CuH-2L](-) were characterized by the metal ion co-ordination of the terminal amino group, carbonyl oxygen or one or two deprotonated amide nitrogens in joined five-membered chelates from the N-termini, while the fourth co-ordination site of the metal ion was occupied by nitrogen donors of imidazole in the form of a macrochelate. The stability of the macrochelate was decreased upon increasing the length of the peptide molecule. For the penta- and hexa-peptides the species [CuH-3L](2-) was characterized as a 4N-complex with equatorial co-ordination of the terminal amino group and subsequent three deprotonated amide nitrogens, with unco-ordinated imidazolyl residues, while a 5N-species was suggested to form for Gly(3)His with axial interaction of the imidazole-N donor atom. Copper(II) complexes of Gly(2)His and pentaglycine were also investigated for reliable comparison.
Tárgyszavak:	Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk
Megjelenés:	Journal of the Chemical Society. Dalton Transactions. - 2000 : 4 (2000), p. 467-472. -
További szerzők:	Szabó Julianna (vegyész) Sóvágó Imre (1946-) (vegyész) Malandrinos, Gerasimos Hadjiliadis, Nick Sanna, Daniele (1956-) (vegyész) Micera, Giovanni
Pályázati támogatás:	OTKA-T19337 OTKA TéT GR-1/96 egyéb
Internet cím:	Szerző által megadott URL DOI Intézményi repozitóriumban (DEA) tárolt változat
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