Copper(II) complexes of terminally protected pentapeptides containing three histidyl residues in alternating positions, Ac-His-Xaa-His-Yaa-His-NH2

dc.contributor.authorKallay, C.en
dc.contributor.authorVarnagy, K.en
dc.contributor.authorMalandrinos, G.en
dc.contributor.authorHadjiliadis, N.en
dc.contributor.authorSanna, D.en
dc.contributor.authorSovago, I.en
dc.date.accessioned2015-11-24T16:54:58Z
dc.date.available2015-11-24T16:54:58Z
dc.identifier.issn1477-9226-
dc.identifier.urihttps://olympias.lib.uoi.gr/jspui/handle/123456789/10231
dc.rightsDefault Licence-
dc.subjecttransition-metal-complexesen
dc.subjectimidazole nitrogen donorsen
dc.subjectamyloid precursor proteinen
dc.subjectprion proteinen
dc.subjection coordinationen
dc.subjectmodel peptidesen
dc.subjectbinding siteen
dc.subjectcu2+ ionsen
dc.subjectstabilityen
dc.subjectfragmentsen
dc.titleCopper(II) complexes of terminally protected pentapeptides containing three histidyl residues in alternating positions, Ac-His-Xaa-His-Yaa-His-NH2en
heal.abstractCopper(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.en
heal.accesscampus-
heal.fullTextAvailabilityTRUE-
heal.identifier.primaryDoi 10.1039/B608190h-
heal.identifier.secondary<Go to ISI>://000240935300003-
heal.identifier.secondaryhttp://pubs.rsc.org/en/content/articlepdf/2006/dt/b608190h-
heal.journalNameDalton Transactionsen
heal.journalTypepeer reviewed-
heal.languageen-
heal.publicationDate2006-
heal.publisherRoyal Society of Chemistryen
heal.recordProviderΠανεπιστήμιο Ιωαννίνων. Σχολή Θετικών Επιστημών. Τμήμα Χημείαςel
heal.typejournalArticle-
heal.type.elΆρθρο Περιοδικούel
heal.type.enJournal articleen

Αρχεία

Φάκελος/Πακέτο αδειών

Προβολή: 1 - 1 of 1
Φόρτωση...
Μικρογραφία εικόνας
Ονομα:
license.txt
Μέγεθος:
1.74 KB
Μορφότυπο:
Item-specific license agreed upon to submission
Περιγραφή: