title: Short-chain oligopeptides with copper(II) binding properties: The impact of specific structural modifications on the copper(II) coordination abilities.
abstract: A series of linear tetrapeptides containing two histidyl residues in position 2 and 4, namely DHGH, DHGdH, KHGH, KHGdH, Ac-DHGH-NH(2), Ac-DHGdH-NH(2), Ac-KHGH-NH(2), and Ac-KHGdH-NH(2), were synthesized and characterised. Their copper(II) binding properties were investigated in depth through a variety of physicochemical methods. Potentiometric titrations were first carried out to establish the stoichiometry and the stability of the resulting copper(II)-peptide complexes. The copper(II) chromophores that are formed in the various cases in dependence of pH were subsequently characterised by extensive spectroscopic analysis (UV-Vis, EPR, CD) in strict correlation with potentiometric data. The effects of the nature of the first amino acid (Lys versus Asp) and of N-terminal amino group protection on copper(II) binding were specifically addressed. On turn, the careful comparison of the copper(II) coordination abilities of the linear peptides with those of their cyclic analogs provided insight into the effects of cyclization on the overall metal binding properties.
authors.affiliation: Department of Inorganic Chemistry, Medical University of Wrocław, Szewska, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Matera-Witkiewicz
authors.forename: Justyna
authors.initials: J
authors.lastname: Brasuń
authors.forename: Jolanta
authors.initials: J
authors.lastname: Swiatek-Kozłowska
authors.forename: Alessandro
authors.initials: A
authors.lastname: Pratesi
authors.forename: Mauro
authors.initials: M
authors.lastname: Ginanneschi
authors.forename: Luigi
authors.initials: L
authors.lastname: Messori
mesh_terms: D002942:Circular Dichroism; D003300:Copper / Q000737:chemistry / Q000378:metabolism*; D009842:Oligopeptides / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism*; D011199:Potentiometry; D013329:Structure-Activity Relationship
chemical_list: D009842:Oligopeptides; D003300:Copper