The cyclopeptides with the multi-His motif as ligands for copper(II)

The impact of two –GlyProGly– motifs on formation of di-copper complexes by His4-cyclopeptides

“…[6][7][8] The previous studies performed for His 2 -cyclotetrapeptides and His 3 -cyclohexapeptides have shown that below pH 7 they involve only imidazole nitrogen and coordination of amide nitrogens takes place in the same range of pH (E7). [9][10][11][12][13][14] The coordination abilities of cyclopeptides can be affected by the optical isomerism of His residues and the acid-base properties of the side chain of amino acids, 9 the amino acid sequence 12 or the size of the peptide cycle. 13 The interesting coordination abilities toward copper ions were found for the cyclic His 4 -octapeptide with the c(HKHPHKHP) sequence.…”

The Analysis of Cu(II)/Zn(II) Cyclopeptide System as Potential Cu,ZnSOD Mimic Center

“…Moreover the cyclic structure of the peptide chain makes it less flexible and influences the steric arrangement of the side chains groups (Hruby 1982 ; Hruby et al 1990 ) as well as coordination abilities (Brasun et al 2004 ; Fragoso et al 2013 ). The copper (II) binding by cyclopeptides strongly depends on the acid–base properties of the side chain groups (Czapor et al 2011 ; Matera et al 2008 ), its optical isomerism (Matera et al 2008 ), number of His residues in the peptide chain as well as the size of the peptide ring (Brasuń et al 2009 ). Moreover, the insertion of two Pro amino acid residues in their sequence allows for creating of two well defined binding sites for metal ions (Kotynia et al 2012 , 2014 ).…”

The Cu2+ Binding Properties of Branched Peptides Based on l-2,3-Diaminopropionic Acid

“…This result indicates the effect of histidine on Cu 2+ binding, which is known for the linear 31,33,34 and cyclic peptides. 35,36 It appears that the presence of histidine results in the ceasing of any interactions between the Cu 2+ ion and amide donors similarly to linear peptides. 31 At physiological pH, in case of 2HG almost all of Cu 2+ is bound without the deprotonation of amide donors, whereas in case of 3G almost 90% of copper is bound to 2N − donors.…”