Dual mode of voltammetric studies on Cu() complexes of His2 peptides: phosphate and peptide sequence recognition

• Published in: Dalton transactions : an international journal of inorganic chemistry Vol. 51; no. 47; pp. 18143 - 18151
• Main Authors: Tobolska, Aleksandra, G owacz, Klaudia, Ciosek-Skibi ska, Patrycja, Bal, Wojciech, Wróblewski, Wojciech, Wezynfeld, Nina E
• Format: Journal Article
• Language: English
• Published: England Royal Society of Chemistry 06.12.2022
• Subjects: Biomolecules; Copper; Electrochemical analysis; Histidine; Oxidation; Peptides; Phosphates; Recognition; Residues; Voltammetry
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/d2dt03078k

Copper( ii ) complexes of peptides with a histidine residue at the second position (His2 peptides) provide a unique profile of electrochemical behavior, offering signals of both Cu( ii ) reduction and Cu( ii ) oxidation. Furthermore, their structures with vacant positions in the equatorial coordination plane could facilitate interactions with other biomolecules. In this work, we designed a library of His2 peptides based on the sequence of Aβ 5-9 (RHDSG), an amyloid beta peptide derivative. The changes in the Aβ 5-9 sequence highly affect the Cu( ii ) oxidation signals, altered further by anionic species. As a result, Cu( ii ) complexes of Arg1 peptides without Asp residues were chosen as the most promising peptide-based molecular receptors for phosphates. The voltammetric data on Cu( ii ) oxidation for binary Cu( ii )-His2 peptide complexes and ternary Cu( ii )-His2 peptide/phosphate systems were also tested for His2 peptide recognition. We achieved a highly promising identification of subtle modifications in the peptide sequence. Thus, we introduce voltammetric measurement as a potential novel tool for peptide sequence recognition. In this work, we have proposed the double application of voltammetric studies on the Cu( ii ) oxidation process of Cu( ii )-peptide complexes in the recognition of phosphate species and identification of His2 peptide sequences.