Influence of amino acid sequence in a peptidic Cu+-responsive luminescent probe inspired by the copper chaperone CusF. Issue 31 (20th July 2018)

• Record Type: Journal Article
• Authors: Roux, A.; Isaac, M.; Chabert, V.; Denisov, S. A.; McClenaghan, N. D.; Sénèque, O.
• Is Part Of: Organic & biomolecular chemistry. Volume 16:Issue 31(2018)
• Page Start: 5626
• Page End: 5634
• Publication Date: 2018-07-20
• Subjects: Chemistry, Organic -- Periodicals; Bioorganic chemistry -- Periodicals; Chemistry, Physical organic -- Periodicals; 547
• DOI: 10.1039/c8ob01044g
• Languages: English
• ISSNs: 1477-0520

Abstract

Abstract : Amino acid sequence influences the luminescence behavior of a family of bio-inspired Cu + -responsive probes. Abstract : Copper(i ) is a soft metal ion that plays an essential role in living organisms and Cu + -responsive probes are required to detect Cu + ions in physiological conditions and understand its homeostasis as well as the diseases associated with its misregulation. In this article, we describe a series of cyclic peptides, which are structurally related to the copper chaperone CusF, and that behave as Cu + -repsonsive probes. These peptide probes comprise the 16-amino acid loop of CusF cyclized by a β-turn inducer dipeptide and functionalized by a Tb 3+ complex for its luminescence properties. The mechanism of luminescence enhancement relies on the modulation of the antenna effect between a tryptophan residue and the Tb 3+ ion within the probe when Cu + forms a cation–π interaction with the tryptophan. Here, we investigate the influence of the amino acid sequence of these cyclic peptides on the copper-induced modulation of Tb 3+ emission and show that the rigid β-turn inducer Aib-d -Pro and insertion of the Tb 3+ complex close to its tryptophan antenna are required to obtain turn-on Cu + responsive probes. We also show that the amino acid sequence, especially the number and position of proline residues has a significant impact on metal-induced luminescence enhancement and metal-binding constant of the probes.