REAL

Exploring the boundaries of direct detection and characterization of labile isomers - a case study of copper(II)-dipeptide systems

Tóth, Eszter N. and Nagy, Nóra Veronika and Rockenbauer, Antal and Peintler, Gábor and Gyurcsik, Béla (2017) Exploring the boundaries of direct detection and characterization of labile isomers - a case study of copper(II)-dipeptide systems. DALTON TRANSACTIONS, 46 (25). pp. 8157-8166. ISSN 1477-9226

[img]
Preview
Text
Manuscript_ET_GYB_realhoz.pdf

Download (761kB) | Preview

Abstract

The investigation of the linkage isomers of biologically essential and kinetically labile metal complexes in aqueous solutions poses a challenge, as these microspecies cannot be separately studied. Therefore, derivatives are commonly used to initially determine the stability or spectral characteristics of at least one of the isomers. Here we directly detect the isomers, describe the metal ion coordination sphere, speciation and thermodynamic parameters by a synergistic application of temperature dependent EPR and CD spectroscopic measurements in copper(II)-dipeptide systems including His-Gly and His-Ala ligands. The Delta H = (-23 +/- 4) kJ mol(-1) value of the standard enthalpy change corresponding to the peptide-type to histamine-type isomerisation equilibrium of the [CuL](+) complex was corroborated by several techniques. The preferential coordination of the side-chains was observed at lower temperatures, whereas, metal-binding of the backbone atoms became favourable upon increasing temperature. This study exemplifies the necessity of using temperature dependent multiple methodologies for a reliable description of similar systems for upstream applications.

Item Type: Article
Uncontrolled Keywords: MAGNETIC-FIELD; TOPOLOGICAL ISOMERISM; 2-DIMENSIONAL SIMULATION; COORDINATION MODES; LINKAGE ISOMERISM; BOND-STRETCH ISOMERISM; ELECTRON-SPIN-RESONANCE; VISIBLE CIRCULAR-DICHROISM; TRANSITION-METAL-COMPLEXES; X-RAY-DIFFRACTION
Subjects: Q Science / természettudomány > QD Chemistry / kémia
SWORD Depositor: MTMT SWORD
Depositing User: MTMT SWORD
Date Deposited: 25 Sep 2017 12:43
Last Modified: 01 Sep 2019 23:15
URI: http://real.mtak.hu/id/eprint/63659

Actions (login required)

Edit Item Edit Item