engleski

Influence of Amino Acid Side Chains on Water Binding to the Copper(II) in bis(N, N-dimethyl- L- -isoleucinato)copper(II): an EPR and Molecular Mechanics Study

The EPR spectra of bis(N, N-dimethyl-L- -isoleucinato)copper(II) dissolved in deuterated methanol were measured in the temperature interval from 276 to 332 K [1]. The spectra pointed out different properties of the copper(II) complex below and above 300 K. Below 300 K the complex behaved as an aqua-complex while above 300 K it adopted properties characteristic for a copper(II) complex not having the apically bounded water molecule. The effect led to the hypothesis that binding or release of the water molecules from the copper(II) ion in its complex with N, N-dimethyl-L- -isoleucine has to be related to the conformational changes of the amino acid side chains. In order to examine the validity of the hypothesis, i.e., the influence of the amino acid side chains' conformations on water binding to the copper(II), the conformational analysis of bis(N, N-dimethyl-L- -isoleucinato)copper(II) has been attempted with a molecular mechanics force field developed to reproduce and predict properties of both aqua and anhydrous copper(II) amino acid complexes. [1] V. Noethig-Laslo, N. Paulić, R. Pogni and R. Basosi, submitted to PCCP

copper; EPR; molecular mechanics; force field; amino acids; isoleucine; simulation

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