Interaction studies of cysteine with Li⁺, Na⁺, K⁺, Be²⁺, Mg²⁺, and Ca²⁺metal cation complexes

Abstract

The coordination geometries, electronic features, metal ion affinities, entropies, and the energetics of Li+, Na+, K+, Be2+, Mg2+, and Ca2+ metal cations with different possible conformations of cysteine complexes were studied. The complexes were optimized using density functional theory (B3LYP) and second order Moller–Plesset Perturbation (MP2) theory methods using 6‐311 + +G** basis set. The interactions of the metal cations at different nucleophilic sites of cysteine conformations were considered after a careful selection among several binding sites. All the metal cations coordinate with cysteine in a tridentate manner and also the most preferred position for the interaction. It is found that, the overall structural parameters of cysteine are not altered by metal ion substitution, but, the metal ion‐binding site has undergone a noticeable change. All the complexes were characterized by an electrostatic interaction between ligand and metal ions that appears slightly more pronounced for lithium and beryllium metal complexes. The metal ion affinity (MIA) and basis set superposition error (BSSE) corrected interaction energy were also computed for all the complexes. The effect of metal cations on the infrared (IR) stretching vibrational modes of amino NH bond, side chain thiol group SH bond, hydroxyl OH bond, and Carbonyl CO bond in cysteine molecules have also been studied. The nature of the metal ion‐ligand bond and the coordination properties were examined using natural bond order (NBO) at bond critical point (electron density and their Laplacian of electron density) through Atoms in Molecules (AIM) analyses. Copyright © 2010 John Wiley & Sons, Ltd.

Mechanism of gelation in low-concentration aqueous solutions of silver nitrate with l-cysteine and its derivatives

“…54,55 At that, a metal ion can coordinate both a special functional group of SM and a few groups together. 56 Therefore, the silver mercaptide aggregates that belong to complexes containing also metal ions interact with water molecules other than those that are in the unbound state, since functional groups coordinated by metal ions do not form hydrogen bonds with water. [57][58][59] We can conclude that the addition of salt leads to the coordination of some functional groups by metal ions on the surface of SM supramonomers.…”

Gas‐phase interactions of organotin compounds with cysteine

“…Authors used electrospray ionization (ESI) coupled to MS to characterize the resulting complexes and confirmed the high affinity of cobalt(II) towards the sulfur atom. Energetic studies involving interactions of cysteine with alkali metal cations, Be 2+ , Ca 2+ and Mg 2+ , have also been published . Concerning the interactions between organotins and cysteine, various studies using potentiometry and Mössbauer spectroscopic methods have been reported .…”

“…Energetic studies involving interactions of cysteine with alkali metal cations, Be 2+ , Ca 2+ and Mg 2+ , have also been published. [28][29][30][31][32][33] Concerning the interactions between organotins and cysteine, various studies using potentiometry [13,14] and Mössbauer spectroscopic methods have been reported. [15][16][17] To the best of our knowledge, the interactions taking place between OTCs and cysteine have not been explored so far by MS, and this is the purpose of the present study.…”

Effect of l-cysteine and lactose on color stability of porcine red blood cell during freeze-drying and powder storage

“…It must involve a different path. It is well known that L-cysteine has antioxidant ability (31) and coordination ability with metallic ion (32), and thus hindering dexoy-hemoglobin or/and oxy-hemoglobin from oxidation. As for α-lactose, it might be related to its reducing property or its water retention ability during dehydration (23), thereby limiting oxygen accessibility to heme iron (33).…”