Studies of DNA- and HSA-binding properties of new nano-scale green synthesized Ni (II) complex as anticancer agent using spectroscopic methods, viscosity measurement, molecular docking, MD simulation and QM/MM

Alterations in the conformation and function of human serum albumin induced by the binding of methyl hydrogen phthalate

Phthalate esters (PAEs) are widely used as plasticizer components in production. Methyl hydrogen phthalate (MHP) is a metabolite of dimethyl phthalate (DMP, a kind of PAEs), and its toxic residues accumulate in the nature and can enter the human body. Here, the interaction between MHP and human serum albumin (HSA) was probed by using multi-spectral, computer simulations, and biochemical techniques. The results showed that MHP was spontaneously embedded in site I of HSA to form a complex by H-bonds and van der Waals forces (ΔH < 0, ΔS < 0). The binding constant (K_a) of the HSA-MHP system was 1.136 ± 0.026 × 10⁴ M^-1 (298 K). The combination of MHP produced conformational variations of HSA, as shown by the 3D fluorescence spectrum, CD spectra, and molecular dynamics simulation. Additionally, molecular docking indicated that MHP was surrounded by multiple residues, such as Lys199, Leu203, Phe206, and Trp214. Specifically, Lys199 and Trp214 exerted a crucial effect on the interaction of HSA and MHP. The residues with important energy contribution were mostly located in site I. The ASA values of the aromatic amino acids of HSA changed after combining with MHP. The R_g and SASA values of HSA increased after adding MHP, suggesting that the structure of HSA was less compact. Moreover, the esterase-like activity of HSA increased after adding MHP to HSA, indicating that MHP may disturb the normal physiological activities in the human body. This study was helpful to understand the biological function of MHP and provided some insights for its side effect in the human body.

A new class of nickel(II) oxyquinoline-bipyridine complexes as potent anticancer agents induces apoptosis and autophagy in A549/DDP tumor cells through mitophagy pathways

A new class of nickel(II) oxyquinoline-bipyridine complexes, namely, [Ni(La1)2(Lb6)] (Ni1), [Ni(La1)2(Lb2)] CH3OH (Ni2), [Ni(La7)2(Lb11)]2H2O (Ni3), [Ni(La1)2(Lb9)] (Ni4), [Ni(La1)2(Lb8)] (Ni5), [Ni(La2)2(Lb1)] (Ni6), [Ni(La2)2(Lb6)]CH3OH (Ni7), [Ni(La2)2(Lb11)]CH3OH (Ni8), [Ni(La2)2(Lb3)] (Ni9), [Ni(La2)2(Lb2)]CH3OH (Ni10), [Ni(La2)2(Lb5)]CH3OH...

Multispectroscopic analysis, atomic force microscopy, molecular docking and molecular dynamic simulation studies of the interaction between [SnMe2Cl2(Me2phen)] complex and ct-DNA in the presence of glucose

In this study, the spectroscopic methods (UV-vis, fluorimetric), Atomic force microscopy, and computational studies (molecular docking and molecular dynamic simulation) were used to investigate the interaction of [SnMe₂Cl₂(Me₂phen)] complex with CT-DNA in the presence of glucose. The results showed the complex in the medium containing glucose has less effect on calf thymus DNA (ct-DNA) than the medium without glucose. Cytotoxicity of [SnMe₂Cl₂(Me₂phen)] complex on MCF-7 cells was examined and showed Sn(IV) complex possesses potential cytotoxicity against this cell line. Molecular docking study showed that Sn(IV) complex interacts with DNA by groove binding mode. Radius of gyration (Rg) was smaller upon binding of the Sn(IV) complex suggesting a more compact structure of DNA in the presence of Sn(IV) complex.Communicated by Ramaswamy H. Sarma.

Biophysical, molecular dynamics and cellular studies on the interaction of nickel oxide nanoparticles with tau proteins and neuron-like cells

Nickel oxide nanoparticles (NiO NPs) have been used in the biological and medical sciences. However, their toxic effects against biological systems such as nervous system have not been well studied. Therefore, the adverse effect of NiO NPs on tau structure was investigated by fluorescence and CD spectroscopic methods as well as TEM study. Also, molecular dynamic study was run to extend the experimental data. Cytotoxic activity of NiO NPs against SH-SY5Y cell was determined by trypan blue exclusion, cell morphology, ROS, and apoptosis assays. ANS, Nile red, ThT assays and electron micrograph investigation revealed that NiO NPs can increase the hydrophobic portions of tau and induce the formation of amorphous tau aggregates. Far and near CD spectroscopic methods revealed that NiO NPs can change the secondary and tertiary structure of tau, respectively. Theoretical studies depicted that NiO NPs lead to folding of tau structure. In the cellular view, NiO NPs induced significant mortality and morphological effects against SH-SY5Y cells. NiO NPs also provided a significant impact on generating intracellular ROS and apoptosis induction. This study determined that NiO NPs could mediate the induction of some undesired effects on the nervous system.

Half Sandwich Rhodium(III) and Iridium(III) Complexes as Cytotoxic and Metallonuclease Agents

Half sandwich complexes of the type [(η5-C₅Me₅)M(L^1-3)Cl]Cl.2H₂O were synthesized using [{(η⁵-C₅Me₅)M(μ-Cl)Cl}₂], where M = Rh(III)/Ir(III) and L^1-3 = pyrimidine-based ligands. The complexes were characterized by spectral analysis. DNA interaction studies by absorption titration and hydrodynamic measurement and suggest intercalative mode of binding of complexes with CT-DNA. The molecular docking study also supports intercalation of the complexes between the stacks of nucleotide base pairs. The gel electrophoresis assay demonstrated the ability of the complexes to interact and cleave plasmid DNA. Minimum inhibitory concentrations (MIC) of the complexes were investigated by the microdilution broth method. The cytotoxic properties of the metal complexes were evaluated using brine shrimp lethality bioassay.