Protein-Protein Stabilization in VO/8-Hydroxyquinoline-Lysozyme Adducts.

The binding of the potential drug [VO(8-HQ)], where 8-HQ is 8-hydroxyquinolinato, with hen egg white lysozyme (HEWL) was evaluated through spectroscopic (electron paramagnetic resonance, EPR, and UV-visible), spectrometric (electrospray ionization-mass spectrometry, ESI-MS), crystallographic (X-ray diffraction, XRD), and computational (DFT and docking) studies. ESI-MS indicates the interaction of [VO(8-HQ)(HO)] and [VO(8-HQ)(HO)] species with HEWL. Room temperature EPR spectra suggest both covalent and non-covalent binding of the two different V-containing fragments.

Non-Covalent and Covalent Binding of New Mixed-Valence Cage-like Polyoxidovanadate Clusters to Lysozyme.

The high-resolution X-ray structures of the model protein lysozyme in the presence of the potential drug [VO(acetylacetonato)] from crystals grown in 1.1 M NaCl, 0.1 M sodium acetate at pH 4.

Experimental and Computational Studies on the Interaction of DNA with Hesperetin Schiff Base Cu Complexes.

The interactions with calf thymus DNA (CT-DNA) of three Schiff bases formed by the condensation of hesperetin with benzohydrazide (HHSB or LH), isoniazid (HIN or LH), or thiosemicarbazide (HTSC or LH) and their Cu complexes (CuHHSB, CuHIN, and CuHTSC with the general formula [CuLH(AcO)]) were evaluated in aqueous solution both experimentally and theoretically. UV-Vis studies indicate that the ligands and complexes exhibit hypochromism, which suggests helical ordering in the DNA helix. The intrinsic binding constants () of the Cu compounds with CT-DNA, in the range (2.

Interaction with CT-DNA and in vitro cytotoxicity of two new copper(II)-based potential drugs derived from octanoic hydrazide ligands.

Two copper(II) complexes [Cu(Hpmoh)(NO)(NCS)] (1) and [Cu(peoh)(N)] (2) were designed and synthesized by reaction of Cu(NO)·3HO with hydrazone Schiff base ligands,abbreviated with Hpmoh and Hpeoh. Hpmoh and Hpeoh were prepared by condensation reaction of octanoic hydrazide with pyridine-2-carboxyaldehyde and 2-acetylpyridine, respectively. Complexes 1 and 2 were characterized using different analytical techniques such as FT-IR, UV-Vis, IR, EPR and single X-ray diffraction (XRD) analyses as well as computational methods (DFT).

Implications of Protein Interaction in the Speciation of Potential VO-Pyridinone Drugs.

Vanadium complexes (VCs) are promising agents for the treatment, among others, of diabetes and cancer. The development of vanadium-based drugs is mainly limited by a scarce knowledge of the active species in the target organs, which is often determined by the interaction of VCs with biological macromolecules like proteins. Here, we have studied the binding of [VO(empp)] (where Hempp is 1-methyl-2-ethyl-3-hydroxy-4(1)-pyridinone), an antidiabetic and anticancer VC, with the model protein hen egg white lysozyme (HEWL) by electrospray ionization-mass spectrometry (ESI-MS), electron paramagnetic resonance (EPR), and X-ray crystallography.

A Series of Non-Oxido V Complexes of Dibasic ONS Donor Ligands: Solution Stability, Chemical Transformations, Protein Interactions, and Antiproliferative Activity.

A series of mononuclear non-oxido vanadium(IV) complexes, [V(L)] (), featuring tridentate bi-negative ONS chelating S-alkyl/aryl-substituted dithiocarbazate ligands HL, are reported. All the synthesized non-oxido V compounds are characterized by elemental analysis, spectroscopy (IR, UV-vis, and EPR), ESI-MS, as well as electrochemical techniques (cyclic voltammetry). Single-crystal X-ray diffraction studies of - reveal that the mononuclear non-oxido V complexes show distorted octahedral ( and ) or trigonal prismatic () arrangement around the non-oxido V center.

Interaction of pharmacologically active pyrone and pyridinone vanadium(IV,V) complexes with cytochrome c.

The interaction between cytochrome c (Cyt) and potential vanadium drugs, formed by 1,2-dimethyl-3-hydroxy-4(1H)-pyridinonate (dhp) and maltolate (ma), was studied by ElectroSpray Ionization-Mass Spectrometry (ESI-MS). Since under physiological conditions redox processes are possible, the binding of the complexes in the oxidation state +IV and +V, [VO(dhp)], [VO(ma)], [VO(dhp)] and [VO(ma)], was examined. In all systems V-L-Cyt adducts are observed, their formation depending on V oxidation state, ligand L and metal concentration.

Binding of V O , V OL, V OL and V O L Moieties to Proteins: X-ray/Theoretical Characterization and Biological Implications.

Vanadium compounds have frequently been proposed as therapeutics, but their application has been hampered by the lack of information on the different V-containing species that may form and how these interact with blood and cell proteins, and with enzymes. Herein, we report several resolved crystal structures of lysozyme with bound V O and V OL , where L=2,2'-bipyridine or 1,10-phenanthroline (phen), and of trypsin with V O(picolinato) and V O (phen) moieties. Computational studies complete the refinement and shed light on the relevant role of hydrophobic interactions, hydrogen bonds, and microsolvation in stabilizating the structure.

Interaction of the potent antitumoral compounds Casiopeinas® with blood serum and cellular bioligands.

Casiopeinas® are among the few Cu compounds patented for their antitumor activity, but their mode of action has not been fully elucidated yet. One of them, Cas II-gly, is formed by 4,7-dimethyl-1,10-phenanthroline (Mephen) and glycinato (Gly). In blood and cells, Cas II-gly can keep its identity or form mixed species with serum or cytosol bioligands (bL or cL) with composition Cu-Mephen-bL/cL, Cu-Gly-bL/cL, or Cu-bL/cL.