scholarly journals Thermodynamic Evaluation of the Interactions between Anticancer Pt(II) Complexes and Model Proteins

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2376
Author(s):  
Chiara Pelosi ◽  
Francesca Saitta ◽  
Caterina Zerino ◽  
Giovanni Canil ◽  
Tarita Biver ◽  
...  
Keyword(s):  
Protein Interactions ◽  
Anticancer Agents ◽  
Covalent Bond ◽  
Binding Mode ◽  
Critical Issue ◽  
Rnase A ◽  
Ionization Mass ◽  
Thermodynamic Evaluation ◽  
Scanning Calorimetry ◽  
Esi Ms

In this work, we have analysed the binding of the Pt(II) complexes ([PtCl(4′-phenyl-2,2′:6′,2″-terpyridine)](CF3SO3) (1), [PtI(4′-phenyl-2,2′:6′,2″-terpyridine)](CF3SO3) (2) and [PtCl(1,3-di(2-pyridyl)benzene) (3)] with selected model proteins (hen egg-white lysozyme, HEWL, and ribonuclease A, RNase A). Platinum coordination compounds are intensively studied to develop improved anticancer agents. In this regard, a critical issue is the possible role of Pt-protein interactions in their mechanisms of action. Multiple techniques such as differential scanning calorimetry (DSC), electrospray ionization mass spectrometry (ESI-MS) and UV-Vis absorbance titrations were used to enlighten the details of the binding to the different biosubstrates. On the one hand, it may be concluded that the affinity of 3 for the proteins is low. On the other hand, 1 and 2 strongly bind them, but with major binding mode differences when switching from HEWL to RNase A. Both 1 and 2 bind to HEWL with a non-specific (DSC) and non-covalent (ESI-MS) binding mode, dominated by a 1:1 binding stoichiometry (UV-Vis). ESI-MS data indicate a protein-driven chloride loss that does not convert into a covalent bond, likely due to the unfavourable complexes’ geometries and steric hindrance. This result, together with the significant changes of the absorbance profiles of the complex upon interaction, suggest an electrostatic binding mode supported by some stacking interaction of the aromatic ligand. Very differently, in the case of RNase A, slow formation of covalent adducts occurs (DSC, ESI-MS). The reactivity is higher for the iodo-compound 2, in agreement with iodine lability higher than chlorine.

2003 Fred Beamish Award Lecture — Exploring the dynamics of biological systems by mass spectrometry

2004 ◽  
Vol 82 (11) ◽  
pp. 1565-1580 ◽  
Author(s):  
Lars Konermann
Keyword(s):  
Mass Spectrometry ◽  
Protein Interactions ◽  
High Throughput Screening ◽  
Structural Changes ◽  
Structural Information ◽  
Ionization Mass ◽  
Time Resolved ◽  
Rapid Mixing ◽  
Esi Ms ◽  
Compound Libraries

This review describes the use of electrospray ionization mass spectrometry (ESI-MS) in conjunction with on-line rapid mixing techniques. This combination, termed "time-resolved" ESI-MS, provides a powerful approach for studying solution-phase reactions on timescales as short as a few milliseconds. Of particular interest is the application of this technique for monitoring protein folding reactions. Time-resolved ESI-MS can provide detailed information on structural changes of the polypeptide chain, while at the same time probing the occurrence of noncovalent ligand–protein interactions. Especially when used in combination with hydrogen–deuterium pulse labeling, these measurements yield valuable structural information on short-lived folding intermediates. Similar approaches can be used to monitor the dynamics of proteins under equilibrium conditions. Another important application of time-resolved ESI-MS are mechanistic studies on enzyme-catalyzed processes. These reactions can be monitored under presteady-state conditions, without requiring artificial chromophoric substrates or radioactive labeling. We also discuss the use of ESI-MS for monitoring noncovalent ligand–protein interactions by diffusion measurements. In contrast to conventional MS-based techniques, this approach does not rely on the preservation of noncovalent interactions in the gas phase. It appears that diffusion measurements by ESI-MS could become an interesting alternative to existing methods for the high throughput screening of compound libraries in the context of drug discovery.Key words: reaction intermediate, rapid mixing, kinetics, protein conformation, protein function.

scholarly journals New Evidence of the Bidentate Binding Mode in 3-MBA Protected Gold Clusters: Analysis of Aqueous 13–18 kDa Gold-Thiolate Clusters by HPLC-ESI-MS Reveals Special Compositions Aun(3-MBA)p, (n = 48–67, p = 26–30)

Nanomaterials ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1303 ◽  
Author(s):  
David Black ◽  
M. Hoque ◽  
Germán Plascencia-Villa ◽  
Robert Whetten
Keyword(s):  
Liquid Chromatography ◽  
Mass Spectrometer ◽  
High Performance ◽  
Binding Mode ◽  
Gold Clusters ◽  
Ionization Mass ◽  
Esi Ms ◽  
Mobile Phases ◽  
First Results ◽  
Gold Thiolate

Gold clusters protected by 3-MBA ligands (MBA = mercaptobenzoic acid, –SPhCO2H) have attracted recent interest due to their unusual structures and their advantageous ligand-exchange and bioconjugation properties. Azubel et al. first determined the core structure of an Au68-complex, which was estimated to have 32 ligands (3-MBA groups). To explain the exceptional structure-composition and reaction properties of this complex, and its larger homologs, Tero et al. proposed a “dynamic stabilization” via carboxyl O–H––Au interactions. Herein, we report the first results of an integrated liquid chromatography/mass spectrometer (LC/MS) analysis of unfractionated samples of gold/3-MBA clusters, spanning a narrow size range 13.4 to 18.1 kDa. Using high-throughput procedures adapted from bio-macromolecule analyses, we show that integrated capillary high performance liquid chromatography electrospray ionization mass spectrometer (HPLC-ESI-MS), based on aqueous-methanol mobile phases and ion-pairing reverse-phase chromatography, can separate several major components from the nanoclusters mixture that may be difficult to resolve by standard native gel electrophoresis due to their similar size and charge. For each component, one obtains a well-resolved mass spectrum, nearly free of adducts or signs of fragmentation. A consistent set of molecular mass determinations is calculated from detected charge-states tunable from 3− (or lower), to 2+ (or higher). One thus arrives at a series of new compositions (n, p) specific to the Au/3-MBA system. The smallest major component is assigned to the previously unknown (48, 26); the largest one is evidently (67, 30), vs. the anticipated (68, 32). Various explanations for this discrepancy are considered. A prospective is given for the various members of this novel series, along with a summary of the advantages and present limitations of the micro-scale integrated LC/MS approach in characterizing such metallic-core macro-molecules, and their derivatives.

scholarly journals Polymorphic Nucleic Acid Binding of Bioactive Isoquinoline Alkaloids and Their Role in Cancer

2010 ◽  
Vol 2010 ◽  
pp. 1-23 ◽  
Author(s):  
Motilal Maiti ◽  
Gopinatha Suresh Kumar
Keyword(s):  
Nucleic Acid ◽  
Anticancer Agents ◽  
Titration Calorimetry ◽  
Ionization Mass ◽  
Nucleic Acid Binding ◽  
Isoquinoline Alkaloids ◽  
Scanning Calorimetry ◽  
Ionization Mass Spectroscopy ◽  
Important Position ◽  
Thermal Melting

Bioactive alkaloids occupy an important position in applied chemistry and play an indispensable role in medicinal chemistry. Amongst them, isoquinoline alkaloids like berberine, palmatine and coralyne of protoberberine group, sanguinarine of the benzophenanthridine group, and their derivatives represent an important class of molecules for their broad range of clinical and pharmacological utility. In view of their extensive occurrence in various plant species and significantly low toxicities, prospective development and use of these alkaloids as effective anticancer agents are matters of great current interest. This review has focused on the interaction of these alkaloids with polymorphic nucleic acid structures (B-form, A-form, Z-form,HL-form, triple helical form, quadruplex form) and their topoisomerase inhibitory activity reported by several research groups using various biophysical techniques like spectrophotometry, spectrofluorimetry, thermal melting, circular dichroism, NMR spectroscopy, electrospray ionization mass spectroscopy, viscosity, isothermal titration calorimetry, differential scanning calorimetry, molecular modeling studies, and so forth, to elucidate their mode and mechanism of action for structure-activity relationships. The DNA binding of the planar sanguinarine and coralyne are found to be stronger and thermodynamically more favoured compared to the buckled structure of berberine and palmatine and correlate well with the intercalative mechanism of sanguinarine and coralyne and the partial intercalation by berberine and palmatine. Nucleic acid binding properties are also interpreted in relation to their anticancer activity.

scholarly journals Generation and Characterization of a DNA-GCN4 Oligonucleotide-Peptide Conjugate: The Impact DNA/Protein Interactions on the Sensitization of DNA

Molecules ◽  
2020 ◽  
Vol 25 (16) ◽  
pp. 3630
Author(s):  
Paweł Wityk ◽  
Rafał Piątek ◽  
Robert Nowak ◽  
Dorota Kostrzewa-Nowak
Keyword(s):  
Dna Damage ◽  
Protein Interactions ◽  
Click Reaction ◽  
Covalent Bond ◽  
Thermodynamic Characteristics ◽  
Scanning Calorimetry ◽  
Complementary Oligonucleotide ◽  
Dna Fragment ◽  
The Impact

Radiotherapy, the most common therapy for the treatment of solid tumors, exerts its effects by inducing DNA damage. To fully understand the extent and nature of this damage, DNA models that mimic the in vivo situation should be utilized. In a cellular context, genomic DNA constantly interacts with proteins and these interactions could influence both the primary radical processes (triggered by ionizing radiation) and secondary reactions, ultimately leading to DNA damage. However, this is seldom addressed in the literature. In this work, we propose a general approach to tackle these shortcomings. We synthesized a protein-DNA complex that more closely represents DNA in the physiological environment than oligonucleotides solution itself, while being sufficiently simple to permit further chemical analyses. Using click chemistry, we obtained an oligonucleotide-peptide conjugate, which, if annealed with the complementary oligonucleotide strand, forms a complex that mimics the specific interactions between the GCN4 protein and DNA. The covalent bond connecting the oligonucleotide and peptide constitutes a part of substituted triazole, which forms due to the click reaction between the short peptide corresponding to the specific amino acid sequence of GCN4 protein (yeast transcription factor) and a DNA fragment that is recognized by the protein. DNAse footprinting demonstrated that the part of the DNA fragment that specifically interacts with the peptide in the complex is protected from DNAse activity. Moreover, the thermodynamic characteristics obtained using differential scanning calorimetry (DSC) are consistent with the interaction energies calculated at the level of metadynamics. Thus, we present an efficient approach to generate a well-defined DNA-peptide conjugate that mimics a real DNA-peptide complex. These complexes can be used to investigate DNA damage under conditions very similar to those present in the cell.

Engineering “Antimicrobial Peptides” and Other Peptides to Modulate Protein-Protein Interactions in Cancer

2020 ◽  
Vol 20 (32) ◽  
pp. 2970-2983
Author(s):  
Samuel J.S. Rubin ◽  
Nir Qvit
Keyword(s):  
Antimicrobial Peptides ◽  
Protein Interactions ◽  
Anticancer Agents ◽  
Cancer Therapeutics ◽  
Target Cells ◽  
Protein Protein Interactions ◽  
Peptide Backbone ◽  
Modified Peptides ◽  
Selective Death ◽  
Drug Leads

Antimicrobial peptides (AMPs) are a class of peptides found across a wide array of organisms that play key roles in host defense. AMPs induce selective death in target cells and orchestrate specific or nonspecific immune responses. Many AMPs exhibit native anticancer activity in addition to antibacterial activity, and others have been engineered as antineoplastic agents. We discuss the use of AMPs in the detection and treatment of cancer as well as mechanisms of AMP-induced cell death. We present key examples of cathelicidins and transferrins, which are major AMP families. Further, we discuss the critical roles of protein-protein interactions (PPIs) in cancer and how AMPs are well-suited to target PPIs based on their unique drug-like properties not exhibited by small molecules or antibodies. While peptides, including AMPs, can have limited stability and bioavailability, these issues can be overcome by peptide backbone modification or cyclization (e.g., stapling) and by the use of delivery systems such as cellpenetrating peptides (CPPs), respectively. We discuss approaches for optimizing drug properties of peptide and peptidomimetic leads (modified peptides), providing examples of promising techniques that may be applied to AMPs. These molecules represent an exciting resource as anticancer agents with unique therapeutic advantages that can target challenging mechanisms involving PPIs. Indeed, AMPs are suitable drug leads for further development of cancer therapeutics, and many studies to this end are underway.

Arylhydrazono/Aryldiazenyl Pyrazoles: Green One-Pot Solvent-Free Synthesis and Anticancer Evaluation

2020 ◽  
Vol 17 (10) ◽  
pp. 772-778
Author(s):  
Abdulrhman Alsayari ◽  
Abdullatif Bin Muhsinah ◽  
Yahya I. Asiri ◽  
Jaber Abdullah Alshehri ◽  
Yahia N. Mabkhot ◽  
...  
Keyword(s):  
Anticancer Activity ◽  
Cell Lines ◽  
Anticancer Agents ◽  
Binding Mode ◽  
Docking Studies ◽  
Solvent Free ◽  
Pyrazole Derivatives ◽  
One Pot ◽  
Solvent Free Conditions ◽  
Hybrid Molecules

The aim of this study was to synthesize and evaluate the biological activity of pyrazole derivatives, in particular, to perform a “greener” one-pot synthesis using a solvent-free method as an alternative strategy for synthesizing hydrazono/diazenyl-pyridine-pyrazole hybrid molecules with potential anticancer activity. Effective treatment for all types of cancers is still a long way in the future due to the severe adverse drug reactions and drug resistance associated with current drugs. Therefore, there is a pressing need to develop safer and more effective anticancer agents. In this context, some hybrid analogues containing the bioactive pharmacophores viz. pyrazole, pyridine, and diazo scaffolds were synthesized by one-pot method. Herein, we describe the expedient synthesis of pyrazoles by a onepot three-component condensation of ethyl acetoacetate/acetylacetone, isoniazid, and arenediazonium salts under solvent-free conditions, and the evaluation of their cytotoxicity using a sulforhodamine B assay on three cancer cell lines. Molecular docking studies employing tyrosine kinase were also carried out to evaluate the binding mode of the pyrazole derivatives under study. 1-(4-Pyridinylcarbonyl)-3- methyl-4-(2-arylhydrazono)-2-pyrazolin-5-ones and [4-(2-aryldiazenyl)-3,5-dimethyl-1H-pyrazol-1- yl]-4-pyridinylmethanones, previously described, were prepared using an improved procedure. Among these ten products, 1-isonicotinoyl-3-methyl-4-[2-(4-nitrophenyl)hydrazono]-2-pyrazolin-5-one (1f) displayed promising anticancer activity against the MCF-7, HepG2 and HCT-116 cell lines, with an IC50 value in the range of 0.2-3.4 μM. In summary, our findings suggest that pyrazoles containing hydrazono/ diazenyl and pyridine pharmacophores constitute promising scaffolds for the development of new anticancer agents.

scholarly journals Molecular modeling study, synthesis and biological evaluation of combretastatin A-4 analogues as anticancer agents and tubulin inhibitors

MedChemComm ◽  
2018 ◽  
Vol 9 (2) ◽  
pp. 316-327 ◽  
Author(s):  
Yang Ping Quan ◽  
Li Ping Cheng ◽  
Tian Chi Wang ◽  
Wan Pang ◽  
Fan Hong Wu ◽  
...  
Keyword(s):  
Molecular Modeling ◽  
Anticancer Agents ◽  
Hepg2 Cells ◽  
Binding Mode ◽  
Biological Evaluation ◽  
Tubulin Inhibitors ◽  
Molecular Modeling Study ◽  
Synthesis And Biological Evaluation ◽  
Modeling Study

Compound 13a, more effective than CA-4 against HepG2 cells and tubulin, and the proposed binding mode for 13a.

scholarly journals A highly sensitive octopus-like azobenzene fluorescent probe for determination of abamectin B1 in apples

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhenlong Guo ◽  
YiFei Su ◽  
Kexin Li ◽  
MengYi Tang ◽  
Qiang Li ◽  
...  
Keyword(s):  
Fluorescent Probe ◽  
Limit Of Detection ◽  
Quantitative Detection ◽  
Fluorescence Signal ◽  
Ionization Mass ◽  
Limit Of Quantification ◽  
Visible Absorption ◽  
Esi Ms ◽  
Relative Standard ◽  
Ft Ir

AbstractThe development of detecting residual level of abamectin B1 in apples is of great importance to public health. Herein, we synthesized a octopus-like azobenzene fluorescent probe 1,3,5-tris (5′-[(E)-(p-phenoxyazo) diazenyl)] benzene-1,3-dicarboxylic acid) benzene (TPB) for preliminary detection of abamectin B1 in apples. The TPB molecule has been characterized by ultraviolet–visible absorption spectrometry, 1H-nuclear magnetic resonance, fourier-transform infrared (FT-IR), electrospray ionization mass spectroscopy (ESI-MS) and fluorescent spectra. A proper determination condition was optimized, with limit of detection and limit of quantification of 1.3 µg L−1 and 4.4 μg L−1, respectively. The mechanism of this probe to identify abamectin B1 was illustrated in terms of undergoing aromatic nucleophilic substitution, by comparing fluorescence changes, FT-IR and ESI-MS. Furthermore, a facile quantitative detection of the residual abamectin B1 in apples was achieved. Good reproducibility was present based on relative standard deviation of 2.2%. Six carboxyl recognition sites, three azo groups and unique fluorescence signal towards abamectin B1 of this fluorescent probe demonstrated reasonable sensitivity, specificity and selectivity. The results indicate that the octopus-like azobenzene fluorescent probe can be expected to be reliable for evaluating abamectin B1 in agricultural foods.

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