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11 pages, 837 KiB

Open AccessArticle

Computational Modeling of Gold Nanoparticle Interacting with Molecules of Pharmaceutical Interest in Water

by Massimo Fusaro, Andrzej Leś, Elżbieta U. Stolarczyk and Krzysztof Stolarczyk

Molecules 2023, 28(20), 7167; https://doi.org/10.3390/molecules28207167 - 19 Oct 2023

Cited by 4 | Viewed by 2237

We derived a theory of biomolecule binding to the surface of Au_n clusters and of the Au plane based on the hard soft acid base (HSAB) principle and the free electron metallic surface model. With the use of quantum mechanical calculations, the [...] Read more.

We derived a theory of biomolecule binding to the surface of Au_n clusters and of the Au plane based on the hard soft acid base (HSAB) principle and the free electron metallic surface model. With the use of quantum mechanical calculations, the chemical potential (μ) and the chemical hardness (η) of the biomolecules are estimated. The effect of the gold is introduced via the empirical value of the gold chemical potential (−5.77 eV) as well as by using the expression (modified here) for the chemical hardness (η). The effect of an aqueous environment is introduced by means of the ligand molecular geometry influenced by the PCM field. This theory allows for a fast and low-cost estimation of binding biomolecules to the AuNPs surface. The predicted binding of thiolated genistein and abiraterone to the gold surface is about 20 kcal/mol. The model of the exchange reaction between these biomolecules and citrates on the Au surface corresponds well with the experimental observations for thiolated abiraterone. Moreover, using a model of the place exchange of linear mercaptohydrocarbons on 12-mercaptododecane acid methyl ester bound to the Au surface, the present results reflect the known relation between exchange energy and the size of the reagents. Full article

(This article belongs to the Section Computational and Theoretical Chemistry)

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23 pages, 9922 KiB

Open AccessReview

On the Coordination Role of Pyridyl-Nitrogen in the Structural Chemistry of Pyridyl-Substituted Dithiocarbamate Ligands

by Edward R.T. Tiekink

Crystals 2021, 11(3), 286; https://doi.org/10.3390/cryst11030286 - 14 Mar 2021

Cited by 16 | Viewed by 3054

Abstract

A search of the Cambridge Structural Database was conducted for pyridyl-substituted dithiocarbamate ligands. This entailed molecules containing both an NCS₂⁻ residue and pyridyl group(s), in order to study their complexation behavior in their transition metal and main group element crystals, i.e., [...] Read more.

A search of the Cambridge Structural Database was conducted for pyridyl-substituted dithiocarbamate ligands. This entailed molecules containing both an NCS₂⁻ residue and pyridyl group(s), in order to study their complexation behavior in their transition metal and main group element crystals, i.e., d- and p-block elements. In all, 73 different structures were identified with 30 distinct dithiocarbamate ligands. As a general observation, the structures of the transition metal dithiocarbamates resembled those of their non-pyridyl derivatives, there being no role for the pyridyl-nitrogen atom in coordination. While the same is true for many main group element dithiocarbamates, a far greater role for coordination of the pyridyl-nitrogen atoms was evident, in particular, for the heavier elements. The participation of pyridyl-nitrogen in coordination often leads to the formation of dimeric aggregates but also one-dimensional chains and two-dimensional arrays. Capricious behaviour in closely related species that adopted very different architectures is noted. Sometimes different molecules comprising the asymmetric-unit of a crystal behave differently. The foregoing suggests this to be an area in early development and is a fertile avenue for systematic research for probing further crystallization outcomes and for the rational generation of supramolecular architectures. Full article

(This article belongs to the Special Issue A 10 Years Journey: Chemical, Physical, and Biological Properties and Applications of Crystals)

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25 pages, 5114 KiB

Open AccessReview

A Structural Survey of Poly-Functional Dithiocarbamate Ligands and the Aggregation Patterns They Sustain

by See Mun Lee and Edward R. T. Tiekink

Inorganics 2021, 9(1), 7; https://doi.org/10.3390/inorganics9010007 - 15 Jan 2021

Cited by 20 | Viewed by 4246

Abstract

An overview is presented of the crystal structures of transition metal, main group element, and lanthanide compounds containing poly-functional dithiocarbamate ligands, namely species containing two or more connected NCS₂⁻ residues. In all, there are 40 different ligands of this type that [...] Read more.

An overview is presented of the crystal structures of transition metal, main group element, and lanthanide compounds containing poly-functional dithiocarbamate ligands, namely species containing two or more connected NCS₂⁻ residues. In all, there are 40 different ligands of this type that have been characterised crystallographically in their heavy-element compounds with up to six NCS₂⁻ residues; all are bridging. In most cases, the resulting aggregates are zero-dimensional, often di-nuclear, but aggregates of up to 36 metal (gold) atoms are noted. There are smaller numbers of one-, two-, and three-dimensional architectures sustained by poly-functional dithiocarbamate ligands in their respective crystals. The survey highlights the opportunities afforded by this generally under-studied class of ligand. Full article

(This article belongs to the Special Issue Metal Dithiocarbamate Complexes: Versatile Ligands in Coordination Chemistry with Applications in Medicine, Materials Science, and Beyond)

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11 pages, 1590 KiB

Open AccessArticle

Post-Synthesis Modification of Photoluminescent and Electrochemiluminescent Au Nanoclusters with Dopamine

by Jae Hyun Kim and Joohoon Kim

Nanomaterials 2021, 11(1), 46; https://doi.org/10.3390/nano11010046 - 27 Dec 2020

Cited by 8 | Viewed by 2967

Abstract

Here, we report a post-synthesis functionalization of the shell of Au nanoclusters (NCs) synthesized using glutathione as a thiolate ligand. The as-synthesized Au NCs are subjected to the post-synthesis functionalization via amidic coupling of dopamine on the cluster shell to tailor photoluminescence (PL) [...] Read more.

Here, we report a post-synthesis functionalization of the shell of Au nanoclusters (NCs) synthesized using glutathione as a thiolate ligand. The as-synthesized Au NCs are subjected to the post-synthesis functionalization via amidic coupling of dopamine on the cluster shell to tailor photoluminescence (PL) and electrochemiluminescence (ECL) features of the Au NCs. Because the NCs’ PL at ca. 610 nm is primarily ascribed to the Au(I)-thiolate (SG) motifs on the cluster shell of the NCs, the post-synthesis functionalization of the cluster shell enhanced the PL intensity of the Au NCs via rigidification of the cluster shell. In contrast to the PL enhancement, the post-synthesis modification of the cluster shell does not enhance the near-infrared (NIR) ECL of the NCs because the NIR ECL at ca. 800 nm is ascribed to the Au(0)-SG motifs in the metallic core of the NCs. Full article

(This article belongs to the Special Issue Multifunctional Nanomaterials and Hybrid Structures for Sensors, Actuators and Smart Technologies)

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7 pages, 1023 KiB

Open AccessFeature PaperArticle

Catenane Structures of Homoleptic Thioglycolic Acid-Protected Gold Nanoclusters Evidenced by Ion Mobility-Mass Spectrometry and DFT Calculations

by Clothilde Comby-Zerbino, Martina Perić, Franck Bertorelle, Fabien Chirot, Philippe Dugourd, Vlasta Bonačić-Koutecký and Rodolphe Antoine

Nanomaterials 2019, 9(3), 457; https://doi.org/10.3390/nano9030457 - 19 Mar 2019

Cited by 15 | Viewed by 5398

Abstract

Thiolate-protected metal nanoclusters have highly size- and structure-dependent physicochemical properties and are a promising class of nanomaterials. As a consequence, for the rationalization of their synthesis and for the design of new clusters with tailored properties, a precise characterization of their composition and [...] Read more.

Thiolate-protected metal nanoclusters have highly size- and structure-dependent physicochemical properties and are a promising class of nanomaterials. As a consequence, for the rationalization of their synthesis and for the design of new clusters with tailored properties, a precise characterization of their composition and structure at the atomic level is required. We report a combined ion mobility-mass spectrometry approach with density functional theory (DFT) calculations for determination of the structural and optical properties of ultra-small gold nanoclusters protected by thioglycolic acid (TGA) as ligand molecules, Au₁₀(TGA)₁₀. Collision cross-section (CCS) measurements are reported for two charge states. DFT optimized geometrical structures are used to compute CCSs. The comparison of the experimentally- and theoretically-determined CCSs allows concluding that such nanoclusters have catenane structures. Full article

(This article belongs to the Special Issue Supramolecular Gold Chemistry: From Atomically Precise Thiolate-Protected Gold Nanoclusters to Gold-Thiolate Nanostructures)

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15 pages, 869 KiB

Open AccessReview

Mammalian Metallothionein-3: New Functional and Structural Insights

by Milan Vašák and Gabriele Meloni

Int. J. Mol. Sci. 2017, 18(6), 1117; https://doi.org/10.3390/ijms18061117 - 24 May 2017

Cited by 83 | Viewed by 8791

Abstract

Metallothionein-3 (MT-3), a member of the mammalian metallothionein (MT) family, is mainly expressed in the central nervous system (CNS). MT-3 possesses a unique neuronal growth inhibitory activity, and the levels of this intra- and extracellularly occurring metalloprotein are markedly diminished in the brain [...] Read more.

Metallothionein-3 (MT-3), a member of the mammalian metallothionein (MT) family, is mainly expressed in the central nervous system (CNS). MT-3 possesses a unique neuronal growth inhibitory activity, and the levels of this intra- and extracellularly occurring metalloprotein are markedly diminished in the brain of patients affected by a number of metal-linked neurodegenerative disorders, including Alzheimer’s disease (AD). In these pathologies, the redox cycling of copper, accompanied by the production of reactive oxygen species (ROS), plays a key role in the neuronal toxicity. Although MT-3 shares the metal-thiolate clusters with the well-characterized MT-1 and MT-2, it shows distinct biological, structural and chemical properties. Owing to its anti-oxidant properties and modulator function not only for Zn, but also for Cu in the extra- and intracellular space, MT-3, but not MT-1/MT-2, protects neuronal cells from the toxicity of various Cu(II)-bound amyloids. In recent years, the roles of zinc dynamics and MT-3 function in neurodegeneration are slowly emerging. This short review focuses on the recent developments regarding the chemistry and biology of MT-3. Full article

(This article belongs to the Special Issue Metallothioneins in Bioinorganic Chemistry: Recent Developments)

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19 pages, 4227 KiB

Open AccessReview

Residue Modification and Mass Spectrometry for the Investigation of Structural and Metalation Properties of Metallothionein and Cysteine-Rich Proteins

by Gordon W. Irvine and Martin J. Stillman

Int. J. Mol. Sci. 2017, 18(5), 913; https://doi.org/10.3390/ijms18050913 - 26 Apr 2017

Cited by 12 | Viewed by 5980

Abstract

Structural information regarding metallothioneins (MTs) has been hard to come by due to its highly dynamic nature in the absence of metal-thiolate cluster formation and crystallization difficulties. Thus, typical spectroscopic methods for structural determination are limited in their usefulness when applied to MTs. [...] Read more.

Structural information regarding metallothioneins (MTs) has been hard to come by due to its highly dynamic nature in the absence of metal-thiolate cluster formation and crystallization difficulties. Thus, typical spectroscopic methods for structural determination are limited in their usefulness when applied to MTs. Mass spectrometric methods have revolutionized our understanding of protein dynamics, structure, and folding. Recently, advances have been made in residue modification mass spectrometry in order to probe the hard-to-characterize structure of apo- and partially metalated MTs. By using different cysteine specific alkylation reagents, time dependent electrospray ionization mass spectrometry (ESI-MS), and step-wise “snapshot” ESI-MS, we are beginning to understand the dynamics of the conformers of apo-MT and related species. In this review we highlight recent papers that use these and similar techniques for structure elucidation and attempt to explain in a concise manner the data interpretations of these complex methods. We expect increasing resolution in our picture of the structural conformations of metal-free MTs as these techniques are more widely adopted and combined with other promising tools for structural elucidation. Full article

(This article belongs to the Special Issue Metallothioneins in Bioinorganic Chemistry: Recent Developments)

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16 pages, 3029 KiB

Open AccessArticle

Solution Structure of the Circular γ-Domain Analog from the Wheat Metallothionein E_c-1

by Katsiaryna Tarasava, Silke Johannsen and Eva Freisinger

Molecules 2013, 18(11), 14414-14429; https://doi.org/10.3390/molecules181114414 - 21 Nov 2013

Cited by 8 | Viewed by 6275

Abstract

The first cyclic analog of a metallothionein (MT) was prepared and analyzed by UV and (magnetic) circular dichroism spectroscopy, ESI-MS as well as NMR spectroscopy. Results reveal that the evaluated cyclic g-E_c-1 domain of the wheat MT E_c-1 retains [...] Read more.

The first cyclic analog of a metallothionein (MT) was prepared and analyzed by UV and (magnetic) circular dichroism spectroscopy, ESI-MS as well as NMR spectroscopy. Results reveal that the evaluated cyclic g-E_c-1 domain of the wheat MT E_c-1 retains its ability to coordinate two Zn(II) or Cd(II) ions and adopts a three-dimensional structure that is highly similar to the one of the linear wild-type form. However, the reduced flexibility of the protein backbone facilitates structure solution significantly and results in a certain stabilization of metal binding to the protein. Full article

(This article belongs to the Special Issue NMR of Proteins and Small Biomolecules)

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11 pages, 3963 KiB

Open AccessArticle

Nanocomposites Based on Metal and Metal Sulfide Clusters Embedded in Polystyrene

by Gianfranco Carotenuto, Cinzia Giannini, Dritan Siliqi and Luigi Nicolais

Polymers 2011, 3(3), 1352-1362; https://doi.org/10.3390/polym3031352 - 22 Aug 2011

Cited by 6 | Viewed by 8076

Abstract

Transition-metal alkane-thiolates (i.e., organic salts with formula Me(SR)_x, where R is a linear aliphatic hydrocarbon group, –C_nH_2n+1) undergo a thermolysis reaction at moderately low temperatures (close to 200 °C), which produces metal atoms or metal [...] Read more.

Transition-metal alkane-thiolates (i.e., organic salts with formula Me(SR)_x, where R is a linear aliphatic hydrocarbon group, –C_nH_2n+1) undergo a thermolysis reaction at moderately low temperatures (close to 200 °C), which produces metal atoms or metal sulfide species and an organic by-product, disulfide (RSSR) or thioether (RSR) molecules, respectively. Alkane-thiolates are non-polar chemical compounds that dissolve in most techno-polymers and the resulting solid solutions can be annealed to generate polymer-embedded metal or metal sulfide clusters. Here, the preparation of silver and gold clusters embedded into amorphous polystyrene by thermolysis of a dodecyl-thiolate precursor is described in detail. However, this chemical approach is quite universal and a large variety of polymer-embedded metals or metal sulfides could be similarly prepared. Full article

(This article belongs to the Special Issue Polymer-Inorganic Hybrids and Their Applications)

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