Ligand Binding Interactions Research Articles

Structural insights into thyroid hormone receptors.

Thyroid hormone receptors (TRs) are essential components of the endocrine system, mediating the cellular effects of thyroid hormones. The two TR genes, THRA and THRB, encode four isoforms, with TRα1 and TRβ1 being the most prevalent. TRs are ligand-dependent transcription factors and members of the nuclear receptor superfamily, indispensable for human growth, development and metabolism. Dysfunctional TR signaling can lead to conditions like resistance to thyroid hormone (RTH) syndrome, thyroid cancer, and metabolic disorders. Structurally, TRs comprise several domains: a variable N-terminal domain, a conserved DNA-binding domain, and a ligand-binding domain that mediates interaction with hormones and transcriptional coregulators. TRs predominantly function as heterodimers with the retinoid X receptor (RXR), binding to thyroid hormone response elements (TREs) in target genes to regulate their transcription. This review examines the structural studies on TRs, primarily performed through X-ray crystallography, that have provided detailed insights into TR functions, including DNA recognition, ligand binding, and coregulator interactions. We also discuss how these findings have deepened our understanding of TR mechanisms and contributed to the interpretation of pathogenic mutations.

Machine learning-based prediction of bioactivity in HIV-1 protease: insights from electron density analysis.

Aim: To develop a model for predicting the biological activity of compounds targeting the HIV-1 protease and to establish factors influencing enzyme inhibition.Materials & methods: Machine learning models were built based on a combination of Richard Bader's theory of Atoms in Molecules and topological analysis of electron density using experimental x-ray 'protein-ligand' complexes and inhibition constants data.Results & conclusion: Among all the models tested, logistic regression achieved the highest accuracy of 0.76 on the test set. The model's ability to differentiate between less active and highly active classes was relatively good, as indicated by an AUC-ROC score of 0.77. The analysis identified several critical factors affecting the biological activity of HIV-1 protease inhibitors, including the electron density contribution of hydrogen atoms, bond-critical points and particular amino acid residues. These findings provide new insights into how these molecular factors influence HIV-1 protease inhibition, emphasizing the importance of hydrogen bonding, glycine's flexibility and hydrophobic interactions in ligand binding.

Characterization, expressional and evolutionary analysis of five fish-specific CCRs (CCR4La, CCR4Lc, CCR12a1, CCR12a2, and CCR12b) in largemouth bass (Micropterus salmoides)

CC chemokine receptors (CCRs), the numbers of the G protein-coupled receptor (GPCR) superfamily, had crucial roles in treating infection, inflammation, and tissue damage by binding to their ligands. In this study, five fish-specific CCRs, namely CCR4La, CCR4Lc, CCR12a1, CCR12a2, and CCR12b, were identified in largemouth bass (Micropterus salmoides). The correction of nomenclatures of these CCRs were confirmed by phylogenetic analysis, structural analysis and genomic synteny analysis. Following 1×106 CFU/mL and 1×107 CFU/mL Edwardsiella piscicida infection, these five CCRs were significantly induced in spleen of largemouth bass, indicating their important roles in the immune response against bacterial infection. Selection pressure analysis revealed that CCR4La, CCR4Lc, CCR12a1, and CCR12a2 underwent negative selection pressure, whereas CCR12b experienced positive selection pressure. Robust selection site detection methods identified that positive selected sites of CCR4La, CCR4Lc, CCR12a1, and CCR12a2 mainly distributed in their extracellular regions, which involved in ligand binding and pathogen interaction. Similarly, the positive selected sites of CCR12b were also located in its extracellular regions. The accuracy of the pressure selected sites were also validated by molecular docking analysis. The potential ligands for these five CCRs were identified by molecular docking analysis, with finding that CCL3 and CCL5 might be the ligands of largemouth bass CCR4La/Lc, and CCL5, CCL8, CCL7, CCL13 and CCL26 might be that of largemouth bass CCR12a1/a2/b. Our results provided basis for elucidating the functions of chemokine-receptor complex in largemouth bass.

In silico DFT and molecular modeling of novel pyrazine-bearing thiazolidinone hybrids derivatives: elucidating invitro anti-cancer and urease inhibitors.

In the present work, one of the leading health issues i.e.cancer was targeted by synthesizing and biologically investigating the potential of pyrazine-based thiazolidinone derivatives (1-13). The basic structure of the synthesized compounds was determined using a variety of spectroscopic techniques, including 1H NMR, 13C NMR, and HREI-MS. These scaffolds were studied for their biological profiles as anti-cancer as well as anti-urease agents. The biological effectiveness of these compounds was compared using the reference tetrandrine (IC50=4.50±0.20 µM) and thiourea (IC50=5.10±0.10 µM), respectively. Among novel compounds, scaffold 3, 6, 7 and 10 demonstrated an excellent potency with highest inhibitory potential (IC50=1.70±0.10 and 1.30±0.20 µM), (IC50=4.20±0.10 and 5.10±0.30 µM), (IC50=2.10±0.10 and 3.20±0.20 µM) and (IC50=2.70±0.20 and 4.20±0.20 µM), respectively, out of which scaffold 3 emerged as the leading compound due to the presence of highly reactive-CF3 moiety which interacts via hydrogen bonding. Molecular docking investigations of the potent compounds was also carried out which revealed the binding interactions of ligands with the active sites of enzyme. Moreover, the electronic properties, nucleophilic and electrophilic sited of the lead compounds were also studied under density functional theory (DFT).

F116I mutation in CYP9A25 associated with resistance to emamectin benzoate in Spodoptera litura.

The F116V mutation in the substrate recognition site 1 (SRS1) of Spodoptera exigua CYP9A186 has been demonstrated to confer ~200-fold resistance to emamectin benzoate (EB). In this study, a novel mutation (F116I) in CYP9A25, orthologous to CYP9A186, was detected in a field population of Spodoptera litura (YJ22) collected from Yuanjiang, Yunnan province, China in 2022. The association of this mutation with EB resistance was investigated. Two homozygous strains, YJ22-116F (wild-type at 116 position of CYP9A25) and YJ22-116I (mutant) were isolated from YJ22 through two rounds of crossing and DNA genotyping. Compared with YJ22-116F, the mutant strain YJ22-116I exhibited 31.8-fold resistance to EB. Resistance in YJ22-116I was shown to be incompletely dominant, and genetically linked with the F116I mutation. Further, heterologous expression and in vitro metabolism assays confirmed that the recombinant CYP9A25 protein with 116I mutation obtained metabolic capability against EB, whereas the wild-type CYP9A25 protein (with 116F) did not metabolize EB. Molecular modeling showed that the F116I mutation within SRS1 reduces the steric hindrance to substrate entry and improves ligand-binding interactions. The causal association between the F116I mutation in CYP9A25 and medium-level EB resistance in S. litura has been verified. This finding is critical for the field monitoring of such mutations and thus for developing adaptive resistance management tactics for field populations of S. litura. © 2024 Society of Chemical Industry.

Sanger Sequencing Reveals Novel Variants in GLO-1, ACE, and CBR1 Genes in Patients of Early and Severe Diabetic Nephropathy.

Background and Objectives: Diabetes is a global health issue, with approximately 50% of patients developing diabetic nephropathy (DN) and 25% experiencing early and severe forms of the disease. The genetic factors contributing to rapid disease progression in a subset of these patients are unclear. This study investigates genetic variations in the GLO-1, CBR-1, and ACE genes associated with early and severe DN. Materials and Methods: Sanger DNA sequencing of the exons of CBR1, GLO1, and ACE genes was conducted in 113 patients with early and severe DN (defined as occurring within 10 years of the diagnosis of diabetes and with eGFR < 45 mL/min/1.73 m2) and 100 controls. The impact of identified genetic variations was analyzed using computational protein models created in silico with SWISS-Model and SWISS-Dock for ligand binding interactions. Results: In GLO1, two heterozygous missense mutations, c.102G>T and c.147C>G, and one heterozygous nonsense mutation, c.148G>T, were identified in patients. The SNP rs1049346 (G>A) at location 6:38703061 (GRCh38) was clinically significant. The c.147C>G mutation (C19S) was associated with ligand binding disruption in the GLO1 protein, while the nonsense mutation resulted in a truncated, non-functional protein. In CBR1, two heterozygous variations, one missense c.358G>A, and one silent mutation c.311G>C were observed, with the former (D120N) affecting the active site. No significant changes were noted in ACE gene variants concerning protein structure or function. Conclusions: The study identifies four novel and five recurrent mutations/polymorphisms in GLO1, ACE, and CBR1 genes associated with severe DN in Pakistani patients. Notably, a nonsense mutation in GLO1 led to a truncated, non-functional protein, while missense mutations in GLO1 and CBR1 potentially disrupt enzyme function, possibly accelerating DN progression.

Microwave-assisted green synthesis and molecular docking study of some new 4-thiazolidinone derivatives as possible bioactive agents

We have developed an economical and environmentally friendly microwave-assisted efficient method for the synthesis of a series of new 4-oxo-thiazolidine derivatives (4a-d). The method involves microwave irradiated cyclocondensation reaction of Schiff bases (3a-d) and thioglycolic acid in drug master file (DMF). 4-oxo-thiazolidine derivatives (4a-d) was also synthe 4-Oxo-Thiazolidine derivatives were also synthesized by conventional heating procedures and consequence were Compared with Microwave assisted green method. The results suggest that microwave-assisted syntheses lead to higher yields within very short reaction times. Antimicrobial screening of all the synthesized compounds was carried out using Gram-positive strains Staphylococcus aureus and Gram-negative strain encompassing Escherichia coli, Proteus vulgaris, and Salmonella typhi. The results were compared with the standard drug chloramphenicol. All the synthesized compounds were subsequently examined using molecular docking experiments against peptide deformylase (PDB ID: 1G2A), which evaluates the binding interaction of ligands with enzyme active sites.. KEYWORDS :Microwave irradiation, Thiazolidinone, Molecular docking, Peptide deformylase, Antimicrobial screening.

A novel class of thiazole based thiadiazole hybrids: The privileged scaffolds of potent anti-Alzheimer's activity along with molecular docking and ADME analysis

A novel series of thiazole-thiadiazole based schiff base derivatives (1–16) were synthesized and examined for their inhibitory profile against acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). All the compounds exhibited excellent inhibitory activity ranging from IC50= 1.87 ± 1.47 to 27.4 ± 2.45 µM for AChE and 1.72 ± 1.43 to 29.4 ± 1.87 µM for BuChE when compared with the standard drug donepezil (IC50= 3.87 ± 1.14 µM and 3.56 ± 2.52 µM for AChE and BuChE, respectively). Among the members of the whole series, compounds-6 (IC50 = 3.49 ± 1.20 µM, 3.18 ± 0.27 µM), 7 (IC50 = 3.20 ± 1.14 µM, 3.21 ± 0.49 µM), 8 (IC50 =1.87 ± 1.47 µM, IC50 = 1.72 ± 1.43) and 9 (IC50 = 2.18 ± 1.02 µM, IC50 = 2.02 ± 0.49 µM), showed remarkable potency against AChE and BuChE and emerged as anti-alzheimer's agents. Molecular docking study revealed the excellent binding interactions of ligands with different amino acids of the target enzymes. Structure activity relationship (SAR) study was also conducted to evaluate inhibitory potency of all the derivatives that depends on the position, number and nature of the substituents. Furthermore, ADME outcomes authenticate the drug likeness of the potent analogs. Structural confirmation of the derivatives was achieved through different spectroscopic techniques, including 13C NMR, 1H NMR and HREI-MS.

Fluorescence Turn-Off Ligand for Parallel G-Quadruplexes.

Parallel-stranded G-quadruplex structures are found to be common in the human promoter sequences. We tested highly fluorescent 9-methoxyluminarine ligand (9-MeLM) binding interactions with different parallel G-quadruplexes DNA by spectroscopic methods such as fluorescence and circular dichroism (CD) titration as well as UV melting profiles. The results showed that the studied 9-MeLM ligand interacted with the intramolecular parallel G-quadruplexes (G4s) with similar affinity. The binding constants of 9-methoxyluminarine with different parallel G4s were determined. The studies upon oligonucleotides with different flanking sequences on c-MYC G-quadruplex suggest that 9-methoxyluminarine may preferentially interact with 3'end of the c-MYC promoter. The high decrease in 9-MeLM ligand fluorescence upon binding to all tested G4s indicates that 9-methoxyluminarine molecule can be used as a selective fluorescence turn-off probe for parallel G-quadruplexes.

Pyrazine based novel molecules as potential therapeutic agents: Synthesis, in vitro biological screening, in silico ADMET profiling and molecular docking study

The current study described the synthesis of pyrazine-based novel molecules (1–15) using stepwise processes and their structures have been identified using various characterization techniques such as 1HNMR, 13CNMR, and HREI-MS. Furthermore, biological assessment of these scaffolds as anti-Alzheimer, anti-bacterial, and anti-fungal activities were evaluated. Their inhibitory potentials were determined using the minimum inhibitory concentration (MIC) in the presence of standard drugs donepezil (IC50 = 8.90 ± 0.20 µM), streptomycin (inhibition = 36.5 %), and Terbinafine (inhibition = 31.7 %) respectively. Among the screened molecules against acetylcholinesterase enzyme, the potent behavior was shown by scaffolds 1 (IC50 = 3.20 ± 0.40 µM), 2 (IC50 = 2.10 ± 0.20 µM), 4 (IC50 = 2.90 ± 0.10 µM), 5 (IC50 = 5.80 ± 0.30 µM), 6 (IC50 = 7.20 ± 0.20 µM), 8 (IC50 = 6.30 ± 0.30 µM), 9 (IC50 = 6.50 ± 0.20 µM), 10 (IC50 = 7.30 ± 0.20 µM) and 11 (IC50 = 7.10 ± 0.20 µM). Structure-activity relationship was carried out which mainly depends upon the substitution pattern around the phenyl ring. These compounds were further investigated by molecular docking studies which explore the binding interaction of ligands with active sites of enzymes. Moreover, ADMET prediction was also studied for potent scaffolds that displayed drug-like properties.

Protein Thermal Stability Changes Induced by the Global Methylation Inhibitor 3-Deazaneplanocin A (DZNep).

DZNep (3-deazaneplanocin A) is commonly used to reduce lysine methylation. DZNep inhibits S-adenosyl-l-homocysteine hydrolase (AHCY), preventing the conversion of S-adenosyl-l-homocysteine (SAH) into L-homocysteine. As a result, the SAM-to-SAH ratio decreases, an indicator of the methylation potential within a cell. Many studies have characterized the impact of DZNep on histone lysine methylation or in specific cell or disease contexts, but there has yet to be a study looking at the potential downstream impact of DZNep treatment on proteins other than histones. Recently, protein thermal stability has provided a new dimension for studying the mechanism of action of small-molecule inhibitors. In addition to ligand binding, post-translational modifications and protein-protein interactions impact thermal stability. Here, we sought to characterize the protein thermal stability changes induced by DZNep treatment in HEK293T cells using the Protein Integral Solubility Alteration (PISA) assay. DZNep treatment altered the thermal stability of 135 proteins, with over half previously reported to be methylated at lysine residues. In addition to thermal stability, we identify changes in transcript and protein abundance after DZNep treatment to distinguish between direct and indirect impacts on thermal stability. Nearly one-third of the proteins with altered thermal stability had no changes at the transcript or protein level. Of these thermally altered proteins, CDK6 had a stabilized methylated peptide, while its unmethylated counterpart was unaltered. Multiple methyltransferases were among the proteins with thermal stability alteration, including DNMT1, potentially due to changes in the SAM/SAH levels. This study systematically evaluates DZNep's impact on the transcriptome, the proteome, and the thermal stability of proteins.

Design, Synthesis of 3-(Aryl)-1-(2-p-tolylthiazol-4-yl)prop-2-en-1-ones as Alpha(α)-Amylase Inhibitors.

α-Amylase inhibition is vital in controlling diabetic complications. Herein, we have synthesized a hybrid scaffold based on thiazole-chalcone to access α-amylase inhbition. The proposed structures were verified with spectroscopic techniques (UV-Vis., FT-IR, 1H-, 13C-NMR, and elemental analysis). The synthesized compounds were evaluated for their α-amylase and antioxidant potential. In vitro hemolytic assay was performed to test biocompatibility of all compounds. Among tested compounds, 4 c (IC50=3.8 μM), 4 g (IC50=14.5 μM), and 4 f (IC50=17.1 μM) were found excellent α-amylase inhibitors. However, none of the tested compounds exhibited significant antioxidant activity. All compounds showed less lysis than Triton X-100, but compounds 4 f and 4 h had the least lysis at all tested concentrations and were found to be safe for human erythrocytes. Molecular docking study was performed to evaluate the binding interactions of ligands with human pancreatic α-amylase (HPA). The binding score -8.09 to -8.507 kcal/mol revealed strong binding interactions in the ligand-protein complex. The docking results supplemented the observed α-amylase inhibition and hence augment the scaffold to serve as leads for the antidiabetic drug development.

Combinatorial Libraries of Bipodal Binders of the Insulin Receptor.

The binding process of insulin to its transmembrane receptor entails a sophisticated interplay between two proteins, each possessing two binding sites. Given the difficulties associated with the use of insulin in the treatment of diabetes, despite its remarkable efficacy, there is interest in smaller and more stable compounds than the native hormone that would effectively activate the receptor. Our study adopts a strategy focused on synthesizing extensive combinatorial libraries of bipodal compounds consisting of two distinct peptides linked to a molecular scaffold. These constructs, evaluated in a resin bead-bound format, were designed to assess their binding to the insulin receptor. Despite notable nonspecific binding, our approach successfully generated and tested millions of compounds. Rigorous evaluations via flow cytometry and specific antibodies revealed peptide sequences with specific interactions at either receptor binding Site 1 or 2. Notably, these sequences bear similarity to peptides discovered through phage display by other researchers. This convergence of chemical and biological methods underscores nature's beauty, revealing general principles in peptide binding to the insulin receptor. Overall, our study deepens the understanding of molecular interactions in ligand binding to the insulin receptor, highlighting the challenges of targeting large proteins with small synthetic peptides.

Indolyl imine compounds as multi-target agents; synthesis, antidiabetic, anticholinesterase, antioxidant activities and molecular modeling

A new range of indolyl imine system 3d-l has been successfully prepared from 4,6-dimethoxy-2,3-diphenyl-indole-7-carbaldehyde 2a and 4,6-dimethoxy-3-aryl-indole-7-carbaldehyde 2b-cvia Schiff base reaction. The structure of targeted compounds was confirmed by 1H and 13C NMR, FT-IR, mass spectrometry and single crystal X-ray diffraction techniques. The indolyl imine derivatives were also subjected to in vitro antidiabetic activities employing α-glucosidase and α-amylase enzymes. In terms of antidiabetic investigation, the α-glucosidase enzyme was found to be potential target due to the comparable inhibition concentrations with the standard acarbose and the compound 3e exhibited better potency than the standard. The anticholinesterase potency of the compounds was investigated towards the acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes. The compounds displayed moderate efficiency against the BChE enzyme with the best inhibition concentration of 30.48 μM by the compound 3h. The antioxidant properties of final compounds were determined by DPPH radical scavenging, ABTS Cation Radical Decolarization and CUPRAC Cupric Reducing Antioxidant Capacity assay methods. The ABTS cation scavenging assay provided the best responses for the compounds and the candidates 3k and 3l were determined as promising targets for the antioxidant activity. Plausible binding mode and interaction of ligands with the selected enzyme have been studied by molecular docking, supporting the experimental results. In silico ADME showed high drug likeness of the synthesized compounds.

Native Top-Down Mass Spectrometry for Characterizing Sarcomeric Proteins Directly from Cardiac Tissue Lysate.

Native top-down mass spectrometry (nTDMS) has emerged as a powerful structural biology tool that can localize post-translational modifications (PTMs), explore ligand-binding interactions, and elucidate the three-dimensional structure of proteins and protein complexes in the gas-phase. Fourier-transform ion cyclotron resonance (FTICR) MS offers distinct capabilities for nTDMS, owing to its ultrahigh resolving power, mass accuracy, and robust fragmentation techniques. Previous nTDMS studies using FTICR have mainly been applied to overexpressed recombinant proteins and protein complexes. Here, we report the first nTDMS study that directly analyzes human heart tissue lysate by direct infusion FTICR MS without prior chromatographic separation strategies. We have achieved comprehensive nTDMS characterization of cardiac contractile proteins that play critical roles in heart contraction and relaxation. Specifically, our results reveal structural insights into ventricular myosin light chain 2 (MLC-2v), ventricular myosin light chain 1 (MLC-1v), and alpha-tropomyosin (α-Tpm) in the sarcomere, the basic contractile unit of cardiac muscle. Furthermore, we verified the calcium (Ca2+) binding domain in MLC-2v. In summary, our nTDMS platform extends the application of FTICR MS to directly characterize the structure, PTMs, and metal-binding of endogenous proteins from heart tissue lysate without prior separation methods.

Nitrogen-containing heterocyclic compounds: A ray of hope in depression?

Depression is not similar to daily mood fluctuations and temporary emotional responses to day-to-day activities. Depression is not a passing problem; it is an ongoing problem. It deals with different episodes consisting of several symptoms that last for at least 2 weeks. It can be seen for several weeks, months, or years. At its final stage, or can say, in its worst condition, it can lead to suicide. Antidepressants are used to inhibit the reuptake of the neurotransmitters by some selective receptors, which increase the concentration of specific neurotransmitters around the nerves in the brain. Drugs that are currently being used for the management of various types of depression include selective serotonin reuptake inhibitors, tricyclic antidepressants, atypical antidepressants, serotonin, noradrenaline reuptake inhibitors, etc. In this review, we have outlined different symptoms, causes, and recent advancements in nitrogen-containing heterocyclic drug candidates for the management of depression. This article highlights the various structural features along with the structure-activity relationship (SAR) of nitrogen-containing heterocyclics that play a key role in binding at target sites for potential antidepressant action. The in silico studies were carried out to determine the binding interactions of the target ligands with the receptor site to determine the potential role of substitution patterns at core pharmacophoric features. This article will help medicinal chemists, biochemists, and other interested researchers in identifying the potential pharmacophores as lead compounds for further development of new potent antidepressants.

Virtual screening of flavonoids as potential RIPK1 inhibitors for neurodegeneration therapy.

Global prevalence of neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease is increasing gradually, whereas approvals of successful therapeutics for central nervous system disorders are inadequate. Accumulating evidence suggests pivotal roles of the receptor-interacting serine/threonine-protein kinase 1 (RIPK1) in modulating neuroinflammation and necroptosis. Discoveries of potent small molecule inhibitors for RIPK1 with favorable pharmacokinetic properties could thus address the unmet medical needs in treating neurodegeneration. In a structure-based virtual screening, we performed site-specific molecular docking of 4,858 flavonoids against the kinase domain of RIPK1 using AutoDock Vina. We predicted physicochemical descriptors of the top ligands using the SwissADME webserver. Binding interactions of the best ligands and the reference ligand L8D were validated using replicated 500-ns Gromacs molecular dynamics simulations and free energy calculations. From Vina docking, we shortlisted the top 20 flavonoids with the highest binding affinities, ranging from -11.7 to -10.6 kcal/mol. Pharmacokinetic profiling narrowed down the list to three orally bioavailable and blood-brain-barrier penetrant flavonoids: Nitiducarpin, Pinocembrin 7-O-benzoate, and Paratocarpin J. Next, trajectories of molecular dynamics simulations of the top protein-ligand complexes were analyzed for binding interactions. The root-mean-square deviation (RMSD) was 1.191 Å (±0.498 Å), 1.725 Å (±0.828 Å), 1.923 Å (±0.942 Å), 0.972 Å (±0.155 Å) for Nitiducarpin, Pinocembrin 7-O-benzoate, Paratocarpin J, and L8D, respectively. The radius of gyration (Rg) was 2.034 nm (±0.015 nm), 2.0.39 nm (± 0.025 nm), 2.053 nm (±0.021 nm), 2.037 nm (±0.016 nm) for Nitiducarpin, Pinocembrin 7-O-benzoate, Paratocarpin J, and L8D, respectively. The solvent accessible surface area (SASA) was 159.477 nm2 (±3.021 nm2), 159.661 nm2 (± 3.707 nm2), 160.755 nm2 (±4.252 nm2), 156.630 nm2 (±3.521 nm2), for Nitiducarpin, Pinocembrin 7-O-benzoate, Paratocarpin J, and L8D complexes, respectively. Therefore, lower RMSD, Rg, and SASA values demonstrated that Nitiducarpin formed the most stable complex with the target protein among the best three ligands. Finally, 2D protein-ligand interaction analysis revealed persistent hydrophobic interactions of Nitiducarpin with the critical residues of RIPK1, including the catalytic triads and the activation loop residues, implicated in the kinase activity and ligand binding. Our target-based virtual screening identified three flavonoids as strong RIPK1 inhibitors, with Nitiducarpin exhibiting the most potent inhibitory potential. Future in vitro and in vivo studies with these ligands could offer new hope for developing effective therapeutics and improving the quality of life for individuals affected by neurodegeneration.

Design, synthesis, in vitro biological assessment and in silico molecular modeling study of thiazole-thiazolidinone derivatives as potent anti-cancer agents

The current study addressed the synthesis of thiazole-based thiazolidinone derivatives (1–18) using stepwise reaction processes, and their structure was confirmed using various characterization techniques such as 1HNMR, 13CNMR, and HREI-MS. Furthermore, the biological features of these analogues as anti-cancer drugs against human cancer cell lines (HCC78 and H3122) were identified. Their inhibitory potentials were determined using the half-maximal inhibitory concentration (MIC50) in the presence of their standard drugs Tetrandrineb (IC50 = 10.70 ± 0.30 µM), respectively. Structure activity relationship (SAR) was established for all the synthesized scaffolds and compared their inhibitory potentials with standard, in which scaffolds 1 (IC50 = 5.20 ± 0.40 µM), 2 (IC50 = 4.10 ± 0.20 µM), 3 (IC50 = 6.30 ± 0.20 µM), 4 (IC50 = 8.90 ± 0.10 µM), 6 (IC50 = 8.10 ± 0.20 µM), 7 (IC50 = 8.70 ± 0.10 µM), 8 (IC50 = 3.90 ± 0.30 µM), 9 (IC50 = 2.10 ± 0.20 µM), 10 (IC50 = 3.30 ± 0.20 µM) and 16 (IC50 = 8.90 ± 0.20 µM) exhibited the most influential activity. These compounds were subsequently examined using molecular docking experiments, which evaluate the binding interactions of ligands with enzyme active sites.

Cardiac human bitter taste receptors contain naturally occurring variants that alter function

Bitter taste receptors (T2R) are a subfamily of G protein-coupled receptors that enable humans to detect aversive and toxic substances. The ability to discern bitter compounds varies between individuals and is attributed mainly to naturally occurring T2R polymorphisms. T2Rs are also expressed in numerous non-gustatory tissues, including the heart, indicating potential contributions to cardiovascular physiology. In this study. T2Rs that have previously been identified in human cardiac tissues (T2Rs – 10, 14, 30, 31, 46 and 50) and their naturally occurring polymorphisms were functionally characterised. The ligand-dependent signaling responses of some T2R variants were completely abolished (T2R30 Leu252 and T2R46 Met228), whereas other receptor variants had moderate changes in their maximal response, but not potency, relative to wild type. Using a cAMP fluorescent biosensor, we reveal the productive coupling of T2R14, but not the T2R14 Phe201 variant, to endogenous Gαi. Modeling revealed that these variants resulted in altered interactions that generally affected ligand binding (T2R30 Leu252) or Gα protein interactions (T2R46 Met228 and T2R14 Phe201), rather than receptor structural stability. Interestingly, this study is the first to show a difference in signaling for T2R50 Tyr203 (rs1376251) which has been associated with cardiovascular disease. The observation of naturally occurring functional variation in the T2Rs with the greatest expression in the heart is important, as their discovery should prove useful in deciphering the role of T2Rs within the cardiovascular system.

Nonclassical Nucleation and Crystallization of LiNbO3 Nanoparticles from the Aqueous Solvothermal Alkoxide Route.

The exact molecular reaction pathway and crystallization mechanisms of LiNbO3 nanoparticles under solvothermal conditions are derived through extensive time- and temperature-resolved experiments allowing to track all the transient molecular and solid species. Starting with a simple mixing of Li/Nb ethoxides, water addition is used to promote condensation after ligand exchange with different co-solvents including alcohols and glycols of variable carbon-chain length. A nonclassical nucleation scheme is first demonstrated after the identification of new octanuclear complexes with a {Li4Nb4O10} core whose solvophobic interactions mediate their aggregation, thus, resulting in a colloidal gel at room-temperature. Upon heating, a more or less frustrated aggregation-mediated crystallization process is then evidenced leading to LiNbO3 nanocrystals of adjustable mean size between 20 and 100nm. Such a fine control can be attributed to the variable Nb-OR (R = alkoxy/glycoxy ligand) binding interactions at the surface of crystalline intermediates. Demonstration of such a nonclassical nucleation process and crystallization mechanism for LiNbO3 not only sheds light on the entire growth process of multifunctional nanomaterials with non-perovskite crystalline structures, but also opens new avenues for the identification of novel bimetallic oxoclusters involved in the formation of several mixed oxides from the aqueous alkoxide route.