Search Results (1,056)

Chalcone Synthase (CHS) plays a vital role in flavonoid synthesis, influencing plant growth, development, and responses to both biotic and abiotic stress. In this study, 11 CHS genes were identified in Poncirus trifoliata using bioinformatics methods, with their distribution across five chromosomes and unassigned contigs. Each gene contains 2–3 exons and 3–8 conserved motifs. In silico prediction suggested that the PtrCHS proteins are localized in the cytoplasm. PtrCHS9 and PtrCHS11 share identical protein tertiary structures. Phylogenetic analysis classified the CHS family members into four subgroups. Synteny analysis revealed one set of collinear gene pairs within Poncirus trifoliata. Between Poncirus trifoliata and Arabidopsis thaliana, two sets of collinear gene pairs were identified, while one such set was found between Poncirus trifoliata and Oryza sativa. Promoter element analysis showed the presence of various hormone response and stress response elements within PtrCHS promoters. RNA-Seq data demonstrated tissue-specific expression patterns of PtrCHSs. RT-qPCR results indicated that all CHS genes, except PtrCHS11, respond to salt stress with dynamic, member-specific patterns. Additionally, four PtrCHSs (PtrCHS3, PtrCHS5, PtrCHS7, and PtrCHS10) were significantly upregulated in response to cold treatment. Notably, PtrCHS7 and PtrCHS10 maintained high expression levels at both 6 and 12 h, implying they may be key players in cold stress response in Poncirus trifoliata. Clones of PtrCHS7 and PtrCHS10 were obtained, and overexpression vectors were constructed in preparation for gene transformation. Overall, this study provides a solid foundation for future research into the functions of the PtrCHSs. Full article

Despite significant advances in understanding the genetics of Parkinson’s disease (PD) and Parkinsonism, the diagnostic yield remains low. Pathogenic variants of GBA1, which encodes the lysosomal enzyme β-glucocerebrosidase and causes recessive Gaucher dis-ease, are recognized as the most important genetic risk factor for PD in heterozygous carriers. This study focuses on the functional genomics of rare genetic variations in other lysosomal hydrolytic enzymes genes in patient-derived fibroblasts. We examined 49 early-onset PD patients using whole exome sequencing and in silico panel analysis based on a curated PD gene list. Two patients were found to carry the p.Asp313Tyr variant in the X-linked GLA gene (encoding GALA, typically associated with Fabry disease), and one patient carried the p.Arg419Gln variant in GLB1 (encoding β-Gal, linked to the recessive GM1 gangliosidosis and mucopolysaccharidosis type IVB). The in silico study of both variants supports a potentially damaging impact on the encoded protein function and structural destabilization. Additional candidate variants were found related to lysosomes, Golgi apparatus and neurodegeneration, suggesting a multifactorial contribution to the disease. However, none of these variants met diagnostic standards. Functional assays showed a significant decrease in GALA expression and partial retention of the enzyme in the trans-Golgi network in fibroblasts with GLA:p.Asp313Tyr, while altered Golgi morphology was observed in fibroblasts with GLB1:p.Arg419Gln. Moreover, all patients exhibited abnormalities in lysosomal morphology, altered lysosomal pH, and impaired autophagic flux. Our findings suggest that rare, heterozygous variants in lysosomal-related genes, even when individually insufficient for monogenic disease, can converge to impair lysosomal homeostasis and autophagic flux in EOPD. The underlying genetic and cellular heterogeneity among patients emphasizes the importance of combining genetic and functional approaches to better understand the mechanisms behind the EOPD, which could enhance both diagnosis and future treatments. Full article

Background: The ESR2 gene encodes Estrogen Receptor-β1 (ERβ1), a putative tumor suppressor in hormone-dependent malignancies. Although ERβ biology has been studied extensively at the expression level, the functional impact of nonsynonymous SNPs (nsSNPs) and untranslated-region (UTR) variants in ESR2 remains underexplored. Methods: We retrieved variants from Ensembl and performed an integrative in silico assessment using PredictSNP, I-Mutant, MUpro, HOPE, MutPred2, and CScape for pathogenicity, oncogenicity and structural stability; STRING/KEGG/GO for pathway context; RegulomeDB and polymiRTS for regulatory effects; and cBioPortal for pan-cancer clinical outcomes (breast (BRCA), endometrial (UCEC), and ovarian (OV)). We evaluated effects of nsSNPs on ERβ1 stability, ligand-binding/DNA-binding domains, co-factor recruitment, and post-transcriptional regulation. Results: Across tools, 93 missense nsSNPs were consistently predicted to be deleterious. Notably, several variants were found to destabilize ERβ1, particularly within the ligand-binding domains (LBD) and DNA-binding domains (DBD). Putative oncogenic drivers R198P and D154N showed high CScape scores and very low population frequencies, consistent with pathogenicity. Several substitutions were predicted to impair coactivator binding and disrupt interactions with key transcriptional partners, including JUN, NCOA1, and SP1. At the post-transcriptional level, rs139004885 was predicted to disrupt miRNA binding, while 3′UTR rs4986938 showed strong regulatory potential and comparatively high population frequency; by contrast, most other identified SNPs were rare. Clinically, pan-cancer survival analyses indicated worse overall survival (OS) in BRCA for ESR2-Altered cases (HR ≈ 2.25; q < 0.001), but better OS in UCEC (HR ≈ 0.24; q ≈ 0.014) and OV (HR ≈ 0.29; q < 0.001), highlighting a tumor-type-specific association. Conclusions: This integrative analysis prioritizes high-impact ESR2 variants that likely impair ERβ1 structure and shows context-dependent clinical effects. Despite their generally low frequency (except for rs4986938), prospective validation linking variant class to ERβ expression and survival outcomes is needed to support biomarker development and therapeutic applications. Full article

Inherited retinal dystrophies (IRDs) are clinically and genetically heterogeneous disorders. Most IRDs follow a monogenic inheritance pattern. However, an increasing number of unresolved cases suggest the possible contribution of oligogenic or digenic mechanisms. Here, we report two ultra-rare missense variants—AIPL1 R302L and BBS2 P134R—that co-segregate with early-onset nonsyndromic retinal degeneration in affected individuals from a non-consanguineous family. We performed a multi-level computational investigation to assess whether these variants may act through a convergent pathogenic mechanism. Using AlphaFold2-predicted structures, we modeled both wild-type and mutant proteins, introduced point mutations, and performed energy minimization and validation. FoldX, DynaMut2, and DUET all predicted destabilizing effects at the variant sites, corroborated by local disruption of secondary structure and altered surface electrostatics. Comparative docking (via HDOCK and ClusPro) identified a putative interaction interface between the TPR domain of AIPL1 and the β-sheet face of BBS2. This interface was destabilized in the double-mutant model. At the systems level, transcriptomic profiling confirmed co-expression of AIPL1 and BBS2 in human retina and fetal eye, while functional enrichment analysis highlighted overlapping involvement in ciliary and proteostasis pathways. Network propagation suggested that the two proteins may converge on shared interactors relevant to photoreceptor maintenance. Collectively, these in silico results provide structural and systems-level support for a candidate digenic mechanism involving AIPL1 and BBS2. While experimental validation remains necessary, our study proposes a testable mechanistic hypothesis and underscores the value of computational approaches in uncovering complex genetic contributions to IRDs. Full article

Oxidative stress, caused by excessive free radicals, leads to cellular damage and various diseases. Antioxidant peptides from natural proteins offer potential in alleviating this stress. In this study, antioxidant peptides were identified from deer antler proteins using in silico enzymatic hydrolysis and machine learning. Peptides with high prediction scores and non-toxic profiles were selected for evaluation. The antioxidant activities of top candidates, PHPAPTL and VPHGL, were confirmed by radical scavenging assays and their protective effects in HepG2 cells. Molecular dynamics simulations revealed stable binding of these peptides to Keap1, enhancing system stability and reducing residue fluctuations at the ligand-binding interface. Key interactions involved Arg415, Arg483, Arg380, and Ser555. Secondary structure analysis showed peptide binding induced local conformational transitions, notably increasing parallel β-sheet formation near active sites. These findings provide mechanistic insight into their antioxidant effects and support their potential application in functional food development. Full article

RAC3 encodes a small Rho-family GTPase essential for cytoskeletal regulation and neurodevelopment, and de novo RAC3 variants typically act as gain-of-function alleles that cause severe neurodevelopmental disorders. In this study, we analyzed a fetus with multisystem congenital anomalies and identified a de novo RAC3 p.(T17R) variant by genome sequencing. To elucidate the pathogenicity of this variant, we combined in silico variant prioritization, structural and energetic modeling, and pathogenicity prediction with in vitro biochemical assays, including GDP/GTP exchange, GTP hydrolysis, effector pull-down, and luciferase reporter analyses in COS7 cells, as well as morphological analysis of primary hippocampal neurons. Furthermore, we performed in vivo analyses using a mouse in utero electroporation to assess cortical neuron migration, axon extension, and dendritic development. Our biochemical results suggest that RAC3-T17R exhibits markedly increased GDP/GTP exchange, with a preference for GDP binding, and undetectable GTP hydrolysis. The mutant displayed minimal binding to canonical RAC effectors (PAK1, MLK2, and N-WASP) and failed to activate SRF-, NFκB-, or AP1-dependent transcription. Neuronal overexpression of RAC3-T17R impaired axon formation in vitro, while in vivo expression delayed cortical neuron migration and axon extension and reduced dendritic arborization. Clinically, the fetus exhibited corpus callosum agenesis, microcephaly, organomegaly, and limb contractures. Collectively, these findings indicate that the RAC3 p.(T17R) variant may represent a signaling-deficient allele with pleiotropic, variant-specific mechanisms that disrupt corticogenesis and broader organogenesis. Our multi-tiered in silico–in vitro–in vivo approach demonstrates that noncanonical RAC3 variants can produce complex, multisystem developmental phenotypes beyond previously recognized RAC3-related neurodevelopmental disorders. Full article

Background: The pathophysiology of Alzheimer’s disease (AD) is strongly linked to damage to the cholinergic systems of the central nervous system (CNS), mainly due to the formation of β-amyloid peptide plaques, which trigger intense inflammatory responses and are currently the main cause of the symptoms of the disease. Among the therapeutic strategies under investigation, classes of natural products with immunomodulatory properties, action on the CNS, and potent antioxidant activity, which contribute to neuroprotection, stand out. Methods: We aimed to evaluate the flavonoid quercetin using in silico, in vitro, and in vivo methods for the treatment of AD. Initially, the compounds were selected, and molecular dynamics simulations were performed. The in vitro assays included tests of antioxidant activity (DPPH), enzymatic inhibition of acetylcholinesterase (AChE), and prediction of oral toxicity. The in vivo studies investigated the effects on scopolamine-induced learning deficits and conducted histopathological analysis of the brain. Results: Quercetin showed structural stability in the complex with (AChE), with no significant alterations in the Root Mean Square Deviation (RMSD), SASA and radius of gyration (Rg) parameters. Through the same method it was possible to predict stability between the quercetin and inducible nitric oxide synthase (iNOS) complex, a possible mechanism for quercetin immunomodulation in the CNS. In the AChE inhibition test, the IC₅₀ obtained for quercetin was 59.15 μg mL⁻¹, while in the antioxidant test with DPPH, the concentration of 33.1 µM exhibited 50% of the scavenging of reactive oxygen species. This corroborates the perspective of quercetin having neuroprotective activity. This activity was also corroborated in vivo, in a zebrafish model, in which quercetin reduced the cognitive deficit induced by scopolamine. Histopathological analysis revealed its ability to prevent atrophy, caused by scopolamine, in the nervous tissue of animals, reinforcing the potential of quercetin as a neuroprotective agent. Conclusions: The results of the tests carried out with quercetin suggest that this molecule has antioxidant, AChE inhibitory, and neuroprotective activities, making it a good candidate for use in future clinical trials to ensure its efficacy and safety. Full article

Parkinson’s disease is a neurodegenerative disorder characterized by the degeneration of dopaminergic neurons, resulting in multiple motor and cognitive impairments. Among the hypotheses proposed for its etiology, oxidative stress mediated by the enzyme monoamine oxidase B (MAO-B) stands out, as it is directly associated with dopamine metabolism. In this context, the search for molecules with potential antiparkinsonian activity and low toxicity, particularly those of natural origin, has been extensively investigated using computational approaches. In the present study, a pharmacophore-based virtual screening was carried out on molecules belonging to the alkaloid and flavonoid groups, followed by the evaluation of their pharmacokinetic, toxicological, and biological activity profiles, as well as ligand–receptor interaction analysis through molecular docking. The results indicated that palmatine, genistein, ZINC00597214, and ZINC72342127 exhibited superior performance compared to the other analyzed structures, considering all evaluated criteria. Therefore, this study, through in silico methodologies, demonstrated the antiparkinsonian potential of several chemical structures, attributable to their inhibitory activity on the MAO-B enzyme. Further experimental investigations, both in vitro and in vivo, are necessary to more comprehensively characterize the properties of these molecules, with the ultimate goal of developing new therapeutic strategies for the treatment of Parkinson’s disease. Full article

In silico forensic toxicology refers to the emerging application of computational models based on Quantitative Structure–Activity Relationships (QSARs), molecular docking, and predictions regarding Absorption, Distribution, Metabolism, Excretion, and Toxicity (ADMET) as used to predict the toxicological behavior of various substances, particularly in medico-legal contexts. These computational models replicate metabolic pathways, providing insights into the metabolism of substances in the human body, while the results of this approach effectively reflect the necessary compounds, reducing the need for direct laboratory work. This review aims to evaluate whether forensic settings and in silico methods present a cost-effective strategy for investigating unknown substances, aiding in toxicological interpretations, and steering laboratory process analyses. Additionally, financial considerations, such as break-even analysis and Bland–Altman plots, were conducted, indicating that forensic labs conducting over 625 analyses each year can achieve cost efficiency by integrating in silico strategies, thus making them a viable alternative to conventional methods in high-throughput settings. Recent studies have emphasized how machine learning enhances predictive accuracy, thereby boosting forensic toxicology’s capacity to effectively evaluate toxicity endpoints. In silico methods are essential for cases involving novel psychoactive substances (NPSs) or unclear toxicological findings. They are also useful as a supporting method in legal contexts, as they uphold expert testimonies and reinforce evidence claims. The future of forensic toxicology is likely to see the increased implementation of AI-powered techniques, streamlining toxicological investigations and enhancing overall accuracy in forensic evaluations. Full article

A series of twenty-five salicylic acid derivatives was synthesized and structurally characterized by ¹H and ¹³C-APT NMR and IR spectroscopic techniques, and HRMS analysis. The derivatives were subjected to biological evaluation against species of the genus Candida (C. albicans ATCC 90028, C. albicans CBS 5602, C. tropicalis CBS 94, and C. krusei CBS 573). In assays were used the broth microdilution method to determine the minimum inhibitory concentration (MIC) and verify the probable mechanism of action for antifungal activity. In the antifungal evaluation, compounds N-isobutyl-2-hidroxybenzamide (14), N-cyclohexyl-2-hydroxybenzamide (15), N-benzyl-2-hydroxybenzamide (16), N-4-methylbenzyl-2-hydroxybenzamide (17), N-4-methoxybenzyl-2-hydroxybenzamide (18), N-2,4-dimethoxybenzyl-2-hydroxybenzamide (19), N-4-fluorbenzyl-2-hiydroxybenzamide (22), and N-4-chlorobenzyl-2-hydroxybenzamide (23) were bioactive against at least one fungal strain. The compound with the best antifungal profile was N-cyclohexyl-2-hydroxybenzamide (15), which presented a MIC of 570.05 μM against most of the strains tested. The tests using ergosterol and sorbitol demonstrated that the compound does not act by altering cell wall functions or the plasmatic membrane in Candida species. The in silico analysis of 15 for antifungal activity in various biological targets suggested a probable multitarget mechanism. Therefore, the synthesis of salicylic acid derivatives resulted in compounds with a good antifungal profile. Full article

In recent years, we have observed a growing interest in molecular hybridization, which involves combining chemically and pharmacologically diverse fragments into a single molecule. In this study, we designed and synthesized a series of indole–pyrazole hybrids, variously substituted at the pyrazole ring. The compounds were characterized by spectroscopic methods, and the structures of most of them were confirmed by X-ray analysis. Reactions of 3-(dimethylaminomethyl)indole with bromo-methyl-pyrazole derivatives proceeded in a tautomer-selective mode: the 4-bromo-3(5)-methyl-((1H-pyrazol-1-yl)methyl)-1H-indole tautomers, obtained from the 4-bromo-3-methyl-1H-pyrazole, could be isolated by column chromatography. In contrast, the 3-bromo-5-methyl-1H-pyrazole yielded the ((5-bromo-3-methyl-1H-pyrazol-1-yl)methyl)-1H-indole as the dominant reaction product. The 3-bromo-5-methyl tautomer could not be isolated nor could its presence be identified in solution. However, traces of it were recognized in the crystal of 5-bromo-3-methyl tautomer as a binary solid solution. In silico studies provided the physicochemical parameters of all compounds, enabling the estimation of some derivatives affinity to certain enzymes. In vitro evaluation of the hemolytic and cytoprotective properties of all derivatives showed that most of the compounds exhibited no hemolytic activity, while all demonstrated significant cytoprotective effects on human erythrocytes under oxidative stress. Full article

Background/Objectives: Neurodevelopmental disorders (NDDs) are genetically heterogeneous conditions with a complex molecular etiology involving numerous genes. Biallelic pathogenic variants in INTS1 cause a rare autosomal recessive NDD characterized by congenital cataracts, growth retardation, facial dysmorphism, and global developmental delay. To date, the clinical description of this disorder has been based solely on individual case reports, and its phenotypic spectrum remains incompletely defined. Methods: A 9-year-old female proband was evaluated for developmental delay, multiple congenital anomalies, and distinctive craniofacial features. Whole-exome sequencing (WES) was performed, followed by Sanger validation and segregation analysis. Variant pathogenicity was assessed using in silico prediction tools and 3D protein structural modeling. Results: Whole-exome sequencing identified two novel compound heterozygous missense variants in INTS1, c.1145G>A (p.Arg382Gln) and c.1195G>A (p.Gly399Ser), both located in exon 9. Segregation analysis showed that c.1145G>A was inherited from the father and c.1195G>A from the mother, and both variants are extremely rare in population databases. Conclusions: We report a patient carrying novel biallelic INTS1 variants, whose clinical presentation differs from previously reported cases, including those with milder phenotypes characterized by preserved speech development and absence of intellectual disability. This observation broadens the clinical spectrum of INTS1-related disease and underscores its phenotypic heterogeneity. Full article

Nucleotide diphosphate hydrolase type 5 (NUDT5) plays a significant role in the estrogen-signaling pathway and is overexpressed in breast cancer. This study aimed to explore the anti-breast cancer potential of quercetin and its 52 structural analogs by targeting the NUDT5 enzyme using the in silico molecular docking method. Moreover, Molecular Mechanics/General Born Surface Area (MM/GBSA) calculations were performed for compounds with superior binding affinity scores than quercetin. Their drug-likeness, according to Lipinski’s rule of five, water solubility, and Caco-2 permeability were predicted. In addition, the absorption, distribution, metabolism, excretion, and toxicity (ADMET) profile was determined for the top-scoring compounds from the docking studies and MM/GBSA calculations, as well as for those that complied with the rules of Lipinski and exhibited high permeability. The obtained results showed that all the tested ligands interact with the active site of NUDT5. Their binding energies ranged from −11.24 to −7.36 kcal/mol. The MM/GBSA calculations further supported the binding affinity predictions. ADMET analysis enabled the selection of compounds with favorable pharmacokinetic profiles in comparison to quercetin. Quercetin analogs L1 and L28 were identified as promising anti-breast cancer drug candidates worthy of further experimental evaluation. Full article

Identifying the most reactive conformation of a molecule is a central challenge in computational chemistry, particularly when reactivity depends on subtle conformational effects. While most conformation search tools aim to find the lowest-energy structure, they often overlook the electronic descriptors that govern chemical reactivity. In this work, we present GAELLE, a cheminformatics tool that combines conformer generation with quantum reactivity descriptors to identify the most reactive structure of a molecule in solution. GAELLE integrates an evolutionary algorithm with fast semiempirical quantum chemical calculations (xTB), enabling the automated ranking of conformers based on HOMO–LUMO gap minimization (Pearson’s principle of maximum hardness) and electrophilicity index (Parr’s electrophilicity scale). Solvent effects are accounted for via implicit solvation models (GBSA/ALPB) to ensure realistic evaluation of reactivity in solution. The method is fully SMILES-driven, open-source, and scalable to medium-sized drug-like molecules. Applications to reactive intermediates, bioactive conformations, and pre-reactive complexes demonstrate the method’s relevance for mechanism elucidation, molecular design, and in silico screening. GAELLE is publicly available and offers a reactivity-focused alternative to traditional energy-minimization tools in conformational analysis. Full article

The hepatitis D virus (HDV) is a small, defective RNA virus that induces the most severe form of viral hepatitis. Despite its severity, HDV infections are under-diagnosed due to non-standardized and costly diagnostic screening methods. However, limited research has been conducted on characterizing HDV-specific antibodies as alternative tools for diagnosis. Thus, we generated HDV-specific, polyclonal antibodies by immunizing rabbits with the HDV protein, small hepatitis delta antigen (SHDAg), in its oligomeric or denatured form. We identified SHDAg-specific linear epitopes by peptide array analysis and compared them to epitopes identified in HDV-infected patients. Using in silico structural analysis, we show that certain highly immunogenic domains in SHDAg, such as the coiled-coil domain, are masked in the oligomeric conformation of the protein; others, such as the second arginine-rich motif, are exposed. The nuclear localization signal is presumably exposed only by specific interaction of oligomeric HDAg with the HDV-RNA genome. Through surface plasmon resonance analysis, we identified two polyclonal antibodies derived from rabbit antisera with affinities in the lower nanomolar range. These antibodies were used to establish an ELISA that can quantitatively detect HDV virions in vitro and upon further optimization could be used as a promising alternative diagnostic screening method. Full article