Contribution of hydrogen bonds to protein stability

Evaluation of the antimicrobial efficiency of three novel chimeric peptides through biochemical and biophysical analyses

Three chimeric membrane-active antimicrobial peptides (AMPs) were designed from previously characterized parental molecules, namely pandinin-2, ascaphin-8, and maximin-3. The aim of constructing these chimeras was to obtain sequences with improved therapeutic indices or increased activity, while simultaneously investigating the functional roles of key segments of the parental peptides. Chimera-1 was the most active peptide against clinically relevant bacterial species, followed by chimera-2, and chimera-3, respectively, with no clear preference towards Gram-negative or Gram-positive strains. Escherichia coli and Pseudomonas aeruginosa were the most sensitive bacteria, while Klebsiella pneumoniae and Staphylococcus aureus were resistant to AMP activity. All peptides presented significantly lower activities towards human erythrocytes, with chimera-1 being the most selective. Additionally, only chimera-2 showed cytotoxicity towards Vero cells. Calcein leakage and dynamic light scattering assays using liposomal formulations indicated that the chimeras conserved the pore forming membrane perturbation mechanisms of the parental molecules. Peptide interaction also reduced membrane fluidity. Circular dichroism (CD) data showed disordered peptides in aqueous solution that transitioned into alpha helical structures lipid bilayer environments. In silico assessments correlated well with microbiological and in vitro experimental data. All peptides established greater contact with the bacterial biomimetic membrane compared to the erythrocyte system, as analyzed by distance from membrane surface, number of contacts, solvent accessible surface area, and number of hydrogen bonds. Additionally, the presence of the bilayer lipid patches favored peptide folding, consistent with CD experiments. Molecular dynamics simulations of peptide aggregation revealed that chimera-2 formed the largest oligomers, consistent with the predicted aggregation propensities and the predicted physico-chemical properties. Interaction with membrane surfaces resulted in smaller clusters while low or lack of interaction favored larger aggregates. Overall, the chimeric peptides displayed higher activity and selectivity compared to the parental ones. The contribution of the flanking regions of pandidin-2 and maximin-3 with respect to the core region of ascaphin-8 was not clear.

ATP1A3 Variants, Variably Penetrant Short QT Intervals, and Lethal Ventricular Arrhythmias

Importance

Alternating hemiplegia of childhood (AHC) is a disorder that can result from pathogenic variants in ATP1A3-encoded sodium-potassium adenosine triphosphatase alpha 3 (ATP1A3). While AHC is primarily a neurologic disease, some individuals experience sudden unexplained death (SUD) potentially associated with cardiac arrhythmias.

Objective

To determine the impact of ATP1A3 variants on cardiac electrophysiology and whether lethal ventricular arrhythmias are associated with SUD in patients with AHC.

Design, Setting, and Participants

In this international, multicenter case-control study from 12 centers across 10 countries, patients with AHC were grouped by ATP1A3 variant status (positive vs negative) and into subgroups with the most common AHC variants (D801N, E815K, G947R, and other). A healthy control cohort was established for comparison. Blinded, manual measurements of QT intervals and corrected QT interval (QTc) were performed independently by 2 pediatric cardiac electrophysiologists. Induced pluripotent stem cell cardiomyocytes were derived from patients with AHC who were positive for the D801N variant of ATP1A3 (iPSC-CMD801N cells). Data analysis was performed from April to June 2022.

Exposure

Presence of ATP1A3 variant.

Main Outcomes and Measures

The primary outcome was QTc. Outcomes, including survival, were abstracted and variants were mapped on cryogenic electron microscopy structure maps. iPSC-CMD801N cells were used to validate ventricular repolarization and arrhythmic susceptibility in vitro.

Results

Among the 222 individuals included (148 with AHC and 74 control), the mean (SD) age at diagnostic electrocardiography was 11.0 (9.4) years and 119 (54%) were female. The cohort with AHC consisted of 148 largely unrelated probands (mean [SD] age at diagnostic electrocardiography, 11.5 [10.5] years). Of these, 123 individuals were ATP1A3 genotype positive, including 35 (28%) with the D801N variant, 21 (17%) with the E815K variant, 8 (7%) with the G947R variant, and 8 (7%) with a loss-of-function variant. Probands with the D801N variant had shorter mean (SD) QTcs (381.8 [36.6] milliseconds; 24 [69%] with QTc <370 milliseconds) compared with those who had the E815K variant (393.6 [43.1] milliseconds; P = .001; 4 [19%] with QTC <370 milliseconds), the G947R variant (388.4 [26.5] milliseconds; P = .02; 1 [13%] with QTc <370 milliseconds), a loss-of-function variant (403.0 [33.5] milliseconds; P < .001; 1 [13%] with QTc <370 milliseconds), all other variants (387.8 [37.1] milliseconds; P < .001; 44 [86%] with QTc <370 milliseconds), and healthy controls (415.4 [21.0] milliseconds; P < .001; 0 with QTc <370 milliseconds). Three D801N-positive individuals had a major cardiac event, compared with 0 major cardiac events in all other individuals (P = .02). The D801N variant and 4 rare variants (D805N, P323S, S772R, and C333F) found in individuals with the shortest QTcs localized to the potassium-binding domain of ATP1A3. IPSC-CMD801N lines demonstrated shortened action potential duration, higher mean diastolic potential, and delayed afterdepolarizations compared with controls.

Conclusions and Relevance

Nearly 70% of individuals with D801N variants of ATP1A3 had short QTcs (<370 milliseconds), with an association between ventricular arrhythmias and cardiac arrest. This may underlie the SUD etiology in AHC.

Ethanol Inhalation for Respiratory Infections due to Enveloped Viruses

Ethanol has demonstrated high efficacy in inactivating enveloped viruses in vitro and in vivo (in animal and human studies). The inhalation route has been a significant method of drug administration for respiratory disorders since ancient times. Infections with enveloped viruses cause many respiratory diseases. This concise review explores the general structural characteristics of enveloped viruses and examines the potential role of inhaled ethanol as a low-cost therapy for respiratory diseases. Current literature data suggest that ethanol inhalation could be beneficial in treating respiratory infections caused by enveloped viruses. However, there is a clear gap in well-designed clinical trials assessing the safety and efficacy of ethanol inhalation in treating respiratory infections from enveloped viruses. This low-cost therapy could become an important therapeutic option, especially for large numbers of patients simultaneously infected, as was the case during the coronavirus disease 2019 (COVID-19) pandemic. In addition, inhaled ethanol could be a successful approach for vulnerable patients such as patients with cancer because it is likely to have no or minimal effects on already established life-saving treatments. Further investigation by national and international institutions is urgently needed to validate these findings and refine treatment protocols.

Microstructure of Sea Cucumber Parastichopus tremulus Peptide Hydrogels and Bioactivity in Caco-2 Cell Culture Model

Wider availability of marine proteins for the development of food and biomedical applications has a high importance. Sea cucumber body wall proteins have specific functional properties that could be very promising for such product development. However, protein extraction from whole animals is costly and complex, whereas peptide hydrogel production using biotechnological methods can be considered an economically viable approach. Body-wall derived peptides from sea cucumber Parastichopus tremulus have been suggested as a nontraditional source of potentially edible hydrocolloids. In the current work, four peptides were produced through custom synthesis. Scanning electron microscopy (SEM) of the combined mix of the four peptides (1:1 ratio; 15 mM concentration) in a calcium ion-containing buffer confirmed untargeted self-assembly with long, thick fibrillar formations at a microscale (measured mean cross-section 2.78 µm and length sizes of 26.95 µm). The antioxidant activity of the peptides separately, and in combination (1:1 molar ratio), was studied in vitro through ORAC (values in the range from 279 to 543 µmol TE/g peptide), ABTS (from 80.4 to 1215 µmol TE/g peptide), and DPPH (from 5.2 to 19.9 µmol TE/g) assays, and confirmed for protection against oxidation in a Caco-2 cell culture model. Angiotensin-I converting enzyme inhibitory activity was also confirmed for two of the four peptides, with the highest IC 50 of 7.11 ± 0.84 mg/mL.

Galloway-mowat syndrome 3 (GAMOS3): a novel disease-causing variant in OSGEP gene and expansion of the clinical spectrum

INTRODUCTION

Galloway-Mowat syndrome type 3 (GAMOS3) is a rare genetic disorder with renal and neurological complications caused by pathogenic variants in the OSGEP gene. Here, we report the molecular basis and clinical features in an Iranian family.

METHODS

Our proband, a 10-month-old female patient, presented with microcephaly, global developmental delay, lower limb spasticity, facial dysmorphisms, and renal tubulopathy. Brain magnetic resonance imaging (MRI), electroencephalography (EEG), and laboratory tests were performed to evaluate the clinical features. WES, Sanger sequencing, computational variant analysis, and gene expression analysis were conducted to identify, validate, and evaluate the genetic cause. Additionally, I-TASSER, HADDOCK, and GROMACS tools were utilized for protein modeling, computational docking, and molecular dynamics simulation (MDS), respectively.

RESULTS

Blood and urine tests revealed proteinuria, hypercalciuria, and hypoalbuminemia. Brain MRI detected craniosynostosis, global parenchymal atrophy, and dysgenesis of the corpus callosum. Exome sequencing identified a previously unreported homozygous variant (NM_017807.4, c.689 G > T/p.C230F) in OSGEP, demonstrating co-segregation with the condition in the family. This missense variant did not significantly change the mRNA transcription. In-silico experiments predicted that this variant would likely alter the protein's structure and impair its normal functioning. Molecular docking results indicated that this variant significantly affects the protein interactions between OSGEP and LAGE3 proteins. Furthermore, MDS findings demonstrated that the p.C230F variant induced a conformational change in the mutant structure, potentially modifying its flexibility and stability.

CONCLUSION

Identification of this variant contributes to expanding the OSGEP gene variant database, establishing a solid scientific foundation for precise clinical diagnosis and treatment.

Virtual screening and molecular dynamics simulation of natural compounds as potential inhibitors of serine/threonine kinase 16 for anticancer drug discovery

Serine/threonine kinase 16 (STK 16) is involved in many facets of cellular regulation; activation of STK 16 plays a crucial role in the migration of cancer cells. Therefore, it is a novel target for the discovery of anticancer agents. Herein, virtual screening and dynamics simulation were used to screen a large library of natural compounds against STK 16 using Schrodinger suit 2021-2 and GROMACS 2021.6. The results predicted five molecules with high binding affinity against the target, with NPC132329 (Arcyriaflavin C) and NPC160898 having higher binding affinity and molecular mechanics generalized born surface area (MM/GBSA), suggesting that it is better than the standard inhibitor. The molecular dymanics (MD) simulation studies showed that the STK 16-NPC132329 complex has the lowest root mean square deviation, and STK 16-NPC160898 was the most stable compared with the standard drug and selective STK 16 inhibitor. The minimal fluctuation was observed in the STK 16-NPC132329 and STK 16-NPC160898 complexes based on the root mean square fluctuation trajectory with NPC132329 and NPC160898 forming 2 and 3 hydrogen bonds respectively with the amino acid residue of the target's binding site. Overall, NPC132329 and NPC160898 are better STK 16 inhibitors than the standard drug and selective inhibitor, which can be further studied to discover novel anticancer drugs.

In-silico evaluation of Bismurrayaquinone-A phytochemical as a potential multifunctional inhibitor targeting dihydrofolate reductase: implications for anticancer and antibacterial drug development

Dihydrofolate reductase (DHFR) has gained significant attention in drug development, primarily due to marked distinctions in its active site among different species. DHFR plays a crucial role in both DNA and amino acid metabolism by facilitating the transfer of monocarbon residues through tetrahydrofolate, which is vital for nucleotide and amino acid synthesis. This considers its potential as a promising target for therapeutic interventions. In this study, our focus was on conducting a virtual screening of phytoconstituents from the IMPPAT2.0 database to identify potential inhibitors of DHFR. The initial criterion involved assessing the binding energy of molecules against DHFR and we screened top 20 compounds ranging energy -13.5 to -11.4 (kcal/Mol) while Pemetrexed disodium bound with less energy -10.2 (kcal/Mol), followed by an analysis of their interactions to identify more effective hits. We prioritized IMPHY007679 (Bismurrayaquinone-A), which displayed a high binding affinity and crucial interaction with DHFR. We also evaluated the drug-like properties and biological activity of IMPHY007679. Furthermore, MD simulation was done, RMSD, RMSF, Rg, SASA, PCA and FEL explore the time-evolution impact of IMPHY007679 comparing it with a reference drug, Pemetrexed disodium. Collectively, our findings suggest that IMPHY007679 recommend further investigation in both in vitro and in vivo settings for its potential in developing anticancer and antibacterial therapies. This compound holds promise as a valuable candidate for advancing drug research and treatment strategies.

Computational molecular insights into ibrutinib as a potent inhibitor of HER2-L755S mutant in breast cancer: gene expression studies, virtual screening, docking, and molecular dynamics analysis

Background

The proposed study integrates several advanced computational techniques to unravel the molecular mechanisms underlying breast cancer progression and drug resistance.

Methods

We investigated HER2-L755S mutation through a multi-step approach, including gene expression analysis, molecular docking, and molecular dynamics simulations.

Results and Discussion

By conducting a network-based analysis of gene expression data from breast cancer samples, key hub genes such as MYC, EGFR, CDKN2A, ERBB2, CDK1, E2F1, TOP2A, MDM2, TGFB1, and FOXM1 were identified, all of which are critical in tumor growth and metastasis. The study mainly focuses on the ERBB2 gene, which encodes the HER2 protein, and its common mutation HER2-L755S, associated with breast cancer and resistance to the drug lapatinib. The HER2-L755S mutation contributes to both tumorigenesis and therapeutic failure. To address this, alternative therapeutic strategies were investigated using combinatorial computational approaches. The stability and flexibility of the HER2-L755S mutation were evaluated through comparative molecular dynamics simulations over 1000 ns using Gromacs in the unbound (Apo) state. Virtual screening with Schrodinger Glide identified ibrutinib as a promising alternative to lapatinib for targeting the HER2-L755S mutant. Detailed docking and molecular dynamics simulations in the bound (Holo) state demonstrated that the HER2-L755S-ibrutinib complex exhibited higher binding affinity and lower binding energy, indicating more stable interactions compared to other complexes. MM-PBSA analysis revealed that the HER2-L755S-ibrutinib complex had more negative binding energy than the HER2-L755S-afatinib, HER2-L755S-lapatinib, and HER2-L755S-neratinib complexes, suggesting that ibrutinib forms the most stable complex with favorable binding interactions.

Conclusion

These results provide in-depth atomic-level insights into the binding mechanisms of these inhibitors, highlighting ibrutinib as a potentially effective inhibitor for the clinical treatment of breast cancer.

Adoption of an in-silico analysis approach to assess the functional and structural impacts of rpoB-encoded protein mutations on Chlamydia pneumoniae sensitivity to antibiotics

BACKGROUND

Antibiotics are frequently used to treat infections caused by Chlamydia pneumoniae; an obligate intracellular gram-negative bacterium commonly associated with respiratory diseases. However, improper or overuse of these drugs has raised concerns about the development of antibiotic resistance, which poses a significant global health challenge. Previous studies have revealed a link between mutations in the rpoB-encoded protein of C. pneumoniae and antibiotic resistance. This study assessed these mutations via various bioinformatics tools to predict their impact on function, structural stability, antibiotic binding, and, ultimately, their effect on bacterial sensitivity to antibiotics.

RESULTS

Eight mutations in the rpoB-encoded protein (R421S, F450S, L456I, S454F, D461E, S476F, L478S, and S519Y) are associated with resistance to rifampin and rifalazil. These mutations occur in conserved regions of the protein, leading to decreased stability and affecting essential functional sites of RNA polymerase, the target of these antibiotics. Although the structural differences between the native and mutant proteins are minimal, notable changes in local hydrogen bonding have been observed. Despite similar binding energies, variations in hydrogen bonds and hydrophobic interactions in certain mutants (for instance, D461E for rifalazil and S476F for rifampin) indicate that these changes may diminish ligand affinity and specificity. Furthermore, protein-protein network analysis demonstrated a strong correlation between wild-type rpoB and ten C. pneumoniae proteins, each fulfilling specific functional roles. Consequently, some of these mutations can reduce the bacterium's sensitivity to rifampin and rifalazil, thereby contributing to antibiotic resistance.

CONCLUSION

The findings of this study indicate that mutations in the rpoB gene, which encodes the beta subunit of RNA polymerase, are pivotal in the resistance of C. pneumoniae to rifampin and rifalazil. Some of these mutations may result in reduced protein stability and changes in the structure, function, and antibiotic binding. As a consequence, the efficacy of these drugs in inhibiting RNA polymerase is compromised, allowing the bacteria to persist in transcription and replication even in the presence of antibiotics. Overall, these insights enhance our understanding of the resistance mechanisms in C. pneumoniae and could guide the development of strategies to address this challenge.

CLINICAL TRIAL NUMBER

Not applicable.

Molecular Balances as Physical Organic Chemistry Tools to Quantify Non-Covalent Interactions

Non-covalent interactions are present in numerous synthetic and biological systems, playing an essential role in vital life processes, such as the stabilization of proteins' structures or reversible binding in substrate-receptor complexes. Their study is relevant but faces challenges due to its inherent weak nature. In this context, molecular balances (MBs) are one of the most efficient physical organic chemistry tools to quantify non-covalent interactions, bringing beneficial knowledge regarding their nature and strength. Herein, we report an overview and critical discussion of recent studies related to various MBs in the quantification of a collection of non-covalent interactions, covering from the well-known aryl • • • aryl and CH • • • aryl interaction to the newest fullerene • • • aryl and chalcogen • • • chalcogen interactions.

In silico identification of novel ligands targeting stress-related human FKBP5 protein in mental disorders

FK506-binding protein 51 (FKBP51 or FKBP5) serves as a crucial stress modulator implicated in mental disorders, presenting a potential target for intervention. Inhibitors like SAFit2, rapamycin, and tacrolimus exhibit promising interactions with this protein. Despite these advances, challenges persist in diversifying FKBP5 ligands, prompting further exploration of interaction partners. Hence, this study aims to identify other potential ligands. Employing molecular docking, we generated complexes with various ligands (rapamycin, tacrolimus, SAFit2-Selective antagonist of FKBP51 by induced fit, ascomycin, pimecrolimus, rosavin, salidroside, curcumin, apigenin, uvaricin, ruscogenin, neoruscogenin, pumicalagin, castalagin, and grandinin). We identified the top 3 best ligands, of which ruscogenin and neoruscogenin had notable abilities to cross the blood-brain barrier and have high gastrointestinal absorption, like curcumin. Toxicity predictions show ruscogenin and neoruscogenin to be the least toxic based on oral toxicity classification (Class VI). Tyrosine (Tyr113) formed consistent interactions with all ligands in the complex, reinforcing their potential and involvement in stress modulation. Molecular dynamic (MD) simulation validated strong interactions between our three key ligands and FKBP5 protein and provided an understanding of the stability of the complex. The binding free energy (ΔG) of the best ligands (based on pharmacological properties) from MD simulation analysis is -31.78 kcal/mol for neoruscogenin, -30.41 kcal/mol for ruscogenin, and -27.6 kcal/mol for curcumin. These molecules, therefore, can serve as therapeutic molecules or biomarkers for research in stress-impacted mental disorders. While offering therapeutic implications for mental disorders by attenuating stress impact, it is crucial to emphasize that these ligands' transition to clinical applications necessitates extensive experimental research, including clinical trials, to unravel the intricate molecular and neural pathways involved in these interactions.

Biomimetic Second Coordination Sphere Effect within Cu-Peptoid Electrocatalyst Enables Homogeneous Water Oxidation at pH 7

A dinuclear Cu-peptoid, Cu2(BDiE)2, having a diol side chain was developed as a homogeneous electrocatalyst for oxygen evolution reaction (OER) at neutral pH. The molecular structure of Cu2(BDiE)2 was characterized and concluded by ESI-MS, UV-vis, and single-crystal X-ray diffraction. Electrochemical, spectroscopic, and mechanistic studies revealed that borate buffer (the solution medium) has a minor effect during electrocatalysis; however, the diol side chain promotes a second coordination sphere effect via multiple hydrogen bonds which highly stabilize the complex, leading to an OER. Based on these observations and the collected data, we also suggest two different and unique mechanism pathways: a major one, which involves interactions of radical intermediates, which is buffer independent, and a minor one that resembles water nucleophilic attack (WNA) and is assisted by the borate buffer.

A novel anion replaced gemini surfactant: Investigation on the primary interaction between gemini surfactant and BSA

Gemini surfactants (GS) could serve as the drug carrier agents for the delivery of macromolecules due to the excellent properties and tuneable structures. Little attention has been paid to the impact of counterion change on GS and the interaction between GS and protein. In this work, ibuprofen (Ibu) replaced quaternary ammonium ion GS (GS-Ibu) with the hydrophobic chain length of 8, 10, 12, 14 and 16 carbon atoms were prepared for the first-time using extraction technology. The prepared GS-Ibu has stronger electrostatic interaction compared to traditional gemini surfactants with bromide anions (GS-Br). GS were further incubated with the model macromolecule, bovine serum albumin (BSA), to form BSA/GS complexes. The colloid stability of BSA could be affected by the concentration of GS, the length of hydrophobic chain and the type of anion. GS-Ibu exhibited better ability to prevent BSA from aggregating based the result of PAGE test. The molecular level change of BSA after the introduction of GS was first reflected by UV-Visible absorption spectrum. CD spectrum results further revealed that the primary interaction leading to the change in the secondary structure of BSA is electrostatic interaction. Molecular docking and molecular dynamic simulations confirmed the presence of hydrophobic and electrostatic interaction between BSA and GS. In conclusion, the anion replaced GS could be a promising strategy to stabilize the proteins.

Terahertz wave targeting modulates the dedocking of neurotransmitters with receptors

Neurotransmitters are essential in regulating the functions of the nervous, cardiovascular, endocrine, and various other tissue systems. Neurodegenerative diseases such as Parkinson's disease, depression, and Alzheimer's disease involve the loss of catecholamine neurons. One of the main challenges is the accumulation of catecholamine (CA) metabolites. Reducing the metabolic aggregation toxicity of the transmitter molecules remains an open question. In this work, we proposed a novel physical method, terahertz-triggered dedocking, to unbind ligand molecules that accumulate around receptor proteins, potentially alleviating neurodegenerative diseases. We found that electromagnetic stimulation at 44.5 THz successfully dissociates the DA ligand from the binding sites at the receptor by breaking weak hydrogen bonds. Using molecular docking, we identified multiple binding sites for CA neurotransmitter molecules within the dopamine receptor D2 (DRD2). We also characterized the terahertz fingerprints and theoretical spectra of CAs across the 0.5 to 50 THz range, revealing their microscopic vibrational modes at characteristic peak positions and elucidating how specific vibrations influence molecular conformational changes. This finding highlights the potential of terahertz radiation in regulating the nervous system and provides new theoretical support for neural drug discovery and the intervention of neurological disorders.

Decoding the therapeutic landscape of alpha-linolenic acid: a network pharmacology and bioinformatics investigation against cancer-related epigenetic modifiers

Omega-3 (n - 3) and omega-6 (n - 6) polyunsaturated fatty acids (PUFAs) are vital for human health, but an imbalance between these types is associated with chronic diseases, including cancer. Alpha-linolenic acid (ALA), a n - 3 PUFA, shows promise as an anticancer agent in both laboratory and animal studies. However, the precise molecular mechanisms underlying ALA's actions against cancer-related epigenetic modifiers (CaEpM) remain unclear. To understand this, we employed network pharmacology (NP) and molecular docking techniques. Our study identified 51 potential ALA targets and GO and KEGG pathway analysis revealed possible molecular targets and signaling pathways of ALA against CaEpM. From PPI analysis, EZH2, KAT2B, SIRT1, KAT2A, KDM6B, EHMT2, WDR5, SETD7, SIRT2, and HDAC3 emerged as the top 10 potential targets. Additionally, GeneMANIA functional association (GMFA) network analysis of these top 10 targets was performed to enhance NP insights and explore ALA's multi-target approach. After an exhaustive analysis of the core FGN subnetwork, it became evident that 9 out of the 15 targets-namely EZH2, SUZ12, EED, PARP1, HDAC3, DNMT1, NCOR2, KAT2B, and TRRAP-manifested evidently strong and abundant interconnections among each other. Molecular docking of both top 10 targets and core FGN targets confirmed strong binding affinity between ALA and SIRT2, WDR5, KDM6B, EHMT2, HDAC3, EZH2, PARP1, and KAT2B, underscoring their roles in ALA's anti-CaEpM mechanism. Our findings suggest that ALA may target key signaling pathways related to transcriptional regulation, microRNA involvement, stem cell pluripotency and cellular senescence in cancer epigenetics. These findings illuminate ALA's potential as a multi-target agent against CaEpM.Communicated by Ramaswamy H. Sarma.

Identification of potential inhibitors of hypoxanthine-guanine phosphoribosyl transferase for cancer treatment by molecular docking, dynamics simulation and in vitro studies

Hypoxanthine guanine phosphoribosyltransferase 1 (HPRT1) is a mutational biomarker and a housekeeping human reporter gene that is predominantly employed to assess mutation frequencies associated with cancer development. In this study, our purpose was to identify potential inhibitors against the human hypoxanthine guanine phosphoribosyltransferase (HPRT) protein encoded by HPRT1 gene by employing an integrated in silico approach. The library of 17,967 phytochemicals (IMPPAT 2.0 database) was screened for drug-like properties followed by molecular docking, resulting in the selection of top 20 phytochemicals. Further interaction profile revealed that IMPHY008718 (Gibberellin A34) and IMPHY011650 (Chasmanthin) binds at the GMP binding site of the HPRT1 protein. ADMET properties and biological function predictions of the selected compounds indicate their anticancer potential. Both IMPHY008718 and IMPHY011650 docked complexes were examined in 200 ns MD simulations. Comprehensive MD trajectory analysis was performed in addition to principal component, free energy and MM/PBSA analysis. Furthermore, in vitro human HPRT inhibition assay confirmed and revealed inhibitory potential for Gibberellin A34 (Ki 0.121 µM) and Chasmanthin (Ki 0.368 µM), as compared to standard inhibitor, HGPRT/TBrHGPRT1-IN-1 (Ki 0.032 µM). Overall, these results strongly recommend further experimental work concerning these plant-based molecules as human HPRT inhibitors for anticancer drug development.

A computational study on structural and functional consequences of nsSNPs in human dopa decarboxylase

The Dopa Decarboxylase (DDC) gene plays an important role in the synthesis of biogenic amines such as dopamine, serotonin, and histamine. Non-synonymous single nucleotide polymorphisms (nsSNPs) in the DDC gene have been linked with various neurodegenerative disorders. In this study, a comprehensive in silico analysis of nsSNPs in the DDC gene was conducted to assess their potential functional consequences and associations with disease outcomes. Using publicly available databases, a complete list of nsSNPs in the DDC gene was obtained. 29 computational tools and algorithms were used to characterise the effects of these nsSNPs on protein structure, function, and stability. In addition, the population-based association studies were performed to investigate possible associations between specific nsSNPs and arthritis. Our research identified four novel DDC gene nsSNPs that have a major impact on the structure and function of proteins. Through molecular dynamics simulations (MDS), we observed changes in the stability of the DDC protein induced by specific nsSNPs. Furthermore, population-based association studies have revealed potential associations between certain DDC nsSNPs and various neurological disorders, including Parkinson's disease and dementia. The in silico approach used in this study offers insightful information about the functional effects of nsSNPs in the DDC gene. These discoveries provide insight into the cellular processes that underlie cognitive disorders. Furthermore, the detection of disease-associated nsSNPs in the DDC gene may facilitate the development of tailored and targeted therapy approaches.

Thermodynamic versus kinetic basis for the high conformational stability of nanobodies for therapeutic applications

Nanobodies (NB) are powerful tools for biotechnological and therapeutic applications. They strongly bind to their targets and are very stable. Early studies showed that NB unfolding is reversible and can be analyzed by equilibrium thermodynamics, whereas more recent studies focused on their kinetic stability in very harsh conditions that are far from storage or physiological temperatures (4-37 °C). Here, we show that the thermodynamic view of NB stability holds in a wide range of temperatures (18-100 °C). The thermodynamic stability of three different NBs did not correlate with binding affinity for their target. Alpha-Fold 2 analyses of these NBs showed structural differences in the binding site and hydrogen bond networks. We expect that our approach will be helpful to improve our capacity to enhance structure-function-stability relationships of NB.

Determination of Trends Underlying Aspartic Acid Isomerization in Intact Proteins Reveals Unusually Rapid Isomerization of Tau

Spontaneous chemical modifications in long-lived proteins can potentially change protein structure in ways that impact proteostasis and cellular health. For example, isomerization of aspartic acid interferes with protein turnover and is anticorrelated with cognitive acuity in Alzheimer's disease. However, few isomerization rates have been determined for Asp residues in intact proteins. To remedy this deficiency, we used protein extracts from SH-SY5Y neuroblastoma cells as a source of a complex, brain-relevant proteome with no baseline isomerization. Cell lysates were aged in vitro to generate isomers, and extracted proteins were analyzed by data-independent acquisition (DIA) liquid chromatography-mass spectrometry (LC-MS). Although no Asp isomers were detected at day 0, isomerization increased over time and was quantifiable for 105 proteins by day 50. Data analysis revealed that the isomerization rate is influenced by both primary sequence and secondary structure, suggesting that steric hindrance and backbone rigidity modulate isomerization. Additionally, we examined lysates extracted under gentle conditions to preserve protein complexes and found that protein-protein interactions often slow isomerization. Base catalysis was explored as a means to accelerate Asp isomerization due to findings of accelerated asparagine deamidation. However, no substantial rate enhancement was found for isomerization, suggesting fundamental differences in acid-base chemistry. With an enhanced understanding of Asp isomerization in proteins in general, we next sought to better understand Asp isomerization in tau. In vitro aging of monomeric and aggregated recombinant tau revealed that tau isomerizes significantly faster than any similar protein within our data set, which is likely related to its correlation with cognition in Alzheimer's disease.

Large-Scale AI-Based Structure and Activity Prediction Analysis of ShK Domain Peptides from Sea Anemones in the South China Sea

Sea anemone peptides represent a valuable class of biomolecules in the marine toxin library due to their various structures and functions. Among these, ShK domain peptides are particularly notable for their selective inhibition of the Kv1.3 channel, holding great potential for applications in immune regulation and the treatment of metabolic disorders. However, these peptides' structural complexity and diversity have posed challenges for functional prediction. In this study, we compared 36 ShK domain peptides from four species of sea anemone in the South China Sea and explored their binding ability with Kv1.3 channels by combining molecular docking and dynamics simulation studies. Our findings highlight that variations in loop length, residue composition, and charge distribution among ShK domain peptides affect their binding stability and specificity. This work presents an efficient strategy for large-scale peptide structure prediction and activity screening, providing a valuable foundation for future pharmacological research.

Simulations of pH and thermal effects on SARS-CoV-2 spike glycoprotein

We performed triplicate and long-time all-atom molecular dynamics simulations to investigate the structures and dynamics of the SARS-CoV-2 spike glycoprotein (S-protein) for a broad range of pH = 1 through 11 and temperatures of 3°C through 75°C. This study elucidates the complex interplay between pH and thermal effects on S-protein structures, with implications for its behavior under diverse conditions, and identifies the RBD as a primary region of the structural deviations. We found: 1) Structural deviations in the S-protein backbone at pH = 1 are 210% greater than those at pH = 7 at 75°C, with most of the deviations appearing in the receptor-binding domain (RBD). Smaller structural changes are observed at pH = 3 and 11. 2) The pH and thermal conditions impact on the protein structures: substantial acidic and basic conditions expand the protein's solvent exposure, while high heat contracts. This effect is primarily pH-driven at extreme acidity and thermo-driven at moderate pH. 3) The Gibbs free energy landscape reveals that pH as the main driver of structural changes. 4) The parametrized methods enable the predictions of the S-protein properties at any reasonable pH and thermal conditions without explicit MD simulations.

An Active-Site Bro̷nsted Acid-Base Catalyst Destabilizes Mandelate Racemase and Related Subgroup Enzymes: Implications for Catalysis

Enzymes of the enolase superfamily (ENS) are mechanistically diverse, yet share a common partial reaction, i.e., the metal-assisted, Bro̷nsted base-catalyzed abstraction of the α-proton from a carboxylate substrate to form an enol(ate) intermediate. Although the catalytic machinery responsible for the initial deprotonation reaction has been conserved, divergent evolution has led to numerous ENS members that catalyze different overall reactions. Using differential scanning calorimetry, we examined the contribution of the Bro̷nsted acid-base catalysts to the thermostability (Tm) of four members of the mandelate racemase (MR)-subgroup of the ENS: MR, d-tartrate dehydratase, l-talarate/galactarate dehydratase, and l-fuconate dehydratase. Each enzyme contains an active-site Lys (part of a KxK motif) and His, which act as Bro̷nsted acid-base catalysts. The KxK → KxM substitutions increased the thermostability in all four enzymes with the effect being most prominent for MR (ΔTm = +8.6 °C). The KxK → MxK substitutions decreased the thermostability in all four enzymes, and the His → Asn substitution had a significant stabilizing effect only on MR. Thus, the active sites of MR-subgroup enzymes are destabilized by the Lys Bro̷nsted acid-base catalyst, suggesting that the destabilization energy may be used to drive a conformational change of the enzyme to yield a catalytically competent protonation state upon substrate binding.

Predictive Production of a New Highly Soluble Glucoside, Corylin-7-O-β-Glucoside with Potent Anti-inflammatory and Anti-melanoma Activities

Computational tools can now facilitate screening precursors and selecting suitable biotransformation enzymes for producing new bioactive compounds. This study applied the data-mining approach to screen for candidate precursors of glycosyltransferases to produce new glucosides from 412 commercial natural compounds. Among five candidates, experimental results showed that only corylin could be glycosylated by the bacterial glycosyltransferase, BsUGT489. Analysis of interaction potential between candidates and glycosyltransferase by molecular docking tools also found that corylin was the only compatible substrate. The new glucoside was purified and confirmed to be corylin-7-O-β-glucoside. The aqueous solubility of corylin-7-O-β-glucoside was 14.2 times more than its precursor aglycone, corylin. Corylin-7-O-β-glucoside retained anti-inflammatory activity in lipopolysaccharide-induced nitric oxide production of murine macrophage RAW 264.7 cells, with an IC50 value of 121.1 ± 9.5 µM. Further, corylin-7-O-β-glucoside exhibited more potent anti-melanoma activity against murine B16 and human A2058 melanoma cells than corylin. Together, predictive studies facilitate the production of a new glucoside, corylin-7-O-β-glucoside, which is highly soluble and possesses anti-inflammatory and anti-melanoma activities and therefore has promising future applications in pharmacology.

Exploring the potential of Halalkalibacterium halodurans laccase for endosulfan and chlorophacinone degradation: insights from molecular docking and molecular dynamics simulations

Pesticides are widely used in agriculture but at the same time, a majority of them are known to cause serious harm to health and the environment. In the recent past, laccases have been reported as key enzymes having the ability to degrade pollutants by converting them into less toxic forms. In this investigation, laccase from polyextremophilic bacterium Halalkalibacterium halodurans C-125 was analyzed for its structural, physicochemical, and functional characterization using in silico approaches. The 3D model of the said enzyme is unknown; therefore, the model was generated by template-independent modeling using ROBETTA, I-TASSER, and Alphafold server. The best-generated model from Alphafold with a confidence of 0.95 was validated from ERRAT and Verify 3D scores of 89.95 and 91.80%, respectively. The Ramachandran plot generated using the PROCHECK server further predicted the accuracy of the model with 93.7% and 5.9% of residues present in most favored and additional allowed regions of the plot respectively. The active sites, ion binding sites, and subcellular localization of laccase were also predicted. The generated model was docked with 121 pollutants (pesticides, insecticides, herbicides, fungicides, and rodenticides) for its degradation potential towards these pollutants. Two ligands chlorophacinone (based on the highest binding energy) and endosulfan (based on agricultural uses) were selected for molecular dynamic simulation studies. Endosulfan as a pesticide is banned but in some countries governments allow its use for special purposes which need serious consideration on developing bioremediation approaches for endosulfan degradation. MD simulation studies revealed that both chlorophacinone and endosulfan form hydrogen bonds and hydrophobic bonds with the active site of laccase and chlorophacinone-laccase complex were more stable in comparison to endosulfan. The present investigation provides insight into the structural features of laccase and its potential for the degradation of pesticides which can be further validated by experimental data.Communicated by Ramaswamy H. Sarma.

Rational Design Engineering of 5-Aminolevulinate Synthase with Activity and Stability Enhancement

5-Aminolevulinic acid synthase (ALAS) is the key rate-limiting enzyme in the synthesis of the vital biosynthetic intermediate 5-aminolevulinic acid (ALA). However, its catalytic efficiency is compromised due to its low activity and poor stability. Here, we obtained the mutant I325M/V390Y/H391I (T6), which exhibited a 7.0-fold increase in specific activity (2.53 U/mg) compared to the wild type through the application of isothermal compressibility (βT) perturbation engineering in conjunction with two thermal stability prediction algorithms. Moreover, molecular dynamics simulations indicate that positive changes in intermolecular interactions, the substrate channel, and the binding pocket account for the improved catalytic activity of T6. Furthermore, T6 was immobilized on magnetic chitosan nanoparticles, maintaining 73.5% of its original activity after 10 reaction cycles. Overall, combination approaches were employed to construct a superior ALAS variant, providing a novel concept for the synthesis of ALA and a valuable benchmark for optimizing industrial enzymes in related fields.

Lovastatin and Resveratrol Synergistically Improve Wound Healing and Inhibit Bacterial Growth

Wound healing is a complex physiological process, with scarring and infection caused by Staphylococcus aureus and Pseudomonas aeruginosa being the most common complications. The reutilization of known medications has received increased attention for their role in cell function as small molecules. Examples of these include lovastatin, a cholesterol-lowering agent, and resveratrol, which have multiple biological properties. Both molecules have been reported to improve wound healing and possess antibacterial properties, with conflicting results. The wound-healing capabilities of human mesenchymal stem cells were evaluated after exposure to lovastatin, resveratrol, and their combination through scratch test, migrations assay, and qPCR. Protein docking was performed to assess the lovastatin/resveratrol combination as potential wound-healing targets. AlamarBlue assay was used to determine cell viability. Additionally, the impact of lovastatin and resveratrol combination to inhibit the growth of S. aureus and P. aeruginosa was tested using broth microdilution test and checkerboard assay to determine synergism. The combination of lovastatin 0.1 μM and resveratrol 0.1 μM synergistically improved wound healing and demonstrated an additive effect against S. aureus and P. aeruginosa, presenting potential antibacterial applications.

A comprehensive high-throughput screening approach for discovering inhibitors targeting the menin-MLL1 interaction

The prognosis for mixed-lineage leukemia (MLL), particularly in young children, remains a significant health concern due to the limited therapeutic options available. MLL refers to KMT2A chromosomal translocations that produce MLL fusion proteins. The protein menin, which is essential for the malignant potential of these MLL fusion proteins, offers novel targets for acute leukemia treatment. This study reports the identification of potential new inhibitors of MLL-mediated leukemia targeting menin through the screening of two distinct drug libraries and existing inhibitors. The 3D structure of the protein was retrieved from the Protein Data Bank (ID: 8IG0). The drug libraries, sourced from public repositories such as the 'Epigenetic Drug Library' and 'The FDA-anticancer Drug Library,' yielded top candidates like Tozaseritib and Panobinostat, which exhibited the highest binding energy scores in the Glide virtual screening module. Additionally, 31 known menin-MLL1 inhibitors were identified through PDB screening and subsequently docked with the menin protein. The top three inhibitors (M-525, M-808, and MI-89) were selected for further analysis. Five menin-ligand complexes were validated using molecular dynamics analysis and Molecular Mechanics Poisson-Boltzmann Surface Area (MM-PBSA) calculations to verify the stability and binding mechanisms.These findings provide insights into the molecular mechanisms of these drugs and lay the groundwork for future clinical development aimed at improving outcomes for acute myeloid leukemia (AML) patients.

PPP2R5E: New gene potentially involved in specific learning disorders and myopathy

Protein phosphatase 2A (PP2A) is a family of multifunctional enzymatic complexes crucial for cellular signalling, playing a pivotal role in brain function and development. Mutations in specific genes encoding PP2A complexes have been associated with neurodevelopmental disorders with hypotonia and high risk of seizures. In the current work, we present an individual with specific learning problems, motor coordination disorders, hypotonia and behavioural issues. Although whole exome sequencing (WES) did not unveil pathogenic variants in known genes related to these symptoms, a de novo heterozygous variant Glu191Lys was identified within PPP2R5E, encoding the PP2A regulatory subunit B56ε. The novel variant was not observed in the four healthy brothers and was not detected as parental somatic mosaicism. The mutation predicted a change of charge of the mutated amino acid within a conserved LFDSEDPRER motif common to all PPP2R5 B-subunits. Biochemical assays demonstrated a decreased interaction with the PP2A A and C subunits, leading to disturbances in holoenzyme formation, and thus likely, function. For the first time, we report a potential causal link between the observed variant within the PPP2R5E gene and the symptoms manifested in the subject, spanning specific learning problems and motor coordination disorders potentially associated with myopathy.

Clear insight into complex multimodal resins and impurities to overcome recombinant protein purification challenges: A review

Increasing attention has been paid to the purity of therapeutic proteins imposing extensive costs and challenges to the downstream processing of biopharmaceuticals. One of the efforts, that has been exerted to overcome such limitations, was developing multimodal or mixed-mode chromatography (MMC) resins for launching selective, orthogonal, non-affinity purification platforms. Despite relatively extensive usage of MMC resins, their real potential and fulfillment have not been extensively reviewed yet. In this work, the explanation of practical and key aspects of downstream processing of recombinant proteins with or without MMC resins was debated, as being useful for further purification process development. This review has been written as a step-by-step guide to deconvolute both inherent protein purification and MMC complexities. Here, after complete elucidation of the potential of MMC resins, the effects of frequently used additives (mobile phase modifiers) and their possible interactions during the purification process, the critical characteristics of common product-related impurities (e.g., aggregates, charge variants, fragments), host-related impurities (e.g., host cell protein and DNA) and process related impurities (e.g., endotoxin, and viruses) with solved or unsolved challenges of traditional and MMC resins have been discussed. Such collective experiences which are reported in this study could be considered as an applied guide for developing successful downstream processing in challenging conditions by providing a clear insight into complex MMC resins and impurities.

Elucidating the potential of bioactive of Trichoderma sp.. in combating pathogenesis by Fusarium sp.. by targeting pectin lyases: a bioinformatics approach

Pectin lyase is an industrially important enzyme, predominately used in fruit juice clarification and retting of fibers. It also promotes pathogenesis via the degradation of the pectin. The phytopathogen, Fusarium infects various crops and causes several diseases. Trichoderma sp. is a promising biocontrol agent that is vital in maintaining plant health and disease prevention. In the current study, a computational approach utilizing structure prediction, molecular docking, molecular dynamics, and MM-PBSA analysis was used to analyze the potential role of bioactive compounds secreted by Trichoderma sp. in inhibiting the pectin lyase enzyme from Fusarium proliferatum, F. fujikuroi, F. graminearum, F. oxysporum and F. verticillioides. Molecular docking with secondary metabolites revealed that Viridiofungin A secreted by Trichoderma harzianum and Virone secreted by T. virens are bioactive compounds with immense potential to inhibit PNLs of Fusarium species. Further, the rigidity of the structure and stability of the docked complex were confirmed via Molecular dynamic simulations assessed through multiple parameters from the simulation trajectory data. Dual culture assay of T. harzianum and T. virens with F. proliferatum, F. fujikuroi, F. graminearum, F. oxysporum, and F. verticillioides showed variable mycelial inhibition. The research provides insight into the potential of the bioactive compounds secreted by Trichoderma species as an effective agent for the inhibition of pectin lyases produced by phytopathogens, especially Fusarium species. The proposed research can be used to develop bioformulations that function as biopesticides, offering a sustainable replacement for chemical products.

An immunoinformatics and extensive molecular dynamics study to develop a polyvalent multi-epitope vaccine against cryptococcosis

Cryptococcosis is a lethal mycosis instigated by the pathogenic species Cryptococcus neoformans and Cryptococcus gattii, primarily affects the lungs, manifesting as pneumonia, and the brain, where it presents as meningitis. Mortality rate could reach 100% if infections remain untreated in cryptococcal meningitis. Treatment options for cryptococcosis are limited and and there are no licensed vaccines clinically available to treat or prevent cryptococcosis. Our study utilizes an integrated bioinformatics approaches to develop a polyvalent multiepitope subunit vaccine focusing on the key virulent proteins Heat shock transcription factor and Chaperone DnaK of both C. neoformans and C. gatti. Then in silico analysis was done to predict highly antigenic epitopes by assessing antigenicity, transmembrane topology screening, allergenecity, toxicity, and molecular docking approaches. Following this analysis, we designed two vaccine constructs integrating a compatible adjuvant and suitable linkers. These constructs exhibited notable characteristics including high antigenicity, non-toxicity, solubility, stability, and compatibility with Toll-like receptors (TLRs). The interaction between both vaccine constructs and TLR2, TLR3, and TLR9 was assessed through molecular docking analysis. Molecular dynamics simulations and MM-PBSA calculations suggest the substantial stabilizing property and binding affinity of Vaccine Construct V1 against TLR9. Both the vaccines revealed to have a higher number of interchain hydrogen bond with TLR9. These findings serve as a crucial stepping stone towards a comprehensive solution for combating cryptococcus infections induced by both C. neoformans and C. gattii. Further validation through in vivo studies is crucial to confirm the effectiveness and potential of the vaccine to curb the spread of cryptococcosis. Subsequent validation through in vivo studies is paramount to confirm the effectiveness and potential of the vaccine in reducing the spread of cryptococcosis.

In Silico Modeling and Characterization of Epstein-Barr Virus Latent Membrane Protein 1 Protein

Latent membrane protein 1 (LMP1) plays a crucial role in Epstein-Barr virus (EBV)'s ability to establish latency and is involved in developing and progressing EBV-associated cancers. Additionally, EBV-infected cells affect the immune responses, making it challenging for the immune system to eliminate them. Due to the aforementioned reasons, it is crucial to understand the structural features of LMP1, which are essential for the development of novel cancer therapies that target its signaling pathways. To date, there is yet to be a complete LMP1 protein structure; therefore, in our work, we modeled the full-length LMP1 containing the short cytoplasmic N-terminus, six transmembrane domains (TMDs), and a long-simulated C-terminus. Our model showed good stability and protein compactness evaluated through accelerated-molecular dynamics, where the conformational ensemble exhibited compact folds, particularly in the TMDs. Our results suggest that specific domains or motifs, predominantly in the C-terminal domain of LMP1, show promise as potential drug targets. As a whole, our work provides insights into key structural features of LMP1 that will allow the development of novel LMP1 therapies.

Multi-epitope Based Peptide Vaccine Candidate Against Babesia Infection From Rhoptry-Associated Protein 1 (RAP-1) Antigen Using Immuno-Informatics: An In Silico Approach

Objective

Babesiosis is a significant haemoparasitic infection caused by apicomplexan parasites of the genus Babesia. This infection has continuously threatened cattle farmers owing to its devastating effects on productivity and severe economic implications. Failure to curb the increase of the infection has been attributed to largely ineffective vaccines. This study was designed to develop a potential vaccine candidate.

Method

Rhoptry-associated protein-1 (RAP-1) was used to identify and design a potential multi-epitope vaccine candidate due to its immunogenic properties through an immunoinformatics approach.

Results and conclusions

A multi-epitope vaccine comprising 11 CD8+, 17 CD4+, and 3 B-cell epitopes was constructed using the AAY, GPGPG, and KK linkers. Beta-defensin-3 was added as an adjuvant to potentiate the immune response using the EAAK linker. The designed vaccine was computationally predicted to be antigenic (antigenicity scores: 0.6), soluble (solubility index: 0.730), and non-allergenic. The vaccine construct comprises 595 amino acids with a molecular weight of 64 152 kDa, an instability and aliphatic index of 13.89 and 65.82, which confers stability with a Grand average of hydropathicity (GRAVY) value of 0.122, indicating the hydrophobicity of the construct. Europe has the highest combined class population coverage, with a percentage of 96.07%, while Central America has the lowest population coverage, with a value of 22.94%. The DNA sequence of the vaccine construct was optimized and successfully cloned into a pET-28a (+) plasmid vector. Analysis of binding interactions indicated the stability of the complex when docked with Toll-like receptor-2 (TLR-2). The subunit vaccine construct was predicted to induce and boost sufficient host cellular and humoral responses in silico. However, further experimental research and analysis is required to validate the findings.

Limitation

This study is purely computational, and further experimental validation of these findings through in vivo and in vitro conditions is required.

Unusually Rapid Isomerization of Aspartic Acid in Tau

Spontaneous chemical modifications in long-lived proteins can potentially change protein structure in ways that impact proteostasis and cellular health. For example, isomerization of aspartic acid interferes with protein turnover and is anticorrelated with cognitive acuity in Alzheimer's disease. However, few isomerization rates have been determined for Asp residues in intact proteins. To remedy this deficiency, we used protein extracts from SH-SY5Y neuroblastoma cells as a source of a complex, brain-relevant proteome with no baseline isomerization. Cell lysates were aged in vitro to generate isomers, and extracted proteins were analyzed by data-independent acquisition (DIA) liquid chromatography-mass spectrometry (LC-MS). Although no Asp isomers were detected at Day 0, isomerization increased across time and was quantifiable for 105 proteins by Day 50. Data analysis revealed that isomerization rate is influenced by both primary sequence and secondary structure, suggesting that steric hindrance and backbone rigidity modulate isomerization. Additionally, we examined lysates extracted under gentle conditions to preserve protein complexes and found that protein-protein interactions often slow isomerization. Base catalysis was explored as a means to accelerate Asp isomerization due to findings of accelerated asparagine deamidation. However, no substantial rate enhancement was found for isomerization, suggesting fundamental differences in acid-base chemistry. With an enhanced understanding of Asp isomerization in proteins in general, we next sought to better understand Asp isomerization in tau. In vitro aging of monomeric and aggregated recombinant tau revealed that tau isomerizes significantly faster than any similar protein within our dataset, which is likely related to its correlation with cognition in Alzheimer's disease.

Deciphering the Monomeric and Dimeric Conformational Landscapes of the Full-Length TDP-43 and the Impact of the C-Terminal Domain

The aberrant aggregation of TAR DNA-binding protein 43 kDa (TDP-43) in cells leads to the pathogenesis of multiple fatal neurodegenerative diseases. Decoding the proposed initial transition between its functional dimeric and aggregation-prone monomeric states can potentially design a viable therapeutic strategy, which is presently limited by the lack of structural detail of the full-length TDP-43. To achieve a complete understanding of such a delicate phase space, we employed a multiscale simulation approach that unearths numerous crucial features, broadly summarized in two categories: (1) state-independent features that involve inherent chain collapsibility, rugged polymorphic landscape dictated by the terminal domains, high β-sheet propensity, structural integrity preserved by backbone-based intrachain hydrogen bonds and electrostatic forces, the prominence of the C-terminal domain in the intrachain cross-domain interfaces, and equal participation of hydrophobic and hydrophilic (charged and polar) residues in cross-domain interfaces; and (2) dimerization-modulated characteristics that encompass slower collapsing dynamics, restricted polymorphic landscape, the dominance of side chains in interchain hydrogen bonds, the appearance of the N-terminal domain in the dimer interface, and the prominence of hydrophilic (specifically polar) residues in interchain homo- and cross-domain interfaces. In our work, the ill-known C-terminal domain appears as the most crucial structure-dictating domain, which preferably populates a compact conformation with a high β-sheet propensity in its isolated state stabilized by intrabackbone hydrogen bonds, and these signatures are comparatively faded in its integrated form. Validation of our simulated observables by a complementary spectroscopic approach on multiple counts ensures the robustness of the computationally predicted features of the TDP-43 aggregation landscape.

Exploring the inhibitory potential of xanthohumol on MEK1/2: a molecular docking and dynamics simulation investigation

Background and purpose

Xanthohumol (Xn), a small molecule found in Humulus lupulus, has shown promise as an anti-cancer compound. This in silico study was performed to understand the mechanism of action of Xn as a natural compound on MEK1/2 by simulation.

Experimental approach

After ligand and protein preparation, the best binding energy was determined using Autodock 4.2. Additionally, molecular dynamics simulations of the MEK1/2-Xn and BRaf-MEK1/2-Xn complexes were conducted using GROMACS 2022.1 software and compared to the complexes of MEK1/2-trametinib (Tra) and BRaf-MEK1/2-Tra.

Findings/Results

The docking results revealed that the best binding energies for MEK1-Xn (-10.70 Kcal/mol), MEK2-Xn (-9.41 Kcal/mol), BRaf-MEK1-Xn (-10.91 Kcal/mol), and BRaf-MEK2-Xn (-8.54 Kcal/mol) were very close to those of the Tra complexes with their targets, MEK1 and MEK2. Furthermore, Xn was found to interact with serine 222 at the active site of these two kinases. The results of the molecular dynamics simulations also indicated that Xn induced changes in the secondary structure of the studied proteins. The root mean square of proteins and the mean radius of gyration showed significant fluctuations.

Conclusion and implications

The findings of the study suggested that Xn, as a novel bioactive compound, potentially inhibits the MEK1/2 function in cancer cells.

Cm-p5, a molluscan-derived antifungal peptide exerts its activity by a membrane surface covering in a non-penetrating mode

Amidst the health crisis caused by the rise of multi-resistant pathogenic microorganisms, Antimicrobial Peptides (AMPs) have emerged as a potential alternative to traditional antibiotics. In this sense, Cm-p5 is an AMP with fungistatic activity against the yeast Candida albicans. Its antimicrobial activity and selectivity have been well characterized; however, the mechanism of action is still unknown. This study used biophysical approaches to gain insight into how this peptide exerts its activity. Stability and fluidity of lipid membrane were explored by liposome leakage and Laurdan generalized polarization (GP) respectively, suggesting that Cm-p5 does not perturb lipid membranes even at very high concentrations (≥100 µm.L-1). Likewise, no depolarizing action was observed using 3,3'-propil-2,2'-thyodicarbocianine, a potential membrane fluorescent reporter, with C. albicans cells or the corresponding liposome models. Changes in liposome size were analyzed by Dynamic Light Scattering (DLS) data, indicating that Cm-p5 covers the vesicular surface slightly increasing liposome hydrodynamic size, without liposome rupture. These results were further corroborated with Langmuir monolayer isotherms, where no significant changes in lateral pressure or area per lipid were detected, indicating little or no insertion. Finally, data obtained from molecular dynamics simulations aligned with in vitro observations, whereby Cm-p5 slightly interacted with the fungal membrane model surface without causing significant perturbation. These results suggest Cm-p5 is not a pore-forming anti-fungal peptide and that other mechanisms of action on the membrane as some limitation of fungal nutrition or receptor-dependent transduction for depressing growth development should be explored.

Natural Compounds Targeting Thymic Stromal Lymphopoietin (TSLP): A Promising Therapeutic Strategy for Atopic Dermatitis

Atopic dermatitis (AD) is a chronic inflammatory skin disease with rising prevalence, marked by eczematous lesions, itching, and a weakened skin barrier often tied to filaggrin gene mutations. This breakdown allows allergen and microbe entry, with thymic stromal lymphopoietin (TSLP) playing a crucial role by activating immune pathways that amplify the allergic response. TSLP's central role in AD pathogenesis makes it a promising therapeutic target. Consequently, in this study, we used the virtual drug screening, molecular dynamics simulation, and binding free energies calculation approaches to explore the African Natural Product Database against the TSLP protein. The molecular screening identified four compounds with high docking scores, namely SA_0090 (-7.37), EA_0131 (-7.10), NA_0018 (-7.03), and WA_0006 (-6.99 kcal/mol). Furthermore, the KD analysis showed a strong binding affinity of these compounds with TSLP, with values of -5.36, -5.36, -5.34, and -5.32 kcal/mol, respectively. Moreover, the strong binding affinity of these compounds was further validated by molecular dynamic simulation analysis, which revealed that the WA_0006-TSLP is the most stable complex with the lowest average RMSD. However, the total binding free energies were -40.5602, -41.0967, -27.3293, and -51.3496 kcal/mol, respectively, showing the strong interaction between the selected compounds and TSLP. Likewise, these compounds showed excellent pharmacokinetics characteristics. In conclusion, this integrative approach provides a foundation for the development of safe and effective treatments for AD, potentially offering relief to millions of patients worldwide.

Computational approach towards repurposing of FDA approved drug molecules: strategy to combat antibiotic resistance conferred by Pseudomonas aeruginosa

Antimicrobial resistance is recognized as a major worldwide public health dilemma in the current century. Pseudomonas aeruginosa, a Gram-negative opportunistic pathogen, causes nosocomial infections like respiratory tract infections, urinary tract infections, dermatitis, and cystic fibrosis. It manifests antibiotic resistance via intrinsic, acquired, and adaptive pathways, where efflux pumps function in the extrusion of antibiotics from the cell. MexB protein, part of the tripartite efflux pumps MexAB-OprM present in P.aeruginosa, expels the penems and β-lactam antibiotics, thereby enhancing Pseudomonas resistance. The current study was intended to screen around 1602 clinically approved drugs to understand their ability to inhibit the MexB protein. Amongst them, the top 5 drug molecules were selected based on the binding energies for analyzing their physio-chemical and toxicity properties. Lomitapide was found to have the maximum negative binding energy followed by Nilotinib, whereas Nilotinib's number of hydrogen bonds was higher than that of Lomitapide. ADMET study revealed that all 5 drug molecules had limited solubility. Also, Lomitapide and Venetoclax showed low bioavailability scores, while Nilotinib, Eltrombopag, and Conivaptan demonstrated higher potential for therapeutic levels. A molecular dynamic simulation study of the 5 drugs against MexB was carried out for 200 nanoseconds. The RMSD, RMSF, Hydrogen bond formation, Radius of gyration, SASA, PCA, DCCM, DSSP and MM-PBSA binding energy calculation along with demonstrated high stability of the MexB-Nilotinib complex with lesser distortions. Our study concludes, that Nilotinib is a potential inhibitor and can be developed as a therapeutic agent against MexB protein for controlling P. aeruginosa infections.

Investigating the effect of 1,2-Dibenzoylhydrazine on Staphylococcus aureus using integrated computational approaches

Staphylococcus aureus, a notorious member of the ESKAPE pathogens, poses significant public health challenges due to its virulence and multidrug-resistant nature, particularly in methicillin-resistant S. aureus (MRSA) strains. With the increasing threat of antibiotic resistance, there is an urgent need to develop novel antibiotic agents. This study therefore aims to explore the antibacterial potential of 1,2-dibenzoylhydrazine (DBH) as a scaffold against S. aureus drug target enzymes, using integrated computational approaches. The study utilized molecular docking, lead optimization, and structure-based virtual screening techniques to evaluate the binding affinities of DBH and its derivatives against various S. aureus enzymes. Prime/MM-GBSA calculations were performed to validate the binding affinities obtained, and molecular dynamics (MD) simulations were conducted to assess the stability of the DBHs-enzyme complexes. Results indicated that, out of twenty enzymes from S. aureus examined against DBH, carotenoid dehydrosqualene synthase was predicted as a suitable target enzyme for DBH, showing a binding affinity of -8.027 kcal/mol. A lead optimization operation of the compound generated 27 DBH derivatives out of which four exhibited enhanced binding affinities compared to both DBH and a standard antibiotic, ofloxacin. The QSAR model predicted that, DBH and molecule_D_1 have higher PIC50 of 4.779 µM compared with the standard drug (ofloxacin = 4.678 µM). MD simulations confirmed the stability of the top-scoring derivatives within the enzyme's binding pocket, with RMSD and RMSF analyses supporting their potential as inhibitors of the enzyme. In conclusion, this study has predicted the effect of DBH derivatives on S. aureus based on their in silico inhibitory capacity against the carotenoid dehydrosqualene synthase from the organism. Future work will seek to experimentally validate these findings against the suggested enzyme.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40203-024-00278-1.

Molecular docking and molecular dynamics of hypoxia-inducible factor (HIF-1alpha): towards potential inhibitors

HIF-1α is a primary regulator in the adaptation of cancer cells to hypoxia. The aim was to find out new inhibitors of the HIF-1α. A molecular dynamic (MD) simulation performed on HIF-1α showed stable dynamic features. Virtual screening of 217 anticancer drugs was performed along with a positive control (2-Methoxyestradiolm, 2-ME2) on an optimized HIF-1α and dynamically simulated structure. Docking results produced two compounds namely pycnidione and nilotinib of high binding affinity -9.34 kcal/mol and -9.04 kcal/mol respectively, whereas 2-ME2 displayed a relatively lower affinity (-6.68 kcal/mol). For the three complexes, MD of 200 ns simulation was run. Data analysis showed that the three medications behaved similarly in the MD simulation. Nilotinib had a lower RMSD and higher SASA than the other complexes. In addition, the Nilotinib-HIF-1α combination had a lower RMSF value, a flatter Rg, and a number of hydrogen bonds similar to other complexes. MM-GBSA analysis revealed that nilotinib, pycnidione and 2-ME2 compounds had free binding energy of -23.77 ± 5.29, -21.85 ± 4.24 and -7.53 ± 6.62 kcal/mol respectively. Nilotinib and pycnidione bind competitively to HIF-1α, with nilotinib showing consistent molecular-dynamic properties. They relatively pass the blood-brain barrier, non-carcinogenic, and have IV-category acute oral toxicity. They have low CYP inhibitory characteristics. Further investigations are therefore warranted to elucidate their implications in hypoxia pathways, cell proliferation, apoptosis, survival, and metastatic potential.

Interrogating Explicit Solvent Effects on the Mechanism and Site-Selectivity of Aryl Halide Oxidative Addition to L2Pd(0)

We report a study of solvent effects on the rate, selectivity, and mechanism of (hetero)aryl (pseudo)halide oxidative addition to Pd(PCy3)2 as an exemplar of L2Pd(0) species. First, 2-chloro-3-aminopyridine is observed to undergo faster oxidative addition in toluene compared to more polar solvents, which is not consistent with the trend we observe with many other 2-halopyridines. We attribute this to solvent basicity hydrogen bonding between solvent and substrate. Greater hydrogen bond donation from the substrate leads to a more electron-rich aromatic system, and therefore slower oxidative addition. We demonstrate how this affects rate and site-selectivity for hydrogen bond donating substrates. Second, electron-deficient multihalogenated pyridines exhibit improved site-selectivity in polar solvents, which we attribute to different C-X sites undergoing oxidative addition by two different mechanisms. The C-X site that favours the more polar nucleophilic displacement transition state is preferred over the site that favours a less-polar 3-centered transition state. Finally, (hetero)aryl triflates consistently undergo faster oxidative addition in more polar solvents, which we attribute to highly polar nucleophilic displacement transition states. This leads to improved site-selectivity for C-OTf oxidative addition, even in the presence of highly reactive 2-pyridyl halides.

Inferring the existence of hydrogen bonds directly from statistical analysis of molecular dynamics trajectories

As a demonstration of how fundamental chemical concepts can be gleaned from data using machine learning methods, we demonstrate the automated detection of hydrogen bonds by statistical analysis of molecular dynamics trajectories. In particular, we infer the existence and nature of electrostatically driven noncovalent interactions by examining the relative probability of supramolecular configurations with and without electrostatic interactions. Then, using Laplacian eigenmaps clustering, we identify hydrogen bonding motifs in hydrogen fluoride, water, and methanol. The hydrogen bonding motifs that we identify support traditional geometric criteria.

Computational design and evaluation of a polyvalent vaccine for viral nervous necrosis (VNN) in fish to combat Betanodavirus infection

Viral nervous necrosis (VNN) poses a significant threat to the aquaculture industry, causing substantial losses and economic burdens. The disease, attributed to nervous necrosis viruses within the Betanodavirus genus, is particularly pervasive in the Mediterranean region, affecting various fish species across all production stages with mortality rates reaching 100%. Developing effective preventive measures against VNN is imperative. In this study, we employed rigorous immunoinformatics techniques to design a novel multi-epitope vaccine targeting VNN. Five RNA-directed RNA polymerases, crucial to the lifecycle of Betanodavirus, were selected as vaccine targets. The antigenicity and favorable physicochemical properties of these proteins were confirmed, and epitope mapping identified cytotoxic T lymphocyte, helper T lymphocyte, and linear B lymphocyte epitopes essential for eliciting a robust immune response. The selected epitopes, characterized by high antigenicity, non-allergenicity, and non-toxicity, were further enhanced by adding PADRE sequences and hBD adjuvants to increase immunogenicity. Two vaccine constructs were developed by linking epitopes using appropriate linkers, demonstrating high antigenicity, solubility, and stability. Molecular dynamics simulations revealed stable interactions between the vaccine constructs and Toll-like receptors (TLRs), essential for pathogen recognition and immune response activation in fish. Notably, vaccine construct V2 exhibited superior stability and binding affinity with TLR8, suggesting its potential as a promising candidate for VNN prevention. Overall, our study presents a comprehensive approach to VNN vaccine design utilizing immunoinformatics, offering safe, immunogenic, and effective solutions across multiple Betanodavirus species. Further experimental validation in model animals is recommended to fully assess the vaccine's efficacy. This research contributes to improved vaccine development against diverse fish pathogens by addressing emerging challenges and individualized immunization requirements in aquaculture.

Rational design of novel peptide-based vaccine against the emerging OZ virus

Oz virus (OZV) belongs to the Orthomyxoviridae family which includes viruses with a negative-sense, single-stranded, and segmented RNA genome. OZV is a zoonotic pathogen, particularly since the virus can cause deadly illness when injected intracerebrally into nursing mice. OZV is an emerging pathogen with the potential to spark a pandemic as there is no preventive and licensed treatment against this virus. The goal of this study was to develop a novel multi-epitope vaccination against OZV proteins utilizing immunoinformatics and immunological simulation analysis. This work evaluated immunological epitopes (B cells, MHC-I, and MHC-II) to identify highly antigenic OZV target proteins. Shortlisted epitopes were joined together by using appropriate linkers and adjuvants to design multi-epitope vaccine constructs (MEVC). The vaccine models were designed, improved, validated, and the globular regions and post-translational modifications (PTMs) were also evaluated in the vaccine's structure. Molecular docking analysis with the Toll-like receptor (TLR4) showed strong interactions and appropriate binding energies. Molecular dynamics (MD) simulation confirmed stable interactions between the vaccines and TLR4. Bioinformatics tools helped optimize codons, resulting in successful cloning into appropriate host vectors. This study showed that the developed vaccines are stable and non-allergenic in the human body and successfully stimulated immunological responses against OZV. Finally, a mechanism of action for the designed vaccine construct was also proposed. Further experimental validations of the designed vaccine construct will pave the way to create a potentially effective vaccine against this emerging pathogen.

In silico identification of potential protein kinase C alpha inhibitors from phytochemicals from IMPPAT database for anticancer therapeutics: a virtual screening approach

Protein Kinase C alpha (PKCα) is a critical signaling molecule that plays a crucial role in various physiological processes, including cell growth, differentiation, and survival. Over the years, there has been a growing interest in targeting PKCα as a promising drug target for the treatment of various diseases, including cancer. Targeting PKCα can, therefore, serve as a potential strategy to prevent cancer progression and enhance the efficacy of conventional anticancer therapies. We conducted a systematic search for promising compounds for their anticancer potential that target PKCα using natural compounds from the IMPPAT database. The initial compounds were screened through various tests, including analysis of their physical and chemical properties, PAINS filter, ADMET analysis, PASS analysis, and specific interaction analysis. We selected those that showed high binding affinity and specificity to PKCα from the screened compounds, and we further analyzed them using molecular dynamics simulations (MDS) and principal component analysis (PCA). Various systematic parameters from the MDS analyses suggested that the protein-ligand complexes were stabilized throughout the simulation trajectories of 100 nanoseconds (ns). Our findings indicated that compounds Nicandrenone and Withaphysalin D bind to PKCα with high stability and affinity, making them potential candidates for further research in cancer therapeutics innovation in clinical contexts.Communicated by Ramaswamy H. Sarma.

Network pharmacology and experimental verification unraveled the mechanism of Bailing Capsule against asthma

Asthma is a serious public health challenge around the world. Recent studies into traditional Chinese medicine preparations for asthma have yielded promising findings regarding Bailing Capsule's potential in bronchial asthma prevention and treatment. This study aims to initially clarify the potential mechanism of Bailing Capsule in the treatment of asthma using network pharmacology and in vitro experimental approaches. Network pharmacology was adopted to detect the active ingredients of Bailing Capsule via Traditional Chinese Medicine Systems Pharmacology Database, and the key targets and signaling pathways in the treatment of asthma were predicted. Docking and molecular dynamics simulations were conducted to verify the most important interactions formed by these probes within different regions of the binding site. The predicted targets were validated in lipopolysaccharide-induced 16HBE cell experiment. Seven active ingredients were screened from Bailing Capsule, 294 overlapping targets matched with asthma were considered potential therapeutic targets, such as SRC, TP53, STAT3, and E1A binding protein P300. The main functional pathways involving these key targets include phosphatidylinositol 3-kinase/protein kinase B, mitogen-activated protein kinase, renin-angiotensin system and other signaling pathways, which were mainly involved in the inflammatory response, apoptosis, and xenobiotic stimulus. Moreover, molecular docking showed that Cerevisterol have higher affinity for SRC, TP53, STAT3, and E1A binding protein P300 than other main active components, which is close to the docking results of the co-crystallized ligands to proteins. Consequently, Cerevisterol was selected for molecular dynamics simulation and the results show that Cerevisterol can bind most tightly to SRC, TP53, and STAT3. Bailing Capsule can promote the growth of 16HBE cell, reduce the production of IL-4, TNF-α and IL-6, and down-regulate the levels of SRC and STAT3 mRNA. This study preliminarily reveals the potential mechanism of Bailing Capsule against asthma with the aid of network pharmacology and in vitro cell experiment, which provided reference and guidance for in-depth research and clinical application.

p70S6K as a Potential Anti-COVID-19 Target: Insights from Wet Bench and In Silico Studies

The onset of SARS-CoV-2 infection in 2019 sparked a global COVID-19 pandemic. This infection is marked by a significant rise in both viral and host kinase activity. Our primary objective was to identify a pivotal host kinase essential for COVID-19 infection and the associated phenomenon of the cytokine storm, which may lead to long-term COVID-19 complications irrespective of viral genetic variations. To achieve this, our study tracked kinase phosphorylation dynamics in RAW264.7 macrophages following SPIKE transfection over time. Among the kinases surveyed, p70S6K (RPS6KB1) exhibited a 3.5-fold increase in phosphorylation at S418. This significant change prompted the selection of p70S6K for in silico investigation, utilizing its structure bound to M2698 (PDB: 7N93). M2698, an oral dual Akt/p70S6K inhibitor with an IC50 of 1.1 nM, exhibited psychosis side effects in phase I clinical trials, potentially linked to its interaction with Akt2. Our secondary objective was to discover a small-molecule analogue of M2698 that exhibits a distinct binding preference for p70S6K over Akt2 through computational modeling and analysis. The in silico part of our project began with validating the prediction accuracy of the docking algorithm, followed by an OCA analysis pinpointing specific atoms on M2698 that could be modified to enhance selectivity. Subsequently, our investigation led to the identification of an analog of M2698, designated as S34, that showed a superior docking score towards p70S6K compared to Akt2. To further assess the stability of S34 in its protein-ligand (PL) complexes with p70S6K and Akt2, MD simulations were conducted. These simulations suggest that S34, on average, forms two hydrogen bond interactions with p70S6K, whereas it only forms one hydrogen bond interaction with Akt2. This difference in hydrogen bond interactions likely contributed to the observed larger root mean square deviation (RMSD) of 0.3 nm in the S34-Akt2 complex, compared to 0.1 nm in the S34-p70S6K complex. Additionally, we calculated free binding energy to predict the strength of the binding interactions of S34 to p70S6K and Akt2, which showed ~2-fold favorable binding affinity of S34 in the p70S6K binding pocket compared to that in the Akt2 binding pocket. These observations may suggest that the S34-p70S6K complex is more stable than the S34-Akt2 complex. Our work focused on identifying a host kinase target and predicting the binding affinity of a novel small molecule to accelerate the development of effective treatments. The wet bench results specifically highlight p70S6K as a compelling anti-COVID-19 target. Meanwhile, our in silico investigations address the known off-target effects associated with M2698 by identifying a close analog called S34. In conclusion, this study presents novel and intriguing findings that could potentially lead to clinical applications with further investigations.

Screening of phytoconstituents from Bacopa monnieri (L.) Pennell and Mucuna pruriens (L.) DC. to identify potential inhibitors against Cerebroside sulfotransferase

Cerebroside sulfotransferase (CST) is considered a target protein in developing substrate reduction therapy for metachromatic leukodystrophy. This study employed a multistep virtual screening approach for getting a specific and potent inhibitor against CST from 35 phytoconstituents of Bacopa monnieri (L.) Pennell and 31 phytoconstituents of Mucuna pruriens (L.) DC. from the IMPPAT 2.0 database. Using a binding score cutoff of -8.0 kcal/mol with ADME and toxicity screening, four phytoconstituents IMPHY009537 (Stigmastenol), IMPHY004141 (alpha-Amyrenyl acetate), IMPHY014836 (beta-Sitosterol), and IMPHY001534 (jujubogenin) were considered for in-depth analysis. In the binding pocket of CST, the major amino acid residues that decide the orientation and interaction of compounds are Lys85, His84, His141, Phe170, Tyr176, and Phe177. The molecular dynamics simulation with a 100ns time span further validated the stability and rigidity of the docked complexes of the four hits by exploring the structural deviation and compactness, hydrogen bond interaction, solvent accessible surface area, principal component analysis, and free energy landscape analysis. Stigmastenol from Bacopa monnieri with no potential cross targets was found to be the most potent and selective CST inhibitor followed by alpha-Amyrenyl acetate from Mucuna pruriens as the second-best performing inhibitor against CST. Our computational drug screening approach may contribute to the development of oral drugs against metachromatic leukodystrophy.