Methylglyoxal (MG) is a precursor for advanced glycation end-products (AGEs), which have a significant role in diabetes. The present study is designed to probe the immunological response of native and glycated low-density lipoprotein (LDL) in experimental animals. The second part of this study is to probe glycoxidative lesion detection in low-density lipoproteins (LDL) in diabetes subjects with varying disease duration. The neo-epitopes attributed to glycation-induced glycoxidative lesion of LDL in DM patients’ plasma were, analyzed by binding of native and MG-modified LDL immunized animal sera antibodies using an immunochemical assay. The plasma purified human LDL glycation with MG, which instigated modification in LDL. Further, the NewZealand-White rabbits were infused with unmodified natural LDL (N-LDL) and MG-glycatedLDL to probe its immunogenicity. The glycoxidative lesion detection in LDL of DM with disease duration (D.D.) of 5–15 years and D.D. > 15 years was found to be significantly higher as compared to normal healthy subjects (NHS) LDL. The findings support the notion that prolonged duration of diabetes can cause structural alteration in LDL protein molecules, rendering them highly immunogenic in nature. The presence of LDL lesions specific to MG-associated glycoxidation would further help in assessing the progression of diabetes mellitus.
23 January 2023 in Applied Biochemistry and Biotechnology
Background: Melanin protects skin and hair from the effects of ultraviolet (UV) radiation damage, which contributes to all forms of skin cancer, including melanoma. Human melanocytes produce two main types of melanin: eumelanin provides effective photoprotection, and pheomelanin offers less protection against UV-induced skin damage. The agouti signaling protein (ASIP) antagonizes the melanocortin-1 receptor (MC1R), hinders melanocyte signaling, and shifts pigmentation toward pheomelanin, promoting UV vulnerability. In this study, we aim to discover compounds that inhibit ASIP–MC1R interaction and effectively preserve eumelanogenic signaling. Methods: The ASIP–MC1R interface-based pharmacophore model from ASIP is implicated in MC1R receptor protein engagement. We performed virtual screening with a validated pharmacophore model for ~4000 compounds curated from ZINCPharmer and applied drug-likeness filters, viz. ADMET and toxicity profiling tests. Further, the screened candidates were targeted for docking to the ASIP C-terminal domain corresponding to the MC1R-binding moiety. Top compounds underwent a 100-nanosecond (ns) run of molecular dynamics (MD) simulations to assess complex stability and persistence of key contacted residues. Results: Sequential triage, including pharmacophore, ADME–toxicity (ADMET), and docking/ΔG, yielded a focused group of candidates against ASIP antagonists with a favorable fit value. The MD run for 100 ns supported pose stability at the targeted pocket. Based on these predictions and analyses, compound ZINC14539068 was screened as a new potent inhibitor of ASIP to preserve α-MSH-mediated signaling of MC1R. Conclusions: Our in silico pipeline identifies ZINC14539068 as a potent inhibitor of ASIP at its C-terminal interface. This compound is predicted to disrupt ASIP–MC1R binding, thereby maintaining eumelanin-biased signaling. These findings motivate experimental validation in melanocytic models and in vivo studies to confirm pathway modulation and anti-melanoma potential.
Background/Objectives: Antibiotic resistance in bacteria poses a major health problem worldwide. Therefore, to counteract this life-threatening problem, we sought to investigate in the present study the possible potentiation of the efficacy of amoxicillin (AMX) and clavulanic acid (CA) by 1,8-cineole (CN), a candidate resistance-modulating agent. The approach seeks to investigate, in vitro and in silico, the interactions among these three molecules. Methods: The antibacterial activity was determined against resistant Escherichia coli (E. coli) using microdilution methods, synergy tests, and time-kill assays for AMX, CA, and CN, used either separately or in combinations: AMX–CA, AMX–CN, CA–CN, and AMX–CA–CN. Furthermore, an in silico drug design methodology was employed, utilizing an integrated workflow that combines Density Functional Theory (DFT) for ligand optimization with molecular docking simulations to evaluate binding energies and interactions between the penicillin-binding protein (PBP) and ligands. Results: In vitro synergy experiments and time-kill assays revealed substantial antibacterial efficacy of the AMX–CA–CN combination. In silico analyses, performed under the simplifying assumption of a pre-assembled multi-ligand entity, were consistent with these findings: within our docking model, the AMX–CA–CN combination exhibited the most favorable computed binding affinity to a representative penicillin-binding protein (PBP3, PDB 7ONW). Conclusions: 1,8-cineole can potentiate the antibacterial effects of AMX–CA, indicating that the AMX–CA–CN combination warrants further evaluation as a candidate adjunctive strategy against ESBL-producing E. coli.
The main protease (MPro) of coronaviruses (CoVs) is an essential enzyme involved in viral replication and represents an attractive target for antiviral drug discovery. Based on the similar binding pocket residues within the MPro of different CoVs, this study aimed to identify potential inhibitors of SARS-CoV-2 MPro from PDB ID 6M2N using integrated computational approaches. Interaction-based pharmacophore modeling, virtual screening, molecular docking, MM-GBSA binding energy calculation, and molecular dynamics simulation (MDS) were performed using BIOVIA Discovery Studio. The validated pharmacophore model was utilized to screen the ZINC database, followed by docking and 100 ns MDS analyses of the top-ranked compounds. The pharmacophore model 01 demonstrated favorable predictive performance (AUC = 0.781). Virtual screening identified 483 compounds, from which 15 compounds were selected for docking studies. Among them, ZINC95473654 (Lig-1), ZINC95473725 (Lig-2), and ZINC08792368 (Lig-3) exhibited strong binding affinity toward MPro. Lig-1 demonstrated the best docking score and binding free energy, along with stable interactions with key catalytic residues HIS41, CYS145, and GLU166. MDS analyses further confirmed that Lig-1, Lig-2 and Lig-3 maintained stable conformations. The hydrogen bond distance monitoring and post MDS-MM-GBSA results suggest Lig-1 followed by Lig-3 as an inhibitor for MPro and persistent intermolecular interactions throughout the 100 ns simulation period. The findings suggest that Lig-1, followed by Lig-3, may serve as promising computational lead compounds targeting SARS-CoV-2 MPro, representing promising candidates for further experimental validation.