Pondicherry University

Plant viruses pose a serious threat to global agriculture and although chemical, genetic, and biological control strategies exist, but each method have limitations in effectiveness and sustainability. Recently, the use of microbial peptides for curbing the movement of plant viruses has gained momentum. In this work, five peptides viz. Peptamine, indolicidin 10R, indolicidin 11R, Recombinant Thanatin (RT) and Recombinant Chimeric Lactoferricin + Lactoferrampin (RCLL), were identified and analysed for their role in disrupting the virus movement. The Sesbania Mosaic Virus (SeMV) is known to use a trafficking complex (a heteroprotein complex consisting of movement protein (MP), RdRp, VPg, and P10) for its intercellular movement. In this work, the ability of these peptides in binding to the major constituents of the trafficking complex (the MP and the RdRp) and their ability to disrupt the formation of trafficking complex was analysed using in silico tools. All five peptides were found to be disrupting the formation of the trafficking complex. Our findings suggest that these peptides can serve as potential antiviral agents by interfering with essential viral functions. This study provides new insights into peptide-based inhibition of plant viruses, offering an alternative to conventional control strategies.

Ideonella and Thermobifida were the most promising bacterial candidates for degrading plastic polymers. A comparative pan- and phylogenomic analysis of 33 Ideonella and Thermobifida strains was done to determine their plastic degradation potential, niche adaptation and speciation. Our study disclosed that more accessory genes in the strains showed phenotypic plasticity, according to the BPGA data. Pan and core genes were employed for the phylogenetic reconstruction. Pathway enrichment analyses scrutinized the functional roles of the core and adaptive-associated genes. KEGG annotation revealed that most genes were associated with the metabolism of amino acids and carbohydrates. The detailed COG analysis disclosed that approximately 40% of the pan genes performed metabolic functions. The unique gene pool consisted of genes chiefly involved in "general function prediction" and "amino acid transport and metabolism". Our in silico study revealed that these strains could assist in agronomic applications in the future since they devour nitrogen compounds and their central metabolic pathways are involved in amino acid metabolism. The rational selection of strains of Ideonella is far more effective at depolymerising plastics than Thermobifida. A greater number of unique genes, 1701 and 692, were identified for Ideonella sakaiensis 201-F6 and Thermobifida alba DSM-43795, respectively. Furthermore, we examined the singletons involved in xenobiotic catabolism. The unique singleton data were used to construct a supertree. To characterize the conserved patterns, we used SMART and MEME to identify domain and transmembrane regions in the unique protein sequences. Therefore, our study unraveled the genomic insights into the ecology-driven speciation of Ideonella and Thermobifida.

A new cyclic dipeptide, cyclo(phenylalanine-proline) (cFP), was isolated from the marine bacterium Exiguobacterium profundum SW22 and characterized by NMR and high-resolution mass spectrometry. In silico profiling predicted favorable pharmacokinetic and drug-like properties for cFP. The compound demonstrated dose-dependent cytotoxicity against human breast (MDA MB-231), pancreatic (PAN C1), and prostate (PC 3) cancer cell lines with IC₅₀ values of 47.24 ± 0.42, 40.96 ± 0.68, and 110 ± 1.48 µM, respectively, accompanied by apoptosis-associated morphological changes. Biophysical studies demonstrated strong binding affinity between cFP and human serum albumin (HSA), confirmed through UV-visible absorption spectroscopy, fluorescence quenching, and circular dichroism analyses, with validation using well-characterized reference ligand warfarin as control. Results suggest static quenching via ground-state complex formation with negligible lifetime changes, consistent with control molecule (warfarin) binding via hydrogen bonding and van der Waals interactions, accompanied by ligand-induced decreases in HSA α-helical content. Molecular docking studies of HSA with cFP and warfarin revealed strong binding affinities for both compounds. Further, the molecular dynamics simulations over a 50 ns timeframe confirmed the enhanced stability and persistent interaction of the cFP-HSA complex. Results highlight the cFP as a promising bioactive peptide with potential anticancer, pharmacokinetic and serum binding efficacies advocating further preclinical development for anticancer therapy.