Interrogating the Role of Endocytosis Pathway and Organelle Trafficking for Doxorubicin-Based Combination Ionic Nanomedicines.

We have studied the endocytic mechanisms that determine subcellular localization for three carrier-free chemotherapeutic-photothermal (chemo-PTT) combination ionic nanomedicines (INMs) composed of doxorubicin (DOX) and an near-infrared (NIR) dye (ICG, IR820, or IR783). This study aims to understand the cellular basis for previously published enhanced toxicity results of these combination nanomedicines toward MCF-7 breast cancer cells. The active transport mechanism of INMs, unlike free DOX, which is known to employ passive transport, was validated by conducting temperature-dependent cellular uptake of the drug in MCF-7 cells using confocal microscopy. The internalization pathway of these INMs was further probed in the presence and absence of different endocytosis inhibitors. Detailed examination of the mode of entry of the carrier-free INMs in MCF-7 cells revealed that they are primarily internalized through clathrin-mediated endocytosis. In addition, time-dependent subcellular localization studies were also investigated. Examination of time-dependent confocal images indicated that the INMs targeted multiple organelles, in contrast to free DOX that primarily targets the nucleus. Collectively, the high cellular endocytic uptake in cancerous cells (EPR effect) and the multimode targeting ability demonstrated the main reason for the low half-maxima inhibitory concentration (IC50) value (the high cytotoxicity) of these carrier-free INMs as compared to their respective parent chemo and PTT drugs.

Nocardioides agri sp. nov., isolated from garden soil.

A novel bacterial strain, designated as MAH-18T, was isolated from soil sampled in a flower garden. Cells of strain MAH-18T were Gram-stain-positive, aerobic, motile, and rod-shaped. The colonies were beige in colour, smooth, and spherical when grown on Reasoner's 2A agar medium. Strain MAH-18T grew at 20-40 °C, pH 6.0-8.0, and 0-1.0 % NaCl. Cells were able to hydrolyse aesculin, gelatin, and Tween 20. According to the 16S rRNA gene sequence comparisons, the isolate was determined to be a member of the genus Nocardioides and most closely related to Nocardioides pyridinolyticus OS4T (97.9 %), Nocardioides hankookensis DS-30T (97.9 %), Nocardioides aquiterrae GW-9T (97.6 %), Nocardioides soli mbc-2T (97.5 %), Nocardioides conyzicola HWE 2-02T (97.4 %), and Nocardioides mangrovi GBK3QG-3T (96.3 %). Strain MAH-18T has a draft genome size of 4 788 325 bp (eight contigs), 4572 protein-coding genes, 46 tRNA, and three rRNA genes. The average nucleotide identity and digital DNA-DNA hybridization values between strain MAH-18T and the closest type strains were 81.5-83.4 % and 24.4-25.8 %, respectively. In silico genome mining revealed several biosynthetic gene clusters in the genome of the novel strain MAH-18T. The G+C content of the genomic DNA of strain was 72.2 mol% and the predominant isoprenoid quinone was MK-8 (H4). The main polar lipids were phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, and unknown phospholipids. The major cellular fatty acids were determined to be C16:0 iso and C17 : 1 ω6c. The DNA-DNA hybridization results and phenotypic, genotypic, and chemotaxonomic data demonstrated that strain MAH-18T represents a novel species, for which the name Nocardioides agri sp. nov. is proposed, with MAH-18T as the type strain (=KACC 19744T=CGMCC 1.13656T).

Comprehensive analysis of genomic variation, pan-genome and biosynthetic potential of Corynebacterium glutamicum strains.

Corynebacterium glutamicum is a non-pathogenic species of the Corynebacteriaceae family. It has been broadly used in industrial biotechnology for the production of valuable products. Though it is widely accepted at the industrial level, knowledge about the genomic diversity of the strains is limited. Here, we investigated the comparative genomic features of the strains and pan-genomic characteristics. We also observed phylogenetic relationships among the strains based on average nucleotide identity (ANI). We found diversity between strains at the genomic and pan-genomic levels. Less than one-third of the C. glutamicum pan-genome consists of core genes and soft-core genes. Whereas, a large number of strain-specific genes covered about half of the total pan-genome. Besides, C. glutamicum pan-genome is open and expanding, which indicates the possible addition of new gene families to the pan-genome. We also investigated the distribution of biosynthetic gene clusters (BGCs) among the strains. We discovered slight variations of BGCs at the strain level. Several BGCs with the potential to express novel bioactive secondary metabolites have been identified. Therefore, by utilizing the characteristic advantages of C. glutamicum, different strains can be potential applicants for natural drug discovery.

Aquincola agrisoli sp. nov., isolated from rhizospheric soil of eggplant and in silico genome mining for the prediction of biosynthetic gene clusters.

A Gram-stain negative, aerobic, rod-shaped, motile and flagellated novel bacterial strain, designated MAHUQ-54T, was isolated from the rhizospheric soil of eggplant. The colonies were observed to be light pink coloured, smooth, spherical and 0.2-0.6 mm in diameter when grown on R2A agar medium for 2 days. MAHUQ-54T was able to grow at 15-40 °C, at pH 5.5-9.0 and in the presence of 0-0.5 % NaCl (w/v). The strain gave positive results for both catalase and oxidase tests. The strain was positive for hydrolysis of l-tyrosine, urea, Tween 20 and Tween 80. On the basis of the results of 16S rRNA gene sequence comparisons, the isolate was identified as a member of the genus Aquincola and is closely related to Aquincola tertiaricarbonis L10T (98.8 % sequence similarity) and Leptothrix mobilis Feox-1T (98.2 %). MAHUQ-54T has a draft genome size of 5 994 516 bp (60 contigs), annotated with 5348 protein-coding genes, 45 tRNA and 5 rRNA genes. The average nucleotide identity (ANI) and digital DNA-DNA hybridisation (dDDH) values between MAHUQ-54T and its closest phylogenetic neighbours were 75.8-83.3 and 20.8-25.3 %, respectively. In silico genome mining revealed that MAHUQ-54T has a significant potential for the production of novel natural products in the future. The genomic DNA G+C content was determined to be 70.4 %. The predominant isoprenoid quinone was ubiquinone-8. The major fatty acids were identified as C16  :  0, summed feature 3 (comprising C16  :  1ω7c and/or C16  :  1ω6c) and summed feature 8 (comprising C18  :  1ω7c and/or C18  :  1ω6c). On the basis of dDDH, ANI value, genotypic analysis, chemotaxonomic and physiological data, strain MAHUQ-54T represents a novel species within the genus Aquincola, for which the name Aquincola agrisoli sp. nov. is proposed, with MAHUQ-54T (=KACC 22001T = CGMCC 1.18515T) as the type strain.

Genome-wide identification and characterization of protein phosphatase 2C (PP2C) gene family in sunflower (Helianthus annuus L.) and their expression profiles in response to multiple abiotic stresses.

Plant protein phosphatase 2C (PP2C) plays vital roles in responding to various stresses, stimulating growth factors, phytohormones, and metabolic activities in many important plant species. However, the PP2C gene family has not been investigated in the economically valuable plant species sunflower (Helianthus annuus L.). This study used comprehensive bioinformatics tools to identify and characterize the PP2C gene family members in the sunflower genome (H. annuus r1.2). Additionally, we analyzed the expression profiles of these genes using RNA-seq data under four different stress conditions in both leaf and root tissues. A total of 121 PP2C genes were identified in the sunflower genome distributed unevenly across the 17 chromosomes, all containing the Type-2C phosphatase domain. HanPP2C genes are divided into 15 subgroups (A-L) based on phylogenetic tree analysis. Analyses of conserved domains, gene structures, and motifs revealed higher structural and functional similarities within various subgroups. Gene duplication and collinearity analysis showed that among the 53 HanPP2C gene pairs, 48 demonstrated segmental duplications under strong purifying selection pressure, with only five gene pairs showing tandem duplications. The abundant segmental duplication was observed compared to tandem duplication, which was the major factor underlying the dispersion of the PP2C gene family in sunflowers. Most HanPP2C proteins were localized in the nucleus, cytoplasm, and chloroplast. Among the 121 HanPP2C genes, we identified 71 miRNAs targeting 86 HanPP2C genes involved in plant developmental processes and response to abiotic stresses. By analyzing cis-elements, we identified 63 cis-regulatory elements in the promoter regions of HanPP2C genes associated with light responsiveness, tissue-specificity, phytohormone, and stress responses. Based on RNA-seq data from two sunflower tissues (leaf and root), 47 HanPP2C genes exhibited varying expression levels in leaf tissue, while 49 HanPP2C genes showed differential expression patterns in root tissue across all stress conditions. Transcriptome profiling revealed that nine HanPP2C genes (HanPP2C12, HanPP2C36, HanPP2C38, HanPP2C47, HanPP2C48, HanPP2C53, HanPP2C54, HanPP2C59, and HanPP2C73) exhibited higher expression in leaf tissue, and five HanPP2C genes (HanPP2C13, HanPP2C47, HanPP2C48, HanPP2C54, and HanPP2C95) showed enhanced expression in root tissue in response to the four stress treatments, compared to the control conditions. These results suggest that these HanPP2C genes may be potential candidates for conferring tolerance to multiple stresses and further detailed characterization to elucidate their functions. From these candidates, 3D structures were predicted for six HanPP2C proteins (HanPP2C47, HanPP2C48, HanPP2C53, HanPP2C54, HanPP2C59, and HanPP2C73), which provided satisfactory models. Our findings provide valuable insights into the PP2C gene family in the sunflower genome, which could play a crucial role in responding to various stresses. This information can be exploited in sunflower breeding programs to develop improved cultivars with increased abiotic stress tolerance.

Leveraging immunoinformatics for developing a multi-epitope subunit vaccine against Helicobacter pylori and Fusobacterium nucleatum.

Gastric ulcers caused by Helicobacter pylori and Fusobacterium nucleatum remain a significant global health concern without an established vaccine. In this study, we utilized immunoinformatics methods to design a multi-epitope vaccine targeting these pathogens. Outer membrane proteins from H. pylori and F. nucleatum were scrutinized to identify high antigenic T-cell and B-cell epitopes. The resulting vaccine comprised carefully analyzed and evaluated epitopes, including cytotoxic T-lymphocytes, helper T-lymphocytes, and linear B-lymphocytes epitopes. This vaccine exhibited notable antigenicity, suitable immunogenicity, and demonstrated non-allergenicity and non-toxicity. It displayed favorable physiochemical characteristics and high solubility. In interaction studies, the vaccine exhibited robust binding to toll-like receptor 4 (TLR4). Molecular dynamic simulations revealed cohesive structural integrity and stable attachment. Codon adaptation utilizing Escherichia coli K12 host yielded a vaccine with elevated Codon Adaptation Index (CAI) and optimal GC content. In silico cloning into the pET28+(a) vector demonstrated efficient expression. Immune simulations indicated the vaccine's ability to initiate immune responses in humans, mirroring real-life scenarios. Based on these comprehensive findings, we propose that our developed vaccine has the potential to confer robust immunity against H. pylori and F. nucleatum infections.Communicated by Ramaswamy H. Sarma.

Identification of genetic biomarkers, drug targets and agents for respiratory diseases utilising integrated bioinformatics approaches.

Respiratory diseases (RD) are significant public health burdens and malignant diseases worldwide. However, the RD-related biological information and interconnection still need to be better understood. Thus, this study aims to detect common differential genes and potential hub genes (HubGs), emphasizing their actions, signaling pathways, regulatory biomarkers for diagnosing RD and candidate drugs for treating RD. In this paper we used integrated bioinformatics approaches (such as, gene ontology (GO) and KEGG pathway enrichment analysis, molecular docking, molecular dynamic simulation and network-based molecular interaction analysis). We discovered 73 common DEGs (CDEGs) and ten HubGs (ATAD2B, PPP1CB, FOXO1, AKT3, BCR, PDE4D, ITGB1, PCBP2, CD44 and SMARCA2). Several significant functions and signaling pathways were strongly related to RD. We recognized six transcription factor (TF) proteins (FOXC1, GATA2, FOXL1, YY1, POU2F2 and HINFP) and five microRNAs (hsa-mir-218-5p, hsa-mir-335-5p, hsa-mir-16-5p, hsa-mir-106b-5p and hsa-mir-15b-5p) as the important transcription and post-transcription regulators of RD. Ten HubGs and six major TF proteins were considered drug-specific receptors. Their binding energy analysis study was carried out with the 63 drug agents detected from network analysis. Finally, the five complexes (the PDE4D-benzo[a]pyrene, SMARCA2-benzo[a]pyrene, HINFP-benzo[a]pyrene, CD44-ketotifen and ATAD2B-ponatinib) were selected for RD based on their strong binding affinity scores and stable performance as the most probable repurposable protein-drug complexes. We believe our findings will give readers, wet-lab scientists, and pharmaceuticals a thorough grasp of the biology behind RD.

Bioactive ZnO Nanoparticles: Biosynthesis, Characterization and Potential Antimicrobial Applications.

In recent years, biosynthesized zinc oxide nanoparticles (ZnONPs) have gained tremendous attention because of their safe and non-toxic nature and distinctive biomedical applications. A diverse range of microbes (bacteria, fungi and yeast) and various parts (leaf, root, fruit, flower, peel, stem, etc.) of plants have been exploited for the facile, rapid, cost-effective and non-toxic synthesis of ZnONPs. Plant extracts, microbial biomass or culture supernatant contain various biomolecules including enzymes, amino acids, proteins, vitamins, alkaloids, flavonoids, etc., which serve as reducing, capping and stabilizing agents during the biosynthesis of ZnONPs. The biosynthesized ZnONPs are generally characterized using UV-VIS spectroscopy, TEM, SEM, EDX, XRD, FTIR, etc. Antibiotic resistance is a serious problem for global public health. Due to mutation, shifting environmental circumstances and excessive drug use, the number of multidrug-resistant pathogenic microbes is continuously rising. To solve this issue, novel, safe and effective antimicrobial agents are needed urgently. Biosynthesized ZnONPs could be novel and effective antimicrobial agents because of their safe and non-toxic nature and powerful antimicrobial characteristics. It is proven that biosynthesized ZnONPs have strong antimicrobial activity against various pathogenic microorganisms including multidrug-resistant bacteria. The possible antimicrobial mechanisms of ZnONPs are the generation of reactive oxygen species, physical interactions, disruption of the cell walls and cell membranes, damage to DNA, enzyme inactivation, protein denaturation, ribosomal destabilization and mitochondrial dysfunction. In this review, the biosynthesis of ZnONPs using microbes and plants and their characterization have been reviewed comprehensively. Also, the antimicrobial applications and mechanisms of biosynthesized ZnONPs against various pathogenic microorganisms have been highlighted.

Isolation and characterization of Pinibacter soli sp. nov., and in silico genome mining of Pinibacter for biosynthetic gene cluster prediction.

A Gram-stain-negative, aerobic, rod-shaped, non-motile and non-flagellated novel bacterial strain, designated MAH-24T, was isolated from the rhizospheric soil of a pine garden. The colonies were observed to be orange-coloured, smooth, spherical and 0.4-0.8 mm in diameter when grown on Reasoner's 2A agar medium for 2 days. Strain MAH-24T was found to be able to grow at 10-35 °C, at pH 6.0-9.0 and in the presence of 0-1.0 % NaCl (w/v). The strain was found to be positive for the catalase and oxidase tests. The strain was positive for hydrolysis of aesculin and l-tyrosine. According to the 16S rRNA gene sequence comparisons, the isolate was identified as a member of the genus Pinibacter and to be closely related to Pinibacter aurantiacus MAH-26T (99.2 % sequence similarity). The novel strain MAH-24T has a draft genome size of 5 918 133 bp (13 contigs), annotated with 4613 protein-coding genes, 47 tRNA and three rRNA genes. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between strain MAH-24T and the closest type strain P. aurantiacus MAH-26T were in the range of 85.3 and 29.9 %, respectively. In silico genome mining revealed that both novel strain MAH-24T and P. aurantiacus MAH-26T have a significant potential for the production of novel natural products in the future. The genomic DNA G+C content was determined to be 41.0 mol%. The predominant isoprenoid quinone was menaquinone-7. The major fatty acids were identified as C15:0 iso, C15:1 iso G and C17:0 iso 3OH. On the basis of dDDH, ANI, genotypic, chemotaxonomic and physiological data, strain MAH-24T represents a novel species within the genus Pinibacter, for which the name Pinibacter soli sp. nov. is proposed, with MAH-24T (=KACC 19747T=CGMCC 1.13659T) as the type strain.

Bacterial mediated green synthesis of silver nanoparticles and their antibacterial and antifungal activities against drug-resistant pathogens.

In the healthcare sector, the production of bioactive silver nanoparticles (AgNPs) with antimicrobial properties is of great importance. In this study, a novel bacterial strain, Paenibacillus sp. MAHUQ-63, was identified as a potential candidate for facile and rapid biosynthesis of AgNPs. The synthesized AgNPs were used to control the growth of human pathogens, Salmonella Enteritidis and Candida albicans. The bacterial culture supernatant was used to synthesize the nanoparticles (NPs). Field emission transmission electron microscope examination showed spherical-shaped NPs with 15-55 nm in size. Fourier transform-infrared analysis identified various functional groups. The synthesized AgNPs demonstrated remarkable activity against S. Enteritidis and C. albicans. The zones of inhibition for 100 µl (0.5 mg ml-1) of AgNPs against S. Enteritidis and C. albicans were 18.0 ± 1.0 and 19.5 ± 1.3 mm, respectively. The minimum inhibitory concentrations were 25.0 and 12.5 µg ml-1 against S. Enteritidis and C. albicans, respectively. Additionally, the minimum bactericidal concentrations were 25.0 µg ml-1 against both pathogenic microbes. The field emission scanning electron microscopy analysis showed that the treatment of AgNPs caused morphological and structural damage to both S. Enteritidis and C. albicans. Therefore, these AgNPs can be used as a new and effective antimicrobial agent.

Sphingobium agri sp. nov., isolated from rhizospheric soil of eggplant.

A Gram-stain-negative, aerobic, short rod-shaped and motile bacterial strain, designated MAH-33T, was isolated from rhizospheric soil of eggplant. The colonies were observed to be yellow-coloured, smooth, spherical and 0.1-0.3 mm in diameter when grown on TSA agar medium for 2 days. Strain MAH-33T was found to be able to grow at 10-40 °C, at pH 5.0-10.0 and at 0-3.0 % NaCl (w/v). The strain was found to be positive for both oxidase and catalase tests. The strain was positive for hydrolysis of tyrosine and aesculin. According to the 16S rRNA gene sequence comparisons, the isolate was identified as a member of the genus Sphingobium and to be closely related to Sphingobium quisquiliarum P25T (98.4 % similarity), Sphingobium mellinum WI4T (97.8 %), Sphingobium fuliginis TKPT (97.3 %) and Sphingobium herbicidovorans NBRC 16415T (96.9 %). The novel strain MAH-33T has a draft genome size of 3 908 768 bp (28 contigs), annotated with 3689 protein-coding genes, 45 tRNA and three rRNA genes. The average nucleotide identity and digital DNA-DNA hybridization values between strain MAH-33T and closely related type strains were in the range of 79.8-81.6 % and 23.2-24.5 %, respectively. The genomic DNA G+C content was determined to be 62.2 %. The predominant isoprenoid quinone was ubiquinone 10. The major fatty acids were identified as C16 : 0 and summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c). The polar lipids identified in strain MAH-33T were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, sphingoglycolipid, phosphatidylcholine; one unknown phospholipid and one unknown lipid. On the basis of digital DNA-DNA hybridization, ANI value, genotypic analysis, chemotaxonomic and physiological data, strain MAH-33T represents a novel species within the genus Sphingobium, for which the name Sphingobium agri sp. nov. is proposed, with MAH-33T (=KACC 19973T = CGMCC 1.16609T) as the type strain.

Sphingomonas oryzagri sp. nov., isolated from a rice field.

A Gram-stain-negative, aerobic, short rod-shaped and motile novel bacterial strain, designated MAHUQ-71T, was isolated from the soil of a rice field. The colonies were observed to be milky yellow-coloured, smooth, spherical and 0.1-0.4 mm in diameter when grown on Reasoner's 2A agar medium for 2 days. Strain MAHUQ-71T was found to be able to grow at 15-37 °C, pH 5.0-10.0 and with 0-3.0 % NaCl (w/v). The strain was found to be positive for the catalase test, but negative for the oxidase test. The strain was positive for hydrolysis of aesculin and Tween 20. According to the 16S rRNA gene sequence comparisons, the isolate was identified as a member of the genus Sphingomonas and to be closely related to Sphingomonas chungangi MAH-6T (98.5 % sequence similarity), Sphingomonas polyaromaticivorans B2-7T (98.4 %) and Sphingomonas oligoaromativorans SY-6T (96.6 %). Strain MAHUQ-71T has a draft genome size of 4 255 278 bp (10 contigs), annotated with 4098 protein-coding genes, 47 tRNA and three rRNA genes. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between strain MAHUQ-71T and the closest type strain S. chungangi MAH-6T were in the range of 85.6 and 30.6 %, respectively. The genomic DNA G+C content was determined to be 66.7 mol%. The predominant isoprenoid quinone was ubiquinone 10. The major fatty acids were identified as summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c), C16 : 0 and C14 : 0 2OH. The main polar lipids were phosphatidylcholine, phosphatidylethanolamine, diphosphatidylglycerol and sphingoglycolipid. On the basis of dDDH and ANI values, as well as the results of genotypic, chemotaxonomic and physiological analyses, strain MAHUQ-71T represents a novel species within the genus Sphingomonas, for which the name Sphingomonas oryzagri sp. nov. is proposed, with MAHUQ-71T (=KACC 22252T=CGMCC 1.19065T) as the type strain.

A subunit vaccine against pneumonia: targeting Streptococcus pneumoniae and Klebsiella pneumoniae.

Community-acquired pneumonia is primarily caused by Streptococcus pneumoniae and Klebsiella pneumoniae, two pathogens that have high morbidity and mortality rates. This is largely due to bacterial resistance development against current antibiotics and the lack of effective vaccines. The objective of this work was to develop an immunogenic multi-epitope subunit vaccine capable of eliciting a robust immune response against S. pneumoniae and K. pneumoniae. The targeted proteins were the pneumococcal surface proteins (PspA and PspC) and choline-binding protein (CbpA) of S. pneumoniae and the outer membrane proteins (OmpA and OmpW) of K. pneumoniae. Different computational approaches and various immune filters were employed for designing a vaccine. The immunogenicity and safety of the vaccine were evaluated by utilizing many physicochemical and antigenic profiles. To improve structural stability, disulfide engineering was applied to a portion of the vaccine structure with high mobility. Molecular docking was performed to examine the binding affinities and biological interactions at the atomic level between the vaccine and Toll-like receptors (TLR2 and 4). Further, the dynamic stabilities of the vaccine and TLRs complexes were investigated by molecular dynamics simulations. While the immune response induction capability of the vaccine was assessed by the immune simulation study. Vaccine translation and expression efficiency was determined through an in silico cloning experiment utilizing the pET28a(+) plasmid vector. The obtained results revealed that the designed vaccine is structurally stable and able to generate an effective immune response to combat pneumococcal infection. Supplementary Information: The online version contains supplementary material available at 10.1007/s13721-023-00416-3.

Identification of potent COVID-19 main protease inhibitors by loading of favipiravir on Mg12O12 and Zn12O12 nanoclusters: an in silico strategy for COVID-19 treatment.

Pandemic new severe acute respiratory syndrome coronavirus (SARS-CoV-2) virus has increased throughout the world. There is no effective treatment against this virus until now. Since its appearance in Wuhan, China in December 2019, SARS-CoV-2 becomes the largest challenge the world is opposite today, including the discovery of an antiviral drug for this virus. Several viral proteins have been prioritized as SARS-CoV-2 antiviral drug targets, among them the papain-like protease (PLpro) and the main protease (Mpro). Inhibition of these proteases would target viral replication, viral maturation and suppression of host innate immune responses. Potential candidates have been identified to show inhibitory effects against Mpro, both in biochemical assays and viral replication in cells. There are different molecules such as lopinavir and favipiravir considerably inhibit the activity of Mpro in vitro. Different studies have shown that structurally improved favipiravir and other similar compounds can inhibit SARS-CoV-2 main protease. In this work, we study the interactions between favipiravir with Mg12O12 and Zn12O12 nanoclusters by density functional theory (DFT) and quantum mechanics atoms in molecules (QMAIM) methods to summarize the ability to load favipiravir onto Mg12O12 and Zn12O12 nanoclusters. Favipiravir-Mg12O12 and favipiravir-Zn12O12 lowest structures complexes were chosen to dock inside the SARS-CoV-2 main protease by molecular docking study. The molecular docking analysis revealed that the binding affinity of Mg12O12 and Zn12O12 nanoclusters inside the Mpro receptor is larger than that of favipiravir. Also, the loading of favipiravir on the surface of Mg12O12 and Zn12O12 nanoclusters increased the binding affinity against the Mpro receptor. Subsequently, 100 ns molecular dynamics simulation of the favipiravir-Mg12O12, and favipiravir-Zn12O12 docked inside the Mpro complexes established that favipiravir-Mg12O12, forms the most stable complex with the Mpro. Further molecular mechanics Poisson Boltzmann surface area (MMPBSA) analyses using the MD trajectories also demonstrated the higher binding affinity of favipiravir-Mg12O12 inside the Mpro. In summary, this study demonstrates a new way to characterize leads for novel anti-viral drugs against SARS-CoV-2, by improving the drug ability of favipiravir via loading it on Mg12O12 and Zn12O12 nanoclusters.Communicated by Ramaswamy H. Sarma.

Pseudomonas oryzagri sp. nov., isolated from a rice field soil.

A Gram-stain-negative, aerobic, rod-shaped and non-motile novel bacterial strain, designated MAHUQ-58T, was isolated from soil sample of a rice field. The colonies were observed to be light pink-coloured, smooth, spherical and 0.6-1.0 mm in diameter when grown on nutrient agar (NA) medium for 2 days. Strain MAHUQ-58T was found to be able to grow at 15-40 °C, at pH 5.5-10.0 and with 0-1.0 % NaCl (w/v). Cell growth occurred on tryptone soya agar, Luria-Bertani agar, NA, MacConkey agar and Reasoner's 2A agar. The strain was found to be positive for both oxidase and catalase tests. The strain was positive for hydrolysis of Tween 20 and l-tyrosine. According to the 16S rRNA gene sequence comparisons, the isolate was identified as a member of the genus Pseudomonas and to be closely related to Pseudomonas oryzae WM-3T (98.9 % similarity), Pseudomonas linyingensis LYBRD3-7T (97.7 %), Pseudomonas sagittaria JCM 18195 T (97.6 %) and Pseudomonas guangdongensis SgZ-6T (97.2 %). The novel strain MAHUQ-58T has a draft genome size of 4 536 129 bp (46 contigs), annotated with 4064 protein-coding genes, 60 tRNA genes and four rRNA genes. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between strain MAHUQ-58T and four closely related type strains were in the range of 85.5-89.5 % and 29.5-38.0 %, respectively. The genomic DNA G+C content was determined to be 67.0 mol%. The predominant isoprenoid quinone was ubiquinone 9. The major fatty acids were identified as C16:0, summed feature 3 (C16 : 1 ω6c and/or C16 : 1 ω7c) and summed feature 8 (C18 : 1 ω6c and/or C18 : 1 ω7c). On the basis of dDDH and ANI values, genotypic results, and chemotaxonomic and physiological data, strain MAHUQ-58T represents a novel species within the genus Pseudomonas, for which the name Pseudomonas oryzagri sp. nov. is proposed, with MAHUQ-58T (=KACC 22005T=CGMCC 1.18518T) as the type strain.

Design of a multi-epitope vaccine against SARS-CoV-2: immunoinformatic and computational methods.

A novel infectious agent, SARS-CoV-2, is responsible for causing the severe respiratory disease COVID-19 and death in humans. Spike glycoprotein plays a key role in viral particles entering host cells, mediating receptor recognition and membrane fusion, and are considered useful targets for antiviral vaccine candidates. Therefore, computational techniques can be used to design a safe, antigenic, immunogenic, and stable vaccine against this pathogen. Drawing upon the structure of the S glycoprotein, we are trying to develop a potent multi-epitope subunit vaccine against SARS-CoV-2. The vaccine was designed based on cytotoxic T-lymphocyte and helper T-lymphocyte epitopes with an N-terminal adjuvant via conducting immune filters and an extensive immunoinformatic investigation. The safety and immunogenicity of the designed vaccine were further evaluated via using various physicochemical, allergenic, and antigenic characteristics. Vaccine-target (toll-like receptors: TLR2 and TLR4) interactions, binding affinities, and dynamical stabilities were inspected through molecular docking and molecular dynamic (MD) simulation methods. Moreover, MD simulations for dimeric TLRs/vaccine in the membrane-aqueous environment were performed to understand the differential domain organization of TLRs/vaccine. Further, dynamical behaviors of vaccine/TLR systems were inspected via identifying the key residues (named HUB nodes) that control interaction stability and provide a clear molecular mechanism. The obtained results from molecular docking and MD simulation revealed a strong and stable interaction between vaccine and TLRs. The vaccine's ability to stimulate the immune response was assessed by using computational immune simulation. This predicted a significant level of cytotoxic T cell and helper T cell activation, as well as IgG, interleukin 2, and interferon-gamma production. This study shows that the designed vaccine is structurally and dynamically stable and can trigger an effective immune response against viral infections.

Immune epitopes identification and designing of a multi-epitope vaccine against bovine leukemia virus: a molecular dynamics and immune simulation approaches.

BACKGROUND: Bovine leukemia virus (BLV) is an oncogenic delta-retrovirus causing bovine leucosis. Studies on BLV have shown the association with human breast cancer. However, the exact molecular mechanism is neither known nor their appropriate preventative measure to halt the disease initiation and progression. In this study, we designed a multi-epitope vaccine against BLV using a computational analyses. METHODS: Following a rigorous assessment, the vaccine was constructed using the T-cell epitopes from each BLV-derived protein with suitable adjuvant and linkers. Both physicochemistry and immunogenic potency as well as the safeness of the vaccine candidate were assessed. Population coverage was done to evaluate the vaccine probable efficiency in eliciting the immune response worldwide. After homology modeling, the three-dimensional structure was refined and validated to determine the quality of the designed vaccine. The vaccine protein was then subjected to molecular docking with Toll-like receptor 3 (TLR3) to evaluate the binding efficiency followed by dynamic simulation for stable interaction. RESULTS: Our vaccine construct has the potential immune response and good physicochemical properties. The vaccine is antigenic and immunogenic, and has no allergenic or toxic effect on the human body. This novel vaccine contains a significant interactions and binding affinity with the TLR3 receptor. CONCLUSIONS: The proposed vaccine candidate would be structurally stable and capable of generating an effective immune response to combat BLV infections. However, experimental evaluations are essential to validate the exact safety and immunogenic profiling of this vaccine.

Bioinformatics approaches identified dasatinib and bortezomib inhibit the activity of MCM7 protein as a potential treatment against human cancer.

Minichromosome Maintenance Complex Component 7 (MCM7) is a key component of the DNA replication licensing factor and hexamer MCM (MCM2-7) complex that regulates the DNA replication process. The MCM7 protein is associated with tumor cell proliferation that plays an important role in different human cancer progression. As the protein is highly expressed during the cancer development process, therefore, inhibition of the protein can be utilized as a treatment option for different human cancer. However, the study aimed to identify potential small molecular drug candidates against the MCM7 protein that can utilize treatment options for human cancer. Initially, the compounds identified from protein-drugs network analysis have been retrieved from NetworkAnalyst v3.0 server and screened through molecular docking, MM-GBSA, DFT, pharmacokinetics, toxicity, and molecular dynamics (MD) simulation approach. Two compounds namely Dasatinib (CID_3062316) and Bortezomib (CID_387447) have been identified throughout the screening process, which have the highest negative binding affinity (Kcal/mol) and binding free energy (Kcal/mol). The pharmacokinetics and toxicity analysis identified drug-like properties and no toxicity properties of the compounds, where 500 ns MD simulation confirmed structural stability of the two compounds to the targeted proteins. Therefore, we can conclude that the compounds dasatinib and bortezomib can inhibit the activity of the MCM7 and can be developed as a treatment option against human cancer.

Designing a multi-epitope vaccine against SARS-CoV-2: an immunoinformatics approach.

Ongoing COVID-19 outbreak has raised a drastic challenge to global public health security. Most of the patients with COVID-19 suffer from mild flu-like illnesses such as cold and fever; however, few percentages of the patients progress from severe illness to death, mostly in an immunocompromised individual. The causative agent of COVID-19 is an RNA virus known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Despite these debilitating conditions, no medication to stop the disease progression or vaccination is available till now. Therefore, we aimed to formulate a multi-epitope vaccine against SARS-CoV-2 by utilizing an immunoinformatics approach. For this purpose, we used the SARS-CoV-2 spike glycoprotein to determine the immunodominant T- and B-cell epitopes. After rigorous assessment, we designed a vaccine construct using four potential epitopes from each of the three epitope classes such as cytotoxic T-lymphocytes, helper T-lymphocyte, and linear B-lymphocyte epitopes. The designed vaccine was antigenic, immunogenic, and non-allergenic with suitable physicochemical properties and has higher solubility. More importantly, the predicted vaccine structure was similar to the native protein. Further investigations indicated a strong and stable binding interaction between the vaccine and the toll-like receptor (TLR4). Strong binding stability and structural compactness were also evident in molecular dynamics simulation. Furthermore, the computer-generated immune simulation showed that the vaccine could trigger real-life-like immune responses upon administration into humans. Finally, codon optimization based on Escherichia coli K12 resulted in optimal GC content and higher CAI value followed by incorporating it into the cloning vector pET28+(a). Overall, these results suggest that the designed peptide vaccine can serve as an excellent prophylactic candidate against SARS-CoV-2.Communicated by Ramaswamy H. Sarma.

Combination of QSAR, molecular docking, molecular dynamic simulation and MM-PBSA: analogues of lopinavir and favipiravir as potential drug candidates against COVID-19.

Pandemic COVID-19 infections have spread throughout the world. There is no effective treatment against this disease. Viral RNA-dependent RNA polymerase (RdRp) catalyzes the replication of RNA from RNA and the main protease (Mpro) has a role in the processing of polyproteins that are translated from the RNA of SARS-CoV-2, and thus these two enzymes are strong candidates for targeting by anti-viral drugs. Small molecules such as lopinavir and favipiravir significantly inhibit the activity of Mpro and RdRp in vitro. Studies have shown that structurally modified lopinavir, favipiravir, and other similar compounds can inhibit COVID-19 main protease (Mpro) and RNA-dependent RNA polymerase (RdRp). In this study, lopinavir and its structurally similar compounds were chosen to bind the main protease, and favipiravir was chosen to target RNA-dependent RNA polymerase. Molecular docking and the quantitative structure-activity relationships (QSAR) study revealed that the selected candidates have favorable binding affinity but less druggable properties. To improve the druggability, four structural analogues of lopinavir and one structural analogue of favipiravir was designed by structural modification. Molecular interaction analyses have displayed that lopinavir and favipiravir analogues interact with the active site residues of Mpro and RdRp, respectively. Absorption, distribution, metabolism, excretion and toxicity (ADMET) properties, medicinal chemistry profile, and physicochemical features were shown that all structurally modified analogues are less toxic and contain high druggable properties than the selected candidates. Subsequently, 50 ns molecular dynamics simulation of the top four docked complexes demonstrated that CID44271905, a lopinavir analogue, forms the most stable complex with the Mpro. Further MMPBSA analyses using the MD trajectories also confirmed the higher binding affinity of CID44271905 towards Mpro. In summary, this study demonstrates a new way to identify leads for novel anti-viral drugs against COVID-19. Communicated by Ramaswamy H. Sarma.