Predicting the possibility of two newly isolated phenetheren ring containing compounds from Aristolochia manshuriensis as CDK2 inhibitors

Antiquorum sensing and antibiofilm potential of biosynthesized silver nanoparticles of Myristica fragrans seed extract against MDR Salmonella enterica serovar Typhi isolates from asymptomatic typhoid carriers and typhoid patients

Globally, Salmonella infection poses a major public health problem. Here, we report antibiofilm activity and quorum sensing inhibition of aqueous seeds extract of Myristica fragrans (nutmeg) and biosynthesized silver nanoparticles (AgNPs) against multidrug resistant (MDR) Salmonella enterica serovar Typhi (S. Typhi) isolated from typhoid patients and asymptomatic carriers. S. Typhi isolates revealed higher percentage (46%) of biofilm production identified by tissue culture plate (TCP) than Congo red agar (CRA) and tube adherence (TA) methods. The inhibition of biofilm-producing MDR S. Typhi isolates and pigment production of Chromobacterium violaceum (indicator bacteria) demonstrated the quorum sensing potential of nutmeg. The aqueous seed extract of nutmeg exhibited 87% of antibiofilm activity, while the biosynthesized AgNPs showed 99.1% of antibiofilm activity. Molecular docking studies of bioactive compounds of nutmeg against transcriptional regulatory protein RcsB and sensor kinase protein RcsC revealed interaction with the target proteins. It is proposed that biosynthesized AgNPs could be used as one of the effective candidates in treating asymptomatic typhoid carriers or typhoid patients and to control the subsistence of biofilm-producing S. Typhi strains or other pathogenic bacteria in the environment or industrial settings.

Computational analysis, structural modeling and ligand binding site prediction of Plasmodium falciparum 1-deoxy-d-xylulose-5-phosphate synthase

Malaria remains one of the most serious infectious diseases in the world. There are five human species of the Plasmodium genus, of which Plasmodium falciparum is the most virulent and responsible for the vast majority of malaria related deaths. The unique biochemical processes that exist in Plasmodium falciparum provide a useful way to develop novel inhibitors. One such biochemical pathway is the methyl erythritol phosphate pathway (MEP), required to synthesize isoprenoid precursors. In the present study, a detailed computational analysis has been performed for 1-deoxy-d-xylulose-5-phosphate synthase, a key enzyme in MEP. The protein is found to be stable and residues from 825 to 971 are highly conserved across species. The homology model of the enzyme is developed using three web-based servers and Modeller software. It has twelve disordered regions indicating its druggability. Virtual screening of ZINC database identifies ten potential compounds in thiamine diphosphate binding region of the enzyme.

In silico Analysis Revealed High-risk Single Nucleotide Polymorphisms in Human Pentraxin-3 Gene and their Impact on Innate Immune Response against Microbial Pathogens

Pentraxin-3 (PTX-3) protein is an evolutionary conserved protein that acts as a soluble pattern-recognition receptor for pathogens and plays important role in innate immune response. It recognizes various pathogens by interacting with extracellular moieties such as glactomannan of conidia (Aspergillus fumigatus), lipopolysaccharide of Pseudomonas aeruginosa, Streptococcus pneumonia and Salmonella typhimurium. Thus, PTX-3 protein helps to clear these pathogens by activating downstream innate immune process. In this study, computational methods were used to analyze various non-synonymous single nucleotide polymorphisms (nsSNPs) in PTX-3 gene. Three different databases were used to retrieve SNP data sets followed by seven different in silico algorithms to screen nsSNPs in PTX-3 gene. Sequence homology based approach was used to identify nsSNPs. Conservation profile of PTX-3 protein amino acid residues were predicted by ConSurf web server. In total, 10 high-risk nsSNPs were identified in pentraxin-domain of PTX-3 gene. Out of these 10 high-risk nsSNPs, 4 were present in the conserved structural and functional residues of the pentraxin-domain, hence, selected for structural analyses. The results showed alteration in the putative structure of pentraxin-domain. Prediction of protein–protein interactions analysis showed association of PTX-3 protein with C1q component of complement pathway. Different functional and structural residues along with various putative phosphorylation sites and evolutionary relationship were also predicted for PTX-3 protein. This is the first extensive computational analyses of pentraxin protein family with nsSNPs and will serve as a valuable resource for future population based studies.

Structural modeling and in silico analysis of non-synonymous single nucleotide polymorphisms of human 3β-hydroxysteroid dehydrogenase type 2

Single-nucleotide polymorphisms (SNPs), a most common type of genetic mutations, result from single base pair alterations. Non-synonymous SNPs (nsSNP) occur in the coding regions of a gene and result in single amino acid substitution which might have the potential to affect the function as well as structure of the corresponding protein. In human the 3β-hydroxysteroid dehydrogenases/Δ^4,5-isomerase type 2 (HSD3B2) is an important membrane-bound enzyme involved in the dehydrogenation and Δ^4,5-isomerization of the Δ⁵-steroid precursors into their respective Δ⁴-ketosteroids in the biosynthesis of steroid hormones such as glucocorticoids, mineralocorticoids, progesterone, androgens, and estrogens in tissues such as adrenal gland, ovary, and testis. Most of the nsSNPs of HSD3B2 are still uncharacterized in terms of their disease causing potential. So, this study has been undertaken to explore and extend the knowledge related to the effect of nsSNPs on the stability and function of the HSD3B2. In this study sixteen nsSNP of HSD3B2 were subjected to in silico analysis using nine different algorithms: SIFT, PROVEAN, PolyPhen, MutPred, SNPeffect, nsSNP Analyzer, PhD SNP, stSNP, and I Mutant 2.0. The results obtained from the analysis revealed that the prioritization of diseases associated amino acid substitution as evident from possible alteration in structure–function relationship. Structural phylogenetic analysis using ConSurf revealed that the functional residues are highly conserved in human HSD3B2; and most of the disease associated nsSNPs are within these conserved residues. Structural theoritical models of HSD3B2 were created using HHPred, Phyre2 and RaptorX server. The predicted models were evaluated to get the best one for structural understanding of amino acid substitutions in three dimensional spaces.

Functional and Structural Consequences of Damaging Single Nucleotide Polymorphisms in Human Prostate Cancer Predisposition Gene RNASEL

A commonly diagnosed cancer, prostate cancer (PrCa), is being regulated by the gene RNASEL previously known as PRCA1 codes for ribonuclease L which is an integral part of interferon regulated system that mediates antiviral and antiproliferative role of the interferons. Both somatic and germline mutations have been implicated to cause prostate cancer. With an array of available Single Nucleotide Polymorphism data on dbSNP this study is designed to sort out functional SNPs in RNASEL by implementing different authentic computational tools such as SIFT, PolyPhen, SNPs&GO, Fathmm, ConSurf, UTRScan, PDBsum, Tm-Align, I-Mutant, and Project HOPE for functional and structural assessment, solvent accessibility, molecular dynamics, and energy minimization study. Among 794 RNASEL SNP entries 124 SNPs were found nonsynonymous from which SIFT predicted 13 nsSNPs as nontolerable whereas PolyPhen-2 predicted 28. SNPs found on the 3' and 5' UTR were also assessed. By analyzing six tools having different perspectives an aggregate result was produced where nine nsSNPs were found to be most likely to exert deleterious effect. 3D models of mutated proteins were generated to determine the functional and structural effect of the mutations on ribonuclease L. The initial findings were reinforced by the results from I-Mutant and Project HOPE as these tools predicted significant structural and functional instability of the mutated proteins. Expasy-ProSit tool defined the mutations to be situated in the functional domains of the protein. Considering previous analysis this study revealed a conclusive result deducing the available SNP data on the database by identifying the most damaging three nsSNP rs151296858 (G59S), rs145415894 (A276V), and rs35896902 (R592H). As such studies involving polymorphisms of RNASEL were none to be found, the results of the current study would certainly be helpful in future prospects concerning prostate cancer in males.

Identification of functional SNPs in BARD1 gene and in silico analysis of damaging SNPs: based on data procured from dbSNP database

BACKGROUND

The BARD1 gene encodes for the BRCA1-associated RING domain (BARD1) protein. Germ line and somatic mutations in BARD1 are found in sporadic breast, ovarian and uterine cancers. There is a plethora of single nucleotide polymorphisms (SNPs) which may or may not be involved in the onset of female cancers. Hence, before planning a larger population study, it is advisable to sort out the possible functional SNPs. To accomplish this goal, data available in the dbSNP database and different computer programs can be used. To the best of our knowledge, until now there has been no such study on record for the BARD1 gene. Therefore, this study was undertaken to find the functional nsSNPs in BARD1.

RESULT

2.85% of all SNPs in the dbSNP database were present in the coding regions. SIFT predicted 11 out of 50 nsSNPs as not tolerable and PolyPhen assessed 27 out of 50 nsSNPs as damaging. FastSNP revealed that the rs58253676 SNP in the 3' UTR may have splicing regulator and enhancer functions. In the 5' UTR, rs17489363 and rs17426219 may alter the transcriptional binding site. The intronic region SNP rs67822872 may have a medium-high risk level. The protein structures 1JM7, 3C5R and 2NTE were predicted by PDBSum and shared 100% similarity with the BARD1 amino acid sequence. Among the predicted nsSNPs, rs4986841, rs111367604, rs13389423 and rs139785364 were identified as deleterious and damaging by the SIFT and PolyPhen programs. Additionally, I-Mutant showed a decrease in stability for these nsSNPs upon mutation. Finally, the ExPASy-PROSIT program revealed that the predicted deleterious mutations are contained in the ankyrin ring and BRCT domains.

CONCLUSION

Using the available bioinformatics tools and the data present in the dbSNP database, the four nsSNPs, rs4986841, rs111367604, rs13389423 and rs139785364, were identified as deleterious, reducing the protein stability of BARD1. Hence, these SNPs can be used for the larger population-based studies of female cancers.