Aliphatic Index Research Articles

Optimized Signal Peptide for Secretory Expression of Human Recombinant Somatropin in E. coli.

Purpose: The human somatropin is a single-chain polypeptide with a pivotal role in various biological processes. Although Escherichia coli is considered as a preferred host for the production of human somatropin, the high expression of this protein in E. coli results in the accumulation of protein as inclusion bodies. Periplasmic expression using signal peptides could be used to overcome the formation of inclusion bodies; still, the efficiency of each of the signal peptides in periplasmic transportation is varied and often is protein specific. The present study aimed to use in silico analysis to identify an appropriate signal peptide for the periplasmic expression of human somatropin in E. coli. Methods: A library containing 90 prokaryotic and eukaryotic signal peptides were collected from the signal peptide database, and each signal's characteristics and efficiency in connection with the target protein were analyzed by different software. The prediction of the secretory pathway and the cleavage position was determined by the signalP5 server. Physicochemical properties, including molecular weight, instability index, gravity, and aliphatic index, were investigated by ProtParam software. Results: The results of the present study showed that among all the signal peptides studied, five signal peptides ynfB, sfaS, lolA, glnH, and malE displayed high scores for periplasmic expression of human somatropin in E. coli, respectively. Conclusion: In conclusion, the results indicated that in-silico analysis could be used for the identification of suitable signal peptides for the periplasmic expression of proteins. Further laboratory studies can evaluate the accuracy of the results of in silico analysis.

Performance of Novel Antimicrobial Protein Bg_9562 and In Silico Predictions on Its Properties with Reference to Its Antimicrobial Efficiency against Rhizoctonia solani.

Bg_9562 is a potential broad-spectrum antifungal effector protein derived from the bacteria Burkholderia gladioli strain NGJ1 and is effective against Rhizoctonia solani, the causal agent of sheath blight in rice. In the present study, in vitro antifungal assays showed that Bg_9562 was efficient at 35 °C and 45 °C and ineffective either at high acidic pH (3.0) or alkaline pH (9.5) conditions. Compatibility studies between the native bioagents Trichoderma asperellum TAIK1 and Bacillus subtilis BIK3 indicated that Bg_9562 was compatible with the bioagents. A field study using foliar spray of the Bg_9562 protein indicated the need of formulating the protein before its application. In silico analysis predicted that Bg_9562 possess 111 amino acid residues (46 hydrophobic residues, 12 positive and 8 negative residues) with the high aliphatic index of 89.92, attributing to its thermostability with a half-life of 30 h. Bg_9562 (C491H813N137O166S5) possessed a protein binding potential of 1.27 kcal/mol with a better possibility of interacting and perturbing the membrane, the main target for antimicrobial proteins. The secondary structure revealed the predominance of random coils in its structure, and the best 3D model of Bg_9562 was predicted using an ab initio method with Robetta and AlphaFold 2. The predicted binding ligands were nucleic acids and zinc with confidence scores of 0.07 and 0.05, respectively. The N-terminal region (1–14 residues) and C-terminal region (101 to 111) of Bg_9562 residues were predicted to be disordered regions. Stability and binding properties of the protein from the above studies would help to encapsulate Bg_9562 using a suitable carrier to maintain efficiency and improve delivery against Rhizoctonia solani in the most challenging rice ecosphere.

Investigation of influence features on expression of lignocellulases in Escherichia coli and selection of bioinformatic tools for prediction of the enzymes expressibility based on amino acid sequences

Lignocellulases are the most important enzymes for bioeconomy development and have gained many interests in mining new coding-genes from metagenomic DNA data recently. However, the identification of genes suitable for successful expression in E. coli for the enzyme characterization is still a big challenge. In this study, 18 lignocellullase genes from metagenomic data of bacteria in goats' rumen, termite gut and humus were expressed in E. coli. Then 18 nucleotide and amino acid sequences were used to measure 12 impact features and to investigate tools for prediction of their E. coli expressibility. The features closely related to the enzymes expression level included aliphatic side chains of amino acids (aliphatic index: AI), grand average of hydropathicity, protein folding ability (fold index: FI) and FI was the most important factor. The investigation of two models for prediction of the enzymes expressibility in E. coli showed that 100% sequences predicted to be high expressibility by Periscope were the sequences expressed at high level in experiments. In contrast, 100% sequences predicted to be low expressibilty by ESPRESSO constituted a low expression level in experiments. This result can be a good reference for screening genes before expressing in E. coli.

Structural heterogeneity assessment among the isoforms of fungal 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase: a comparative in silico perspective

BackgroundThe primary amino acid sequence of a protein is a translated version from its gene sequence which carries important messages and information concealed therein. The present study unveils the structure-function and evolutionary aspects of 1-aminocyclopropane-1-carboxylic acid deaminase (ACCD) proteins of fungal origin. ACCD, an important plant growth-promoting microbial enzyme, is less frequent in fungi compared to bacteria. Hence, an inclusive understanding of fungal ACC deaminases (fACCD) has brought forth here. ResultsIn silico investigation of 40 fACCD proteins recovered from NCBI database reveals that fACCD are prevalent in Colletotrichum (25%), Fusarium (15%), and Trichoderma (10%). The fACCD were found 16.18–82.47 kDa proteins having 149–750 amino acid residues. The enzyme activity would be optimum in a wide range of pH having isoelectric points 4.76–10.06. Higher aliphatic indices (81.49–100.13) and instability indices > 40 indicated the thermostability nature. The secondary structural analysis further validates the stability owing to higher α-helices. Built tertiary protein models designated as ACCNK1–ACCNK40 have been deposited in the PMDB with accessions PM0083418–39 and PM0083476–93. All proteins were found as homo-dimer except ACCNK13, a homo-tetramer. ConclusionsHence, these anticipated features would facilitate to explore and identify novel variants of fungal ACCD in vitro aiming to industrial-scale applications. Highlights•First comprehensive in silico annotation of fungal ACC deaminases (fACCD).•Colletotrichum, Fusarium, and Trichoderma are predominant to possess fACCD.•fACCD are 16.18–82.47 kDa proteins with optimal pH between 4.76 and 10.06.•Majority are thermostable with higher aliphatic indices and instability indices < 40.•fACCD are found as homo-dimer except ACCNK13, a homo-tetramer. Graphical Abstract▪

Determination of Insecticidal Potential of Lentil (Lens culinaris L.) Lectin through Bio-computational Tools

Plant and animals are the chief source of lectins playing important role in defense system against various pathogens. Lentil (Lens culinaris) lectin (LL) binds to polysaccharides and other glycoconjugates in a reversibly manner which contain glucose or mannose type sugars. In present investigation, the insecticidal potential of LL is determined through In-silico study by using various bio-computational tools against mustard aphid. The physico-chemical property of LL also exhibited theoretical pI is 5.22, GRAVY value is -0.086, aliphatic index is 78.33 and instability index is 27.51. The functional domain exposure of LL showed metal interacting and N-linked glycosylated amino acid residues. The structural behavior and biological activity of LL protein is determined by secondary structure prediction and its other attributes. Present investigation explores the potential of insecticidal activity of lentil lectin against mustard aphid by using numerous In silico approaches. This probably helps in understanding of LL three dimensional protein structures.

Novel Feather Degrading Keratinases from Bacillus cereus Group: Biochemical, Genetic and Bioinformatics Analysis

In this study, five keratinolytic bacteria were isolated from poultry farm waste of Eastern Province, Saudi Arabia. The highest keratinase activity was obtained at 40–45 °C, pH 8–9, feather concentration 0.5–1%, and using white chicken feather as keratin substrate for 72 h. Enhancement of keratinase activity through physical mutagen UV radiation and/or chemical mutagen ethyl methanesulfonate (EMS) resulted in five mutants with 1.51–3.73-fold increased activity over the wild type. When compared with the wild type, scanning electron microscopy validated the mutants’ effectiveness in feather degradation. Bacterial isolates are classified as members of the S8 family peptidase Bacillus cereus group based on sequence analysis of the 16S rRNA and keratinase genes. Interestingly, keratinase KerS gene shared 95.5–100% identity to keratinase, thermitase alkaline serine protease, and thermophilic serine protease of the B. cereus group. D137N substitution was observed in the keratinase KerS gene of the mutant strain S13 (KerS13uv+ems), and also seven substitution variations in KerS26 and KerS26uv of strain S26 and its mutant S26uv. Functional analysis revealed that the subtilisin-like serine protease domain containing the Asp/His/Ser catalytic triad of KerS gene was not affected by the predicted substitutions. Prediction of physicochemical properties of KerS gene showed instability index between 17.5–19.3 and aliphatic index between 74.7–75.7, which imply keratinase stability and significant thermostability. The docking studies revealed the impact of substitutions on the superimposed structure and an increase in binding of mutant D137N of KerS13uv+ems (affinity: −7.17; S score: −6.54 kcal/mol) and seven mutants of KerS26uv (affinity: −7.43; S score: −7.17 kcal/mol) compared to the wild predicted structure (affinity: −6.57; S score: −6.68 kcal/mol). Together, the keratinolytic activity, similarity to thermostable keratinases, and binding affinity suggest that keratinases KerS13uv+ems and KerS26uv could be used for feather processing in the industry.

Computational construction of a glycoprotein multi-epitope subunit vaccine candidate for old and new South-African SARS-CoV-2 virus strains

The discovery of a new SARS-CoV-2 virus strain in South Africa presents a major public health threat, therefore contributing to increased infections and transmission rates during the second wave of the global pandemic. This study lays the groundwork for the development of a novel subunit vaccine candidate from the circulating strains of South African SARS-CoV-2 and provides an understanding of the molecular epidemiological trend of the circulating strains. A total of 475 whole-genome nucleotide sequences from South Africa submitted between December 1, 2020 and February 15, 2021 available at the GISAID database were retrieved based on its size, coverage level and hosts. To obtain the distribution of the clades and lineages of South African SARS-CoV-2 circulating strains, the metadata of the sequence retrieved were subjected to an epidemiological analysis. There was a prediction of the cytotoxic T lymphocytes (CTL), Helper T cells (HTL) and B-cell epitopes. Furthermore, there was allergenicity, antigenicity and toxicity predictions on the epitopes. The analysis of the physicochemical properties of the vaccine construct was performed; the secondary structure, tertiary structure and B-cell 3D conformational structure of the vaccine construct were predicted. Also, molecular binding simulations and dynamics simulations were adopted in the prediction of the vaccine construct's stability and binding affinity with TLRs. Result obtained from the metadata analysis indicated lineage B.1.351 to be in higher circulation among various circulating strains of SARS-CoV-2 in South Africa and GH has the highest number of circulating clades. The construct of the novel vaccine was antigenic, non-allergenic and non-toxic. The Instability index (II) score and aliphatic index were estimated as 41.74 and 78.72 respectively. The computed half-life in mammalian reticulocytes was 4.4 h in vitro, for yeast and in E. coli was >20 h and >10 h in vivo respectively. The grand average of hydropathicity (GRAVY) score is estimated to be −0.129, signifying the hydrophilic nature of the protein. The molecular docking indicates that the vaccine construct has a high binding affinity towards the TLRs with TLR 3 having the highest binding energy (−1203.2 kcal/mol) and TLR 9 with the lowest (−1559.5 kcal/mol). These results show that the vaccine construct is promising and should be evaluated using animal model.

Identifying immunodominant multi-epitopes from the envelope glycoprotein of the Lassa mammarenavirus as vaccine candidate for Lassa fever.

Lassa fever is a zoonotic acute viral hemorrhagic disease caused by Lassa virus (LASV). There is currently no licensed vaccine for the prevention of the disease. This study is aimed at discovering immunodominant epitopes from the envelope glycoprotein of the Lassa mammarenavirus and designing of a multi-epitope vaccine candidate (VC). The amino acid sequences of the envelope glycoprotein of 26 strains of LASV from five countries were selected. After evaluation for antigenicity, immunogenicity, allergenicity, and toxicity, immunodominant CD8, CD4, and linear B lymphocytes were also selected. The selected epitopes were modelled and a molecular docking with the appropriate major histocompatibility complex (MHC) proteins was performed. Using an adjuvant and linkers, a multi-epitope VC was designed. The VC was evaluated for its physicochemical and immunological properties and structurally refined, validated, and mutated (disulphide engineering). The complex formed by the VC and the toll-like receptor-4 receptor was subjected to molecular dynamic simulation (MDS) followed by in silico cloning in a plasmid vector. A VC with 203 sequences, 22.13 kDa weight, isoelectric point of 9.85 (basic), instability index value of 27.62, aliphatic index of 68.87, and GRAVY value of -0.455 (hydrophilic) emerged. The VC is predicted to be non-allergenic with antigenicity, MHC I immunogenicity, and solubility upon overexpression values of 0.81, 2.04, and 0.86 respectively. The VC also has an estimated half-life greater than 10 hours in Escherichia coli and showed stability in all the parameters of MDS. The VC shows good promise in the prevention of Lassa fever but further tests are required to validate its safety and efficacy.

Elucidation of kinetic and structural properties of eye lens ζ-crystallin: an in vitro and in silico approach

The Arabian Camelus dromedarius contains significant concentration of eye lens ζ-crystallin. This enzyme is also present in other life forms including humans, however in lower catalytic amounts. The recombinant camel ζ-crystallin was expressed in the E. coli BL21 (DE3) pLysS strain and purified using HisTrap column. The Km of the enzyme for 9,10-phenanthrenequinone (9,10-PQ) substrate and NADPH cofactor was determined to be 11.66 and 50.93 µM, respectively. The Vmax for 9,10-PQ and NADPH was obtained as 23.19 and 19.98 μM min−1, respectively. The optimum activity of the purified enzyme was found to be at pH 6.0 and at 55 °C. Different physico-chemical parameters were analysed including instability index (II), aliphatic index (AI) and the GRAVY index to establish proper characterization. The sequence of the recombinant ζ-crystallin was subjected to homology modelling using SWISS-MODEL webserver followed by validation of the modelled target structure. The evaluation of the modelled ζ-crystallin was performed by several parameters including Ramachandran plot, Z-score values followed by molecular dynamics (MD) simulation. The cumulative analysis of the physico-chemical, quantitative, qualitative and the essential dynamics of simulation of ζ-crystallin and its complexes with 9,10-PQ and NADPH helped in verifying the acceptable quality and stability of the ζ-crystallin structure. Communicated by Ramaswamy H. Sarma

Wettability alteration by surface adsorption of asphaltene molecular in carbonate porous media

In this study, the effect of four asphaltene samples on the wettability alteration of carbonate reservoir rock is investigated. The wettability of each core, before and after the deposition of asphaltene, is evaluated using two methods: relative permeability and contact angle. Normally, core samples got oil-wet after the asphaltene deposition, and the contact angle on the surface increased. However, the degree of wettability of each crude oil was different based on the asphaltene composition. According to the elemental analysis of asphaltene samples, the H/C index alone cannot show the asphaltene adsorption potential. The sulfur is an element that enhances asphaltene-asphaltene interaction, but weakens calcite-asphaltene interaction. The oxygen can also enhance the adsorption of asphaltene to calcite, depending on the functional group and its location in the molecule. According to the results of the FTIR spectrum of asphaltene and rock powder, there are three main mechanisms for adsorption of asphaltene to calcite surface, followed by wettability alteration. The first mechanism is the electrostatic interaction between asphaltenes and calcite, which is because of the poly-aromatic nature of asphaltene. The intensity of the electrostatic interaction between asphaltene and rock is directly related to the aromaticity and condensation index of asphaltene. The second mechanism is dispersion, in which the side alkyl chain in the aromatic rings causes asphaltene to be adsorbed into the surface of the rock. The intensity of this mechanism is also proportional to the aliphatic index and the long chain index of asphaltene. The third mechanism, which is less important than the two above-mentioned ones, is the hydrogen bond that is proportional to the ROH index, calculated from the FTIR spectrum. To study the relationship between the electrostatic property of the surface after asphaltene adsorption with surface wettability, zeta potential was used. The results showed that asphaltene, because of its acidic nature, adsorbed to the calcite surface, would make its zeta potential negative. However, more negative zeta potential will not necessarily increase the contact angle. In other words, the surface wettability and electrostatic properties of the surface are two distinct categories that do not have a clear relationship. The surface wettability is more dependent on the amount of aromaticity index of asphaltene, whereas the electrostatic property of the surface is a function of the percentage of oxygen and sulfur compounds in the asphaltene structure. Finally, the scanning electron microscopy (SEM), along with the elemental analysis, was used to investigate the dispersion of various elements at the calcite surface after wettability alteration. The calcium and oxygen are the main elements of calcite production; therefore, the elemental mapping indicated that the surface would be covered with calcium and oxygen prior to the deposition of asphaltene (CaCO3). But by asphaltene deposition on the rock surface, calcium will be observed scattered in some points. For this reason, the amount of calcium in the elemental mapping can be related to the level of surface wettability, so that the lower the percentage of calcium in the surface, the more the asphaltene is adsorbed into calcite, and the changes in the contact angle is greater.

Cloning, Amplified Expression and Bioinformatics Analysis of a Putative Nucleobase Cation Symporter-1 (NCS-1) Protein From Rhodococcus erythropolis

The Rhodococcus erythropolis gene DYC18_RS18060 (1437 bp) putatively codes for a secondary transporter of the Nucleobase Cation Symporter-1 (NCS-1) protein family (478 amino acids). The DYC18_RS18060 gene was successfully cloned from R. erythropolis genomic DNA with addition of EcoRI and PstI restriction sites at the 5′ and 3′ ends, respectively, using PCR technology. The amplified gene was introduced into IPTG-inducible plasmid pTTQ18 immediately upstream of the sequence coding for a His6-tag. The construct was transformed into Escherichia coli BL21(DE3), then amplified expression of the DYC18_RS18060-His6 protein was achieved with detection by SDS-PAGE and western blotting. Computational methods predicted that DYC18_RS18060 has a molecular weight of 51.1 kDa and isoelectric point of 6.58. The protein was predicted to be hydrophobic in nature (aliphatic index 113.24, grand average of hydropathicity 0.728) and to form twelve transmembrane spanning α-helices with both N- and C-terminal ends at the cytoplasmic side of the membrane. Whilst database sequence similarity searches and phylogenetic analysis suggested that the substrate of DYC18_RS18060 could be cytosine, this was not certain based on comparisons of residues involved in substrate binding in experimentally characterised NCS-1 proteins. This study has laid foundations for further structural and functional studies of DYC18_RS18060 and other NCS-1 proteins.&#x0D; Copyright(c) The Authors

Annotation of Potential Vaccine Targets and Design of a Multi-Epitope Subunit Vaccine against Yersinia pestis through Reverse Vaccinology and Validation through an Agent-Based Modeling Approach.

Yersinia pestis is responsible for plague and major pandemics in Asia and Europe. This bacterium has shown resistance to an array of drugs commonly used for the treatment of plague. Therefore, effective therapeutics measurements, such as designing a vaccine that can effectively and safely prevent Y. pestis infection, are of high interest. To fast-track vaccine development against Yersinia pestis, herein, proteome-wide vaccine target annotation was performed, and structural vaccinology-assisted epitopes were predicted. Among the total 3909 proteins, only 5 (rstB, YPO2385, hmuR, flaA1a, and psaB) were shortlisted as essential vaccine targets. These targets were then subjected to multi-epitope vaccine design using different linkers. EAAK, AAY, and GPGPG as linkers were used to link CTL, HTL, and B-cell epitopes, and an adjuvant (beta defensin) was also added at the N-terminal of the MEVC. Physiochemical characterization, such as determination of the instability index, theoretical pI, half-life, aliphatic index, stability profiling, antigenicity, allergenicity, and hydropathy of the ensemble, showed that the vaccine is highly stable, antigenic, and non-allergenic and produces multiple interactions with immune receptors upon docking. In addition, molecular dynamics simulation confirmed the stable binding and good dynamic properties of the vaccine–TLR complex. Furthermore, in silico and immune simulation of the developed MEVC for Y. pestis showed that the vaccine triggered strong immune response after several doses at different intervals. Neutralization of the antigen was observed at the third day of injection. Conclusively, the vaccine designed here for Y. pestis produces an immune response; however, further immunological testing is needed to unveil its real efficacy.

Digenic heterozygous mutations of KCNH2 and SCN5A induced young and early-onset long QT syndrome and sinoatrial node dysfunction.

IntroductionLong QT syndrome (LQTS) is a life‐threatening inherited channelopathy, and prolonged QT intervals easily trigger malignant arrhythmias, especially torsades de pointes and ventricular fibrillation.Materials and methodsThe proband with overlapped phenotypes of LQTS and sinoatrial node dysfunction underwent some necessary examinations, including echocardiography, electrocardiogram (ECG), and Holter monitoring. Next, whole‐exome sequencing was performed, and candidate genes were validated by Sanger sequencing. RNA secondary structure and protein physical‐chemical parameter analyses were used to predict the possible structural change of the proteins induced by the mutations.ResultsWe identified the digenic heterozygous mutations of KCNH2 p.307_308del (NM_001204798, c.921_923del) and SCN5A p.R1865H (NM_001160160, c.G5594A) in the female and young proband (II: 1) of LQTS and ventricular fibrillation with repeat syncope at rest. Subsequently, she occurred with obvious sinus arrest with persistent ventricular pacing of implantable cardioverter‐defibrillator. The heterozygous SCN5Ap.R1865H was carried by her father and sister but not carried by I:2. II:1 carried with KCNH2 p.307_308del as a de novo mutation, but not existed in other family members. RNA secondary structure of KCNH2 p.307_308del showed a false regional double helix, and its amino acids' hydrophobicity was significantly weakened. For the Nav1.5 protein property, SCN5A p.R1865H slightly increased the molecular weight and aliphatic index but reduced the instability index.ConclusionsThe digenic heterozygous KCNH2 and SCN5A mutations were associated with young early‐onset long QT syndrome and sinoatrial node dysfunction.

Structural analysis of Panax ginseng glycoproteins and its anti-oligoasthenozoospermia effect in vivo

A component from ginseng in which sugars and proteins are covalently bound is named Panax ginseng glycoproteins (PGG). The contents of neutral carbohydrate, acid carbohydrate, and protein were 45.4%, 4.3% and 51.1%. The average molecular weight was 12,690 Da. The structure analysis showed that PGG had more than 1100 glycoproteins with molecular weight between 308.13 Da and 9991.52 Da, it was divided into two parts: long chain structure and short chain structure. These two parts were compared in molecular mass, number of amino acids, theoretical pI, instability index, aliphatic index and GRAVY. The in vivo distribution test of mice showed that PGG was enriched in mice testis, testicular tissue sections showed strong fluorescence signal expression on the surface of seminiferous tubules. We used cyclophosphamide (CP) to establish a mice model of oligoasthenozoospermia to investigate the anti-oligoasthenozoospermic effect of PGG. The results showed that PGG increased the levels of sex hormones T, FSH, PRL and sperm quality. Histopathology demonstrated that PGG promoted the differentiation process. The organ coefficient indicated that PGG had no obvious toxic and side effects. And the mechanism may be to affect the expression of protein levels such as p-ERK/ERK, p-AKT/AKT, Caspase-3, Bcl-2 and Bax. Therefore, PGG has the potential to develop into drugs for improving spermatogenic disorders.

Antifungal Activity of ToAP2D Peptide Against Sporothrix globosa

Improving clinical efficacy and reducing treatment time have been the focus of sporotrichosis therapy. Antimicrobial peptides ToAP2A, ToAP2C, and ToAP2D were synthesized on the basis of ToAP2 (AP02759), a peptide derived from the antimicrobial peptide database by the database filtering technology, and their physicochemical characteristics were analyzed. Compared with template peptide ToAP2, the modified peptides had much shorter length, lower molecular weight but significantly greater stability, which in return resulted in increases in the aliphatic index, hydrophilicity, and protein binding ability. Here, we show that the three derived peptides inhibit the growth of Sporothrix globosa, among which ToAP2D had the strongest anti-fungal activity. ToAP2D showed good serum stability without acute toxicity. The ToAP2D treatment inhibited the growth of S. globosa and enhanced apoptosis, which was evidenced by the upregulation of apoptosis-related protein caspase-3. The scanning electron microscopy analysis revealed deformation and rupture of S. globosa. The levels of mitochondrial membrane potential were decreased and that of the reactive oxygen species (ROS) were increased in S. globosa upon ToAP2D treatment. Moreover, ToAP2D activated metacaspase. In the in vivo study, we further demonstrated that ToAP2D inhibited the S. globosa infection of mice footpads, and its efficiency was nearly comparable to itraconazole. In summary, our results suggest that antimicrobial peptide ToAP2D has the potential for sporotrichosis therapy.

Heterologous expression and molecular modelling of L-asparaginase from Bacillus subtilis ETMC-2

Bacterial L-asparaginase is the key therapeutic enzyme in cancer therapy and is also witnessing demand as a food processing aid. In this study, L-asparaginase of newly isolated Bacillus subtilis ETMC-2 was cloned and over-expressed in Escherichia coli as an active soluble protein using ligation independent cloning strategy. The molecular mass was estimated to be 40 kDa and was optimally active at 50 °C. Zymography revealed that the enzyme was active in homo-tetramer state (~160 KDa). The encoded protein after BLASTp analysis on NCBI showed 99.73% similarity with L-ASNase that of Bacillus sp. Physico-chemical properties were predicted using Protparam leading to categorization of the enzyme as a stable protein with an instability index (II) of 19.02. The calculated aliphatic index (85.44) indicated the high thermal stability of the protein with GRAVY value of −0.317. Protein-Ligand docking revealed that the residues Thr89, Thr121, and Asp122 were fundamental in protein–ligand complexation. After homology modelling, model validation was performed using Ramachandran plot, VERIFY3D, and RMSD. The paper describes cloning, heterologous expression, catalytic characteristics and physico-chemical properties of the type II B. subtilis L-ASNase.

Advances in understanding the specificity function of transporters by machine learning

Understanding the underlying molecular mechanism of transporter activity is one of the major discussions in structural biology. A transporter can exclusively transport one ion (specific transporter) or multiple ions (general transporter). This study compared categorical and numerical features of general and specific calcium transporters using machine learning and attribute weighting models. To this end, 444 protein features, such as the frequency of dipeptides, organism, and subcellular location, were extracted for general (n = 103) and specific calcium transporters (n = 238). Aliphatic index, subcellular location, organism, Ile-Leu frequency, Glycine frequency, hydrophobic frequency, and specific dipeptides such as Ile-Leu, Phe-Val, and Tyr-Gln were the key features in differentiating general from specific calcium transporters. Calcium transporters in the cell outer membranes were specific, while the inner ones were general; additionally, when the hydrophobic frequency or Aliphatic index is increased, the calcium transporter act as a general transporter. Random Forest with accuracy criterion showed the highest accuracy (88.88% ±5.75%) and high AUC (0.964 ± 0.020), based on 5-fold cross-validation. Decision Tree with accuracy criterion was able to predict the specificity of calcium transporter irrespective of the organism and subcellular location. This study demonstrates the precise classification of transporter function based on sequence-derived physicochemical features.

Computational vaccinology guided design of multi-epitopes subunit vaccine designing against Hantaan virus and its validation through immune simulations.

The Hantaan virus belongs to Bunyaviridae family, an emerging virus that is responsible for hemorrhagic fevers. The virus is distributed worldwide and as of now there is no successful antiviral drug or vaccine developed to protect against the viral infections. Immunization or vaccination is an alternative approach for the protection against viral infections. A cost effective and thermodynamically stable vaccine should be developed to prevent a future possible pandemic. In this study a vaccine candidate was designed against the Hantaan virus, multiple immunoinformatics and reverse vaccinology tools were utilized for the prediction of both B and T cell epitopes for Nuceloprotein, RNA dependent RNA polymerase L and Envelope protein of the Hantaan virus. The individual epitopes were modeled for docking with respective HLAs and a multi-epitopes subunit vaccine candidate was constructued by joining together carefully evaluated B and T cell epitopes with suitable linkers. The vaccine model was evaluated for several physiochameical parameters i.e. Molecular weight, instability index and aliphatic index among the others, followed by 3D modeling of the vaccine for docking with TLR-4. Based on previous studies, Human beta-defensin was liked at the N-terminus of the vaccine sequence as an adjuvant to enhance immunogenicity. The docked complexes of vaccine-TLR-4 were then evaluated for residual interactions. Moreover, to validate final vaccine construct, immune simulations was carried out by C-IMMSIM server. A natural immune reponse was predicted by the immune simulation analysis. In-silico cloning was carried out using E. coli as host resulting in 0.93 CAI value, which suggests that the vaccine construct will attain maximal expression in E. coli host. The vaccine designed in this study needs experimental verification to confirm the immunogenicity and efficacy of the vaccine and ultimately used against Hantaan virus associated infections.

In Silico prediction and Comparative Modeling of proteins in Creeping Fig (Ficus pumila) plant

In the present study, the Ficus pumila have taken to analyze the proteins by their preliminary characters from the database and predicted vital role of different sequences. The F. pumila (Creeping fig) is a prostrate/climbing shrub, experiments proved various active phytochemicals and antioxidant, antimicrobial, antimutagenic, analgesic, anti-inflammatory, antiproliferative, hypoglycemic, hypolipidemic, antihyperprolactinemic, anticholinesterase, nephroprotective properties. In addition to all metabolites, it also constitutes specific proteins that were evaluated through insilico homology modeling. Though it is considered as a poisonous weed, the protein present in this plant is evaluated by physicochemical, phylogeny and amino acid proportions by protparam, Swiss model, SOPMA, Clustal omega tools to describe its structural features and to understand molecular function. The computed theoretical isoelectric point (pI) found to be more than 7 indicates basic nature of proteins. The aliphatic index ranges 67-113 indicates thermal stability of proteins. The predicted Grand average hydropathy(GRAVY) shows possibilities of enhanced interaction of these proteins with water by lowest value. Functional analysis of these proteins was performed by SOSUI server which predicted transmembrane helix and solubility. Secondary structure analysis was carried out by SOPMA revealed that Alpha helix and random coil dominated followed by extended strand, and beta turns among secondary structure elements. The modelling of three-dimensional structure of proteins was performed by Swiss model. The model was validated using protein structure checking tool- VADAR. Particularly, NAD(P)H –quinoneoxidoreductase and Glyceraldehyde-3-phosphate dehydrogenase structures were analysed by phylogenetic analysis to trace relationship and reported. The results suggesting its possible role in cellular and metabolic functions.

Genes Common in Primary Immunodeficiencies and Cancer Display Overrepresentation of Codon CTG and Dominant Role of Selection Pressure in Shaping Codon Usage

Primary immunodeficiencies (PIDs) are disorders of the immune system that involve faulty cellular, humoral, or both cellular and humoral functions. PIDs are present at the crossroad between infections, immune dysregulation, and cancers. A panel encompassing 42 genes involved in both PIDs and cancer has been investigated for the genes’ compositional properties, codon usage patterns, various forces affecting codon choice, protein properties, and gene expression profiles. In the present study, the codon choice of genes was found to be dependent upon the richness of the nucleotide; the viz AT nucleotide rich genome preferred AT ending codons. The dinucleotide TpA adversely affected protein expression, while CpG did not. The CTG codon was the most overrepresented codon in 80.95% of genes. Analysis of various protein properties, including GRAVY, AROMA, isoelectric point, aliphatic index, hydrophobicity, instability index, and numbers of acidic, basic, and neutral amino acid residues revealed that the hydrophobicity index, instability index, and numbers of acidic and basic amino acid residues are the factors affecting gene expression. Based on neutrality analysis, parity analysis, ENc-GC3 analysis, and regression analysis of nucleotides present at the first and third positions of the codon, it was determined that selection pressure, mutation pressure, and compositional constraints all participated in shaping codon usage. The study will help determine the various evolutionary forces acting on genes common to both PIDs and cancer. Codon usage analysis might be helpful in the future to augment both diseases simultaneously. The research also indicates a peculiar pattern adapted by a set of genes involved in any disease.