scholarly journals In silico design and validation of a highly degenerate primer pair: a systematic approach

Author(s):  
Prosper Obed Chukwuemeka ◽  
Haruna Isiyaku Umar ◽  
Oluwatoyin Folake Olukunle ◽  
Oluwaseyi Matthew Oretade ◽  
Christopher Busayo Olowosoke ◽  
...  

Abstract Background The techniques of amplifying genetic materials have enabled the extensive study of several biological activities outside the biological milieu of living systems. More recently, this approach has been extended to amplify population of genes, from evolutionarily related gene family for detection and evaluation of microbial consortial with several unique potentialities (e.g., enzymatic degradability). Conceivably, primer mixtures containing substitutions of different bases at specific sites (degenerate primers) have enabled the amplification of these genes in PCR reaction. However, the degenerate primer design problem (DPD) is a constraint to designing this kind of primer. To date, different algorithms now exist to solve various versions of DPD problem, many of which, only few addresses and satisfy the criteria to design primers that can extensively cover high through-put sequences while striking the balance between specificity and efficiency. The highly degenerate primer (HYDEN) design software program primarily addresses this variant of DPD problem termed “maximum coverage-degenerate primer design (MC-DPD)” and its heuristics have been substantiated for optimal efficiency from significant successes in PCR. In spite of the premium presented for designing degenerate primers, literature search has indicated relatively little use of its heuristics. This has been thought to result from the complexity of the program since it is run only by command-line, hence limiting its accessibility. To solve this problem, researchers have optionally considered the manual design of degenerate primers or design through software programs that provides accessibility through a graphical user interface (GUI). Realizing this, we have attempted in this study to provide a user-friendly approach for researchers with little or no background in bioinformatics to design degenerate primers using HYDEN Results Virtual Tests of our designed degenerate primer pair through in silico PCR substantiated the correspondence between efficiency and coverage with the target sequences as pre-defined by the initial HYDEN output, thereby validating the potentials of HYDEN to effectively solve the MC-DPD problem. Additionally, the designed primer-pair mechanistically amplified all sequences used as a positive control with no amplification observed in the negative controls. Conclusion In this study, we provided a turnkey protocol to simplify the design of degenerate primers using the heuristics of the HYDEN software program.

2021 ◽  
Vol 1162 ◽  
pp. 144-150
Author(s):  
Retno Arianingrum ◽  
Hari Purnomo ◽  
Widya Nur Ramadhina ◽  
Rama Chrismara

Chalcone has a variety of interesting biological activities, including as an antioxidant and anticancer. Antioxidants are molecules that can retard or prevent the oxidation process or inhibit the formation of free radicals. p-Hydroxy-m-Methoxy Chalcone (pHmMC) is a chalcone derivative reported has anticancer activity both in used single and in combination treatment with Doxorubicin (DOX) in breast cancer cell lines. DOX is one of the chemotherapy agents widely used in cancer treatment but the medicine has side effects of cardiotoxicity. This effect is generally associated with free radical formation. This study aims to find out the activity of pHmMC as an antioxidant both in used single and in combination treatment with DOX by in vitro and to explore the potential of pHmMC as an antioxidant by in silico. Activity tests as antioxidants were measured by 1,1-diphenyl-2-picrylhydrazyl (DPPH) test. Ascorbic acid (Vitamin C) was used as a positive control. Antioxidant activity was calculated as the value of 50% Inhibition Concentration (IC50). In silico study was carried out by molecular docking using Protein Ligand ANT System (PLANTS) software with peroxiredoxin 5 [1HD2] as the target. The results showed that the IC50 values of pHmMC, DOX, and Vitamin C were 11.9; 21.6 and 3.3 μ/mL respectively. The combination of pHmMC-DOX has a higher antioxidant activity than single pHmMC or single DOX. The docking molecular showed that there were similarities amino acids involved in the interaction between PRDX5[1HD2]-pHmMC and PRDX5[1HD2]-DOX. This research indicated that pHmMC and pHmMC-DOX are potentially developed as an antioxidant.


2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Javier Alonso Iserte ◽  
Betina Ines Stephan ◽  
Sandra Elizabeth Goñi ◽  
Cristina Silvia Borio ◽  
Pablo Daniel Ghiringhelli ◽  
...  

Designing degenerate PCR primers for templates of unknown nucleotide sequence may be a very difficult task. In this paper, we present a new method to design degenerate primers, implemented in family-specific degenerate primer design (FAS-DPD) computer software, for which the starting point is a multiple alignment of related amino acids or nucleotide sequences. To assess their efficiency, four different genome collections were used, covering a wide range of genomic lengths: Arenavirus ( nucleotides), Baculovirus ( to  bp), Lactobacillus sp. ( to  bp), and Pseudomonas sp. ( to  bp). In each case, FAS-DPD designed primers were tested computationally to measure specificity. Designed primers for Arenavirus and Baculovirus were tested experimentally. The method presented here is useful for designing degenerate primers on collections of related protein sequences, allowing detection of new family members.


2018 ◽  
Vol 15 (2) ◽  
pp. 127-135 ◽  
Author(s):  
Parvesh Singh ◽  
Nomandla Ngcoya ◽  
Ramgopal Mopuri ◽  
Nagaraju Kerru ◽  
Neha Manhas ◽  
...  

Background: Diabetes Mellitus (DM) is a complex metabolic disease illustrated by abnormally high levels of plasma glucose or hyperglycaemia. Accordingly, several α-glucosidase inhibitors have been developed for the treatment of diabetes and other degenerative disorders. While, a coumarin ring has the privilege to represent numerous natural and synthetic compounds with a wide spectrum of biological activities e.g. anti-cancer, anti-HIV, anti-viral, anti-malarial, anti-microbial, anti-convulsant, anti-hypertensive properties. Besides this, coumarins have also shown potential to inhibit α-glucosidase leading to a generation of new promising antidiabetic agents. However, the testing of O-substituted coumarins for α-glucosidase inhibition has evaded the attention of medicinal chemists. Methods: For O-alkylation/acetylation reactions, the hydroxyl coumarins (A-B) initially activated by K2CO3 in dry DMF were reacted with variedly substituted haloalkanes at room temperature under nitrogen. The synthesized compounds were tested for their α-glucosidase (from Saccharomyces cerevisiae) inhibitory activity and anti-oxidant activity using DPPH radical scavenging activity. In silico docking simulations were conducted using CDocker module in DS (Accelrys) to explore the binding modes of the representative compounds in the catalytic site of α-glucosidase. Results: All the coumarin analogues (A1, B1, A2-A10, B2-B8) including their precursors (A-B) were evaluated for their in vitro α-glucosidase inhibition using acarbose as a standard inhibitor. All the mono O-alkylated coumarins (except A1) showed significant (p <0.05) α-glucosidase inhibition relative to the hydroxyl coumarin (A) with IC50 values ranging between 11.084±0.117 to 145.24± 29.22 µg/mL. Compound 7-(benzyloxy)-4, 5-dimethyl-2H-chromen-2-one (A9) bearing a benzyl group (Ph-CH2-) at position 7 showed a remarkable (p <0.05) increase in the activity (IC50 = 11.084±0.117 µg/mL), almost four-fold more than acarbose (IC50 = 40.578±5.999 µg/mL). The introduction of –NO2 group dramatically improved the anti-oxidant activity of coumarin, while the O-alkylation/acetylation decreased the activity. Conclusion: The present study describes the synthesis of functionalized coumarins and their evaluation for α-glucosidase inhibition and antioxidant activity under in vitro conditions. Based on IC50 data, the mono O-alkylated coumarins were observed to be stronger inhibitors of α-glucosidase with respect to their bis O-alkylated analogues. Coumarin (A9) bearing O-benzyloxy group displayed the strongest α-glucosidase inhibition, even higher than the standard inhibitor acarbose. The coumarin (A10) bearing –NO2 group showed the highest anti-oxidant activity amongst the synthesized compounds, almost comparable to the ascorbic acid. Finally, in silico docking simulations revealed the role of hydrogen bonding and hydrophobic forces in locking the compounds in catalytic site of α-glucosidase.


2020 ◽  
Vol 16 ◽  
Author(s):  
Mahboob Ali ◽  
Momin Khan ◽  
Khair Zaman ◽  
Abdul Wadood ◽  
Maryam Iqbal ◽  
...  

: Background: The inhibition of α-amylase enzyme is one of the best therapeutic approach for the management of type II diabetes mellitus. Chalcone possesses a wide range of biological activities. Objective: In the current study chalcone derivatives (1-17) were synthesized and evaluated their inhibitory potential against α-amylase enzyme. Method: For that purpose, a library of substituted (E)-1-(naphthalene-2-yl)-3-phenylprop-2-en-1-ones was synthesized by ClaisenSchmidt condensation reaction of 2-acetonaphthanone and substituted aryl benzaldehyde in the presence of base and characterized via different spectroscopic techniques such as EI-MS, HREI-MS, 1H-, and 13C-NMR. Results: Sixteen synthetic chalcones were evaluated for in vitro porcine pancreatic α-amylase inhibition. All the chalcones demonstrated good inhibitory activities in the range of IC50 = 1.25 ± 1.05 to 2.40 ± 0.09 μM as compared to the standard commercial drug acarbose (IC50 = 1.34 ± 0.3 μM). Conclusion: Chalcone derivatives (1-17) were synthesized, characterized, and evaluated for their α-amylase inhibition. SAR revealed that electron donating groups in the phenyl ring have more influence on enzyme inhibition. However, to insight the participation of different substituents in the chalcones on the binding interactions with the α-amylase enzyme, in silico (computer simulation) molecular modeling analyses were carried out.


2020 ◽  
Vol 20 (4) ◽  
pp. 464-475 ◽  
Author(s):  
Yang Lu ◽  
Wencui Yin ◽  
Mohammad S. Alam ◽  
Adnan A. Kadi ◽  
Yurngdong Jahng ◽  
...  

Background: Cancer is one of the leading causes of mortality globally. To cope with cancer, it is necessary to develop anticancer drugs. Bioactive natural products, i.e. diarylheptanoids, have gained significant attention of researchers owing to their intriguing structures and potent biological activities. In this article, considering the development of anticancer drugs with enhanced selectivity towards cancerous cells, a series of Cyclic Diarylheptanoids (CDHs) are designed, synthesized and evaluated their biological activity. Objective: To establish an easy route for the synthesis of diarylheptanoids, and evaluate their antiproliferative, and topoisomerase-I & -IIα inhibitory activities, for developing potential anticancer drugs among CDHs. Methods: Diarylheptanoids were synthesized from reported linear diarylheptanoids using the classical Ullmann reaction. Antibacterial activity was evaluated by the filter paper disc diffusion method. Cell viability was assessed by measuring mitochondrial dehydrogenase activity with a Cell Counting Kit (CCK-8). Topoisomerases I and II (topo-I and -IIα) inhibitory activity was measured by the assessment of relaxation of supercoiled pBR322 plasmid DNA. IFD protocol of Schrodinger Maestro v11.1 was used to characterize the binding pattern of studied compounds with the ATPase domain of the human topo-IIα. Results: The synthesized CDHs were evaluated for their biological activities (antibacterial, antiproliferative, and topoisomerase-I & -IIα inhibitory activities, respectively). Leading to obtain a series of anticancer agents with the least inhibitory activities against different microbes, improving their selectivity for cancer cells. In brief, most of the synthesized CDHs had excellent antiproliferative activity against T47D (human breast cancer cell line). Pterocarine possessed the strongest activity (2i; IC50 = 0.63µM) against T47D. The cyclic diarylheptanoid 2b induced 30% inhibition of topoisomerase-IIα activity at 100μM compared with the reference of etoposide, which induced 72% inhibition. Among the tested compounds, galeon (2h) displayed very low activity against four bacterial strains. Compounds 2b, 2h, and 2i formed hydrogen bonds with Thr215, Asn91, Asn120, Ala167, Lys168 and Ile141 residues, which are important for binding of ligand compound to the ATPase binding site of topoisomerase IIα by acting as ATP competitive molecule validated by docking study. In silico Absorption, Distribution, Metabolism and Excretion (ADME) analysis revealed the predicted ADME parameters of the studied compounds which showed recommended values. Conclusion: A series of CDHs were synthesized and evaluated for their antibacterial, antiproliferative, and topo-I & -IIα inhibitory activities. SARs study, molecular docking study and in silico ADME analysis were conducted. Five compounds exhibited excellent and selective antiproliferative activity against the human breast cancer cell line (T47D). Among them, a compound 2h showed topo-IIα activity by 30% at 100µM, which represented a moderate intensity of inhibition compared with etoposide. Three of them formed hydrogen bonds with Thr215, Asn91, Asn120, and Ala167 residues, which are considered as crucial residues for binding to the ATPase domain of topoisomerase IIα. According to in silico drug-likeness property analysis, three compounds are expected to show superiority over etoposide in case of absorption, distribution, metabolism and excretion.


Author(s):  
Dnyaneshwar Baswar ◽  
Abha Sharma ◽  
Awanish Mishra

Background: Alzheimer’s disease (AD), an irreversible complex neurodegenerative disorder, is most common type of dementia, with progressive loss of cholinergic neurons. Based on the multi- factorial etiology of Alzheimer’s disease, novel ligands strategy appears as up-coming approach for the development of newer molecules against AD. This study is envisaged to investigate anti-Alzheimer’s potential of 10 synthesized compounds. The screening of compounds (1-10) was carried out using in silico techniques. Methods: For in silico screening of physicochemical properties of compounds molinspiration property engine v.2018.03, Swiss ADME online web-server and pkCSM ADME were used. For pharmacodynamic prediction PASS software while toxicity profile of compounds were analyzed through ProTox-II online software. Simultaneously, molecular docking analysis was performed on mouse AChE enzyme (PDB ID:2JGE, obtained from RSCB PDB) using Auto Dock Tools 1.5.6. Results: Based on in silico studies, compound 9 and 10 have been found to have better drug likeness, LD50 value, and better anti-Alzheimer’s, nootropic activities. However, these compounds had poor blood brain barrier (BBB) permeability. Compound 4 and 9 were predicted with better docking score for AChE enzyme. Conclusion: The outcome of in silico studies have suggested, out of various substitutions at different positions of pyridoxine-carbamate, compound 9 have shown promising drug likeness, with better safety and efficacy profile for anti-Alzheimer’s activity. However, BBB permeability appears as one the major limitation of all these compounds. Further studies are required to confirm its biological activities.


Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1840
Author(s):  
Camilo Febres-Molina ◽  
Jorge A. Aguilar-Pineda ◽  
Pamela L. Gamero-Begazo ◽  
Haruna L. Barazorda-Ccahuana ◽  
Diego E. Valencia ◽  
...  

ND1 subunit possesses the majority of the inhibitor binding domain of the human mitochondrial respiratory complex I. This is an attractive target for the search for new inhibitors that seek mitochondrial dysfunction. It is known, from in vitro experiments, that some metabolites from Annona muricata called acetogenins have important biological activities, such as anticancer, antiparasitic, and insecticide. Previous studies propose an inhibitory activity of bovine mitochondrial respiratory complex I by bis-tetrahydrofurans acetogenins such as annocatacin B, however, there are few studies on its inhibitory effect on human mitochondrial respiratory complex I. In this work, we evaluate the in silico molecular and energetic affinity of the annocatacin B molecule with the human ND1 subunit in order to elucidate its potential capacity to be a good inhibitor of this subunit. For this purpose, quantum mechanical optimizations, molecular dynamics simulations and the molecular mechanics/Poisson–Boltzmann surface area (MM/PBSA) analysis were performed. As a control to compare our outcomes, the molecule rotenone, which is a known mitochondrial respiratory complex I inhibitor, was chosen. Our results show that annocatacin B has a greater affinity for the ND1 structure, its size and folding were probably the main characteristics that contributed to stabilize the molecular complex. Furthermore, the MM/PBSA calculations showed a 35% stronger binding free energy compared to the rotenone complex. Detailed analysis of the binding free energy shows that the aliphatic chains of annocatacin B play a key role in molecular coupling by distributing favorable interactions throughout the major part of the ND1 structure. These results are consistent with experimental studies that mention that acetogenins may be good inhibitors of the mitochondrial respiratory complex I.


Author(s):  
Mohammed S. Alqahtani ◽  
Hanan M. Al-Yousef ◽  
Ali S. Alqahtani ◽  
Md Tabish Rehman ◽  
Mohamed F. AlAjmi ◽  
...  

AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hend M. Tag ◽  
Amna A. Saddiq ◽  
Monagi Alkinani ◽  
Nashwa Hagagy

AbstractHaloferax sp strain NRS1 (MT967913) was isolated from a solar saltern on the southern coast of the Red Sea, Jeddah, Saudi Arabia. The present study was designed for estimate the potential capacity of the Haloferax sp strain NRS1 to synthesize (silver nanoparticles) AgNPs. Biological activities such as thrombolysis and cytotoxicity of biosynthesized AgNPs were evaluated. The characterization of silver nanoparticles biosynthesized by Haloferax sp (Hfx-AgNPs) was analyzed using UV–vis spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR). The dark brown color of the Hfx-AgNPs colloidal showed maximum absorbance at 458 nm. TEM image analysis revealed that the shape of the Hfx-AgNPs was spherical and a size range was 5.77- 73.14 nm. The XRD spectra showed a crystallographic plane of silver nanoparticles, with a crystalline size of 29.28 nm. The prominent FTIR peaks obtained at 3281, 1644 and 1250 cm− 1 identified the Functional groups involved in the reduction of silver ion reduction to AgNPs. Zeta potential results revealed a negative surface charge and stability of Hfx-AgNPs. Colloidal solution of Hfx-AgNPs with concentrations ranging from 3.125 to 100 μg/mL was used to determine its hemolytic activity. Less than 12.5 μg/mL of tested agent showed no hemolysis with high significant decrease compared with positive control, which confirms that Hfx-AgNPs are considered non-hemolytic (non-toxic) agents according to the ISO/TR 7405-1984(f) protocol. Thrombolysis activity of Hfx-AgNPs was observed in a concentration-dependent manner. Further, Hfx-AgNPs may be considered a promising lead compound for the pharmacological industry.


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