The novel corona virus disease 2019 (SARS-CoV 2) pandemic outbreak was alarming. The binding of SARS-CoV (CoV) spike protein (S-Protein) Receptor Binding Domain (RBD) to Angiotensin converting enzyme 2 (ACE 2) receptor initiates the entry of corona virus into the host cells leading to the infection. However, considering the mutations reported in the SARS-CoV 2 (nCoV), the structural changes and the binding interactions of the S-protein RBD of nCoV were not clear. The present study was designed to elucidate the structural changes, hot spot binding residues and their interactions between the nCoV S-protein RBD and ACE2 receptor through computational approaches. Based on the sequence alignment, a total of 58 residues were found mutated in nCoV S-protein RBD. These mutations led to the structural changes in the nCoV S-protein RBD 3d structure with 4 helices, 10 sheets and intermittent loops. The nCoV RBD was found binding to ACE2 receptor with 11 hydrogen bonds and 1 salt bridge. The major hot spot amino acids involved in the binding identified by interaction analysis after simulations includes Glu 35, Tyr 83, Asp 38, Lys 31, Glu 37, His 34 amino acid residues of ACE2 receptor and Gln 493, Gln 498, Asn 487, Tyr 505 and Lys 417 residues in nCoV S-protein RBD. Based on the hydrogen bonding, RMSD and RMSF, total and potential energies, the nCoV was found binding to ACE 2 receptor with higher stability and rigidity. Concluding, the hotspots information will be useful in designing blockers for the nCoV spike protein RBD.

Lipids play a crucial role in the entry and egress of viruses, regardless of whether they are naked or enveloped. Recent evidence shows that lipid involvement in viral infection goes much further. During replication, many viruses rearrange internal lipid membranes to create niches where they replicate and assemble. Because of the close connection between lipids and inflammation, the derangement of lipid metabolism also results in the production of inflammatory stimuli. Due to its pivotal function in the viral life cycle, lipid metabolism has become an area of intense research to understand how viruses seize lipids and to design antiviral drugs targeting lipid pathways. Palmitoylethanolamide (PEA) is a lipid-derived peroxisome proliferator-activated receptor-α (PPAR-α) agonist that also counteracts SARS-CoV-2 entry and its replication. Our work highlights for the first time the antiviral potency of PEA against SARS-CoV-2, exerting its activity by two different mechanisms. First, its binding to the SARS-CoV-2 S protein causes a drop in viral infection of ~70%. We show that this activity is specific for SARS-CoV-2, as it does not prevent infection by VSV or HSV-2, other enveloped viruses that use different glycoproteins and entry receptors to mediate their entry. Second, we show that in infected Huh-7 cells, treatment with PEA dismantles lipid droplets, preventing the usage of these vesicular bodies by SARS-CoV-2 as a source of energy and protection against innate cellular defenses. This is not surprising since PEA activates PPAR-α, a transcription factor that, once activated, generates a cascade of events that leads to the disruption of fatty acid droplets, thereby bringing about lipid droplet degradation through β-oxidation. In conclusion, the present work demonstrates a novel mechanism of action for PEA as a direct and indirect antiviral agent against SARS-CoV-2. This evidence reinforces the notion that treatment with this compound might significantly impact the course of COVID-19. Indeed, considering that the protective effects of PEA in COVID-19 are the current objectives of two clinical trials (NCT04619706 and NCT04568876) and given the relative lack of toxicity of PEA in humans, further preclinical and clinical tests will be needed to fully consider PEA as a promising adjuvant therapy in the current COVID-19 pandemic or against emerging RNA viruses that share the same route of replication as coronaviruses.

Alterations in lipid metabolism have been progressively documented as a characteristic property of cancer cells. Though, human ABHD2 gene was found to be highly expressed in breast and lung cancers, its biochemical functionality is yet uncharacterized. Here we report, human ABHD2 as triacylglycerol (TAG) lipase along with ester hydrolyzing capacity. Sequence analysis of ABHD2 revealed the presence of conserved motifs G²⁰⁵XS²⁰⁷XG²⁰⁹ and H¹²⁰XXXXD¹²⁵. Phylogenetic analysis showed homology to known lipases, D. melanogaster CG3488. To evaluate the biochemical role, recombinant ABHD2 was expressed in S. cerevisiae using pYES2/CT vector and His-tag purified protein showed TAG lipase activity. Ester hydrolase activity was confirmed with pNP acetate, butyrate and palmitate substrates respectively. Further, the ABHD2 homology model was built and the modeled protein was analyzed based on the RMSD and RMSF of the 100ns simulation trajectory. Docking the acetate, butyrate and palmitate ligands with the model confirmed covalent binding of ligands with the Ser²⁰⁷ of the GXSXG motif. The model was validated with a mutant ABHD2 developed with alanine in place of Ser²⁰⁷ and the docking studies revealed loss of interaction between selected ligands and the mutant protein active site. Based on the above results, human ABHD2 was identified as a novel TAG lipase and ester hydrolase.

Mycoremediation of low molecular weight polycyclic aromatic hydrocarbons (PAH) is well studied. This study highlights the degradation of high molecular weight PAH (HMW-PAHs): Benz (a) anthracene (BAA), Dibenz (a, h) anthracene (DBA), and Indeno pyrene (IND) by Aspergillus terricola var americanus. The metabolism of the HMW-PAHs by this fungus was investigated in liquid submerged culture added with 60 mg/L of each compound. Depletion of BAA, DBA, and IND was 94.80, 90.16, and 93.80%, respectively, after 10 days of culture. Fungal broth solvent extracts were analyzed for the presence of metabolites by gas chromatography mass spectrometry and the extracellular enzymes produced were also assayed. The coexistence of two metabolic pathways, cytochrome P450 monooxygenase and ligninolytic pathway were identified. A high laccase activity was observed in BAA cultures on day 4 when compared to other PAH's studied. In conclusion, A. terricola might be a promising fungus for bioremediation of HMW-PAH mixtures co-metabolically.

Enhanced Degradation of Carcinogenic PAHs Benzo (a) Pyrene and Benzo (k) Fluoranthene by a Microbial Consortia

Obesity prevalence continues to be a foremost health concern across the globe leading to the development of major health risk conditions like type II diabetes, hyperlipidemia, hypertension and even cancers. Because of the deprived drug-based management system, there is an urgent need for the development of new drugs aiming at satiety and appetite control targets. Among the reported satiety signaling targets, 5HT_2C receptor plays a crucial role in decreasing appetite and has become a promising target for the development of anti-obesity drugs. Lorcaserin, a 5HT_2C receptor agonist and the only drug available in the market, was designed based on the receptor mechanism of action. Due to limited drug options available and considering the adverse drug effects of Lorcaserin, the development of new drugs which are highly specific toward the 5HT_2C target and with lesser side effects is essential. The present study is majorly focused on developing new 5HT_2C agonists through computational approaches like screening, docking, and simulation using Phase, QikProp, Glide and Desmond applications of the Schrodinger suite. Screening protocols resulted in eight best hit molecules with affinity for the receptor and among them, five hits displayed binding affinity toward the conserved residue Asp 134 of the receptor. The stability of the five molecules in complex with the 5HT_2C receptor was studied through molecular dynamic simulations. Three molecules, ZINC32123870, ZINC40312983 and ZINC32124535, maintained stable interactions with the Asp 134 residue throughout the 50 ns simulation run time. Further, due to the high sequence similarity seen among the receptors of 5HT2 family, the three potential hits were cross validated against other subtypes 5HT_2A and 5HT_2B of the 5HT2 family to determine the specificity of the molecules against the target. Among the three hits, ZINC32124535 was identified as the best potential hit based on the hydrogen bond interaction percentage with Asp residue [5HT_2A (Asp 155:60%); 5HT_2B (Asp155: No interaction); 5HT_2C (Asp 134:86%)]. The ZINC32124535 molecule produced one salt bridge and hydrogen bond interactions with Asp 134, alike the known drug Lorcaserin. Based on the results, ZINC32124535 was identified as the best potential hit against the 5HT_2C receptor.