Whole Genome Sequencing for Revealing the Point Mutations of SARS-CoV-2 Genome in Bangladeshi Isolates and their Structural Effects on Viral Proteins (preprint)

Coronavirus disease-19 (COVID-19) is the recent global pandemic caused by the virus Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2). The virus has already killed more than one million people worldwide and billions are at risk of getting infected. As of now, there is neither any drug nor any vaccine in sight with conclusive scientific evidence that it can cure or provide protection against the illness. Since novel coronavirus is a new virus, mining its genome sequence is of crucial importance for drug/vaccine(s) development. Whole genome sequencing is a helpful tool in identifying genetic changes that occur in a virus when it spreads through the population. In this study, we performed complete genome sequencing of SARS-CoV-2 to unveil the genomic variation and indel, if present. We discovered thirteen (13) mutations in Orf1ab, S and N gene where seven (7) of them turned out to be novel mutations from our sequenced isolate. Besides, we found one (1) insertion and seven (7) deletions from the indel analysis among the 323 Bangladeshi isolates. However, the indel did not show any effect on proteins. Our energy minimization analysis showed both stabilizing and destabilizing impact on viral proteins depending on the mutation. Interestingly, all the variants were located in the binding site of the proteins. Furthermore, drug binding analysis revealed marked difference in interacting residues in mutants when compared to the wild type. Our analysis also suggested that eleven (11) mutations could exert damaging effects on their corresponding protein structures. The analysis of SARS-CoV-2 genetic variation and their impacts presented in this study might be helpful in gaining a better understanding of the pathogenesis of this deadly virus.

Novel Mutations in NSP1 and PLPro of SARS-CoV-2 NIB-1 Genome Mount for Effective Therapeutics (preprint)

Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), the etiologic agent of Coronavirus Disease-2019 (COVID-19), is rapidly accumulating new mutations. Analysis of these mutations is necessary for gaining knowledge regarding different aspects of therapeutic development. Recently, we have reported a Sanger method based genome sequence of a viral isolate named SARS-CoV-2 NIB-1, circulating in Bangladesh. The genome has four novel mutations in V121D, V843F, A889V and G1691C positions. V121D substitution has the potential to destabilize the Non-Structural Protein (NSP-1) which inactivates the type-1 Interferon-induced antiviral system hence this mutant could be the basis of attenuated vaccines against SARS-CoV-V843F, A889V and G1691C are all located in NSP3. G1691C can decrease the flexibility of the protein while V843F and A889V changed the binding pattern of SARS-CoV-2 Papain-Like protease (PLPro) inhibitor GRL0617. V843F PLPro showed reduced affinity for Interferon Stimulating Gene-15 (ISG-15) protein whereas V843F+A889V double mutants exhibited the same binding affinity as wild type PLPro. Here, V843F is a conserved position of PLPro that damaged the structure but A889V, a less conserved residue, most probably neutralized that damage. Mutants of NSP1 could provide attenuated vaccines against coronavirus. Also, these mutations of PLPro could be targeted to develop anti-SARS therapeutics.

Comparative Genomic Study for Revealing the Complete Scenario of COVID-19 Pandemic in Bangladesh (preprint)

As the COVID-19 pandemic continues to ravage across the globe and take millions of lives, worldwide efforts to understand its causative agent, SARS-CoV-2 at the genomic level are also running in full swing. Such studies are providing precious insights about the pathogenesis, evolution, strengths and weaknesses of the virus. As of October 1st, 2020, 323 SARS-CoV-2 genomes have been sequenced across Bangladesh. The current study is aimed at answering some vital questions about these sequences. From our analyses, it was discovered that the majority of the SARS-CoV-2 found in Bangladesh belonged to the lineage B 1.1.25 of GR clade. Dhaka and Chittagong division were the most diverse in terms of SARS-CoV-2 clades while Mymensing was the least. There are more variety of clades in southern parts of Bangladesh than the northern parts. The most commonly found SARS-CoV-2 mutations found in the country were Spike_D614G, NSP12_P323L, N_G204R and N_R203K. Even though no significant pattern of distribution could be drawn between mutations found in Bangladesh and the countries with similar mortality rates and the countries with large Bangladeshi diaspora, to a certain degree they match with those in the UK, Oman, Italy, Greece, South Africa and Russia. Therefore, careful eye should be kept on the performance of vaccines in those countries in the near future as they are likely to work well in Bangladesh if they work well there. Mutational events in Bangladesh were found to increase between April and July, 2020 and decrease since August, 2020. The number of mutations per SARS-CoV-2 virus sample in Bangladesh was calculated to be 6.88 which is lower than the global average of 7.23. The decrease and the lower rate of mutation raise the possibility of a vaccine or drug working sustainably to protect the people. Based on these insights, a clear picture about the ongoing pandemic can be drawn in the context of Bangladesh which will help the country take appropriate measures to combat the virus.

Recognition of Plausible Therapeutic Agents to Combat COVID-19: An Omics Data Based Combined Approach (preprint)

Coronavirus disease-2019 (COVID-19) has become an immense threat to global public health. The causative agent of this disease is a novel zoonotic pathogen called Severe Acute Respiratory Syndrome related Coronavirus-2 (SARS-CoV-2). Since this is a newly evolved pathogen, very limited information is available to develop effective therapeutics against this deadly virus. Although bioinformatics based analysis could be handy to unveil drugs or vaccines against bacteria and fungus, such approaches are hardly seen for acellular viruses. However, in this study we rationally merged several powerful in silico techniques and proposed prospective therapeutics based on available omics data for COVID-19. Through meticulous analysis of conserved regions of 67 SARS-CoV-2 strains, spike and membrane glycoproteins were chosen to develop and propose a chimeric vaccine against this virus. siRNAs were also designed against these glycoprotein genes to silence them. Moreover, six drug compound candidates were suggested to inhibit the conserved RNA-directed RNA polymerase protein. Finally, due to the close relationship of SARS-CoV-2 and SARS-CoV, publicly available gene expression datasets of SARS-CoV were analyzed to identify 13 immunoregulatory genes that might develop interferon based therapy. Our study will quicken the researches among pharmaceuticals, researchers and clinicians to develop rapid therapeutics for controlling this notorious pandemic disease.   Authors Mohammad Uzzal Hossain, Arittra Bhattacharjee, Md. Tabassum Hossain Emon, and Zeshan Mahmud Chowdhury contributed equally to this work.