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Multi-Targeted Molecular Docking and Drug-Likeness Evaluation of some Nitrogen Heterocyclic Compounds Targeting Proteins Involved in the Development of COVID-19

Hui LY, Mun CS, Sing LC, Rajak H, Karunakaran R, Ravichandran V

Med Chem, 2023;19(3):297-309.
PMID: 35713125 DOI: 10.2174/1573406418666220616110351

BACKGROUND: The severe acute respiratory syndrome coronavirus-2 is causing a disaster through coronavirus disease-19 (COVID-19), affecting the world population with a high mortality rate. Although numerous scientific efforts have been made, we do not have any specific drug for COVID-19 treatment.
OBJECTIVE: Aim of the present study was to analyse the molecular interaction of nitrogen heterocyclic based drugs (hydroxychloroquine, remdesivir and lomefloxacin) with various SARSCoV- 2 proteins (RdRp, PLPro, Mpro and spike proteins) using a molecular docking approach.
METHODS: We have performed docking study using PyRx software, and Discovery Studio Visualizer was used to visualise the molecular interactions. The designed nitrogen heterocyclic analogues were checked for Lipinski's rule of five, Veber's Law and Adsorption, Distribution, Metabolism, and Excretion (ADME) threshold. After obtaining the docking results of existing nitrogen heterocyclic drugs, we modified the selected drugs to get molecules with better affinity against SARS-CoV-2.
RESULTS: Hydroxychloroquine bound to RdRp, spike protein, PLPro and Mpro at -5.2, -5.1, -6.7 and -6.0 kcal/mol, while remdesivir bound to RdRp, spike protein, PLPro, and Mpro at -6.1, -6.9, -6.4 and -6.9 kcal/mol, respectively. Lomefloxacin bound to RdRp, spike protein, PLPro and Pro at -6.4, -6.6, -7.2 and -6.9 kcal/mol. ADME studies of all these compounds indicated lipophilicity and high gastro intestine absorbability. The modified drug structures possess better binding efficacy towards at least one target than their parent compounds.
CONCLUSION: The outcome reveals that the designed nitrogen heterocyclics could contribute to developing the potent inhibitory drug SARS-CoV-2 with strong multi-targeted inhibition ability and reactivity.

Matched MeSH terms: Spike Glycoprotein, Coronavirus
Fulltext Probable Pangolin Origin of SARS-CoV-2 Associated with the COVID-19 Outbreak

Zhang T, Wu Q, Zhang Z

Curr Biol, 2020 Apr 06;30(7):1346-1351.e2.
PMID: 32197085 DOI: 10.1016/j.cub.2020.03.022

An outbreak of coronavirus disease 2019 (COVID-19) caused by the 2019 novel coronavirus (SARS-CoV-2) began in the city of Wuhan in China and has widely spread worldwide. Currently, it is vital to explore potential intermediate hosts of SARS-CoV-2 to control COVID-19 spread. Therefore, we reinvestigated published data from pangolin lung samples from which SARS-CoV-like CoVs were detected by Liu et al. [1]. We found genomic and evolutionary evidence of the occurrence of a SARS-CoV-2-like CoV (named Pangolin-CoV) in dead Malayan pangolins. Pangolin-CoV is 91.02% and 90.55% identical to SARS-CoV-2 and BatCoV RaTG13, respectively, at the whole-genome level. Aside from RaTG13, Pangolin-CoV is the most closely related CoV to SARS-CoV-2. The S1 protein of Pangolin-CoV is much more closely related to SARS-CoV-2 than to RaTG13. Five key amino acid residues involved in the interaction with human ACE2 are completely consistent between Pangolin-CoV and SARS-CoV-2, but four amino acid mutations are present in RaTG13. Both Pangolin-CoV and RaTG13 lost the putative furin recognition sequence motif at S1/S2 cleavage site that can be observed in the SARS-CoV-2. Conclusively, this study suggests that pangolin species are a natural reservoir of SARS-CoV-2-like CoVs.

Matched MeSH terms: Spike Glycoprotein, Coronavirus/chemistry
Identifying SARS-CoV-2-related coronaviruses in Malayan pangolins

Lam TT, Jia N, Zhang YW, Shum MH, Jiang JF, Zhu HC, et al.

Nature, 2020 07;583(7815):282-285.
PMID: 32218527 DOI: 10.1038/s41586-020-2169-0

The ongoing outbreak of viral pneumonia in China and across the world is associated with a new coronavirus, SARS-CoV-21. This outbreak has been tentatively associated with a seafood market in Wuhan, China, where the sale of wild animals may be the source of zoonotic infection2. Although bats are probable reservoir hosts for SARS-CoV-2, the identity of any intermediate host that may have facilitated transfer to humans is unknown. Here we report the identification of SARS-CoV-2-related coronaviruses in Malayan pangolins (Manis javanica) seized in anti-smuggling operations in southern China. Metagenomic sequencing identified pangolin-associated coronaviruses that belong to two sub-lineages of SARS-CoV-2-related coronaviruses, including one that exhibits strong similarity in the receptor-binding domain to SARS-CoV-2. The discovery of multiple lineages of pangolin coronavirus and their similarity to SARS-CoV-2 suggests that pangolins should be considered as possible hosts in the emergence of new coronaviruses and should be removed from wet markets to prevent zoonotic transmission.

Matched MeSH terms: Spike Glycoprotein, Coronavirus/genetics; Spike Glycoprotein, Coronavirus/chemistry
Can Costus afer be used for co-treatment of COVID-19, its symptoms and comorbidities? A novel approach for combating the pandemic and implications for sub-Saharan Africa

Jannat K, Hasan A, Bondhon TA, Mahboob T, Paul AK, Jahan R, et al.

Trop Biomed, 2021 Dec 01;38(4):540-551.
PMID: 35001920 DOI: 10.47665/tb.38.4.097

Despite the huge loss of lives and massive disruption of the world economy by the COVID -19 pandemic caused by SARS -CoV-2, scientists are yet to come out with an effective therapeutic against this viral disease . Several vaccines have obtained 'emergency approval ', but difficulties are being faced in the even distribution of vaccines amongst high- and low- income countries . On top of it, comorbidities associated with COVID -19 like diabetes, hypertension and malaria can seriously impede the treatment of the main disease, thus increasing the fatality rate . This is more so in the context of sub -Saharan African and south Asian countries . Our objective was to demonstrate that a single plant containing different phytoconstituents may be used for treatment of COVID -19 and comorbidities . Towards initial selection of a plant, existing scientific literature was scanned for reported relevant traditional uses, phytochemicals and pharmacological activities of a number of plants and their phytoconstituents pertaining to treatment of COVID-19 symptoms and comorbidities. Molecular docking studies were then performed with phytochemicals of the selected plant and SARS-CoV-2 components - Mpro, and spike protein receptor binding domain and hACE2 interface using AutoDock V ina. We showed that crude extracts of an indigenous African plant, Costus afer having traditional antidiabetic and antimalarial uses, has phytochemicals with high binding affinities for Mpro, and /or spike protein receptor binding domain and hACE2 interface; the various phytochemicals with predicted high binding energies include aferoside C, dibutyl phthalate, nerolidol, suginal, and ± -terpinene, making them potential therapeutics for COVID -19. The results suggest that crude extracts and phytochemicals of C. afer can function as a treatment modality for COVID -19 and comorbidities like especially diabetes and malaria .

Matched MeSH terms: Spike Glycoprotein, Coronavirus
Properties of Coronavirus and SARS-CoV-2

Malik YA

Malays J Pathol, 2020 Apr;42(1):3-11.
PMID: 32342926

were identified beginning with the discovery of SARS-CoV in 2002. With the recent detection of SARS-CoV-2, there are now seven human coronaviruses. Those that cause mild diseases are the 229E, OC43, NL63 and HKU1, and the pathogenic species are SARS-CoV, MERS-CoV and SARS-CoV-2 Coronaviruses (order Nidovirales, family Coronaviridae, and subfamily Orthocoronavirinae) are spherical (125nm diameter), and enveloped with club-shaped spikes on the surface giving the appearance of a solar corona. Within the helically symmetrical nucleocapsid is the large positive sense, single stranded RNA. Of the four coronavirus genera (α,β,γ,δ), human coronaviruses (HCoVs) are classified under α-CoV (HCoV-229E and NL63) and β-CoV (MERS-CoV, SARS-CoV, HCoVOC43 and HCoV-HKU1). SARS-CoV-2 is a β-CoV and shows fairly close relatedness with two bat-derived CoV-like coronaviruses, bat-SL-CoVZC45 and bat-SL-CoVZXC21. Even so, its genome is similar to that of the typical CoVs. SARS-CoV and MERS-CoV originated in bats, and it appears to be so for SARS-CoV-2 as well. The possibility of an intermediate host facilitating the emergence of the virus in humans has already been shown with civet cats acting as intermediate hosts for SARS-CoVs, and dromedary camels for MERS-CoV. Human-to-human transmission is primarily achieved through close contact of respiratory droplets, direct contact with the infected individuals, or by contact with contaminated objects and surfaces. The coronaviral genome contains four major structural proteins: the spike (S), membrane (M), envelope (E) and the nucleocapsid (N) protein, all of which are encoded within the 3' end of the genome. The S protein mediates attachment of the virus to the host cell surface receptors resulting in fusion and subsequent viral entry. The M protein is the most abundant protein and defines the shape of the viral envelope. The E protein is the smallest of the major structural proteins and participates in viral assembly and budding. The N protein is the only one that binds to the RNA genome and is also involved in viral assembly and budding. Replication of coronaviruses begin with attachment and entry. Attachment of the virus to the host cell is initiated by interactions between the S protein and its specific receptor. Following receptor binding, the virus enters host cell cytosol via cleavage of S protein by a protease enzyme, followed by fusion of the viral and cellular membranes. The next step is the translation of the replicase gene from the virion genomic RNA and then translation and assembly of the viral replicase complexes. Following replication and subgenomic RNA synthesis, encapsidation occurs resulting in the formation of the mature virus. Following assembly, virions are transported to the cell surface in vesicles and released by exocytosis.

Matched MeSH terms: Spike Glycoprotein, Coronavirus/genetics
Fulltext Protective Immunity against SARS Subunit Vaccine Candidates Based on Spike Protein: Lessons for Coronavirus Vaccine Development

Khalaj-Hedayati A

J Immunol Res, 2020;2020:7201752.
PMID: 32695833 DOI: 10.1155/2020/7201752

The recent outbreak of the novel coronavirus disease, COVID-19, has highlighted the threat that highly pathogenic coronaviruses have on global health security and the imminent need to design an effective vaccine for prevention purposes. Although several attempts have been made to develop vaccines against human coronavirus infections since the emergence of Severe Acute Respiratory Syndrome coronavirus (SARS-CoV) in 2003, there is no available licensed vaccine yet. A better understanding of previous coronavirus vaccine studies may help to design a vaccine for the newly emerged virus, SARS-CoV-2, that may also cover other pathogenic coronaviruses as a potentially universal vaccine. In general, coronavirus spike protein is the major antigen for the vaccine design as it can induce neutralizing antibodies and protective immunity. By considering the high genetic similarity between SARS-CoV and SARS-CoV-2, here, protective immunity against SARS-CoV spike subunit vaccine candidates in animal models has been reviewed to gain advances that can facilitate coronavirus vaccine development in the near future.

Matched MeSH terms: Spike Glycoprotein, Coronavirus/genetics; Spike Glycoprotein, Coronavirus/immunology*
SARS-CoV-2 seroprevalence and antibody trends in vaccinated, multi-ethnic healthcare employees

Beh CC, Zulkufli NS, Loh LM, Cheng KW, Choo LM, Cheah MW, et al.

Trop Biomed, 2021 Dec 01;38(4):552-560.
PMID: 35001921 DOI: 10.47665/tb.38.4.098

Understanding of antibody kinetics against SARS-CoV-2 and its vaccines is rapidly evolving. This study aims to (1) determine post-vaccination seroprevalence; (2) compare antibody levels between vaccine types and various clinical/demographic determinants; and (3) determine post-vaccination antibody concentrations against time. This is a retrospective cross-sectional study involving 148 healthcare employees all over Malaysia. IgG Spike (RBD), IgM Spike and IgG Nucleocapsid concentration medians were compared using Mann-Whitney U or Kruskal-Wallis tests. Chi Square and Spearman correlation coefficient tests were performed to identify variables associated with antibody titers. A scatter plot of IgG Spike (RBD) against time from last vaccine dose was also plotted. At 1-month post-vaccination, all employees successfully seroconverted regardless of vaccine type, health status and COVID- 19 history. Comirnaty, convalescent, female or Malay vaccinees had significantly higher IgG Spike (RBD) titers compared to their respective counterparts. No correlation was found between age and IgG Spike (RBD) levels. Concentration of all three antibodies waned with time post-vaccination, with IgM Spike and IgG Nucleocapsid waning faster than IgG Spike (RBD).

Matched MeSH terms: Spike Glycoprotein, Coronavirus
Isolation of SARS-CoV-2-related coronavirus from Malayan pangolins

Xiao K, Zhai J, Feng Y, Zhou N, Zhang X, Zou JJ, et al.

Nature, 2020 07;583(7815):286-289.
PMID: 32380510 DOI: 10.1038/s41586-020-2313-x

The current outbreak of coronavirus disease-2019 (COVID-19) poses unprecedented challenges to global health1. The new coronavirus responsible for this outbreak-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-shares high sequence identity to SARS-CoV and a bat coronavirus, RaTG132. Although bats may be the reservoir host for a variety of coronaviruses3,4, it remains unknown whether SARS-CoV-2 has additional host species. Here we show that a coronavirus, which we name pangolin-CoV, isolated from a Malayan pangolin has 100%, 98.6%, 97.8% and 90.7% amino acid identity with SARS-CoV-2 in the E, M, N and S proteins, respectively. In particular, the receptor-binding domain of the S protein of pangolin-CoV is almost identical to that of SARS-CoV-2, with one difference in a noncritical amino acid. Our comparative genomic analysis suggests that SARS-CoV-2 may have originated in the recombination of a virus similar to pangolin-CoV with one similar to RaTG13. Pangolin-CoV was detected in 17 out of the 25 Malayan pangolins that we analysed. Infected pangolins showed clinical signs and histological changes, and circulating antibodies against pangolin-CoV reacted with the S protein of SARS-CoV-2. The isolation of a coronavirus from pangolins that is closely related to SARS-CoV-2 suggests that these animals have the potential to act as an intermediate host of SARS-CoV-2. This newly identified coronavirus from pangolins-the most-trafficked mammal in the illegal wildlife trade-could represent a future threat to public health if wildlife trade is not effectively controlled.

Matched MeSH terms: Spike Glycoprotein, Coronavirus/genetics
Fulltext Isolation and molecular characterization of type I and type II feline coronavirus in Malaysia

Amer A, Siti Suri A, Abdul Rahman O, Mohd HB, Faruku B, Saeed S, et al.

Virol J, 2012 Nov 21;9:278.
PMID: 23171743 DOI: 10.1186/1743-422X-9-278

BACKGROUND: Feline infectious peritonitis virus (FIPV) and feline enteric coronavirus (FECV) are two important coronaviruses of domestic cat worldwide. Although FCoV is prevalent among cats; the fastidious nature of type I FCoV to grow on cell culture has limited further studies on tissue tropism and pathogenesis of FCoV. While several studies reported serological evidence for FCoV in Malaysia, neither the circulating FCoV isolated nor its biotypes determined. This study for the first time, describes the isolation and biotypes determination of type I and type II FCoV from naturally infected cats in Malaysia.
FINDINGS: Of the total number of cats sampled, 95% (40/42) were RT-PCR positive for FCoV. Inoculation of clinical samples into Crandell feline kidney cells (CrFK), and Feline catus whole fetus-4 cells (Fcwf-4), show cytopathic effect (CPE) characterized by syncytial cells formation and later cell detachment. Differentiation of FCoV biotypes using RT-PCR assay revealed that, 97.5% and 2.5% of local isolates were type I and type II FCoV, respectively. These isolates had high sequence homology and phylogenetic similarity with several FCoV isolates from Europe, South East Asia and USA.
CONCLUSIONS: This study reported the successful isolation of local type I and type II FCoV evident with formation of cytopathic effects in two types of cell cultures namely the CrFK and Fcwf-4 , where the later cells being more permissive. However, the RT-PCR assay is more sensitive in detecting the antigen in suspected samples as compared to virus isolation in cell culture. The present study indicated that type I FCoV is more prevalent among cats in Malaysia.

Matched MeSH terms: Spike Glycoprotein, Coronavirus