SARS-CoV Spike Protein Research Articles

Thymidine phosphorylase mediates SARS-CoV-2 spike protein enhanced thrombosis in K18-hACE2TG mice

IntroductionThymidine phosphorylase (TYMP), which facilitates platelet activation and thrombosis, is significantly increased in COVID-19 patients. We hypothesize that TYMP mediates SARS-CoV-2 spike protein (SP)-induced thrombosis. Materials and methodsPlasmids encoding wildtype SP or empty vector (p3.1) were transfected into COS-7 cells, and cell lysates were prepared as a reservoir for SP or p3.1 (control), respectively. K18-hACE2TG and K18-hACE2TG/Tymp−/− mice were treated with a single dose of SP or p3.1 by intraperitoneal injection and then subjected to thrombosis studies three days later. The role of SP on inflammatory signaling activation was assessed in BEAS-2B cells. ResultsSARS-CoV-2 SP increased the expression of TYMP, resulting in the activation of STAT3 and NF-κB in BEAS-2B cells. A siRNA-mediated knockdown of TYMP attenuated SP-enhanced activation of STAT3. SP significantly promoted arterial thrombosis in K18-hACE2TG mice. SP-accelerated thrombosis was attenuated by inhibition or genetic ablation of TYMP. SP treatment did not influence ADP- or collagen-induced platelet aggregation but significantly increased platelet adhesion to fibrinogen. SP treatment also significantly shortened activated partial thromboplastin time, which was reversed and even prolonged by TYMP deficiency. Additionally, SP binds to platelet factor 4 (PF4) and TYMP. TYMP does not bind PF4 but enhances the formation of the SP/PF4 complex, which may augment the procoagulant and prothrombotic effect of PF4. ConclusionsWe conclude that SP is prothrombotic and upregulates TYMP expression, and TYMP inhibition or knockout mitigates SP-enhanced thrombosis. These findings suggest that inhibition of TYMP may be a novel therapeutic strategy for COVID-19-associated thrombosis.

An in silico Drug Repurposing Study to Inhibit the Spike Protein of SARS-CoV2

SARS-CoV2 has caused the recent mortal pandemic known as COVID-19. The drug repurposing approach can be employed to find the potential drugs capable of binding SARS-CoV2 structural and nonstructural proteins. The present study aimed to repurpose some common FAD-approved antiviral and non-antiviral drugs computationally for SARS-CoV2 treatment. In the in silico study, 89 FDA-approved drugs and Remdesivir, as the control, were analyzed by molecular docking to inhibit the SARS-CoV2 spike (S) protein as the key player in virus-cell binding. First, the Uniport website was used to find receptor and ganglioside binding domains (RBD and GBD, respectively) of the S protein as the target. The structure of the target was downloaded from RCSB, and 'the ligands' structures were downloaded from PubChem. All structures were refined using SPDV and PyRx software. AutoDock Vina was employed for the docking process. The result showed that 8 drugs, including Ledipasvir, Montelukast, Domperidone, Aprepitant, Folic acid, Losartan, Ticagrelor, and Rivaroxaban, can bind S protein and then inhibit the protein function. In addition, Ledipasvir, Montelukast, and Domperidone can bind GBD of the S protein with higher binding energy (-8.2, -8, -7.9 kcal/mol, respectively). On the other hand, higher RBD binding energy was calculated for Ticagrelor (-6.9 kcal/mol), Folic acid, Montelukast, and Domperidone (-6.5 kcal/mol). Generally, the ligands could inhibit GBD more than RBD. According to the binding energy to S protein and low side effects of the studied medications, Ledipasvir and Losartan can be introduced as the most effective candidates for repurposed drugs. Also, Gly496 and Asn137 are the most engaged amino acids in the ligand-receptor interaction from RBD and GBD, respectively.

In Vitro Inhibitory Effect of Nigella sativa L. Extracts on SARS-COV-2 Spike Protein-ACE2 Interaction

Ethnopharmacological relevanceA catastrophic outbreak of severe acute respiratory syndrome (SARS-CoV-2; Coronavirus disease-19; COVID-19) was first detected in Wuhan, Hubei Province, China, in December 2019. Many experimental and clinical studies have focused on the effectiveness of medicinal plants such as Nigella sativa (NS) in combating SARS-CoV-2. In this study, we aimed to evaluate the in vitro effect of NS seed extract on SARS-CoV-2 spike protein (S1)-angiotensin-converting enzyme 2 (S-ACE2) interaction. Materials and methodsNS seed extracts used for the assay were prepared in chloroform, ethanol, and water by Soxhlet extraction and recovered by rotary evaporation. The inhibition percentage of S1-ACE2 interaction was analyzed using ELISA-SARS-CoV-2 S1 Protein-ACE2 Binding Inhibitor Screening Kit. Chemical finger-printing of the extracts was done using RP-HPLC. ResultsSignificant concentration-dependent inhibition of the S1-ACE2 interaction was observed with chloroform, ethanol, and water extracts, ranging from 0.01 to 10 mg/ml. The P-values for the extracts were as follows: 0.0055, 0.0937, 0.0013, and 0.0003 for chloroform extract; 0.0876, 0.0703, 0.0183, and 0.0071 for ethanol extract; and 0.0915, 0.0312, 0.0006, and 0.0006 for water extract. The 50% inhibitory concentration (IC50) was determined to be 0.132 mg/ml, 0.288 mg/ml, and 4.06 mg/ml for chloroform, ethanol, and water extracts, respectively. ConclusionThe in vitro analysis utilizing SARS-CoV2 spike (S1) and ACE2 proteins proved that NS seed extracts have the potential to inhibit the S-ACE2 interaction, which warrants further studies that could lead to potential drug discovery for SARS-CoV2 infection.

Identification and characterization of malaria box compounds possessing inhibition effect on the SARS-CoV2 spike protein

Identification and characterization of malaria box compounds possessing inhibition effect on the SARS-CoV2 spike protein

Injuries and deaths following Covid-19 vaccination: The ethical and legal case for compensation.

In April 2024, in a class action suit for compensation to families of persons suffering injury or death after vaccination with AstraZeneca's (AZ) Covid-19 vaccine [1], the manufacturer admitted in a UK court that the Oxford-AZ Covid-19 vaccine could cause a rare and potentially fatal blood clotting disorder ("thrombosis with thrombocytopenia syndrome" or TTS, which when triggered by a vaccine is called "vaccine induced thrombocytopenia and thrombosis, or VITT) [2]. The AZ Covid-19 vaccine is a chimpanzee adenovirus vectored vaccine encoding the SARS-CoV2 spike protein (ChAdOx1-S) marketed under the names Covishield and Vaxzevria.

Surface-Based Multimeric Aptamer Generation and Bio-Functionalization for Electrochemical Biosensing Applications.

Multimeric aptamers have gained more attention than their monomeric counterparts due to providing more binding sites for target analytes, leading to increased affinity. This work attempted to engineer the surface-based generation of multimeric aptamers by employing the room temperature rolling circle amplification (RCA) technique and chemically modified primers for developing a highly sensitive and selective electrochemical aptasensor. The multimeric aptamers, generated through surface RCA, are hybridized to modified spacer primers, facilitating the positioning of the aptamers in the proximity of sensing surfaces. These multimeric aptamers can be used as bio-receptors for capturing specific targets. The surface amplification process was fully characterized, and the optimal amplification time for biosensing purposes was determined, using SARS-CoV-2 spike protein (SP). Interestingly, multimeric aptasensors produced considerably higher response signals and affinity (more than 10-fold), as well as higher sensitivity (almost 4-fold) compared to monomeric aptasensors. Furthermore, the impact of surface structures on the response signals was studied by utilizing both flat working electrodes (WEs) and nano-/microislands (NMIs) WEs. The NMIs multimeric aptasensors showed significantly higher sensitivity in buffer and saliva media with the limit of detection less than 2 fg/ml. Finally, the developed NMIs multimeric aptasensors were clinically challenged with several saliva patient samples.

Surface‐Based Multimeric Aptamer Generation and Bio‐Functionalization for Electrochemical Biosensing Applications

AbstractMultimeric aptamers have gained more attention than their monomeric counterparts due to providing more binding sites for target analytes, leading to increased affinity. This work attempted to engineer the surface‐based generation of multimeric aptamers by employing the room temperature rolling circle amplification (RCA) technique and chemically modified primers for developing a highly sensitive and selective electrochemical aptasensor. The multimeric aptamers, generated through surface RCA, are hybridized to modified spacer primers, facilitating the positioning of the aptamers in the proximity of sensing surfaces. These multimeric aptamers can be used as bio‐receptors for capturing specific targets. The surface amplification process was fully characterized, and the optimal amplification time for biosensing purposes was determined, using SARS‐CoV‐2 spike protein (SP). Interestingly, multimeric aptasensors produced considerably higher response signals and affinity (more than 10‐fold), as well as higher sensitivity (almost 4‐fold) compared to monomeric aptasensors. Furthermore, the impact of surface structures on the response signals was studied by utilizing both flat working electrodes (WEs) and nano‐/microislands (NMIs) WEs. The NMIs multimeric aptasensors showed significantly higher sensitivity in buffer and saliva media with the limit of detection less than 2 fg/ml. Finally, the developed NMIs multimeric aptasensors were clinically challenged with several saliva patient samples.

Structural, dynamic behaviour, in-vitro and computational investigations of Schiff’s bases of 1,3-diphenyl urea derivatives against SARS-CoV-2 spike protein

The COVID-19 has had a significant influence on people's lives across the world. The viral genome has undergone numerous unanticipated changes that have given rise to new varieties, raising alarm on a global scale. Bioactive phytochemicals derived from nature and synthetic sources possess lot of potential as pathogenic virus inhibitors. The goal of the recent study is to report new inhibitors of Schiff bases of 1,3-dipheny urea derivatives against SARS COV-2 spike protein through in-vitro and in-silico approach. Total 14 compounds were evaluated, surprisingly, all the compounds showed strong inhibition with inhibitory values between 79.60% and 96.00% inhibition. Here, compounds 3a (96.00%), 3d (89.60%), 3e (84.30%), 3f (86.20%), 3g (88.30%), 3h (86.80%), 3k (82.10%), 3l (90.10%), 3m (93.49%), 3n (85.64%), and 3o (81.79%) exhibited high inhibitory potential against SARS COV-2 spike protein. While 3c also showed significant inhibitory potential with 79.60% inhibition. The molecular docking of these compounds revealed excellent fitting of molecules in the spike protein receptor binding domain (RBD) with good interactions with the key residues of RBD and docking scores ranging from − 4.73 to − 5.60 kcal/mol. Furthermore, molecular dynamics simulation for 150 ns indicated a strong stability of a complex 3a:6MOJ. These findings obtained from the in-vitro and in-silico study reflect higher potency of the Schiff bases of 1,3-diphenyl urea derivatives. Furthermore, also highlight their medicinal importance for the treatment of SARS COV-2 infection. Therefore, these small molecules could be a possible drug candidate.

Complementary Medication for COVID-19 Outbreak Concerns in the Leprosy Community - A Passionate Proposal

Abstract: The number of COVID-19-positive cases continues to climb, causing alarm around the world. The Nilavembu (Andrographis paniculata) Kudineer of Siddha medicine, an alternative medicine practiced in India, has already been shown to be beneficial in viral outbreaks like Chikungunya and Dengue fever. Several investigations have demonstrated that these herbs have anti-inflammatory, analgesic, antipyretic, antibacterial, and antiviral activities against the Herpes simplex virus and Ebstein Barr virus. This herbal remedy has also been shown to have a low risk of negative side effects. There is currently no approved pharmaceutical treatment for COVID-19. Using the phrases 'COVID-19,' 'Ayush,' 'Siddha,' and 'Leprosy,' we searched other databases such as Google, Embase, ScienceDirect, and the Clinical Trial Registry of India. In another research on Siddha treatment, Kabasura Kudineer, a decoction of 15 herbal items was discovered to have activity against the spike protein of SARS COV-2 using an in-silico compound method. As there are no effective treatments available for the prevention and treatment of mild to moderate cases, these two medicines, Nilavembu Kudineer, and Kabasura Kudineer can be used as part of a COVID-19 prophylaxis using a combination of modern and alternative medicine.

Multisystem Inflammatory Syndrome in Neonates Associated with COVID-19 in Neonatal ICU of a Tertiary Care Hospital.

Neonatal multisystem inflammatory syndrome (MIS-N) is a unique disease of neonates described in several case reports from all over the world with a myriad of presentations and the emergence of new cases. Retrospective case series. Place and Duration of the Study: Department of Paediatrics, Fazaia Medical College, Pakistan Air Force Hospital, Islamabad, Pakistan, from December 2021 to November 2022. The study was conducted on neonates who were managed as MIS-N in the neonatal ICU. Data were collected and analysed on SPSS version 24. Patients in this study ranged from newborns to 13 days of age with a mean age of 3.27 ± 4.29 days and average gestational age of 35.18 ± 3.67 weeks. Among these neonates, 7 (63.6%) had bleeding diathesis, 11 (100%) had seizures, 8 (72.2%) presented with haemodynamic instability and shock, and 7 (63.3%) had signs of heart failure. All neonates (100%) had markedly raised SARS-CoV2 IgG antibodies, CRP, ferritin, D-dimers, interleukin 6, procalcitonin, 10 (90.9%) had hypoalbuminemia, and 7 (63.3%) had deranged coagulation profile. Cardiac involvement was seen in all neonates (100%) with raised proBNP and myocardial dysfunction on echocardiography. Pulmonary hypertension was present in 6 (54.4%) neonates. High mortality was observed at 6 (54.5%) among which 4 (66.6%) were premature neonates. MIS-N is a new disease entity which is still under research. There is a high propensity for cardiovascular system involvement and higher mortality among preterm neonates. Neonatal multisystem inflammatory syndrome (MIS-N), Multisystem inflammatory syndrome in children (MIS-C), SARS-CoV2 infection, SARS-CoV2 spike protein, SARS-CoV2 IgG antibodies.

Investigating emodin derivatives against SARS-CoV-2 found in medicinal herbs

SARS-CoV-2 continues to mutate and circulate at alarming levels around the world and is exemplified by the emergence of the new variant JN.1. The emergence of novel SARS-CoV variants underscores the urgency for the development of new drugs. Phytochemicals, known for their safety and efficacy, have been widely used to address various ailments. This study aims at identifying the anti-SARS-CoV potential of emodin, a bioactive anthraquinone, and its derivatives. Key proteins, including hemagglutinin-esterase (HE), papain-like protease (PLpro), major protease (3CLpro), non-structural protein (nsp3) and spike protein(S) of SARS-CoV, were used as protein targets for the virtual screening of 110 emodin derivatives (ED) and remdesivir a proven antiviral drug. Among the 110 derivatives, ED21, ED25, ED5 inhibited HE, 3CLpro and S protein, respectively. ED29 inhibited both PLpro and nsp3 with high binding affinity. Similar receptor binding sites were occupied by remdesivir and emodin derivatives. These emodin derivatives are bound to similar amino acids in receptors as compared to remdesivir. Further dynamic simulations studies with ED21-HE, ED25-3CLpro, ED5-S, ED29-PLpro and ED29-nsp3 complexes showed all of them are stable with minimum root mean square deviation (RMSD), root mean square fluctuation (RMSF), solvent-accessible surface area (SASA) and radius of gyration (Rg) and are comparable to APO protein. All the ligands accepted Lipinski's rule of five. Absorption, distribution, metabolism, excretion, and toxicity (ADMET) analysis revealed only ED21 and ED5 as promising druglike candidates that can have high therapeutic value and no side effects. These in-silico findings contribute to the development of potent SARS-CoV-2 inhibitors, potentially advancing the quest for effective antiviral drugs.

Allosteric pathways of SARS and SARS-CoV-2 spike protein identified by neural relational inference.

The receptor binding domain (RBD) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein must undergo a crucial conformational transition to invade human cells. It is intriguing that this transition is accompanied by a synchronized movement of the entire spike protein. Therefore, it is possible to design allosteric regulators targeting non-RBD but hindering the conformational transition of RBD. To understand the allosteric mechanism in detail, we establish a computational framework by integrating coarse-grained molecular dynamic simulations and a state-of-the-art neural network model called neural relational inference. Leveraging this framework, we have elucidated the allosteric pathway of the SARS-CoV-2 spike protein at the residue level and identified the molecular mechanisms involved in the transmission of allosteric signals. The movement of D614 is coupled with that of Q321. This interaction subsequently influences the movement of K528/K529, ultimately coupling with the movement of RBD during conformational changes. Mutations that weaken the interactions within this pathway naturally block the allosteric signal transmission, thereby modulating the conformational transitions. This observation also offers a rationale for the distinct allosteric patterns observed in the SARS-CoV spike protein. Our result provides a useful method for analyzing the dynamics of potential viral variants in the future.

Evaluation of Glutathione in Spike Protein of SARS-CoV-2 Induced Immunothrombosis and Cytokine Dysregulation.

Thrombotic microangiopathy has been identified as a dominant mechanism for increased mortality and morbidity in coronavirus disease 2019 (COVID-19). In the context of severe COVID-19, patients may develop immunothrombosis within the microvasculature of the lungs, which contributes to the development of acute respiratory distress syndrome (ARDS), a leading cause of death in the disease. Immunothrombosis is thought to be mediated in part by increased levels of cytokines, fibrin clot formation, and oxidative stress. Glutathione (GSH), a well-known antioxidant molecule, may have therapeutic effects in countering this pathway of immunothrombosis as decreased levels of (GSH) have been associated with increased viral replication, cytokine levels, and thrombosis, suggesting that glutathione supplementation may be therapeutic for COVID-19. GSH supplementation has never been explored as a means of treating COVID-19. This study investigated the effectiveness of liposomal glutathione (GSH) as an adjunctive therapy for peripheral blood mononuclear cells (PBMC) treated with SARS CoV-2 spike protein. Upon the addition of GSH to cell cultures, cytokine levels, fibrin clot formation, oxidative stress, and intracellular GSH levels were measured. The addition of liposomal-GSH to PBMCs caused a statistically significant decrease in cytokine levels, fibrin clot formation, and oxidative stress. The addition of L-GSH to spike protein and untreated PBMCs increased total intracellular GSH, decreased IL-6, TGF-beta, and TNF-alpha levels, decreased oxidative stress, as demonstrated through MDA, and decreased fibrin clot formation, as detected by fluorescence microscopy. These findings demonstrate that L-GSH supplementation within a spike protein-treated PBMC cell culture model reduces these factors, suggesting that GSH supplementation should be explored as a means of reducing mediators of immunothrombosis in COVID-19.

The Binding of the SARS-CoV-2 Spike Protein to Platelet Factor 4: A Proposed Mechanism for the Generation of Pathogenic Antibodies.

Pathogenic platelet factor 4 (PF4) antibodies contributed to the abnormal coagulation profiles in COVID-19 and vaccinated patients. However, the mechanism of what triggers the body to produce these antibodies has not yet been clarified. Similar patterns and many comparable features between the COVID-19 virus and heparin-induced thrombocytopenia (HIT) have been reported. Previously, we identified a new mechanism of autoimmunity in HIT in which PF4-antibodies self-clustered PF4 and exposed binding epitopes for other pathogenic PF4/eparin antibodies. Here, we first proved that the SARS-CoV-2 spike protein (SP) also binds to PF4. The binding was evidenced by the increase in mass and optical intensity as observed through quartz crystal microbalance and immunosorbent assay, while the switching of the surface zeta potential caused by protein interactions and binding affinity of PF4-SP were evaluated by dynamic light scattering and isothermal spectral shift analysis. Based on our results, we proposed a mechanism for the generation of PF4 antibodies in COVID-19 patients. We further validated the changes in zeta potential and interaction affinity between PF4 and SP and found that their binding mechanism differs from ACE2-SP binding. Importantly, the PF4/SP complexes facilitate the binding of anti-PF4/Heparin antibodies. Our findings offer a fresh perspective on PF4 engagement with the SARS-CoV-2 SP, illuminating the role of PF4/SP complexes in severe thrombotic events.

Novel pyrazole‐biphenyl‐carboxamides for SARS‐CoV2 entry‐level restriction and microbial infections

AbstractMicrobial diseases including viral infection are big issues globally. Effective medicinal discovery for them is the need for the day. In this study, we report pyrazole‐biphenyl‐carboxamides (4a‐l) validated for their SARS‐CoV2 entry‐level restriction effect over studying the protein–protein interaction of SARS‐CoV2 with human ACE protein. Their extended antimicrobial properties were also evaluated. Online and offline software tools predicted MD simulation and ADMET druggability in silico. The antimicrobial efficacy of all compounds was also evaluated against Gram+ve Streptococcus pneumoniae (MTCC 1936), Staphylococcus aureus (MTCC 737) and Gram‐ve Escherichia coli (MTCC 443), Pseudomonas aeruginosa (MTCC 424) (bacteria). In the results, compounds 4g and 4i were evenly active against both bacteria at a low concentration range (MIC: 1.00 to 9.5 μg/mL) and displayed lesser toxicity to tested mammalian cells (EC100 = 75 μg/mL). Furthermore, it was able to kill metabolically inactive bacterial cells and eradicate established biofilms of Methicillin‐resistant Staphylococcus aureus (MRSA). Both the compounds inhibited DNA gyrase well with an IC50 0.25 μM (96% relative activity) and 0.52 μM (97% relative activity) respectively. Compounds (4a‐l) showed restrictive efficiency of SARS‐CoV2 spike protein (SC2SP) and human angiotensin‐converting enzyme 2 (hACE2) entry‐level association in COVID‐19 in silico. To assess this ability, firstly, we identified the crucial amino acid residues involved in the interface of SARS‐CoV‐2 and hACE2 virtually. We recognized the ability of 4a‐l binding to the binding interface to SARS‐CoV2; thus, the interaction of SC2SP‐hACE2 was effectively inhibited.

Preventing SARS-CoV-2 infection using Fv-antibodies targeting the proprotein convertase (PPC) cleavage site.

Fv-antibodies targeting the proprotein convertase (PPC) region of the SARS-CoV-2 spike protein (SP) were screened from an Fv-antibody library to inhibit SARS-CoV-2 infection. Two selected Fv-antibodies were expressed as soluble recombinant proteins, and their binding affinities were assessed using a surface plasmon resonance biosensor. The binding regions of these Fv-antibodies corresponded to the cleavage sites of furin (S1/S2) and transmembrane serine protease 2 (TMPRSS2, S2'). The neutralizing activities of the two Fv-antibodies were demonstrated using a cell-based infection assay with pseudo-viruses carrying the SP of four different SARS-CoV-2 variants: wild-type (D614), delta (B.1.617.2), omicron (BA.2), and omicron (BA.4/5).

Induction of neutralizing antibodies against SARS-CoV-2 variants by a multivalent mRNA-lipid nanoparticle vaccine encoding SARS-CoV-2/SARS-CoV Spike protein receptor-binding domains in mice.

To address the need for multivalent vaccines against Coronaviridae that can be rapidly developed and manufactured, we compared antibody responses against SARS-CoV, SARS-CoV-2, and several variants of concern in mice immunized with mRNA-lipid nanoparticle vaccines encoding homodimers or heterodimers of SARS-CoV/SARS-CoV-2 receptor-binding domains. All vaccine constructs induced robust anti-RBD antibody responses, and the heterodimeric vaccine elicited an IgG response capable of cross-neutralizing SARS-CoV, SARS-CoV-2 Wuhan-Hu-1, B.1.351 (beta), and B.1.617.2 (delta) variants.

Structure-based drug discovery to identify SARS-CoV2 spike protein–ACE2 interaction inhibitors

After the emergence of the COVID-19 pandemic in late 2019, the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has undergone a dynamic evolution driven by the acquisition of genetic modifications, resulting in several variants that are further classified as variants of interest (VOIs), variants under monitoring (VUM) and variants of concern (VOC) by World Health Organization (WHO). Currently, there are five SARS-CoV-2 VOCs (Alpha, Beta, Delta, Gamma and Omicron), two VOIs (Lambda and Mu) and several other VOIs that have been reported globally. In this study, we report a natural compound, Curcumin, as the potential inhibitor to the interactions between receptor binding domain (RBD(S1)) and human angiotensin-converting enzyme 2 (hACE2) domains and showcased its inhibitory potential for the Delta and Omicron variants through a computational approach by implementing state of the art methods. The study for the first time revealed a higher efficiency of Curcumin, especially for hindering the interaction between RBD(S1) and hACE-2 domains of Delta and Omicron variants as compared to other lead compounds. We investigated that the mutations in the RBD(S1) of VOC especially Delta and Omicron variants affect its structure compared to that of the wild type and other variants and therefore altered its binding to the hACE2 receptor. Molecular docking and molecular dynamics (MD) simulation analyses substantially supported the findings in terms of the stability of the docked complexes. This study offers compelling evidence, warranting a more in-depth exploration into the impact of these alterations on the binding of identified drug molecules with the Spike protein. Further investigation into their potential therapeutic effects in vivo is highly recommended. Communicated by Ramaswamy H. Sarma

Sialylated Glycan Bindings from SARS-CoV-2 Spike Protein to Blood and Endothelial Cells Govern the Severe Morbidities of COVID-19.

Consistent with well-established biochemical properties of coronaviruses, sialylated glycan attachments between SARS-CoV-2 spike protein (SP) and host cells are key to the virus's pathology. SARS-CoV-2 SP attaches to and aggregates red blood cells (RBCs), as shown in many pre-clinical and clinical studies, causing pulmonary and extrapulmonary microthrombi and hypoxia in severe COVID-19 patients. SARS-CoV-2 SP attachments to the heavily sialylated surfaces of platelets (which, like RBCs, have no ACE2) and endothelial cells (having minimal ACE2) compound this vascular damage. Notably, experimentally induced RBC aggregation in vivo causes the same key morbidities as for severe COVID-19, including microvascular occlusion, blood clots, hypoxia and myocarditis. Key risk factors for COVID-19 morbidity, including older age, diabetes and obesity, are all characterized by markedly increased propensity to RBC clumping. For mammalian species, the degree of clinical susceptibility to COVID-19 correlates to RBC aggregability with p = 0.033. Notably, of the five human betacoronaviruses, the two common cold strains express an enzyme that releases glycan attachments, while the deadly SARS, SARS-CoV-2 and MERS do not, although viral loads for COVID-19 and the two common cold infections are similar. These biochemical insights also explain the previously puzzling clinical efficacy of certain generics against COVID-19 and may support the development of future therapeutic strategies for COVID-19 and long COVID patients.

The Exploration of Bioactive Peptides that Docked to SARS-CoV-2 Spike Protein from Goats’ Milk Beta-Casein by In Silico

Beta-casein in milk is known to be a bioactive peptide producer because of its amino acid sequence. Bioactive peptides have prospected molecules that can adhere with SARS-CoV-2 spike protein, so they can inhibit the virus from hooking up with human cell receptor protein. The research is aimed to find any peptides from goat’s milk beta-casein that are prospective candidates as SARS-CoV-2 spike protein inhibitors. Goat’s milk beta-casein was simulated as being digested by the digestive tract. Pepsin, trypsin, and chymotrypsin enzymes cut the beta-casein amino acids sequence into small peptides. Then, their bioavailability was predicted by Lipinski’s Rules of 5 (Ro5), any most fitted peptides to the rules will be simulated to dock to SARS-CoV2 spike protein besides Curcumin as the control ligand. Peptides with the best bind activity with the spike protein will be selected as inhibitor candidates. Peptide QPK is selected as a SARS-CoV-2 inhibitor candidate because it has better affinity energy than Curcumin or other selected peptides.