Id |
Subject |
Object |
Predicate |
Lexical cue |
T150 |
0-22 |
Sentence |
denotes |
2.1 Targeting the RBD |
T151 |
23-135 |
Sentence |
denotes |
Structural investigations of the RBD‐ACE2 complex provided information about essential residues for viral entry. |
T152 |
136-149 |
Sentence |
denotes |
Hsiang et al. |
T153 |
150-289 |
Sentence |
denotes |
35 reported a number of peptides that significantly blocked the interaction of the S protein with ACE2 with IC50 values as low as 1.88 nM. |
T154 |
290-391 |
Sentence |
denotes |
Michael et al. found charged residues between positions 22 and 57 crucial for SARS‐CoV‐1 viral entry. |
T155 |
392-525 |
Sentence |
denotes |
Based on this, they designed peptides P4 (IC50, 50 µM) and P5 (IC50, 6.0 µM) with significant inhibitory activity against SARS‐CoV‐1. |
T156 |
526-794 |
Sentence |
denotes |
The antiviral activity was further improved when they introduced the glycine binding linkage of peptide P4 (residues 22–47) with an ACE2‐derived peptide (residues 351–357) against a SARS‐CoV‐1 pseudovirus with an IC50 of 100 nM and devoid of cytotoxicity up to 200 µM. |
T157 |
795-882 |
Sentence |
denotes |
36 It is worth highlighting that a similar strategy could work for the new SARS‐CoV‐2. |
T158 |
883-1020 |
Sentence |
denotes |
The recently solved cryo‐EM structure of SARS‐CoV‐2 in complex with human ACE2 can provide a structural rationale for the peptide design. |
T159 |
1021-1023 |
Sentence |
denotes |
29 |
T160 |
1024-1197 |
Sentence |
denotes |
For viral entry, MERS‐CoV uses its spike protein (S) to interact with the host‐receptor DPP4, 37 , 38 , 39 also known as adenosine deaminase‐complexing protein‐2 or CD26. |
T161 |
1198-1273 |
Sentence |
denotes |
37 MERS‐CoV was also the first virus reported to use this particular path. |
T162 |
1274-1422 |
Sentence |
denotes |
35 , 37 DPP4 is a type II transmembrane glycoprotein, that forms homodimers on the cell surface, and it is involved in the cleavage of dipeptides. |
T163 |
1423-1538 |
Sentence |
denotes |
37 , 40 In humans, DPP4 is predominantly found on the bronchial epithelial and alveolar cells in the lower lungs. |
T164 |
1539-1547 |
Sentence |
denotes |
40 , 41 |
T165 |
1548-1698 |
Sentence |
denotes |
MERS‐4 and MERS‐27 are monoclonal antibodies targeting the RBD of MERS‐CoV S that were discovered in a nonimmune yeast‐display scFv library screening. |
T166 |
1699-1830 |
Sentence |
denotes |
The more active MERS‐4 potently blocked the infection of DPP4‐expressing Huh‐7 cells with pseudotyped MERS‐CoV (IC50, 0.056 μg/mL). |
T167 |
1831-1938 |
Sentence |
denotes |
It also prevented MERS‐CoV‐induced cytopathogenic effects in MERS‐infected Vero E6 cells (IC50, 0.5 μg/mL). |
T168 |
1939-1941 |
Sentence |
denotes |
42 |
T169 |
1942-2018 |
Sentence |
denotes |
A heptad repeat (HR) is a repeating structural pattern of seven amino acids. |
T170 |
2019-2149 |
Sentence |
denotes |
A crucial membrane fusion framework of SARS‐CoV is the 6‐helix‐bundle (6‐HB) that is formed by HR1 and HR2 of the viral S protein. |
T171 |
2150-2235 |
Sentence |
denotes |
Enfuvirtide (T‐20) is an FDA approved HR2 peptide and the first HIV fusion inhibitor. |
T172 |
2236-2334 |
Sentence |
denotes |
It has opened up new avenues toward identifying and developing peptides as viral entry inhibitors. |
T173 |
2335-2605 |
Sentence |
denotes |
Such molecules represent a promising strategy against enveloped viruses with class 1 fusion proteins such as Nipah virus, Hendra virus, Ebola virus, and other paramyxoviruses, simian immunodeficiency virus, feline immunodeficiency virus, and respiratory syncytial virus. |
T174 |
2606-2805 |
Sentence |
denotes |
43 , 44 , 45 , 46 The HR regions of SARS‐CoV‐1 and SARS‐CoV‐2 S protein share a high degree of conservation, and such fusion inhibitors have potential applications in preventing SARS‐CoV‐2 entry. |
T175 |
2806-2889 |
Sentence |
denotes |
Small molecule entry inhibitors, on the other hand, are reported to target the RBD. |
T176 |
2890-3066 |
Sentence |
denotes |
Compared to peptides, proteins, and biologics, small molecules have several advantages due to lower production costs, improved pharmacokinetics, stability, and dosage accuracy. |
T177 |
3067-3254 |
Sentence |
denotes |
Sarafianos et al. identified the oxazole‐carboxamide derivative SSAA09E2 (1; Figure 4) as an entry inhibitor against SARS‐CoV‐1 by screening a chemical library composed of 3000 compounds. |
T178 |
3255-3472 |
Sentence |
denotes |
47 This inhibitor directly blocks ACE2 recognition by interfering with the RBD with an EC50 value of 3.1 µM and a 50% cytotoxic concentration (CC50) value of greater than 100 µM, not affecting ACE2 expression levels. |
T179 |
3473-3475 |
Sentence |
denotes |
48 |
T180 |
3476-3544 |
Sentence |
denotes |
Figure 4 Inhibitors targeting the receptor‐binding domain Xu et al. |
T181 |
3545-3724 |
Sentence |
denotes |
49 identified two small molecules, TGG (2; Figure 4) and luteolin (3; Figure 4), that can bind avidly to the SARS‐CoV‐1 S2 protein and inhibit its entry into Vero E6 cells (EC50: |
T182 |
3725-3756 |
Sentence |
denotes |
4.5 µM, 10.6 µM; respectively). |
T183 |
3757-3908 |
Sentence |
denotes |
Compounds 2 and 3 showed cytotoxicity (CC50) of 1.08 and 0.155 mM, and the selectivity index (SI) values of 2 and 3 were 240.0 and 14.62, respectively. |
T184 |
3909-4034 |
Sentence |
denotes |
Further studies regarding acute toxicity revealed that the 50% lethal doses of 2 and 3 were ~456 and 232 mg/kg, respectively. |
T185 |
4035-4141 |
Sentence |
denotes |
These results indicate that these small molecules could be used at relatively high concentrations in mice. |
T186 |
4142-4296 |
Sentence |
denotes |
49 Quercetin (4; Figure 4), an analog of 3, also showed antiviral activity against SARS‐CoV‐1, with an EC50 value of 83.4 µM and a CC50 value of 3.32 mM. |
T187 |
4297-4299 |
Sentence |
denotes |
50 |
T188 |
4300-4414 |
Sentence |
denotes |
Ngai et al. reported ADS‐J1 (5; Figure 4) as a potential SARS‐CoV‐1 viral entry inhibitor with an EC50 of 3.89 µM. |
T189 |
4415-4554 |
Sentence |
denotes |
Molecular docking studies predicted that 5 can bind into a deep pocket of the SARS‐CoV‐1 S HR region and block viral entry into host cells. |
T190 |
4555-4756 |
Sentence |
denotes |
51 Imatinib (6; Figure 4), an Abelson kinase inhibitor, could inhibit CoV S protein‐induced fusion with an EC50 value of 10 µM and showed no cytotoxic effects in Vero cells up to 100 µM concentration. |
T191 |
4757-4765 |
Sentence |
denotes |
52 , 53 |