Table 2.
Numbers of hydrogen bond and pi interactions of ACE2, SBP1, SPB25 and designed peptides contributing to SARS-CoV-2-RBD binding.
| System | Number of hydrogen bonds | Residue that forms a hydrogen bond with SARS-CoV-2-RBD using its backbone or side chain | Interaction | |||||
|---|---|---|---|---|---|---|---|---|
| Strong | Medium | Weak | Very weak | Pi–Pi | Cation–Pi | Sigma–Pi | ||
| ACE236 | 2 | 3 | 2 | 25 | S19, Q24, D30, K31, H34, E35, E37, Y41, Q42, Y83, N330, K353, D355 | Y83-F486 |
H34-K417:NZ R393:NH1-Y505 |
K353:HA-Y505 |
| SBP136 | 1 | 2 | 11 | 14 | Q4, D10, K11, H14, E15, E17, D18, Y21, S23 | – |
K11:NZ-Y489 H14-K417:NZ |
– |
| SPB253,6 | 1 | 4 | 11 | 20 | Q4, D10, K11, H14, E15, D18, Y21, Q22 | Y21-Y505 | H14-K417:NZ | – |
| SPB25K11F | 2 | 3 | 6 | 33 | E2, Q4, D10, H14, E17, D18, Y21, Q22, S23, S24, L25 |
F11-Y489 F20-Y505 |
Y21-R403:NH1 Y21-R403:NH2 |
Y21-Y505:HD2 |
| SPB25Q22R | 2 | 4 | 8 | 22 | E3, Q4, D10, H14, E15, E17, Y21, R22, S23, S24, L25 | – |
K11:NZ-Y489 H14-K417:NZ Y21-R403:NH1 Y21-R403:NH2 R22:NH1-Y449 R22:NH2-Y449 |
Y21-Y505:HD1 |
| SPB25F8R/K11W/L25R | 4 | 4 | 5 | 20 | I1, E3, Q4, R8, D10, H14, E17, Y21, Q22, S24, R25 |
W11(pyrrole)-Y489 W11(benzene)-Y489 |
R8:NH2-F486 Y21-R403:NH1 Y21-R403:NH2 |
Y21-Y505:HD2 |
| SPB25F8R/K11F/Q22R/L25R | 4 | 6 | 6 | 16 | Q4, R8, D10, H14, E17, D18, F20, Y21, S24, R25 |
F11-Y489 F20-Y505 |
R8:NH1-F486 R8:NH2-F486 H14-K417:NZ Y21-R403:NH1 Y21-R403:NH2 |
Y21-Y505:HD2 |