Table 2.
Properties and mechanisms of the three types of HIV-1 inhibitory defensins.
| Molecular shape | Non-circular | Circular | |
|---|---|---|---|
| Defensin type | α | β | θ |
| Representative | HNP-1 | HBD-2 | RTD-1 |
| Properties [23, 24] | |||
| APD ID | 176 | 524 | 445 |
| Year discovered | 1985 | 1997 | 1999 |
| Amino acids | 30 | 41 | 18 |
| Net charge | +3 | +7 | +5 |
| Hydrophobic content | 53% | 36% | 55% |
| 3 disulfide bonds C-C | 2–30; 4–19; 9–29 | 8–37; 15–30; 20–38 | 3–16; 5–14; 7–12 |
| 3D Structure | β (3 strands) | αβ (1 helix + 3 strands) | β (2 strands) |
| Mechanisms [99] | |||
| Cells used | PBMC | PBMC | PBMC |
| X4 EC50 (µM) | 2.3 | 6.9 | 3.5 |
| R5 EC50 (µM) | 2.6 | 5.8 | 3.6 |
| HIV-1 entry | No | No | Inhibition |
| After viral entry | Inhibition | Inhibition | No |
| Down-regulation of CXCR4 | Yes | Yes | Yes |
| Down-regulation of CCR5 or CD4 | No | No | No |
| Direct inactivation of R5 HIV-1 | Yes | Yes | No |
| Direct inactivation of X4 HIV-1 | Yes | Yes | Yes |