Blood-borne antimicrobial proteins and peptides of nonmammalian eukaryotes
| Organism . | Class . | Cell source . | Molecular weight (kd) . | Structure . | Spectrum of activity . | Mechanism of action . | Reference . |
|---|---|---|---|---|---|---|---|
| Plants | Plant defense peptides (eg, thionins, defensins, lipid-transfer proteins) | Multiple | 2-9 | Disulfide-rich | B, F | Diverse (membrane-active) | 24 |
| Insects | Cecropins | Fat body (liver equivalent) | 4 | Amphipathic α-helix | B | Membrane-active/channel formation | 130 |
| Defensins (sapecins) | Hemocytes (thrombocytoids) Fat body | 3-5 | Disulfide-rich with α/β motif | B+ | Formation of voltage-dependent channels | 139 | |
| Diptericin | Hemocytes (thrombocytoids) Fat body | 8 | O-glycosylated | B− | Membrane active? | 140 | |
| Drosomycin | Fat body | 5 | Disulfide-rich with α/β motif | F | Membrane active | 141 | |
| Glycine-rich proteins (eg, attacins) | Fat body | 9-30 | Random coil | B− | Sequential membrane permeabilization | 142 | |
| Lysozyme | Hemocytes | 15 | Conserved active site | B+ | Lysis of peptidoglycan | 143 | |
| Proline-rich proteins (eg, drosocin) | Fat body | 2-3 | Linear | B− | Inhibition of protein synthesis? | 144 | |
| Frogs | Dermaseptins | Epithelium | 2-4 | Variable | B, F, P | Membrane active | 145 |
| Magainins | Epithelium | 2 | α-Helical | B, F, P, EV | Formation of multimeric pores | 25 |
| Organism . | Class . | Cell source . | Molecular weight (kd) . | Structure . | Spectrum of activity . | Mechanism of action . | Reference . |
|---|---|---|---|---|---|---|---|
| Plants | Plant defense peptides (eg, thionins, defensins, lipid-transfer proteins) | Multiple | 2-9 | Disulfide-rich | B, F | Diverse (membrane-active) | 24 |
| Insects | Cecropins | Fat body (liver equivalent) | 4 | Amphipathic α-helix | B | Membrane-active/channel formation | 130 |
| Defensins (sapecins) | Hemocytes (thrombocytoids) Fat body | 3-5 | Disulfide-rich with α/β motif | B+ | Formation of voltage-dependent channels | 139 | |
| Diptericin | Hemocytes (thrombocytoids) Fat body | 8 | O-glycosylated | B− | Membrane active? | 140 | |
| Drosomycin | Fat body | 5 | Disulfide-rich with α/β motif | F | Membrane active | 141 | |
| Glycine-rich proteins (eg, attacins) | Fat body | 9-30 | Random coil | B− | Sequential membrane permeabilization | 142 | |
| Lysozyme | Hemocytes | 15 | Conserved active site | B+ | Lysis of peptidoglycan | 143 | |
| Proline-rich proteins (eg, drosocin) | Fat body | 2-3 | Linear | B− | Inhibition of protein synthesis? | 144 | |
| Frogs | Dermaseptins | Epithelium | 2-4 | Variable | B, F, P | Membrane active | 145 |
| Magainins | Epithelium | 2 | α-Helical | B, F, P, EV | Formation of multimeric pores | 25 |
B indicates bacteria; B−, gram-negative bacteria; B+, gram-positive bacteria; F, fungal organisms; P, protozoa; EV, enveloped viruses.