Antimicrobial proteins and peptides of neutrophils
| Protein . | Molecular weight (kd) . | Neutrophil granule . | Epithelial/mucosal expression . | Activity . | Mechanism . |
|---|---|---|---|---|---|
| Lactoferrin | 80 | 20 | Br, Tr, Sl, BAL | B±, F, EV | Iron-binding/membrane-active |
| BPI | 55 | 10 | ? | B− | Binds lipid A of LPS |
| Serprocidins | ∼30 | 10 | ? | B±, F, m, M | Proteolysis/membrane-active |
| Cathelicidins | 10-20 | 20 | Kr, Ts | B±, F | Release of membrane-active peptides |
| Lysozyme | 14.5 | 10 & 20 | Br, Tr, Gs | B+, F | Lysis of peptidoglycan/membrane-active |
| Phospholipase | 14 | (granule) | Liver (APR), Int | B+ | Lysis of bacterial phospholipids |
| Defensins | 4 | 10 | Pul, R, Int, Ug | B±, F, EV, m, M | Formation of voltage-gated multimeric pores |
| Protein . | Molecular weight (kd) . | Neutrophil granule . | Epithelial/mucosal expression . | Activity . | Mechanism . |
|---|---|---|---|---|---|
| Lactoferrin | 80 | 20 | Br, Tr, Sl, BAL | B±, F, EV | Iron-binding/membrane-active |
| BPI | 55 | 10 | ? | B− | Binds lipid A of LPS |
| Serprocidins | ∼30 | 10 | ? | B±, F, m, M | Proteolysis/membrane-active |
| Cathelicidins | 10-20 | 20 | Kr, Ts | B±, F | Release of membrane-active peptides |
| Lysozyme | 14.5 | 10 & 20 | Br, Tr, Gs | B+, F | Lysis of peptidoglycan/membrane-active |
| Phospholipase | 14 | (granule) | Liver (APR), Int | B+ | Lysis of bacterial phospholipids |
| Defensins | 4 | 10 | Pul, R, Int, Ug | B±, F, EV, m, M | Formation of voltage-gated multimeric pores |
10 indicates primary; 20, secondary; (granule), not yet assigned; APR, acute-phase reactant; BAL, bronchoalveolar lavage fluid; Br, breast milk; Gs, gastric secretions; Int, intestinal (Paneth cells); Kr, keratinocytes; Sl, saliva; Tr, tear fluid; Ts, testes; Ug, urogenital tissues; B, bacteria (+ and − refer to Gram staining); F, fungi; m, metazoan parasites; M, mammalian cells; EV, enveloped viruses.