1. Antimicrobial Peptides An ancient immune system? or

2. This frog could save your leg

3. Antimicrobial peptides: Where are they? In everything from Amoebas to Humans In everything from Amoebas to Humans Abundant in vertebrates in: Abundant in vertebrates in: External MucosaExternal Mucosa –eyes, mouth, genitourinary, skin, lung, trachea Immune cellsImmune cells –neutrophils Intestinal tract (duodenum)Intestinal tract (duodenum) –in humans; Paneth cells are the source

4. Cationic, Amphipathic Cationic, Amphipathic Linear  -helical (20-35 AA)Linear  -helical (20-35 AA) –Magainin, cecropins, histatin Pro-Arg rich (more polar)Pro-Arg rich (more polar) –bac 5 and 7 (30-50 AA; 70% pro/arg) Disulfide Rich  -structureDisulfide Rich  -structure –amoebapores, NK-lysin Disulfide Rich  -structureDisulfide Rich  -structure –Defensins: three or more disulfide (30-70 AA) – “Loops” (11-22 AA) tachpyylesins, protegrins,ranalexin, polymyxintachpyylesins, protegrins,ranalexin, polymyxin Antimicrobial peptides: What are they?

5. HUMAN PLANT Defensin-like

6. Helical: PGLa(frog)

7. Small Proteins Small Proteins lysozymelysozyme phospholipase aphospholipase a cathepsinscathepsins Antimicrobial peptides: What are they?

8. Antifungal Antifungal Antibacterial Antibacterial Gram positiveGram positive Gram negativeGram negative Antimicrobial peptides: What do they do? cell wall OM LPS membrane membrane

9. Permeabilize OM, IM Permeabilize OM, IM channelschannels lysislysis –D-analogs sometimes as effective Carry LPS Carry LPS immune stimulation?immune stimulation? Enzyme action Enzyme action cell wall destructioncell wall destruction lipase, proteaselipase, protease –synergistic w/cationic peptides? Antimicrobial peptides: What do they do?

10. Bacteria have : Bacteria have : more negative chargemore negative charge –recall: peptides are cationic no sterols, little phosphatidylcholine or SMno sterols, little phosphatidylcholine or SM a lot of PG/PE/cardiolipin/PSa lot of PG/PE/cardiolipin/PS –some tumor cells too! Antimicrobial peptides: Why are they picky?

11. NF  B-type genetic element seems universal NF  B-type genetic element seems universal like acute phase response in humanslike acute phase response in humans Protective anionic piece is common, Protective anionic piece is common, Antimicrobial peptides: How are they made? signalpropiecemature

12. Mechanisms?

13. Indolicidin analog fights test infections Indolicidin analog fights test infections IP or IVIP or IV Protegrin analog Protegrin analog helps chemotherapy oral mucositishelps chemotherapy oral mucositis Magainin analog, LOCILEX™ Cream underwent clinical trials (now Genaera Corporation ) Magainin analog, LOCILEX™ Cream underwent clinical trials (now Genaera Corporation ) diabetic ulcers, not approveddiabetic ulcers, not approved Squalamine, amino sterol cationic peptide analog-anti-obesity and anti angiogenesisSqualamine, amino sterol cationic peptide analog-anti-obesity and anti angiogenesis Antimicrobial peptides: New Clinical Antibiotics?

14. Proteolysis, Salt, Transport properties Proteolysis, Salt, Transport properties Manufacture Manufacture –chemical synthesis is very expensive;$100’s/gram! –organic mimics or modular design may help –May be possible to produce in bacteria or plants protective piece for bacteriaprotective piece for bacteria TMV with tobacco (GENEWARE ® )TMV with tobacco (GENEWARE ® ) Antimicrobial peptides: Problems with use?