Gramicidin

BeschreibungGramicidin is a polypeptide antibiotic mixture of gramicidin A , gramicidin B, and gramicidin C originally isolated from B. brevis. It is also a component of the antibiotic tyrothricin . Gramicidin is active against the Gram-positive bacterium S. aureus but not Gram-negative E. coli. It also protects mice from Pneumococcus infection in vivo when administered at a dose of 0.002 mg/animal. Gramicidin inhibits growth of bacteria by forming pores and channels in the cell wall, which increases its permeability to monovalent cations. Formulations containing gramicidin have been used as topical agents in the treatment of bacterial skin infections.

VerwendenGramicidins are a family of linear pentadecapeptides isolated from Bacillus brevis by Dubos at the Rockefeller Institute in 1939. Gramicidin is a complex of six closely related analogues A1, A2, B1, B2, C1 and C2 where A1 and A2 are the dominant components. Gramidicins act by forming channels in cell membranes causing ion leakage, and is an essential bioprobe for understanding the nature of the cell membranes.