Cyclic peptide chain is present in ?
Ans. is d i.e., Gramicidin S Gramicidin Gramicidin is a heterogeneous mixture of three antibiotic compounds, gramicidins A, B and C, making up 80%, 6%, and 14%, respectively,all of which are obtained from the soil bacterial species Bacillus brevis and called collectively gramicidin D. Gramicidin D contains linear pentadecapeptides, that is chains made up of 15 amino acid. This is in contrast to gramicidin S, which is a cyclic peptide chain. Gramicidin is active against Gram-positive bacteria, except for the Gram-positive bacilli, and against select Gram-negative organisms, such as Neisseriabacteria. Its therapeutic use is limited to topical application, as it induces hemolysis in lower concentrations than bacteria cell death, so it cannot be administered internally.
Gramicidin A
Gramicidin B
Gramicidin D
Gramicidin S