Antibiotic heavy chain

Figure 2.4 gives a different representation to amplify the fact that only the light chain is responsible for the presence of D-Phe in the sequence. The remaining part of the antibiotic is synthesized by the heavy chain. 

Fig. 4 Stereo illustration of the right-handed double-stranded helieal dimer of the pentadecapeptide antibiotic gramicidin The inner channel has a diameter of approximately 4.6 A. For clarity, heavy atoms in the side chains are shown in a stick representation.

The biosynthesis of the macrolactam polyketide glycoside anti-tumour antibiotic vicenistatin L (1), including its vicenisamine moiety, has been studied using heavy atom-labelled precursors. The bicyclic branched-chain diaminohep-turonic acid derivative 2, a tyrosyl tRNA synthetase inhibitor of unknown absolute stereochemistry, has been isolated from a Microsmonospora species fermentation medium. ... 

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