Actinomycin-producing organisms

An actinomycin-producing organism, when cultured without the addition of amino acids (the normal conditions for fermentation), will usually produce a number of acm forms simultaneously. For example. Strepwmyces cfirysonuiilus produces a mixture of acti-nomycins Cl, C2, and C3, which vary at the D-valine position of the pentapeptide chain (5). Streptomyces antitsoBcas, on the other hand, produces a number of actinomycins that differ at the proline position in the pentapeptide chain (6,7). Growth of producing organ isms in the presence of particular amiiw acids can lead to the predominant synthesis of a... 

In table 1 the present state of characterization of several enzyme systems discussed in this publication is shown. While synthetases for gramicidin S, alamethicin or enniatin are available in purified or partially purified forms, the biosynthesis of actinomycins and valinomycin cannot yet be studied in vitro presumably,because the preparation of a cell free extract of these membrane bound systems needs more subtle and advanced techniques of membrane isolation and fragmentation. A promising approach for the investigation of such systems has been found in the study of protoplasts from the producer organism of these antibiotics. 

Yoshida, T., H. Weissbach, and E. Katz Inhibitory effect of actinomycin upon the producing organism. Arch. Biochem. Biophys. 114, 252 (1966). 

For this review another classification is used. As the majority of peptide antibiotics are of unknown structure and cannot therefore be classified chemically, they are grouped according to the organism which produces them. At the beginning of every section, the peptide antibiotics are listed in a table which gives the known characteristics and the literature. Only the clinically useful members are described in detail. Furthermore, only those peptide antibiotics which consist mainly of amino acids in peptide linkages are fully considered. The important actinomycins , penicillins and cephalosporins, which have been reviewed several times in recent years, are not included here. Amino acids and amino acid residue sequences are denoted in accordance with the suggestions of the committee on nomenclature which reported at the Fifth European Peptide Symposium . When necessaiy the direction of the —CO NH— bond is indicated by an arrow (— )., ... 

Until now, several types of polycyclic aromatic nitrogen heterocycles have been known. In fact, heterocyclic synthesis plays an important role in modern life. Among the nitrogen heterocycles, quinoxaline and phenazine derivatives have attracted great interest because of their wide application in organic and medicinal chemistry. Many phenazine compounds are found in nature and are produced by bacteria. Quinoxalines are the fundamental components of several pharmacological active compounds and some antibiotics such as levomycin, echinomycin, and actinomycin (Bailly et al, 1999 Dell et al, 1975). 

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