Incorporation of sarcosine into the actinomycins synthesized by Streptomyces antibioticus.

Sarcosine is an amino acid apparently not widely distributed in Nature. As a free amino acid, sarcosine has been demonstrated in the radial caeca of the starfish Astropecten aurantiacus (Kossel & Edlbacher, 1915), in the muscles of Elasmobranchii (Tarr, 1958) and in the reindeer moss, Cladonia itlvatica (Linko, Alfthan, Miettinen & Virtanen, 1953). Sarcosine has been found bound in peptides in the antibiotics of the actinomycin (Dalgliesh, Johnson, Todd & Vining, 1950) and etamycin (Sheehan, Zachau & Lawson, 1957) groups. The reported presence of sarcosine in the hydrolysate of groundnut protein (Haworth, MaeGillivray & Peacock, 1951) has recently been questioned (Greenstein & Winitz, 1961). The absence, in cell-free extracts of actinomycin-producing Streptomyeetes, of enzymes activating sarcosine by an ATP-pyrophosphate exchange (Ciferri, Di Girolamo & Bendicenti Di Girolamo, 1961) prompted the following investigation on the incorporation of sarcosine into actinomycins. As will be shown, sarcosine appears to be incorporated as such into the sarcosine portion of the antibiotic. The amino acid is, in addition, utilized as a source of glycine for the synthesis of protein. In the absence of sarcosine from the fermentation media, the data indicate that glycine provides the aminoacetic portion of the sarcosine of the antibiotic. A preliminary note has already appeared (Ciferri, Albertini & Rossi, 1962). While this paper was in preparation, Katz & Weissbach (1963) reported similar results for another strain of Streptomyces antibioticus.