COMPLETE AMINO-ACID-SEQUENCE OF PHENOMYCIN, AN ANTITUMOR POLYPEPTIDE ANTIBIOTIC

The primary structure of phenomycin, an antitumor polypeptide antibiotic isolated from the culture broth of Streptomyes fervens var. phenomyceticus, was determined. Sequence analysis has revealed that it consists of 89 amino acid residues (M(r) 9,524) and no disulfide bridge is present. The sequence of phenomycin at residues 48 approximately 70 was found to be hydrophilic, being surrounded by hydrophobic regions at both sides. Furthermore, clustering of half the lysine residues in this hydrophilic region and marked basicity of phenomycin imply the external disposition of this region. Phenomycin does not show significant sequence homology to any known proteins including antitumor polypeptide antibiotics.