Enzymatic 1-N-acetylation of paromomycin by an actinomycete strain 8 with multiple aminoglycoside resistance and paromomycin sensitivity

Abstract

An actinomycete strain 8 with multiple aminoglycoside (AG) resistance and paromomycin (PRM) sensitivity was examined for its capability of enzymatic modification of AGs. Cell free extracts from the strain converted all of the examined AGs including PRM in the presence of acetyl CoA. PRM was completely modified to at least two products (major and minor spots upon TLC) without significant reduction of the antibiotic activity of the reaction mixture. The structure determination and antibiotic assay of the purified major product revealed 1-N-acetylPRM and its antibiotic activity (12% activity of PRM), indicating the existence of AAC(1). It was thus obvious that the 1-N-acetylation of PRM did not cause PRM resistance. Apramycin, the substrate of the known AAC(1), was not readily acetylated, suggesting that the AAC(1) of strain 8 is a new type. Two diacetylated products (1,2'-di-N-acetylPRM and 1,6'''-di-N-acetylPRM) were found in the minor spot, suggesting the existence of additional AACs.