Inhibition by sakyomicin A of avian myeloblastosis virus reverse transcriptase and proliferation of AIDS-associated virus (HTLV-III/LAV).

In the course of screening for inhibitors of reverse transcriptase, we have isolated an inhibitor from a strain of Nocardia and identified it as sakyomicin A. The antibiotic blocks avian myeloblastosis virus reverse transcriptase reaction: IC50 was ca. 30 micrograms/ml by the method employed. The drug affects proliferation of HTLV-III/LAV in HTLV-I-carrying MT-4 cells: ca. 60% inhibition was observed at an antibiotic concentration of 1.0 microgram/ml and ca. 20% inhibition at 0.1 microgram/ml, and there was no significant cytotoxicity.