The antibiotic patulin was found to inhibit protein prenylation in mouse FM3A cells. Thus, the agent reduced incorporation of [3H]mevalonate into proteins by 50% at a concentration of 7 μM. In a cell-free assay, patulin inhibited rat brain farnesyl:protein transferase, one of the enzymes responsible for protein prenylation. The inhibition was 50% at a concentration of 290 μM.
