KKL-35 is an inhibitor of trans-translation (IC50: 0.9 μM) with broad-spectrum antibiotic activity.

Trans-translation tagging reaction:0.9 µM

KKL-35抑制了DHFR-ns的标记。剂量反应实验显示，KKL-35以IC50=0.9 μM抑制标记。KKL-35阻止了WT S. flexneri的生长，最小抑制浓度(MIC)为6 μM，且向生长中的S. flexneri培养基中添加KKL-35可停止生长[1]。与L. pneumophila的转译后修饰的基本性质一致，KKL-35以亚微摩尔浓度抑制了所有测试菌株的生长。对于已经进化出对大环内酯类抗生素有抗性的L. pneumophila突变体，KKL-35保持同等的活性。KKL-35在几个感染阶段抑制了L. pneumophila在人类巨噬细胞中的增殖[2]。

Overnight cultures of S. flexneri 2a 2457T, B. anthracis, M. smegmatis, JW5503, and NSR253 were grown in lysogeny broth (LB). Cultures were diluted to a final inoculum of ～5 × 10^5 cfu/mL in 96-well microtiter plates, compounds were added at appropriate concentrations, and growth was observed after 24-h incubation at 37 °C. The MIC was determined by the concentration of the compound in the last well that showed no bacterial growth. For MBC assays, 10 μL from wells containing the MIC, 2× MIC, and 4× MIC of each compound was diluted 10-fold, spotted on LB plates, and grown overnight at 37 °C. An inhibitor was scored as bactericidal if it resulted in 1,000-fold reduction in colony-forming units per milliliter from the original inoculum [1].