Laboratory of Biochemistry of Stress in Microorganisms, A.N. Bach Institute of Biochemistry, Federal Research Centre "Fundamentals of Biotechnology" of the Russian Academy of Sciences, Leninsky prospect, 33 (2), Moscow, 119071, Russia.
Laboratory of Biomedicinal Chemistry, A.N. Bach Institute of Biochemistry, Federal Research Centre "Fundamentals of Biotechnology" of the Russian Academy of Sciences, Leninsky prospect, 33 (2), Moscow, 119071, Russia.
Ann Clin Microbiol Antimicrob. 2017 Nov 2;16(1):69. doi: 10.1186/s12941-017-0244-7.
Resuscitation promoting factors (Rpfs) are the proteins involved in the process of reactivation of the dormant cells of mycobacteria. Recently a new class of nitrophenylthiocyanates (NPTs), capable of inhibiting the biological and enzymatic activities of Rpfs has been discovered. In the current study the inhibitory properties of the compounds containing both nitro and thiocyanate groups alongside with the compounds with the modified number and different spatial location of the substituents are compared.
New benzoylphenyl thiocyanates alongside with nitrophenylthiocyanates were tested in the enzymatic assay of bacterial peptidoglycan hydrolysis as well as against strains of several actinobacteria (Mycobacterium smegmatis, Mycobacterium tuberculosis) on in-lab developed models of resuscitation of the dormant forms.
Introduction of the additional nitro and thiocyanate groups to the benzophenone scaffold did not influence the inhibitory activity of the compounds. Removal of the nitro groups analogously did not impair the functional properties of the molecules. Among the tested compounds two molecules without nitro group: 3-benzoylphenyl thiocyanate and 4-benzoylphenyl thiocyanate demonstrated the maximum activity in both enzymatic assay (inhibition of the Rpf-mediated peptidoglycan hydrolysis) and in the resuscitation assay of the dormant M. tuberculosis cells.
The current study demonstrates dispensability of the nitro group in the NPT's structure for inhibition of the enzymatic and biological activities of the Rpf protein molecules. These findings provide new prospects in anti-TB drug discovery especially in finding of molecular scaffolds effective for the latent infection treatment.
复苏促进因子（Rpfs）是参与分枝杆菌休眠细胞再激活过程的蛋白质。最近发现了一类新的硝基苯硫氰酸酯（NPTs），能够抑制 Rpfs 的生物和酶活性。在目前的研究中，比较了同时含有硝基和硫氰酸根的化合物以及取代基数量和空间位置不同的化合物的抑制特性。
新的苯甲酰基苯硫氰酸酯与硝基苯硫氰酸酯一起在细菌肽聚糖水解的酶测定中以及在实验室开发的休眠形式复苏模型中针对几种放线菌（耻垢分枝杆菌、结核分枝杆菌）菌株进行了测试。
在苯甲酮支架上引入额外的硝基和硫氰酸根并没有影响化合物的抑制活性。类似地，去除硝基基团不会损害分子的功能特性。在测试的化合物中，两种不含硝基的化合物：3-苯甲酰基苯硫氰酸酯和 4-苯甲酰基苯硫氰酸酯在酶测定（抑制 Rpf 介导的肽聚糖水解）和休眠结核分枝杆菌细胞的复苏测定中均表现出最大活性。
目前的研究表明，在 NPT 结构中去除硝基基团对于抑制 Rpf 蛋白分子的酶和生物活性是不必要的。这些发现为抗结核药物发现提供了新的前景，特别是在寻找有效治疗潜伏感染的分子支架方面。
