Identification of Small-Molecule Inhibitors of the Salmonella FraB Deglycase Using a Live-Cell Assay.
Identification of Small-Molecule Inhibitors of the Salmonella FraB Deglycase Using a Live-Cell Assay.
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DOI：
10.1128/spectrum.04606-22
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发表时间：
2023-02-21
影响因子：
3.7
通讯作者：
中科院分区：
文献类型：
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非伤寒沙门氏菌病是美国和全球最重要的食源性疾病之一。目前还没有可供人类使用的疫苗来预防这种疾病，只有广谱抗生素可用于治疗这种疾病的复杂病例。然而，抗生素耐药性正在上升，需要新的治疗方法。我们以前确定了沙门氏菌fraB基因，该突变导致小鼠胃肠道适应性减弱。FraB基因产物编码在一个操纵子中，负责果糖-天冬酰胺（F-Asn）的摄取和利用，这是一种在几种人类食物中发现的Amadori产物。fraB中的突变导致FraB底物6-磷酸果糖-天冬氨酸（6-P-F-Asp）的积累，这对沙门氏菌是有毒的。F-Asn分解代谢途径仅存在于非伤寒沙门氏菌血清型、少数柠檬酸杆菌属和克雷伯氏菌属分离株以及少数梭菌属中;在人类中未发现。因此，用新型抗微生物剂靶向FraB预期是沙门氏菌特异性的，使正常微生物群基本上保持完整并且对宿主没有影响。我们进行了高通量筛选（HTS），以确定FraB的小分子抑制剂，使用基于生长的测定比较野生型沙门氏菌和Δfra岛突变对照。我们一式两份筛选了224，009种化合物。在命中分类和验证后，我们发现了三种化合物以依赖于fra的方式抑制沙门氏菌，其50%抑制浓度（IC 50）值范围为89至150 μM。用重组FraB和合成的6-P-F-Asp测试这些化合物，证实它们是FraB的非竞争性抑制剂，Ki′（抑制剂常数）值范围为26 - 116 μM。非伤寒沙门氏菌病在美国和全球都是一个严重的威胁。我们最近发现了一种酶，FraB，当突变使沙门氏菌生长缺陷的体外和不适合在小鼠胃肠炎模型。FraB在细菌中非常罕见，在人类或其他动物中也没有发现。在这里，我们已经确定了抑制沙门氏菌生长的FraB小分子抑制剂。这些可以为治疗提供基础，以减少沙门氏菌感染的持续时间和严重程度。
Nontyphoidal salmonellosis is one of the most significant foodborne diseases in the United States and globally. There are no vaccines available for human use to prevent this disease, and only broad-spectrum antibiotics are available to treat complicated cases of the disease. However, antibiotic resistance is on the rise and new therapeutics are needed. We previously identified the Salmonella fraB gene, that mutation of causes attenuation of fitness in the murine gastrointestinal tract. The FraB gene product is encoded in an operon responsible for the uptake and utilization of fructose-asparagine (F-Asn), an Amadori product found in several human foods. Mutations in fraB cause an accumulation of the FraB substrate, 6-phosphofructose-aspartate (6-P-F-Asp), which is toxic to Salmonella. The F-Asn catabolic pathway is found only in the nontyphoidal Salmonella serovars, a few Citrobacter and Klebsiella isolates, and a few species of Clostridium; it is not found in humans. Thus, targeting FraB with novel antimicrobials is expected to be Salmonella specific, leaving the normal microbiota largely intact and having no effect on the host. We performed high-throughput screening (HTS) to identify small-molecule inhibitors of FraB using growth-based assays comparing a wild-type Salmonella and a Δfra island mutant control. We screened 224,009 compounds in duplicate. After hit triage and validation, we found three compounds that inhibit Salmonella in an fra-dependent manner, with 50% inhibitory concentration (IC50) values ranging from 89 to 150 μM. Testing these compounds with recombinant FraB and synthetic 6-P-F-Asp confirmed that they are uncompetitive inhibitors of FraB with Ki′ (inhibitor constant) values ranging from 26 to 116 μM. IMPORTANCE Nontyphoidal salmonellosis is a serious threat in the United States and globally. We have recently identified an enzyme, FraB, that when mutated renders Salmonella growth defective in vitro and unfit in mouse models of gastroenteritis. FraB is quite rare in bacteria and is not found in humans or other animals. Here, we have identified small-molecule inhibitors of FraB that inhibit the growth of Salmonella. These could provide the foundation for a therapeutic to reduce the duration and severity of Salmonella infections.
DOI：
10.1155/2012/123076
发表时间：
2012
期刊：
International journal of proteomics
影响因子：
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作者：
Brown RN;Sanford JA;Park JH;Deatherage BL;Champion BL;Smith RD;Heffron F;Adkins JN
通讯作者：
Adkins JN