Structure-activity relationship-based screening of antibiotics against Gram-negative Acinetobacter baumannii

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• 作者：Jee-Young Lee^a ; ^c ; Min-Cheol Jeong^b ; ^c ; Dasom Jeon^b ; Yeongjun Lee^b ; Woo Cheol Lee^b ; Yangmee Kim^b ; ^{ymkim@konkuk.ac.kr}
• 关键词：KAS ; Fatty acid synthesis ; Antibiotics ; In silico screening ; Gram-negative bacteria
• 刊名：Bioorganic & Medicinal Chemistry
• 出版年：2017
• 出版时间：1 January 2017
• 年：2017
• 卷：25
• 期：1
• 页码：372-380
• 全文大小：1605 K
• 卷排序：25

文摘

To discover potent antibiotics against the Gram-negative bacteria, we performed a structure-activity relationship (SAR) study of YKsa-6, which was the most potent inhibitor of Staphylococcus aureus β-ketoacyl acyl carrier protein III in our previous study. We identified and selected 11 candidates, and finally screened two active compounds, YKab-4 (4-[(3-chloro-4-methylphenyl)aminoiminomethyl]benzene-1,3-diol) and YKab-6 (4-[[3-(trifluoromethyl)phenyl]aminoiminomethyl]phenol) as inhibitors of Acinetobacter baumannii KAS III (abKAS III). They showed potent antimicrobial activities at 2 or 8 μg/mL, specifically against Acinetobacter baumannii and a strong binding affinity for abKAS III. From the homology modeling, we defined the three-dimensional (3D) structure of abKAS III for the first time and found that it had an extra loop region compared with common Gram-negative bacteria derived KAS IIIs. The docking study revealed that the hydroxyl groups of inhibitors formed extensive hydrogen bonds and the complicated hydrophobic and cation-stacking interactions are important to binding with abKAS III. We confirmed that the hydrophobicity of these compounds might be the essential factor for their antimicrobial activities against Gram-negative bacteria as well as their structural rigidity, a cooperative feature for retaining the hydrophobic interactions between abKAS III and its inhibitors. This study may provide an insight developing strategies for potent antibiotics against A. baumannii.