Wen Yu, Wu Duogeng, Zhang Luxin, Ma Shuxia, Lv Chao
School of Basic Medicine, Jiamusi University, 258 Xuefu Street, Xiangyang District, Jiamusi 154000, China.
Clinical Medical College, Changchun University of Chinese Medicine, 1035 Boshuo Road, Jingyue District, Changchun 130117, China.
J Appl Microbiol. 2025 Feb 3;136(2). doi: 10.1093/jambio/lxaf003.
The aim of this study was to identify sesamin as a Casein hydrolase P (ClpP) inhibitor and to determine whether it could attenuate the virulence of methicillin-resistant Staphylococcus aureus (MRSA).
Through fluorescence resonance energy transfer screening, a natural compound sesamin demonstrated a significant inhibitory effect on ClpP enzyme activity with an IC50 of 20.62 μg/ml. Sesamin suppressed the expression of virulence factors of MRSA such as α-hemolysin (Hla) and Panton-Valentine leucocidin by protein immunoblotting. Thermal shift assay and cellular thermal shift assay showed that sesamin could bind to ClpP and enhance the thermal stability of ClpP. Furthermore, the binding affinity between sesamin and ClpP was determined by surface plasmon resonance with a KD value of 7.18 × 10-6 M. Molecular docking, dynamics simulations and point mutation analysis confirmed the stability of the sesamin-ClpP complex with a -10.184 kcal/mol total binding energy and identified PHE-174 in ClpP as a key binding site. In mice pneumonia model, sesamin combined vancomycin treatment markedly reduced the pathogenicity of MRSA-infected mice, offering protection against fatal lung infections.
Overall, these findings validate sesamin as a promising compound that targets ClpP, reducing virulence factor expression, that holds potential as a hit compound against MRSA infections.
本研究旨在鉴定芝麻素作为酪蛋白水解酶P（ClpP）抑制剂，并确定其是否能减弱耐甲氧西林金黄色葡萄球菌（MRSA）的毒力。
通过荧光共振能量转移筛选，一种天然化合物芝麻素对ClpP酶活性表现出显著抑制作用，IC50为20.62μg/ml。芝麻素通过蛋白质免疫印迹抑制MRSA毒力因子如α-溶血素（Hla）和杀白细胞素的表达。热位移分析和细胞热位移分析表明，芝麻素可与ClpP结合并增强ClpP的热稳定性。此外，通过表面等离子体共振测定芝麻素与ClpP之间的结合亲和力，KD值为7.18×10-6M。分子对接、动力学模拟和点突变分析证实了芝麻素-ClpP复合物的稳定性，总结合能为-10.184kcal/mol，并确定ClpP中的苯丙氨酸-174为关键结合位点。在小鼠肺炎模型中，芝麻素联合万古霉素治疗显著降低了MRSA感染小鼠的致病性，为致命性肺部感染提供了保护。
总体而言，这些发现证实芝麻素是一种有前景的化合物，可靶向ClpP，降低毒力因子表达，有望成为抗MRSA感染的先导化合物。
