Forces Driving the Attachment of Staphylococcus epidermidis to Fibrinogen-Coated Surfaces

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• 作者：Philippe Herman ; Sofiane El-Kirat-Chatel ; Audrey Beaussart ; Joan A. Geoghegan ; Thomas Vanzieleghem ; Timothy J. Foster ; Pascal Hols ; Jacques Mahillon ; Yves F. Dufr锚ne
• 刊名：Langmuir
• 出版年：2013
• 出版时间：October 22, 2013
• 年：2013
• 卷：29
• 期：42
• 页码：13018-13022
• 全文大小：335K
• 年卷期：v.29,no.42(October 22, 2013)
• ISSN：1520-5827

文摘

Cell surface proteins of bacteria play essential roles in mediating the attachment of pathogens to host tissues and, therefore, represent key targets for anti-adhesion therapy. In the opportunistic pathogen Staphylococcus epidermidis, the adhesion protein SdrG mediates attachment of bacteria to the blood plasma protein fibrinogen (Fg) through a binding mechanism that is not yet fully understood. We report the direct measurement of the forces driving the adhesion of S. epidermidis to Fg-coated substrates using single-cell force spectroscopy. We found that the S. epidermidis鈥揊g adhesion force is of 150 pN magnitude and that the adhesion strength and adhesion probability strongly increase with the interaction time, suggesting that the adhesion process involves time-dependent conformational changes. Control experiments with mutant bacteria lacking SdrG and substrates coated with the Fg 尾_6鈥?0 peptide, instead of the full Fg protein, demonstrate that these force signatures originate from the rupture of specific bonds between SdrG and its peptide ligand. Collectively, our results are consistent with a dynamic, multi-step ligand-binding mechanism called 鈥渄ock, lock, and latch鈥?