Formation of supported lipid bilayers of charged E. coli lipids on modified gold by vesicle fusion

Abstract

Graphical abstract

Supported Lipid Bilayers of Escherichia coli Extracted Lipids and Their Calcium Dependence

“…The result is consistent with previous studies, which showed at least ∼2 mM of Ca 2+ is necessary for the formation of PLE-SLB on SiO 2 /Si, mica, TiO 2 , indium tin oxide and gold (Dodd et al, 2008;Merz et al, 2008;Lopes et al, 2010;Unsay et al, 2013;Lind et al, 2015;Hsia et al, 2016;Konarzewska et al, 2017;Márquez and Vélez, 2017). In the previous studies of the bacterial mimic lipid bilayer, however, averaged response from the sample was mainly obtained using QCM and fluorescence microscopy (Dodd et al, 2008;Merz et al, 2008;Lopes et al, 2010;Unsay et al, 2013;Lind et al, 2015;Phan and Shin, 2015;Hsia et al, 2016;Konarzewska et al, 2017;Márquez and Vélez, 2017). The results in this study showed the heterogeneity of SLB especially at the threshold [Ca 2+ ] around 2.5 mM.…”

“…As a bacterial model cell system, reconstituted Escherichia coli (E. coli) cell membrane has been studied (Dodd et al, 2008;Merz et al, 2008;Lopes et al, 2010;Unsay et al, 2013;Lind et al, 2015;Phan and Shin, 2015;Hsia et al, 2016;Konarzewska et al, 2017;Márquez and Vélez, 2017). Understanding the bacterial membrane system helps in revealing the mechanism of molecular recognition and material transportation during bacterial infection for medical technology.…”

“…There are several previous studies on the formation of SLBs containing E. coli lipids such as polar lipid extract (PLE) or total lipid extract (TLE) (Dodd et al, 2008;Merz et al, 2008;Lopes et al, 2010;Unsay et al, 2013;Lind et al, 2015;Hsia et al, 2016;Konarzewska et al, 2017;Márquez and Vélez, 2017). Solid substrates, which are generally used for SLB formation, e.g., glass, oxidized layer on a Si wafer, and mica, are negatively charged.…”

“…Solid substrates, which are generally used for SLB formation, e.g., glass, oxidized layer on a Si wafer, and mica, are negatively charged. Because of the electrostatic repulsion between negatively charged E. coli lipids and the substrates, divalent cation such as Ca 2+ is necessary to form SLB (Merz et al, 2008;Lind et al, 2015;Márquez and Vélez, 2017). Previous QCM and fluorescence microscope studies showed that ∼2 mM Ca 2+ is sufficient for the formation of E. coli lipid SLB (Merz et al, 2008;Lind et al, 2015;Márquez and Vélez, 2017).…”

“…Because of the electrostatic repulsion between negatively charged E. coli lipids and the substrates, divalent cation such as Ca 2+ is necessary to form SLB (Merz et al, 2008;Lind et al, 2015;Márquez and Vélez, 2017). Previous QCM and fluorescence microscope studies showed that ∼2 mM Ca 2+ is sufficient for the formation of E. coli lipid SLB (Merz et al, 2008;Lind et al, 2015;Márquez and Vélez, 2017). Divalent cations bridge negatively charged substances by effectively shielding electrostatic interaction (Rajendran et al, 2011;Ido et al, 2013), and also positively affect the SLB formation from lipid vesicles (Hansma and Laney, 1996;Rivetti et al, 1996;Reviakine and Brisson, 2000;Pastré et al, 2003;Seantier and Kasemo, 2009).…”