Calcium dependent reversible aggregation of Escherichia coli biomimicking vesicles enables formation of supported vesicle layers on silicon dioxide

Show full item record



Permalink

http://hdl.handle.net/10138/300266

Citation

Dusa , F , Chen , W , Witos , J & Wiedmer , S K 2019 , ' Calcium dependent reversible aggregation of Escherichia coli biomimicking vesicles enables formation of supported vesicle layers on silicon dioxide ' , Frontiers in materials , vol. 6 , 23 . https://doi.org/10.3389/fmats.2019.00023

Title: Calcium dependent reversible aggregation of Escherichia coli biomimicking vesicles enables formation of supported vesicle layers on silicon dioxide
Author: Dusa, Filip; Chen, Wen; Witos, Joanna; Wiedmer, Susanne Kristina
Other contributor: University of Helsinki, Department of Chemistry
University of Helsinki, Department of Chemistry

Date: 2019-03-01
Language: eng
Number of pages: 8
Belongs to series: Frontiers in materials
ISSN: 2296-8016
DOI: https://doi.org/10.3389/fmats.2019.00023
URI: http://hdl.handle.net/10138/300266
Abstract: The importance of using biomimicking membranes for various biological applications is rising, as such models are relevant for imitating real organisms. In addition, biomimicking membranes are usually much more repeatable in preparation and easier to handle during analysis than real organisms or biological membranes. In this work, we developed a method for the adsorption of intact small unilamellar Escherichia coli (E. cols) vesicles (Z-average size of 73 nm) on SiO2 substrate material. We describe the adsorption process based on the use of two surface sensitive techniques, i.e., nanoplasmonic sensing (NPS) and quartz crystal microbalance (QCM). The acquired data show that the adsorption follows a two-step process. The first step is a slow adsorption of E coil vesicle aggregates held together by 5 mM of calcium (Z-average size of 531 nm). The Z-average of the aggregates decreased almost three times when the calcium concentration was decreased to 0.1 mM. This suggests that the aggregates were disassembling to some extent when calcium was removed from the system. With both techniques, i.e., NPS and QCM, we observed a second rapid adsorption step after the solution was changed to deionized water. In this second step, the aggregates started to fall apart as the calcium concentration dropped, and the released vesicles started to adsorb onto unoccupied spots at the SiO2 surface of the sensors. Extensive release of mass from the surface was confirmed by QCM, where it was reflected by a sharp increase of frequency, while NPS, due to its lower sensing depth of a few tens of nanometers, did not record such a change. Taken together, we have developed a protocol to form a supported vesicle layer (SVL) of E coli vesicles on SiO2 surface using sodium 4-(2-hydroxyethyppiperazine-1-ethanesulfonate buffer, thus enabling the preparation of E coli biomimicking SVLs for interaction studies of compounds of interest. The immobilization happens via a two-step adsorption process.
Subject: aggregation
biomembrane
Escherichia coli
nanoplasmonic sensing
vesicles
quartz crystal microbalance
ANIONIC LIPOSOMES
CARDIOLIPIN
MEMBRANE
DEFORMATION
ADSORPTION
BACTERIAL
BILAYERS
CATIONS
MODEL
116 Chemical sciences
Rights:


Files in this item

Total number of downloads: Loading...

Files Size Format View
fmats_06_00023.pdf 1.460Mb PDF View/Open

This item appears in the following Collection(s)

Show full item record