Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Lack of association between a cationic protein and a cationic fluorosurfactant
KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface Chemistry (closed 20081231).
KTH, School of Chemical Science and Engineering (CHE), Centres, Industrial NMR Centre.
Department of Physical Chemistry, Uppsala University.
KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface Chemistry (closed 20081231).ORCID iD: 0000-0001-7496-1101
Show others and affiliations
2007 (English)In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 23, no 2, 771-775 p.Article in journal (Refereed) Published
Abstract [en]

Surface tension, F-19 and H-1 NMR spectroscopy, and cryotransmission electron microscopy are used to characterize the state of association in aqueous solutions of a fluorosurfactant CF3(CF2)(n)SO2NH(CH2)(3-4)N(CH3)(3)(+) I- (n = 8, 6) with and without lysozyme added. In the absence of lysozyme, we find monomers, small aggregates, and large vesicles to coexist, with the individual fluorosurfactant molecules exchanging slowly (> 1 ms) among those states. When both lysozyme and fluorosurfactant are present in the solution, they have no measurable influence on the physical state of the other. In contrast, a hydrogenated cationic surfactant with the same headgroup, hexadecyltrimethylammonium bromide, is shown to associate to lysozyme.

Place, publisher, year, edition, pages
2007. Vol. 23, no 2, 771-775 p.
Keyword [en]
Fluorescence; Monomers; Nuclear magnetic resonance; Proteins; Solutions; Surface tension; Transmission electron microscopy; Cationic fluorosurfactants; Cationic proteins; Cryotransmission electron microscopy; Individual fluorosurfactant molecules; Surface active agents; cation; cetrimide; lysozyme; surfactant; article; chemical structure; chemistry; cryoelectron microscopy; hydrogen bond; methodology; nuclear magnetic resonance spectroscopy; physical chemistry; protein folding; surface property; surface tension; transmission electron microscopy; Cations; Cetrimonium Compounds; Chemistry, Physical; Cryoelectron Microscopy; Hydrogen Bonding; Magnetic Resonance Spectroscopy; Microscopy, Electron, Transmission; Molecular Structure; Muramidase; Protein Folding; Surface Properties; Surface Tension; Surface-Active Agents
National Category
Physical Chemistry
Identifiers
URN: urn:nbn:se:kth:diva-7413DOI: 10.1021/la062469zISI: 000243338500061PubMedID: 17209632Scopus ID: 2-s2.0-33846852625OAI: oai:DiVA.org:kth-7413DiVA: diva2:12434
Note

QC 20150721

Available from: 2009-08-30 Created: 2009-08-30 Last updated: 2017-12-14Bibliographically approved
In thesis
1. Interactions Between Biopolymers and Surfactants with Focus on Fluorosurfactants and Proteins
Open this publication in new window or tab >>Interactions Between Biopolymers and Surfactants with Focus on Fluorosurfactants and Proteins
2007 (English)Doctoral thesis, comprehensive summary (Other scientific)
Abstract [en]

The aim of this thesis was to obtain a better understanding of the association between surfactants and biopolymers in bulk solutions and at solid/aqueous liquid interface. In order to do this, the interactions between surfactants and biopolymers were investigated with a variety of experimental techniques.

The main focus has been on the interactions between fluorosurfactants and proteins, which are important during electrophoresis of proteins in silica capillaries. Electrophoretic separation of positively charged proteins is often complicated by non-specific adsorption of protein onto capillary wall, while it was found to improve when cationic fluorosurfactants were added into the background buffer. We investigated the interactions between a cationic fluorosurfactant, FC134, and a positively charged protein, lysozyme. By employing Nuclear Magnetic Resonance (NMR) and tensiometry we could conclude that the cationic fluorosurfactant did not associate with positively charged lysozyme in bulk solutions. At the solid/aqueous liquid interface, the adsorption of fluorosurfactants and lysozyme onto silica was studied by the surface force technique (MASIF), ellipsometry, reflectrometry, Quartz Crystal Microbalance (QCM-D) and Atomic Force Microscopy (AFM). Cationic fluorosurfactant FC134 was found to adsorb onto the silica surface in a form of bilayer aggregates, which led to a charge reversal of the originally negatively charged substrate. The adsorption of lysozyme onto silica was also extensive and it corresponded to the more than monolayer coverage. When adsorbing from mixed solutions, the presence of the cationic fluorosurfactant in the solution led to an elimination of the lysozyme in the resulting adsorbed layer. For the lysozyme concentration of 0.2 mg/ml, which is typical for the electrophoretic separation, it was found that adsorption of protein was suppressed by more than 90% when only 30 μM of FC134 was added into the buffer. The presence of the low amounts of residual proteins in the adsorbed layers caused an enhancement of the adsorption of fluorosurfactants, which was attributed to adsorption of the fluorosurfactants between proteins in a form of large vesicles.

The interactions between a positively charged biopolymer chitosan and an anionic surfactant sodium dodecylsulfate (SDS) were studied with respect to the effect of the ionic strength of the background electrolyte, both in the bulk solution and at the silica/liquid interface. It was shown that SDS and chitosan form complexes in the bulk solution, which reverse their charge at higher SDS concentrations. At SDS concentrations above the critical micellar concentration, large aggregates were formed, which were trapped in long-lived nonequilibrium states at both high and low ionic strengths. SDS did not adsorb at the silica/liquid interface by itself. However, by employing QCM-D and ellipsometry we detected an extensive adsorption of SDS on the silica substrate, which has been modified by adsorbed chitosan. The structure of the chitosan layer on the lowly charged silica was strongly affected by the ionic strength of the solution from which the chitosan adsorption took place. The interactions between SDS and the pre-adsorbed chitosan were found to be similar on lowly charged silica and on highly charged mica.

A novel method based on the Bruggeman effective medium approximation was proposed for the evaluation of ellipsometric data characterizing composite adsorbed layers.

Finally, the effect of the adsorbed layer surface roughness on the QCM-D response in liquid was studied with focus on trapped water. It was found that QCM-D effectively senses water, which is mechanically trapped inside topographical structures with the size in nano-meter scale.

Place, publisher, year, edition, pages
Stockholm: KTH, 2007. 97 p.
Series
Trita-CHE-Report, ISSN 1654-1081 ; 2007:54
National Category
Organic Chemistry
Identifiers
urn:nbn:se:kth:diva-4475 (URN)978-91-7178-739-2 (ISBN)
Public defence
2007-09-14, Salongen, KTH Biblioteket, Osquara backe 31, Stockholm, 09:00
Opponent
Supervisors
Note
QC 20100809Available from: 2009-08-30 Created: 2007-08-30 Last updated: 2010-08-09Bibliographically approved
2. Molecular Association Studied by NMR Spectroscopy
Open this publication in new window or tab >>Molecular Association Studied by NMR Spectroscopy
2006 (English)Doctoral thesis, comprehensive summary (Other scientific)
Abstract [en]

This Thesis presents studies of molecular association in aqueous solution and at the liquid/solid interface. The investigated molecular systems range from self-aggregating surfactants to hydration water in contact with micelles or individual molecules. In most studies, combinations of various NMR methods were applied. These vary from simple chemical shift and intensity measurements to more elaborate self-diffusion and intermolecular cross-relaxation experiments.

Non-ideal mixed micelles of fluorinated and hydrogenated surfactants were studied by an experimental procedure that allows an analysis in terms of micellar structure, using a minimal number of initial assumptions. Quantitative conclusions about micro-phase separation within mixed micelles were obtained within the framework of the regular solution theory. Additionally, NMR was introduced and developed as a powerful method for studying adsorption of surfactants at solid interfaces. Adsorption isotherms for pure and mixed surfactant systems and non-ideal mixing behavior of fluorinated and hydrogenated surfactants at solid surfaces were quantified. Fluorosurfactant-protein association was investigated using the methods described.

Intermolecular cross-relaxation rates between solute and solvent molecules were recorded at several different magnetic fields. The results reveal strong frequency dependence for both small molecules and micelles. This finding demonstrates that intermolecular cross-relaxation is not solely controlled by fast local motions, but also by long-range translational dynamics. Data analysis in terms of recently developed relaxation models provides information about the hydrophobic hydration and micellar structure.

Place, publisher, year, edition, pages
Stockholm: KTH, 2006. 52 p.
Series
Trita-FYK, 0602
Keyword
NMR, spin relaxation, self-diffusion, intermolecular cross-relaxation, chemical shift, fluorinated surfactants, hydrogenated surfactant, micelle, non-ideal mixing, adsorption, hydration, surfactant-protein association
National Category
Physical Chemistry
Identifiers
urn:nbn:se:kth:diva-3947 (URN)91-7178-345 8 (ISBN)
Public defence
2006-05-19, F3, Lindstedtsv. 26, Stockholm, 10:00
Opponent
Supervisors
Note
QC 20100914Available from: 2006-05-10 Created: 2006-05-10 Last updated: 2010-09-14Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textPubMedScopusACS Publications

Authority records BETA

Blomberg, EvaFuro, Istvan

Search in DiVA

By author/editor
Macakova, LubicaNordstierna, LarsBlomberg, EvaFuro, Istvan
By organisation
Surface Chemistry (closed 20081231)Industrial NMR Centre
In the same journal
Langmuir
Physical Chemistry

Search outside of DiVA

GoogleGoogle Scholar

doi
pubmed
urn-nbn

Altmetric score

doi
pubmed
urn-nbn
Total: 88 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf