Teiwes, Nikolas K.

[["dc.bibliographiccitation.firstpage","14175"],["dc.bibliographiccitation.issue","49"],["dc.bibliographiccitation.journal","Langmuir : the ACS journal of surfaces and colloids"],["dc.bibliographiccitation.lastpage","14183"],["dc.bibliographiccitation.volume","33"],["dc.contributor.author","Teske, Nelli"],["dc.contributor.author","Sibold, Jeremias"],["dc.contributor.author","Schumacher, Johannes"],["dc.contributor.author","Teiwes, Nikolas K."],["dc.contributor.author","Gleisner, Martin"],["dc.contributor.author","Mey, Ingo"],["dc.contributor.author","Steinem, Claudia"],["dc.date.accessioned","2018-01-17T13:00:51Z"],["dc.date.available","2018-01-17T13:00:51Z"],["dc.date.issued","2017"],["dc.description.abstract","A number of techniques has been developed and analyzed in recent years to generate pore-spanning membranes (PSMs). While quite a number of methods rely on nanoporous substrates, only a few use micrometer-sized pores to be able to individually resolve suspending membranes by means of fluorescence microscopy. To be able to produce PSMs on pores that are micrometer in size, an orthogonal functionalization strategy resulting in a hydrophilic surface is highly desirable. Here, we report on a method to prepare PSMs based on the evaporation of a thin layer of silicon monoxide on top of the porous substrate. PM-IRRAS experiments demonstrate that the final surface is composed of SiOx with 1 < x < 2. The hydrophilic surface turned out to be well suited to spread giant unilamellar vesicles forming PSMs. As the method does not rely on a gold coating as frequently used for orthogonal functionalization, fluorescence micrographs provide information not only from the freestanding membrane areas but also from the supported ones. The observation of the entire PSM area enabled us to observe phase-separation in these membranes on the freestanding and supported parts as well as protein binding and possible lipid reorganization of the membranes induced by binding of the protein Shiga toxin."],["dc.identifier.doi","10.1021/acs.langmuir.7b02727"],["dc.identifier.pmid","29148811"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/11698"],["dc.language.iso","en"],["dc.notes.status","final"],["dc.relation.eissn","1520-5827"],["dc.title","Continuous Pore-Spanning Lipid Bilayers on Silicon Oxide-Coated Porous Substrates"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","2670"],["dc.bibliographiccitation.issue","14"],["dc.bibliographiccitation.journal","The Analyst"],["dc.bibliographiccitation.lastpage","2677"],["dc.bibliographiccitation.volume","142"],["dc.contributor.author","Schwamborn, Miriam"],["dc.contributor.author","Schumacher, Johannes"],["dc.contributor.author","Sibold, Jeremias"],["dc.contributor.author","Teiwes, Nikolas K."],["dc.contributor.author","Steinem, Claudia"],["dc.date.accessioned","2018-01-17T13:03:01Z"],["dc.date.available","2018-01-17T13:03:01Z"],["dc.date.issued","2017"],["dc.description.abstract","Monitoring the proton pumping activity of proteins such as ATPases in reconstituted single proteoliposomes is key to quantify the function of proteins as well as potential proton pump inhibitors. However, most pH-detecting assays available are either not quantitative, require well-adapted reconstitution protocols or are not appropriate for single vesicle studies. Here, we describe the quantitative and time-resolved detection of F-type ATPase-induced pH changes across vesicular membranes doped with the commercially available pH sensitive fluorophore Oregon Green 488 DHPE. This dye is shown to be well suited to monitor acidification of lipid vesicles not only in bulk but also at the single vesicle level. The pKa value of Oregon Green 488 DHPE embedded in a lipid environment was determined to be 6.1 making the fluorophore well suited for a variety of physiologically relevant proton pumps. The TFOF1-ATPase from a thermophilic bacterium was reconstituted into large unilamellar vesicles and the bulk acidification assay clearly reveals the overall activity of the F-type ATPase in the vesicle ensemble with an average pH change of 0.45. However, monitoring the pH changes in individual vesicles attached to a substrate demonstrates that the fraction of vesicles with a significant observable pH change is only about 5%, a number that cannot be gathered from bulk experiments and which is considerably lower than expected."],["dc.identifier.doi","10.1039/c7an00215g"],["dc.identifier.pmid","28616949"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/11701"],["dc.language.iso","en"],["dc.notes.status","final"],["dc.relation.eissn","1364-5528"],["dc.title","Monitoring ATPase induced pH changes in single proteoliposomes with the lipid-coupled fluorophore Oregon Green 488"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dspace.entity.type","Publication"]]