Witt, Hannes

[["dc.bibliographiccitation.journal","European Biophysics Journal"],["dc.contributor.author","Witt, Hannes"],["dc.contributor.author","Savić, Filip"],["dc.contributor.author","Verbeek, Sarah"],["dc.contributor.author","Dietz, Jörn"],["dc.contributor.author","Tarantola, Gesa"],["dc.contributor.author","Oelkers, Marieelen"],["dc.contributor.author","Geil, Burkhard"],["dc.contributor.author","Janshoff, Andreas"],["dc.date.accessioned","2021-04-14T08:29:19Z"],["dc.date.available","2021-04-14T08:29:19Z"],["dc.date.issued","2021"],["dc.identifier.doi","10.1007/s00249-020-01490-5"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/82863"],["dc.language.iso","en"],["dc.notes.intern","DOI Import GROB-399"],["dc.relation.eissn","1432-1017"],["dc.relation.issn","0175-7571"],["dc.title","Membrane fusion studied by colloidal probes"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","13051"],["dc.bibliographiccitation.issue","46"],["dc.bibliographiccitation.journal","PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA"],["dc.bibliographiccitation.lastpage","13056"],["dc.bibliographiccitation.volume","113"],["dc.contributor.author","Oelkers, Marieelen"],["dc.contributor.author","Witt, Hannes"],["dc.contributor.author","Halder, Partho"],["dc.contributor.author","Jahn, Reinhard"],["dc.contributor.author","Janshoff, Andreas"],["dc.date.accessioned","2018-11-07T10:05:44Z"],["dc.date.available","2018-11-07T10:05:44Z"],["dc.date.issued","2016"],["dc.description.abstract","Fusion of lipid bilayers is usually prevented by large energy barriers arising from removal of the hydration shell, formation of highly curved structures, and, eventually, fusion pore widening. Here, we measured the force-dependent lifetime of fusion intermediates using membrane-coated silica spheres attached to cantilevers of an atomic-force microscope. Analysis of time traces obtained from force-clamp experiments allowed us to unequivocally assign steps in deflection of the cantilever to membrane states during the SNARE-mediated fusion with solid-supported lipid bilayers. Force-dependent lifetime distributions of the various intermediate fusion states allowed us to propose the likelihood of different fusion pathways and to assess the main free energy barrier, which was found to be related to passing of the hydration barrier and splaying of lipids to eventually enter either the fully fused state or a long-lived hemifusion intermediate. The results were compared with SNARE mutants that arrest adjacent bilayers in the docked state and membranes in the absence of SNAREs but presence of PEG or calcium. Only with the WT SNARE construct was appreciable merging of both bilayers observed."],["dc.description.sponsorship","Deutsche Forschungsgemeinschaft [GSC 226/2, SFB 803 B06, B08]"],["dc.identifier.doi","10.1073/pnas.1615885113"],["dc.identifier.isi","000388970100058"],["dc.identifier.pmid","27807132"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/38957"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Natl Acad Sciences"],["dc.relation.issn","0027-8424"],["dc.title","SNARE-mediated membrane fusion trajectories derived from force-clamp experiments"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1582"],["dc.bibliographiccitation.issue","7"],["dc.bibliographiccitation.journal","Biophysical Journal"],["dc.bibliographiccitation.lastpage","1592"],["dc.bibliographiccitation.volume","110"],["dc.contributor.author","Witt, Hannes"],["dc.contributor.author","Savic, Filip"],["dc.contributor.author","Oelkers, Marieelen"],["dc.contributor.author","Awan, Shahid I."],["dc.contributor.author","Werz, Daniel B."],["dc.contributor.author","Geil, Burkhard"],["dc.contributor.author","Janshoff, Andreas"],["dc.date.accessioned","2018-11-07T10:15:33Z"],["dc.date.available","2018-11-07T10:15:33Z"],["dc.date.issued","2016"],["dc.description.abstract","Weak noncovalent intermolecular interactions play a pivotal role in many biological processes such as cell adhesion or immunology, where the overall binding strength is controlled through bond association and dissociation dynamics as well as the cooperative action of many parallel bonds. Among the various molecules participating in weak bonds, carbohydrate-carbohydrate interactions are probably the most ancient ones allowing individual cells to reversibly enter the multicellular state and to tell apart self and nonself cells. Here, we scrutinized the kinetics and thermodynamics of small homomeric Lewis X-Lewis X ensembles formed in the contact zone of a membrane-coated colloidal probe and a solid supported membrane ensuring minimal nonspecific background interactions. We used an atomic force microscope to measure force distance curves at Piconewton resolution, which allowed us to measure the force due to unbinding of the colloidal probe and the planar membrane as a function of contact time. Applying a contact model, we could estimate the free binding energy of the formed adhesion cluster as a function of dwell time and thereby determine the precise size of the contact zone, the number of participating bonds, and the intrinsic rates of association and dissociation in the presence of calcium ions. The unbinding energy per bond was found to be on the order of 1 k(B)T. Approximately 30 bonds were opened simultaneously at an off-rate of k(off) = 7 +/- 0.2 s(-1)."],["dc.identifier.doi","10.1016/j.bpj.2016.03.006"],["dc.identifier.isi","000374209700012"],["dc.identifier.pmid","27074683"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/40833"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Cell Press"],["dc.relation.issn","1542-0086"],["dc.relation.issn","0006-3495"],["dc.title","Size, Kinetics, and Free Energy of Clusters Formed by Ultraweak Carbohydrate-Carbohydrate Bonds"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.journal","European Biophysics Journal"],["dc.bibliographiccitation.volume","44"],["dc.contributor.author","Witt, Hannes"],["dc.contributor.author","Oelkers, Marieelen"],["dc.contributor.author","Savic, Filip"],["dc.contributor.author","Awan, S."],["dc.contributor.author","Werz, Daniel B."],["dc.contributor.author","Geil, Burkhard"],["dc.contributor.author","Janshoff, Andreas"],["dc.date.accessioned","2018-11-07T09:55:36Z"],["dc.date.available","2018-11-07T09:55:36Z"],["dc.date.issued","2015"],["dc.format.extent","S244"],["dc.identifier.isi","000380001400772"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/36784"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Springer"],["dc.publisher.place","New york"],["dc.relation.eventlocation","Dresden, GERMANY"],["dc.relation.issn","1432-1017"],["dc.relation.issn","0175-7571"],["dc.title","Binding enthalpy driven accumulation of Lewis X in the membrane-membrane contact zone"],["dc.type","conference_abstract"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]