Witt, Hannes

[["dc.bibliographiccitation.artnumber","188102"],["dc.bibliographiccitation.issue","18"],["dc.bibliographiccitation.journal","Physical Review Letters"],["dc.bibliographiccitation.volume","123"],["dc.contributor.author","Lorenz, Charlotta"],["dc.contributor.author","Forsting, Johanna"],["dc.contributor.author","Schepers, Anna V."],["dc.contributor.author","Kraxner, Julia"],["dc.contributor.author","Bauch, Susanne"],["dc.contributor.author","Witt, Hannes"],["dc.contributor.author","Klumpp, Stefan"],["dc.contributor.author","Köster, Sarah"],["dc.date.accessioned","2020-12-10T18:25:50Z"],["dc.date.available","2020-12-10T18:25:50Z"],["dc.date.issued","2019"],["dc.description.abstract","The cytoskeleton is a composite network of three types of protein filaments, among which intermediate filaments (IFs) are the most extensible ones. Two very important IFs are keratin and vimentin, which have similar molecular architectures but different mechanical behaviors. Here we compare the mechanical response of single keratin and vimentin filaments using optical tweezers. We show that the mechanics of vimentin strongly depends on the ionic strength of the buffer and that its force-strain curve suggests a high degree of cooperativity between subunits. Indeed, a computational model indicates that in contrast to keratin, vimentin is characterized by strong lateral subunit coupling of its charged monomers during unfolding of α helices. We conclude that cells can tune their mechanics by differential use of keratin versus vimentin."],["dc.identifier.doi","10.1103/PhysRevLett.123.188102"],["dc.identifier.eissn","1079-7114"],["dc.identifier.issn","0031-9007"],["dc.identifier.pmid","31763918"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/75854"],["dc.language.iso","en"],["dc.notes.intern","DOI Import GROB-354"],["dc.relation","info:eu-repo/grantAgreement/EC/H2020/724932/EU//MECHANICS"],["dc.relation.eissn","1079-7114"],["dc.relation.issn","0031-9007"],["dc.relation.orgunit","Fakultät für Physik"],["dc.relation.orgunit","Institut für Röntgenphysik"],["dc.relation.workinggroup","RG Köster (Cellular Biophysics)"],["dc.rights","CC BY-NC-ND 4.0"],["dc.rights.access","openAccess"],["dc.rights.uri","http://creativecommons.org/licenses/by-nc-nd/4.0/"],["dc.subject","intermediate filaments; optical tweezers; atomic force microscopy; cytoskeleton; biomechanics; Monte Carlo simulation"],["dc.subject.ddc","530"],["dc.subject.gro","cytoskeleton"],["dc.subject.gro","cellular biophysics"],["dc.title","Lateral Subunit Coupling Determines Intermediate Filament Mechanics"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original_ja"],["dc.type.version","submitted_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","eaat1161"],["dc.bibliographiccitation.issue","6"],["dc.bibliographiccitation.journal","Science Advances"],["dc.bibliographiccitation.volume","4"],["dc.contributor.author","Block, Johanna"],["dc.contributor.author","Witt, Hannes"],["dc.contributor.author","Candelli, Andrea"],["dc.contributor.author","Danes, Jordi Cabanas"],["dc.contributor.author","Peterman, Erwin J. G."],["dc.contributor.author","Wuite, Gijs J. L."],["dc.contributor.author","Janshoff, Andreas"],["dc.contributor.author","Köster, Sarah"],["dc.date.accessioned","2019-07-09T11:45:54Z"],["dc.date.available","2019-07-09T11:45:54Z"],["dc.date.issued","2018"],["dc.description.abstract","Structure and dynamics of living matter rely on design principles fundamentally different from concepts of traditional material science. Specialized intracellular filaments in the cytoskeleton permit living systems to divide, migrate, and growwith a high degree of variability and durability. Among the three filament systems,microfilaments,microtubules, and intermediate filaments (IFs), the physical properties of IFs and their role in cellular mechanics are the least well understood. We use optical trapping of individual vimentin filaments to investigate energy dissipation, strain history dependence, and creep behavior of stretched filaments. By stochastic and numerical modeling, we link our experimental observations to the peculiar molecular architecture of IFs. We find that individual vimentin filaments display tensile memory and are able to dissipate more than 70% of the input energy.We attribute these phenomena to distinct nonequilibrium folding and unfolding of a helices in the vimentin monomers constituting the filaments."],["dc.description.sponsorship","Open-Access-Publikationsfonds 2018"],["dc.identifier.doi","10.1126/sciadv.aat1161"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/15341"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/59334"],["dc.language.iso","en"],["dc.notes.intern","Merged from goescholar"],["dc.notes.intern","Merged from goescholar"],["dc.relation.issn","2375-2548"],["dc.relation.orgunit","Institut für Röntgenphysik"],["dc.relation.orgunit","Fakultät für Physik"],["dc.relation.workinggroup","RG Köster (Cellular Biophysics)"],["dc.rights","CC BY-NC 4.0"],["dc.rights.uri","https://creativecommons.org/licenses/by/4.0/"],["dc.rights.uri","https://creativecommons.org/licenses/by/4.0"],["dc.subject.ddc","530"],["dc.subject.gro","cytoskeleton"],["dc.subject.gro","cellular biophysics"],["dc.title","Viscoelastic properties of vimentin originate from nonequilibrium conformational changes"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.subtype","original_ja"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","048101"],["dc.bibliographiccitation.firstpage","1"],["dc.bibliographiccitation.issue","4"],["dc.bibliographiccitation.journal","Physical Review Letters"],["dc.bibliographiccitation.lastpage","5"],["dc.bibliographiccitation.volume","118"],["dc.contributor.author","Block, Johanna"],["dc.contributor.author","Witt, Hannes"],["dc.contributor.author","Candelli, Andrea"],["dc.contributor.author","Peterman, Erwin J. G."],["dc.contributor.author","Wuite, Gijs J. L."],["dc.contributor.author","Janshoff, Andreas"],["dc.contributor.author","Köster, Sarah"],["dc.date.accessioned","2020-12-10T18:25:42Z"],["dc.date.available","2020-12-10T18:25:42Z"],["dc.date.issued","2017"],["dc.description.abstract","The mechanical properties of eukaryotic cells are to a great extent determined by the cytoskeleton, a composite network of different filamentous proteins. Among these, intermediate filaments (IFs) are exceptional in their molecular architecture and mechanical properties. Here we directly record stress-strain curves of individual vimentin IFs using optical traps and atomic force microscopy. We find a strong loading rate dependence of the mechanical response, supporting the hypothesis that IFs could serve to protect eukaryotic cells from fast, large deformations. Our experimental results show different unfolding regimes, which we can quantitatively reproduce by an elastically coupled system of multiple two-state elements."],["dc.identifier.doi","10.1103/PhysRevLett.118.048101"],["dc.identifier.eissn","1079-7114"],["dc.identifier.fs","623737"],["dc.identifier.issn","0031-9007"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/17056"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/75797"],["dc.language.iso","en"],["dc.notes.intern","DOI Import GROB-354"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","final"],["dc.relation.eissn","1079-7114"],["dc.relation.issn","0031-9007"],["dc.relation.orgunit","Institut für Röntgenphysik"],["dc.relation.workinggroup","RG Köster (Cellular Biophysics)"],["dc.rights","CC BY 3.0"],["dc.rights.uri","https://creativecommons.org/licenses/by/3.0/"],["dc.subject.gro","cytoskeleton"],["dc.subject.gro","cellular biophysics"],["dc.title","Nonlinear Loading-Rate-Dependent Force Response of Individual Vimentin Intermediate Filaments to Applied Strain"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","unknown"],["dc.type.subtype","original_ja"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.contributor.author","Forsting, Johanna"],["dc.contributor.author","Kraxner, Julia"],["dc.contributor.author","Witt, Hannes"],["dc.contributor.author","Janshoff, Andreas"],["dc.contributor.author","Köster, Sarah"],["dc.date.accessioned","2020-04-24T12:22:06Z"],["dc.date.available","2020-04-24T12:22:06Z"],["dc.date.issued","2019"],["dc.description.abstract","Intermediate filaments (IFs) are part of the cytoskeleton of eukaryotic cells and are thus largely responsible for the cell's mechanical properties. IFs are characterized by a pronounced extensibility and remarkable resilience that enable them to support cells in extreme situations. Previous experiments showed that under strain, alpha-helices in vimentin IFs might unfold to beta-sheets. Upon repeated stretching, the filaments soften, however, the remaining plastic strain is negligible. Here we observe that vimentin IFs do not recover their original stiffness on reasonable time scales, and we explain these seemingly contradicting results by introducing a third, less well-defined conformational state. Reversibility on a microscopic scale can be fully rescued by introducing crosslinkers that prevent transition to the beta-sheet. Our results classify IFs as a material with intriguing mechanical properties, which is likely to play a major role for the cell's local adaption to external stimuli."],["dc.format.extent","21"],["dc.identifier.doi","10.1101/673673"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/64342"],["dc.language.iso","en"],["dc.subject.gro","cellular biophysics"],["dc.title","Vimentin intermediate filaments undergo irreversible conformational changes during cyclic loading"],["dc.type","preprint"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","7349"],["dc.bibliographiccitation.issue","10"],["dc.bibliographiccitation.journal","Nano Letters"],["dc.bibliographiccitation.lastpage","7356"],["dc.bibliographiccitation.volume","19"],["dc.contributor.author","Forsting, Johanna"],["dc.contributor.author","Kraxner, Julia"],["dc.contributor.author","Witt, Hannes"],["dc.contributor.author","Janshoff, Andreas"],["dc.contributor.author","Köster, Sarah"],["dc.date.accessioned","2020-03-04T13:30:18Z"],["dc.date.available","2020-03-04T13:30:18Z"],["dc.date.issued","2019"],["dc.description.abstract","Intermediate filaments (IFs) are part of the cytoskeleton of eukaryotic cells and, therefore, are largely responsible for the cell's mechanical properties. IFs are characterized by a pronounced extensibility and remarkable resilience that enable them to support cells in extreme situations. Previous experiments showed that, under strain, α-helices in vimentin IFs might unfold to β-sheets. Upon repeated stretching, the filaments soften; however, the remaining plastic strain is negligible. Here, we observe that vimentin IFs do not recover their original stiffness on reasonable time scales, and we explain these seemingly contradicting results by introducing a third, less well-defined conformational state. Reversibility on the nanoscale can be fully rescued by introducing cross-linkers that prevent transition to the β-sheet. Our results classify IFs as a nanomaterial with intriguing mechanical properties, which is likely to play a major role for the cell's local adaption to external stimuli."],["dc.identifier.doi","10.1021/acs.nanolett.9b02972"],["dc.identifier.pmid","31498648"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/63104"],["dc.language.iso","en"],["dc.relation.eissn","1530-6992"],["dc.relation.issn","1530-6984"],["dc.relation.issn","1530-6992"],["dc.relation.orgunit","Institut für Röntgenphysik"],["dc.relation.workinggroup","RG Köster (Cellular Biophysics)"],["dc.subject.gro","cytoskeleton"],["dc.subject.gro","cellular biophysics"],["dc.title","Vimentin Intermediate Filaments Undergo Irreversible Conformational Changes during Cyclic Loading"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.subtype","original_ja"],["dspace.entity.type","Publication"]]