Schaap, Iwan A. T.

[["dc.bibliographiccitation.firstpage","282"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","Journal of Structural Biology"],["dc.bibliographiccitation.lastpage","292"],["dc.bibliographiccitation.volume","158"],["dc.contributor.author","Schaap, Iwan A. T."],["dc.contributor.author","Hoffmann, Bernd"],["dc.contributor.author","Carrasco, Carolina"],["dc.contributor.author","Merkel, Rudolf"],["dc.contributor.author","Schmidt, Christoph"],["dc.date.accessioned","2017-09-07T11:49:47Z"],["dc.date.available","2017-09-07T11:49:47Z"],["dc.date.issued","2007"],["dc.description.abstract","Tau is one of the most abundant microtubule-associated proteins involved in kinetic stabilization and bundling of axonal microtubules. Although intense research has revealed much about tau function and its involvement in Alzheimer's disease during the past years, it still remains unclear how exactly tau binds on microtubules and if the kinetic stabilization of microtubules by tau is accompanied, at least in part, by a mechanical reinforcement of microtubules. In this paper, we have used atomic force microscopy to address both aspects by visualizing and mechanically analyzing microtubules in the presence of native tau isoforms. We could show that tau at saturating concentrations forms a 1 nm thick layer around the microtubule, but leaves the protofilament structure well visible. The latter observation argues for tau binding mainly along and not across the protofilaments. The radial elasticity of microtubules was almost unaffected by tau, consistent with tau binding along the tops of the protofilaments. Tau did increase the resistance of microtubules against rupture. Finite-element calculations confirmed our findings. (c) 2006 Elsevier Inc. All rights reserved."],["dc.identifier.doi","10.1016/j.jsb.2006.11.010"],["dc.identifier.gro","3143493"],["dc.identifier.isi","000246927800003"],["dc.identifier.pmid","17329123"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/1014"],["dc.notes.intern","WoS Import 2017-03-10"],["dc.notes.status","final"],["dc.notes.submitter","PUB_WoS_Import"],["dc.publisher","Academic Press Inc Elsevier Science"],["dc.relation.issn","1047-8477"],["dc.title","Tau protein binding forms a 1 nm thick layer along protofilaments without affecting the radial elasticity of microtubules"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","924"],["dc.bibliographiccitation.journal","Applied Surface Science"],["dc.bibliographiccitation.lastpage","928"],["dc.bibliographiccitation.volume","390"],["dc.contributor.author","Ghosh, Moumita"],["dc.contributor.author","Ghosh, Siddharth"],["dc.contributor.author","Seibt, Michael"],["dc.contributor.author","Schaap, Iwan A. T."],["dc.contributor.author","Schmidt, Christoph"],["dc.contributor.author","Rao, G. Mohan"],["dc.date.accessioned","2017-09-07T11:44:31Z"],["dc.date.available","2017-09-07T11:44:31Z"],["dc.date.issued","2016"],["dc.description.abstract","Due to their photoluminescence, metal oxide nanostructures such as ZnO nanostructures are promising candidates in biomedical imaging, drug delivery and bio-sensing. To apply them as label for bio-imaging, it is important to study their structural stability in a bio-fluidic environment. We have explored the effect of water, the main constituent of biological solutions, on ZnO nanostructures with scanning electron microscopy (SEM) and photoluminescence (PL) studies which show ZnO nanorod degeneration in water. In addition, we propose and investigate a robust and inexpensive method to encapsulate these nano structures (without structural degradation) using bio-compatible non-ionic surfactant in non-aqueous medium, which was not reported earlier. This new finding is an immediate interest to the broad audience of researchers working in biophysics, sensing and actuation, drug delivery, food and cosmetics technology, etc. (C) 2016 Elsevier B.V. All rights reserved."],["dc.identifier.doi","10.1016/j.apsusc.2016.08.117"],["dc.identifier.gro","3141594"],["dc.identifier.isi","000385900700112"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/5"],["dc.notes.intern","WoS Import 2017-03-10"],["dc.notes.status","final"],["dc.notes.submitter","PUB_WoS_Import"],["dc.publisher","Elsevier Science Bv"],["dc.relation.eissn","1873-5584"],["dc.relation.issn","0169-4332"],["dc.title","Designing deoxidation inhibiting encapsulation of metal oxide nanostructures for fluidic and biological applications"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","2541"],["dc.bibliographiccitation.issue","10"],["dc.bibliographiccitation.journal","Biophysical Journal"],["dc.bibliographiccitation.lastpage","2549"],["dc.bibliographiccitation.volume","108"],["dc.contributor.author","Wilts, Bodo D."],["dc.contributor.author","Schaap, Iwan A. T."],["dc.contributor.author","Schmidt, Christoph"],["dc.date.accessioned","2017-09-07T11:44:24Z"],["dc.date.available","2017-09-07T11:44:24Z"],["dc.date.issued","2015"],["dc.description.abstract","Cowpea chlorotic mottle virus (CCMV) forms highly elastic icosahedral protein capsids that undergo a characteristic swelling transition when the pH is raised from 5 to 7. Here, we performed nano-indentation experiments using an atomic force microscope to track capsid swelling and measure the shells' Young's modulus at the same time. When we chelated Ca2+ ions and raised the pH, we observed a gradual swelling of the RNA-filled capsids accompanied by a softening of the shell. Control experiments with empty wild-type virus and a salt-stable mutant revealed that the softening was not strictly coupled to the swelling of the protein shells. Our data suggest that a pH increase and Ca2+ chelation lead primarily to a loosening of contacts within the protein shell, resulting in a softening of the capsid. This appears to render the shell metastable and make swelling possible when repulsive forces among the capsid proteins become large enough, which is known to be followed by capsid disassembly at even higher pH. Thus, softening and swelling are likely to play a role during inoculation."],["dc.identifier.doi","10.1016/j.bpj.2015.04.019"],["dc.identifier.gro","3141900"],["dc.identifier.isi","000354827200014"],["dc.identifier.pmid","25992732"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/2322"],["dc.notes.intern","WoS Import 2017-03-10"],["dc.notes.status","final"],["dc.notes.submitter","PUB_WoS_Import"],["dc.publisher","Cell Press"],["dc.relation.eissn","1542-0086"],["dc.relation.issn","0006-3495"],["dc.title","Swelling and Softening of the Cowpea Chlorotic Mottle Virus in Response to pH Shifts"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1661"],["dc.bibliographiccitation.issue","5754"],["dc.bibliographiccitation.journal","Science"],["dc.bibliographiccitation.lastpage","1665"],["dc.bibliographiccitation.volume","310"],["dc.contributor.author","Goodman, Robert"],["dc.contributor.author","Schaap, Iwan A. T."],["dc.contributor.author","Tardin, C. F."],["dc.contributor.author","Erben, C. M."],["dc.contributor.author","Berry, R. M."],["dc.contributor.author","Schmidt, Christoph"],["dc.contributor.author","Turberfield, A. J."],["dc.date.accessioned","2017-09-07T11:53:39Z"],["dc.date.available","2017-09-07T11:53:39Z"],["dc.date.issued","2005"],["dc.description.abstract","Practical components for three-dimensional molecular nanofabrication must be simple to produce, stereopure, rigid, and adaptable. We report a family of DNA tetrahedra, less than 10 nanometers on a side, that can self-assemble in seconds with near-quantitative yield of one diastereomer. They can be connected by programmable DNA linkers. Their triangulated architecture confers structural stability; by compressing a DNA tetrahedron with an atomic force microscope, we have measured the axial compressibility of DNA and observed the buckling of the double helix under high loads."],["dc.identifier.doi","10.1126/science.1120367"],["dc.identifier.gro","3143776"],["dc.identifier.isi","000233961700039"],["dc.identifier.pmid","16339440"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/1327"],["dc.notes.intern","WoS Import 2017-03-10"],["dc.notes.status","final"],["dc.notes.submitter","PUB_WoS_Import"],["dc.publisher","Amer Assoc Advancement Science"],["dc.relation.issn","0036-8075"],["dc.title","Rapid chiral assembly of rigid DNA building blocks for molecular nanofabrication"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","2450"],["dc.bibliographiccitation.issue","10"],["dc.bibliographiccitation.journal","Biophysical Journal"],["dc.bibliographiccitation.lastpage","2456"],["dc.bibliographiccitation.volume","100"],["dc.contributor.author","Schaap, Iwan A. T."],["dc.contributor.author","Carrasco, Carolina"],["dc.contributor.author","Pablo, Pedro J. de"],["dc.contributor.author","Schmidt, Christoph"],["dc.date.accessioned","2017-09-07T11:44:16Z"],["dc.date.available","2017-09-07T11:44:16Z"],["dc.date.issued","2011"],["dc.description.abstract","Motor proteins of the kinesin family move actively along microtubules to transport cargo within cells. How exactly a single motor proceeds on the 13 narrow lanes or protofilaments of a microtubule has not been visualized directly, and there persists controversy on the relative position of the two kinesin heads in different nucleotide states. We have succeeded in imaging Kinesin-1 dimers immobilized on microtubules with single-head resolution by atomic force microscopy. Moreover, we could catch glimpses of single Kinesin-1 dimers in their motion along microtubules with nanometer resolution. We find in our experiments that frequently both heads of one dimer are microtubule-bound at submicromolar ATP concentrations. Furthermore, we could unambiguously resolve that both heads bind to the same protofilament, instead of straddling two, and remain on this track during processive movement."],["dc.identifier.doi","10.1016/j.bpj.2011.04.015"],["dc.identifier.gro","3142727"],["dc.identifier.isi","000290830900016"],["dc.identifier.pmid","21575579"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/163"],["dc.notes.intern","WoS Import 2017-03-10"],["dc.notes.status","final"],["dc.notes.submitter","PUB_WoS_Import"],["dc.publisher","Cell Press"],["dc.relation.issn","0006-3495"],["dc.title","Kinesin Walks the Line: Single Motors Observed by Atomic Force Microscopy"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1521"],["dc.bibliographiccitation.issue","4"],["dc.bibliographiccitation.journal","Biophysical Journal"],["dc.bibliographiccitation.lastpage","1531"],["dc.bibliographiccitation.volume","91"],["dc.contributor.author","Schaap, Iwan A. T."],["dc.contributor.author","Carrasco, Carolina"],["dc.contributor.author","Pablo, Pedro J. de"],["dc.contributor.author","MacKintosh, Frederick C."],["dc.contributor.author","Schmidt, Christoph"],["dc.date.accessioned","2017-09-07T11:52:37Z"],["dc.date.available","2017-09-07T11:52:37Z"],["dc.date.issued","2006"],["dc.description.abstract","We tested the mechanical properties of single microtubules by lateral indentation with the tip of an atomic force microscope. Indentations up to similar to 3.6 nm, i.e., 15% of the microtubule diameter, resulted in an approximately linear elastic response, and indentations were reversible without hysteresis. At an indentation force of around 0.3 nN we observed an instability corresponding to an similar to 1-nm indentation step in the taxol-stabilized microtubules, which could be due to partial or complete rupture of a relatively small number of lateral or axial tubulin-tubulin bonds. These indentations were reversible with hysteresis when the tip was retracted and no trace of damage was observed in subsequent high-resolution images. Higher forces caused substantial damage to the microtubules, which either led to depolymerization or, occasionally, to slowly reannealing holes in the microtubule wall. We modeled the experimental results using finite-element methods and find that the simple assumption of a homogeneous isotropic material, albeit structured with the characteristic proto. lament corrugations, is sufficient to explain the linear elastic response of microtubules."],["dc.identifier.doi","10.1529/biophysj.105.077826"],["dc.identifier.gro","3143644"],["dc.identifier.isi","000239242000037"],["dc.identifier.pmid","16731557"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/1181"],["dc.language.iso","en"],["dc.notes.intern","WoS Import 2017-03-10"],["dc.notes.status","final"],["dc.notes.submitter","PUB_WoS_Import"],["dc.relation.issn","0006-3495"],["dc.title","Elastic response, buckling, and instability of microtubules under radial indentation"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","098101"],["dc.bibliographiccitation.issue","9"],["dc.bibliographiccitation.journal","Physical Review Letters"],["dc.bibliographiccitation.volume","91"],["dc.contributor.author","Pablo, Pedro J. de"],["dc.contributor.author","Schaap, Iwan A. T."],["dc.contributor.author","MacKintosh, F. C."],["dc.contributor.author","Schmidt, Christoph"],["dc.date.accessioned","2017-09-07T11:44:15Z"],["dc.date.available","2017-09-07T11:44:15Z"],["dc.date.issued","2003"],["dc.description.abstract","We probe the local mechanical properties of microtubules at the nanometer scale by radial indentation with a scanning force microscope tip. We find a linear elastic regime that can be described by both thin-shell theory and finite element methods, in which microtubules are modeled as hollow tubes. We also find a nonlinear regime and catastrophic collapse of the microtubules under large loads. The main physics of protein shells at the nanometer scale shows simultaneously aspects of continuum elasticity in their linear response, as well as molecular graininess in their nonlinear behavior."],["dc.identifier.doi","10.1103/PhysRevLett.91.098101"],["dc.identifier.gro","3144066"],["dc.identifier.isi","000185235000054"],["dc.identifier.pmid","14525215"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/1649"],["dc.notes.intern","WoS Import 2017-03-10"],["dc.notes.status","final"],["dc.notes.submitter","PUB_WoS_Import"],["dc.publisher","American Physical Soc"],["dc.relation.issn","0031-9007"],["dc.title","Deformation and collapse of microtubules on the nanometer scale"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","237"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Nano Letters"],["dc.bibliographiccitation.lastpage","242"],["dc.bibliographiccitation.volume","16"],["dc.contributor.author","Chizhik, Anna M."],["dc.contributor.author","Stein, Simon"],["dc.contributor.author","Dekaliuk, Mariia O."],["dc.contributor.author","Battle, Christopher"],["dc.contributor.author","Li, Weixing"],["dc.contributor.author","Huss, Anja"],["dc.contributor.author","Platen, Mitja"],["dc.contributor.author","Schaap, Iwan A. T."],["dc.contributor.author","Gregor, Ingo"],["dc.contributor.author","Demchenko, Alexander P."],["dc.contributor.author","Schmidt, Christoph F."],["dc.contributor.author","Enderlein, Jörg"],["dc.contributor.author","Chizhik, Alexey"],["dc.date.accessioned","2017-09-07T11:54:46Z"],["dc.date.available","2017-09-07T11:54:46Z"],["dc.date.issued","2016"],["dc.description.abstract","Success in super-resolution imaging relies on a proper choice of fluorescent probes. Here, we suggest novel easily produced and biocompatible nanoparticles-carbon nanodots-for super-resolution optical fluctuation bioimaging (SOFT). The particles revealed an intrinsic dual-color fluorescence, which corresponds to two subpopulations of particles of different electric charges. The neutral nanoparticles localize to cellular nuclei suggesting their potential use as an inexpensive, easily produced nucleus-specific label. The single particle study revealed that the carbon nanodots possess a unique hybrid combination of fluorescence properties exhibiting characteristics of both dye molecules and semiconductor nanocrystals. The results suggest that charge trapping and redistribution on the surface of the particles triggers their transitions between emissive and dark states. These findings open up new possibilities for the utilization of carbon nanodots in the various super-resolution microscopy methods based on stochastic optical switching."],["dc.identifier.doi","10.1021/acs.nanolett.5b03609"],["dc.identifier.gro","3141754"],["dc.identifier.isi","000368322700038"],["dc.identifier.pmid","26605640"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/702"],["dc.language.iso","en"],["dc.notes.intern","WoS Import 2017-03-10"],["dc.notes.status","final"],["dc.notes.submitter","PUB_WoS_Import"],["dc.relation.eissn","1530-6992"],["dc.relation.issn","1530-6984"],["dc.title","Super-Resolution Optical Fluctuation Bio-Imaging with Dual-Color Carbon Nanodots"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","7523"],["dc.bibliographiccitation.journal","Nature Communications"],["dc.bibliographiccitation.volume","6"],["dc.contributor.author","Butkevich, Eugenia"],["dc.contributor.author","Bodensiek, Kai"],["dc.contributor.author","Fakhri, Nikta"],["dc.contributor.author","von Roden, Kerstin"],["dc.contributor.author","Schaap, Iwan A. T."],["dc.contributor.author","Majoul, Irina"],["dc.contributor.author","Schmidt, Christoph"],["dc.contributor.author","Klopfenstein, Dieter R."],["dc.date.accessioned","2017-09-07T11:43:42Z"],["dc.date.available","2017-09-07T11:43:42Z"],["dc.date.issued","2015"],["dc.description.abstract","Actin filament organization and stability in the sarcomeres of muscle cells are critical for force generation. Here we identify and functionally characterize a Caenorhabditis elegans drebrin-like protein DBN-1 as a novel constituent of the muscle contraction machinery. In vitro, DBN-1 exhibits actin filament binding and bundling activity. In vivo, DBN-1 is expressed in body wall muscles of C. elegans. During the muscle contraction cycle, DBN-1 alternates location between myosin- and actin-rich regions of the sarcomere. In contracted muscle, DBN-1 is accumulated at I-bands where it likely regulates proper spacing of alpha-actinin and tropomyosin and protects actin filaments from the interaction with ADF/cofilin. DBN-1 loss of function results in the partial depolymerization of F-actin during muscle contraction. Taken together, our data show that DBN-1 organizes the muscle contractile apparatus maintaining the spatial relationship between actin-binding proteins such as alpha-actinin, tropomyosin and ADF/cofilin and possibly strengthening actin filaments by bundling."],["dc.identifier.doi","10.1038/ncomms8523"],["dc.identifier.gro","3141869"],["dc.identifier.isi","000358851600001"],["dc.identifier.pmid","26146072"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/16945"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/1978"],["dc.notes.intern","WoS Import 2017-03-10"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","final"],["dc.notes.submitter","PUB_WoS_Import"],["dc.publisher","Nature Publishing Group"],["dc.relation.issn","2041-1723"],["dc.relation.orgunit","Fakultät für Physik"],["dc.rights","CC BY-NC-ND 4.0"],["dc.rights.uri","http://creativecommons.org/licenses/by-nc-nd/4.0/"],["dc.title","Drebrin-like protein DBN-1 is a sarcomere component that stabilizes actin filaments during muscle contraction"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","616"],["dc.bibliographiccitation.issue","4"],["dc.bibliographiccitation.journal","Nano Letters"],["dc.bibliographiccitation.lastpage","621"],["dc.bibliographiccitation.volume","6"],["dc.contributor.author","Graveland-Bikker, J. F ."],["dc.contributor.author","Schaap, Iwan A. T."],["dc.contributor.author","Schmidt, Christoph"],["dc.contributor.author","Kruif, C. G. de"],["dc.date.accessioned","2017-09-07T11:53:09Z"],["dc.date.available","2017-09-07T11:53:09Z"],["dc.date.issued","2006"],["dc.description.abstract","We report a structural characterization of self-assembling nanostructures. Using atomic force microscopy (AFM), we discovered that partially hydrolyzed alpha-lactalbumin organizes in a 10-start helix forming tubes with diameters of only 21 nm. We probed the mechanical strength of these nanotubes by locally indenting them with an AFM tip. To extract the material properties of the nanotubes, we modeled the experiment using finite element methods. Our study shows that artificial helical protein self-assembly can yield very stable, strong structures that can function either as a model system for artificial self-assembly or as a nanostructure with potential for practical applications."],["dc.identifier.doi","10.1021/nl052205h"],["dc.identifier.gro","3143712"],["dc.identifier.isi","000236916200007"],["dc.identifier.pmid","16608254"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/1256"],["dc.notes.intern","WoS Import 2017-03-10"],["dc.notes.status","final"],["dc.notes.submitter","PUB_WoS_Import"],["dc.publisher","Amer Chemical Soc"],["dc.relation.issn","1530-6984"],["dc.title","Structural and mechanical study of a self-assembling protein nanotube"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original"],["dspace.entity.type","Publication"]]