Holt, Matthew G.

[["dc.bibliographiccitation.artnumber","012015"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Journal of Physics: Conference Series"],["dc.bibliographiccitation.volume","247"],["dc.contributor.affiliation","S Castorph, ; 1Institut für Röntgenphysik, Georg-August-Universität Göttingen, Göttingen, D"],["dc.contributor.affiliation","L Arleth, ; 2Biophysics, Faculty of Life Sciences, University of Copenhagen, Frederiksberg, DK"],["dc.contributor.affiliation","M Sztucki, ; 3European Synchrotron Radiation Facility, Grenoble, F"],["dc.contributor.affiliation","U Vainio, ; 4Hamburger Synchrotronstrahlungslabor at Deutsches Elektronen-Synchrotron, Hamburg, D"],["dc.contributor.affiliation","S K Ghosh, ; 1Institut für Röntgenphysik, Georg-August-Universität Göttingen, Göttingen, D"],["dc.contributor.affiliation","M Holt, ; 5Max Planck Institut für Biophysikalische Chemie, Department of Neurobiology, Göttingen, D"],["dc.contributor.affiliation","R Jahn, ; 5Max Planck Institut für Biophysikalische Chemie, Department of Neurobiology, Göttingen, D"],["dc.contributor.affiliation","T Salditt, ; 1Institut für Röntgenphysik, Georg-August-Universität Göttingen, Göttingen, D"],["dc.contributor.author","Castorph, Simon"],["dc.contributor.author","Arleth, Lise"],["dc.contributor.author","Sztucki, Michael"],["dc.contributor.author","Vainio, Ulla"],["dc.contributor.author","Ghosh, S. K."],["dc.contributor.author","Holt, M."],["dc.contributor.author","Jahn, Reinhard"],["dc.contributor.author","Salditt, Tim"],["dc.date.accessioned","2017-09-07T11:54:07Z"],["dc.date.available","2017-09-07T11:54:07Z"],["dc.date.issued","2010"],["dc.date.updated","2022-02-18T08:56:36Z"],["dc.description.abstract","We discuss different spherically symmetric and anisotropic form factor models and test them against high resolution synchrotron based small-angle x-ray scattering (SAXS) data from synaptic vesicles (SVs), isolated from rat brain. Anisotropy of the model form factors is found to be a key ingredient for the description of the native synaptic vesicle structure. We describe changes in structural parameters due to protease digestion of SVs, and present SAXS data of SVs recorded under different pH conditions."],["dc.identifier.doi","10.1088/1742-6596/247/1/012015"],["dc.identifier.fs","581310"],["dc.identifier.gro","3145120"],["dc.identifier.issn","1742-6596"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/7197"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/2821"],["dc.language.iso","en"],["dc.notes.intern","Crossref Import"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.relation.issn","1742-6596"],["dc.relation.orgunit","Institut für Röntgenphysik"],["dc.relation.orgunit","Fakultät für Physik"],["dc.relation.workinggroup","RG Salditt (Structure of Biomolecular Assemblies and X-Ray Physics)"],["dc.rights.uri","https://publishingsupport.iopscience.iop.org/open_access/"],["dc.subject.gro","x-ray scattering"],["dc.subject.gro","neuro biophysics"],["dc.title","Synaptic Vesicles Studied by SAXS: Derivation and Validation of a Model Form Factor"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","no"],["dc.type.subtype","original_ja"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1200"],["dc.bibliographiccitation.issue","7"],["dc.bibliographiccitation.journal","Biophysical Journal"],["dc.bibliographiccitation.lastpage","1208"],["dc.bibliographiccitation.volume","98"],["dc.contributor.author","Castorph, Simon"],["dc.contributor.author","Riedel, Dietmar"],["dc.contributor.author","Arleth, Lise"],["dc.contributor.author","Sztucki, Michael"],["dc.contributor.author","Jahn, Reinhard"],["dc.contributor.author","Holt, Matthew"],["dc.contributor.author","Salditt, Tim"],["dc.date.accessioned","2017-09-07T11:46:06Z"],["dc.date.available","2017-09-07T11:46:06Z"],["dc.date.issued","2010"],["dc.description.abstract","Synaptic vesicles (SVs) are small, membrane-bound organelles that are found in the synaptic terminal of neurons, and which are crucial in neurotransmission. After a rise in internal [Ca2+] during neuronal stimulation, SVs fuse with the plasma membrane releasing their neurotransmitter content, which then signals neighboring neurons. SVs are subsequently recycled and refilled with neurotransmitter for further rounds of release. Recently, tremendous progress has been made in elucidating the molecular composition of SVs, as well as putative protein-protein interactions. However, what is lacking is an empirical description of SV structure at the supramolecular level which is necessary to enable us to fully understand the processes of membrane fusion, retrieval, and recycling. Using small-angle x-ray scattering, we have directly investigated the size and structure of purified SVs. From this information, we deduced detailed size and density parameters for the protein layers responsible for SV function, as well as information about the lipid bilayer. To achieve a convincing model fit, a laterally anisotropic structure for the protein shell is needed, as a rotationally symmetric density profile does not explain the data. Not only does our model confirm many of the preexisting ideas concerning SV structure, but also for the first time, to our knowledge, it indicates structural refinements, such as the presence of protein microdomains."],["dc.identifier.doi","10.1016/j.bpj.2009.12.4278"],["dc.identifier.gro","3142938"],["dc.identifier.isi","000276582700012"],["dc.identifier.pmid","20371319"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/397"],["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.relation.orgunit","Institut für Röntgenphysik"],["dc.relation.workinggroup","RG Salditt (Structure of Biomolecular Assemblies and X-Ray Physics)"],["dc.subject.gro","x-ray scattering"],["dc.subject.gro","membrane biophysics"],["dc.title","Structure Parameters of Synaptic Vesicles Quantified by Small-Angle X-Ray Scattering"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original_ja"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","284a"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","Biophysical Journal"],["dc.bibliographiccitation.volume","98"],["dc.contributor.author","Castorph, Simon"],["dc.contributor.author","Holt, Matthew G."],["dc.contributor.author","Riedel, Dietmar"],["dc.contributor.author","Arleth, Lise"],["dc.contributor.author","Sztucki, Michael"],["dc.contributor.author","Jahn, Reinhard"],["dc.contributor.author","Salditt, Tim"],["dc.date.accessioned","2018-11-07T08:47:10Z"],["dc.date.available","2018-11-07T08:47:10Z"],["dc.date.issued","2010"],["dc.identifier.doi","10.1016/j.bpj.2009.12.1549"],["dc.identifier.isi","000208762002437"],["dc.identifier.pii","S0006349509033542"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/20881"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/110209"],["dc.language.iso","en"],["dc.notes.intern","DOI-Import GROB-575"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Cell Press"],["dc.publisher.place","Cambridge"],["dc.relation.issn","0006-3495"],["dc.title","Structure Analysis of Synaptic Vesicles by Solution Small-Angle Scattering of X-Rays"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","105004"],["dc.bibliographiccitation.journal","New Journal of Physics"],["dc.bibliographiccitation.volume","12"],["dc.contributor.author","Ghosh, S. K."],["dc.contributor.author","Castorph, S."],["dc.contributor.author","Konovalov, O."],["dc.contributor.author","Jahn, R."],["dc.contributor.author","Holt, M."],["dc.contributor.author","Salditt, T."],["dc.date.accessioned","2017-09-07T11:45:15Z"],["dc.date.available","2017-09-07T11:45:15Z"],["dc.date.issued","2010"],["dc.description.abstract","The fusion of synaptic vesicles (SVs) with the plasma membrane in neurons is a crucial step in the release of neurotransmitters, which are responsible for carrying signals between nerve cells. While many of the molecular players involved in this fusion process have been identified, a precise molecular description of their roles in the process is still lacking. A case in point is the plasma membrane lipid phosphatidylinositol 4,5-bisphosphate (PIP2). Although PIP2 is known to be essential for vesicle fusion, its precise role in the process remains unclear. We have re-investigated the role of this lipid in membrane structure and function using the complementary experimental techniques of x-ray reflectivity, both on lipid monolayers at an air-water interface and bilayers on a solid support, and grazing incidence x-ray diffraction on lipid monolayers. These techniques provide unprecedented access to structural information at the molecular level, and detail the profound structural changes that occur in a membrane following PIP2 incorporation. Further, we also confirm and extend previous findings that the association of SVs with membranes is enhanced by PIP2 incorporation, and reveal the structural changes that underpin this phenomenon. Further, the association is further intensified by a physiologically relevant amount of Ca2+ ions in the subphase of the monolayer, as revealed by the increase in interfacial pressure seen with the lipid monolayer system. Finally, a theoretical calculation concerning the products arising from the fusion of these SVs with proteoliposomes is presented, with which we aim to illustrate the potential future uses of this system."],["dc.identifier.doi","10.1088/1367-2630/12/10/105004"],["dc.identifier.fs","572802"],["dc.identifier.gro","3142842"],["dc.identifier.isi","000284768300002"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/7194"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/290"],["dc.language.iso","en"],["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.relation.issn","1367-2630"],["dc.relation.orgunit","Institut für Röntgenphysik"],["dc.relation.orgunit","Fakultät für Physik"],["dc.relation.workinggroup","RG Salditt (Structure of Biomolecular Assemblies and X-Ray Physics)"],["dc.subject.gro","membrane biophysics"],["dc.subject.gro","neuro biophysics"],["dc.title","In vitro study of interaction of synaptic vesicles with lipid membranes"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original_ja"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","63"],["dc.bibliographiccitation.issue","6"],["dc.bibliographiccitation.journal","The European Physical Journal E"],["dc.bibliographiccitation.volume","34"],["dc.contributor.author","Castorph, S."],["dc.contributor.author","Schwarz Henriques, S."],["dc.contributor.author","Holt, M."],["dc.contributor.author","Riedel, D."],["dc.contributor.author","Jahn, R."],["dc.contributor.author","Salditt, T."],["dc.date.accessioned","2017-09-07T11:44:14Z"],["dc.date.available","2017-09-07T11:44:14Z"],["dc.date.issued","2011"],["dc.description.abstract","The size polydispersity distribution of synaptic vesicles (SVs) is characterized under quasi-physiological conditions by dynamic light scattering (DLS). Highly purified fractions of SVs obtained from rat brain still contain a small amount of larger contaminant structures, which can be quantified by DLS and further reduced by asymmetric-flow field-flow (AFFF) fractionation. The intensity autocorrelation functions g(2)(tau) recorded from these samples are analyzed by a constrained regularization method as well as by an alternative direct modeling approach. The results are in quantitative agreement with the polydispersity obtained from cryogenic electron microscopy of vitrified SVs. Next, different vesicle fusion assays based on samples composed of SVs and small unilamellar proteoliposomes with the fusion proteins syntaxin 1 and SNAP-25A are characterized by DLS. The size increase of the proteoliposomes due to SNARE-dependent fusion with SVs is quantified by DLS under quasi-physiological conditions."],["dc.identifier.doi","10.1140/epje/i2011-11063-2"],["dc.identifier.gro","3142718"],["dc.identifier.isi","000292512700001"],["dc.identifier.pmid","21706281"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/7576"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/153"],["dc.language.iso","en"],["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.relation.issn","1292-8941"],["dc.relation.orgunit","Institut für Röntgenphysik"],["dc.relation.orgunit","Fakultät für Physik"],["dc.relation.workinggroup","RG Salditt (Structure of Biomolecular Assemblies and X-Ray Physics)"],["dc.subject.gro","neuro biophysics"],["dc.title","Synaptic vesicles studied by dynamic light scattering"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original_ja"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1394"],["dc.bibliographiccitation.issue","6"],["dc.bibliographiccitation.journal","Biophysical Journal"],["dc.bibliographiccitation.lastpage","1402"],["dc.bibliographiccitation.volume","102"],["dc.contributor.author","Ghosh, Sajal Kumar"],["dc.contributor.author","Castorph, Simon"],["dc.contributor.author","Konovalov, Oleg"],["dc.contributor.author","Salditt, Tim"],["dc.contributor.author","Jahn, Reinhard"],["dc.contributor.author","Holt, Matthew"],["dc.date.accessioned","2017-09-07T11:48:56Z"],["dc.date.available","2017-09-07T11:48:56Z"],["dc.date.issued","2012"],["dc.description.abstract","Synaptic vesicles (SVs) are small, membrane-bound organelles that are found in the synaptic terminal of neurons. Although tremendous progress has been made in understanding the protein machinery that drives fusion of SVs with the presynaptic membrane, little progress has been made in understanding changes in the membrane structure that accompany this process. We used lipid monolayers of defined composition to mimic biological membranes, which were probed by x-ray reflectivity and grazing incidence x-ray diffraction. These techniques allowed us to successfully monitor structural changes in the membranes at molecular level, both in response to injection of SVs in the subphase below the monolayer, as well as to physiological cues involved in neurotransmitter release, such as increases in the concentration of the membrane lipid PIP2, or addition of physiological levels of Ca2+. Such structural changes may well modulate vesicle fusion in vivo."],["dc.identifier.doi","10.1016/j.bpj.2012.01.006"],["dc.identifier.gro","3142562"],["dc.identifier.isi","000301907400018"],["dc.identifier.pmid","22455922"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/8926"],["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.relation.orgunit","Institut für Röntgenphysik"],["dc.relation.workinggroup","RG Salditt (Structure of Biomolecular Assemblies and X-Ray Physics)"],["dc.subject.gro","membrane biophysics"],["dc.subject.gro","neuro biophysics"],["dc.title","Measuring Ca2+-Induced Structural Changes in Lipid Monolayers: Implications for Synaptic Vesicle Exocytosis"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original_ja"],["dspace.entity.type","Publication"]]