title: Synaptic vesicles studied by dynamic light scattering.
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)(τ) 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.
authors.affiliation: Institut für Röntgenphysik, Georg-August-Universität Göttingen, Germany. scastor@gwdg.de
authors.forename: S
authors.initials: S
authors.lastname: Castorph
authors.forename: S
authors.initials: S
authors.lastname: Schwarz Henriques
authors.forename: M
authors.initials: M
authors.lastname: Holt
authors.forename: D
authors.initials: D
authors.lastname: Riedel
authors.forename: R
authors.initials: R
authors.lastname: Jahn
authors.forename: T
authors.initials: T
authors.lastname: Salditt
mesh_terms: D000818:Animals; D001921:Brain / Q000166:cytology / Q000378:metabolism; D002853:Chromatography, Liquid; D003198:Computer Simulation; D020285:Cryoelectron Microscopy / Q000379:methods*; D008027:Light; D008561:Membrane Fusion; D009419:Nerve Tissue Proteins / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D011510:Proteolipids / Q000032:analysis / Q000138:chemical synthesis / Q000737:chemistry*; D050683:R-SNARE Proteins / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D051381:Rats; D050600:SNARE Proteins / Q000032:analysis* / Q000737:chemistry* / Q000378:metabolism; D012542:Scattering, Radiation; D053838:Scattering, Small Angle; D013572:Synaptic Vesicles / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure*; D050825:Synaptosomal-Associated Protein 25 / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D050827:Syntaxin 1 / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D014961:X-Ray Diffraction / Q000295:instrumentation*
chemical_list: D009419:Nerve Tissue Proteins; D011510:Proteolipids; D050683:R-SNARE Proteins; C494208:SNAP25 protein, human; D050600:SNARE Proteins; D050825:Synaptosomal-Associated Protein 25; D050827:Syntaxin 1; C020485:proteoliposomes