title: Dynamic light scattering analysis of SNARE-driven membrane fusion and the effects of SNARE-binding flavonoids.
abstract: Soluble N-ethylmaleimide-sensitive-factor attachment protein receptor (SNARE) proteins generate energy required for membrane fusion. They form a parallelly aligned four-helix bundle called the SNARE complex, whose formation is initiated from the N terminus and proceeds toward the membrane-proximal C terminus. Previously, we have shown that this zippering-like process can be controlled by several flavonoids that bind to the intermediate structures formed during the SNARE zippering. Here, our aim was to test whether the fluorescence resonance energy transfer signals that are observed during the inner leaflet mixing assay indeed represent the hemifused vesicles. We show that changes in vesicle size accompanying the merging of bilayers is a good measure of progression of the membrane fusion. Two merging vesicles with the same size D in diameter exhibited their hydrodynamic diameters 2D + d (d, intermembrane distance), 2D and 2D as membrane fusion progressed from vesicle docking to hemifusion and full fusion, respectively. A dynamic light scattering assay of membrane fusion suggested that myricetin stopped membrane fusion at the hemifusion state, whereas delphinidin and cyanidin prevented the docking of the vesicles. These results are consistent with our previous findings in fluorescence resonance energy transfer assays.
authors: Department of Genetic Engineering and Center for Human Interface Nanotechnology, Sungkyunkwan University, Suwon 440-746, South Korea; Biomedical Research Institute, Korea Institute of Science and Technology, Seoul 136-791, South Korea.
authors: Yoosoo
authors: Y
authors: Yang
authors: Department of Genetic Engineering and Center for Human Interface Nanotechnology, Sungkyunkwan University, Suwon 440-746, South Korea.
authors: Paul
authors: P
authors: Heo
authors: Department of Genetic Engineering and Center for Human Interface Nanotechnology, Sungkyunkwan University, Suwon 440-746, South Korea.
authors: Byoungjae
authors: B
authors: Kong
authors: Department of Genetic Engineering and Center for Human Interface Nanotechnology, Sungkyunkwan University, Suwon 440-746, South Korea.
authors: Jun-Bum
authors: JB
authors: Park
authors: Department of Genetic Engineering and Center for Human Interface Nanotechnology, Sungkyunkwan University, Suwon 440-746, South Korea.
authors: Young-Hun
authors: YH
authors: Jung
authors: Department of Genetic Engineering and Center for Human Interface Nanotechnology, Sungkyunkwan University, Suwon 440-746, South Korea.
authors: Jonghyeok
authors: J
authors: Shin
authors: Biomedical Research Institute, Korea Institute of Science and Technology, Seoul 136-791, South Korea.
authors: Cherlhyun
authors: C
authors: Jeong
authors: Department of Genetic Engineering and Center for Human Interface Nanotechnology, Sungkyunkwan University, Suwon 440-746, South Korea. Electronic address: dhkweon@skku.edu.
authors: Dae-Hyuk
authors: DH
authors: Kweon
mesh_terms: D000818:Animals; D000067493:Dynamic Light Scattering; D005419:Flavonoids / Q000378:metabolism* / Q000494:pharmacology; D031541:Fluorescence Resonance Energy Transfer; D057446:Hydrodynamics; D008051:Lipid Bilayers / Q000378:metabolism; D008561:Membrane Fusion / Q000187:drug effects / Q000502:physiology*; D046912:Multiprotein Complexes / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D051381:Rats; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D050600:SNARE Proteins / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D005419:Flavonoids; D008051:Lipid Bilayers; D046912:Multiprotein Complexes; D011994:Recombinant Proteins; D050600:SNARE Proteins; C040015:myricetin
keywords: Dynamic light scattering; FRET; Flavonoid; Membrane fusion; SNARE