Lipid-Coated Gold Nanoparticles and FRET Allow Sensitive Monitoring of Liposome Clustering Mediated by the Synaptotagmin-7 C2A Domain

摘要: Synaptotagmin (Syt) family proteins contain tandem C2 domains, C2A and C2B, which insert into anionic membranes in response to increased cytosolic Ca2+ concentration facilitate exocytosis neuronal endocrine cells. The domain from Syt7 binds lipid much more tightly than the corresponding Syt1, but implications of this difference for protein function are not yet clear. In particular, ability isolated initiate membrane apposition and/or aggregation has been previously unexplored. Here, we demonstrate that induces liposomes using Forster resonance energy transfer (FRET) assays, dynamic light scattering, spectroscopic techniques involving lipid-coated gold nanoparticles (LCAuNPs). Protein–membrane binding, apposition, macroscopic three separate phenomena with distinct requirements: threshold binding is lowest, followed by apposit...