[Abstract Title]. - Society for Neuroscience

Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 236.14/D14
Topic: B.06.a. Docking and fusion
Support: MH 069791
DOD/DMEA-H94003-06-2-0608
Title: Investigation of parallel and anti-parallel configurations of syntaxin 1a and synaptobrevin2
interaction
Authors: W. LIU 1 , *V. MONTANA 1 , U. MOHIDEEN 2 , V. PARPURA 1 ;
1 Dept Neurobiol, Univ. Alabama, Birmingham, AL; 2 Dept of Physics and Astronomy, Univ. of
California, Riverside, CA
Abstract: Syntaxin 1A and Synaptobrevin 2 (also known as vesicle-associated membrane
protein 2) along with SNAP25 belong to the SNARE (soluble N-ethylmaleimide-sensitive fusion
protein attachment protein receptors) family of proteins. They are involved in the exocytosis of
synaptic vesicles. It has been shown that both parallel (N-termini of two proteins are aligned at
same end) and anti-parallel (C-terminal of one protein and N-terminal of the other protein are
aligned at same end) configurations are present, while details of the interactions between these
proteins in these configurations have not yet been defined. We used an Atomic Force
Microscope (AFM) in force spectroscopy mode to investigate the mechanical interactions
between syntaxin 1A and synaptobrevin 2 at single molecule level. Various terminal
configurations of proteins (N-N, N-C, C-N and C-C) were studied by attaching the recombinant
proteins via their histidine 6 tags to nickel-coated AFM tips and glass coverslips. The syntaxinsynaptobrevin
intermolecular interaction forces, extensions, spontaneous lifetimes and
interaction energies were obtained. The measured interaction extensions difference (up to 6 nm)
is related to alignment of different terminal configurations. Their activation energy (ΓH)
difference is as large as 5 kBT, and implies that parallel configurations might be energetically
favorable to tether/dock vesicles at the plasma membrane. These findings provide additional
insight on the characteristics of the Sx1A-Sb2 binary complex and they aid better understanding
of the possible role for various configurations of the complex in exocoytosis.
Disclosures: W. Liu, None; V. Montana , None; U. Mohideen, None; V. Parpura, None.
Poster
236. Neurotransmitter Release: Docking and Fusion
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm