Related Experiment Videos
Interaction of substance P with phospholipid bilayers: A neutron diffraction study
J P Bradshaw1, S M Davies, T Hauss
1Department of Preclinical Veterinary Sciences, Royal (Dick) School of Veterinary Sciences, University of Edinburgh, Summerhall, Edinburgh EH9 1QH, Scotland, United Kingdom. j.bradshaw@ed.ac.uk
Biophysical Journal
|July 24, 1998
Summary
Neutron diffraction reveals substance P (SP) interacts with lipid bilayers at two sites: one inserted into the hydrophobic core and another peripheral. SP inserts into zwitterionic bilayers more than anionic ones.
Area of Science:
- Biophysics
- Neuroscience
- Structural Biology
Background:
- Substance P (SP) is a neuropeptide involved in neurotransmission and pain signaling.
- Understanding neuropeptide interactions with cell membranes is crucial for drug development.
- Tachykinins, like SP, play significant roles in the central and peripheral nervous systems.
Purpose of the Study:
- To elucidate the membrane-bound structure of substance P (SP).
- To determine the depth of SP C-terminus penetration in different phospholipid bilayers.
- To investigate the interaction sites of SP with zwitterionic and anionic lipid bilayers.
Main Methods:
- Neutron diffraction was employed to study SP structure.
- Deuteration of leucine 10 (penultimate residue) was used to probe C-terminus penetration.
- Dioleoylphosphatidylcholine (DOPC) and DOPC/DOPG mixtures simulated cell membranes.
Main Results:
- SP interacts with lipid bilayers at two distinct locations: a hydrophobic insertion site and a peripheral site.
- Water distribution profiles indicated SP insertion into the hydrophobic core of bilayers.
- SP showed greater insertion into zwitterionic DOPC bilayers compared to anionic DOPC/DOPG bilayers.
Conclusions:
- SP adopts a dual interaction mode with phospholipid bilayers.
- Membrane charge influences the extent of SP insertion into the hydrophobic core.
- These findings provide insights into SP's membrane interactions and potential therapeutic targeting.