Distinct interfacial ordering of liquid crystal observed by protein-lipid interactions that enabled the label free sensing of cytoplasmic protein at LC-aqueous interface

The Analyst ◽  
2021 ◽  
Author(s):  
Santanu Kumar Pal ◽  
Manisha Devi ◽  
Indu Verma
Keyword(s):  
Liquid Crystal ◽  
Protein Adsorption ◽  
Aqueous Phase ◽  
Protein Interactions ◽  
Cytoplasmic Protein ◽  
Label Free ◽  
Lipid Interactions ◽  
Lipid Protein Interactions

Interfaces formed between lipid decorated liquid crystal (LC) film and aqueous phase can mimic the bimolecular membrane where interfacial occurring biological phenonmenon (e.g., lipid-protein interactions, protein adsorption) can be visually...

Probing Nanoscale Lipid–Protein Interactions at the Interface of Liquid Crystal Droplets

Nano Letters ◽  
2021 ◽  
Author(s):  
Ipsita Pani ◽  
Fidha Nazreen K. M. ◽  
Monika Sharma ◽  
Santanu Kumar Pal
Keyword(s):  
Liquid Crystal ◽  
Protein Interactions ◽  
Lipid Protein Interactions

scholarly journals State-dependent protein-lipid interactions of a pentameric ligand-gated ion channel in a neuronal membrane

2020 ◽  
Author(s):  
Marc A. Dämgen ◽  
Philip C. Biggin
Keyword(s):  
Ion Channels ◽  
Protein Interactions ◽  
Glycine Receptor ◽  
Realistic Model ◽  
Neuronal Membrane ◽  
Lipid Interactions ◽  
State Dependent ◽  
Lipid Protein Interactions ◽  
Dynamics Simulations ◽  
A Site

AbstractPentameric ligand-gated ion channels (pLGICs) are receptor proteins that are sensitive to their membrane environment, but the mechanism for how lipids modulate function under physiological conditions in a state dependent manner is not known. The glycine receptor is a pLGIC whose structure has been resolved in different functional states. Using a realistic model of a neuronal membrane coupled with coarse-grained molecular dynamics simulations, we demonstrate that the lipid-protein interactions are dependent on the receptor state, suggesting that lipids may regulate the receptor’s conformational dynamics. Comparison with existing structural data confirms known lipid binding sites, but we also predict further protein-lipid interactions including a site at the communication interface between the extracellular and transmembrane domain. Moreover, in the active state, cholesterol can bind to the binding site of the positive allosteric modulator ivermectin. These protein-lipid interaction sites could in future be exploited for the rational design of lipid-like allosteric drugs.Author SummaryIon channels are proteins that control the flow of ions into the cell. The family of ion channels known as the pentameric ligand gated ion channels (pLGICS) open in response to the binding of a neurotransmitter, moving the channel from a resting state to an open state. The glycine receptor is a pLGIC whose structure has been resolved in different functional states. It is also known that the response of pLGICs can also be modified by different types of lipid found within the membrane itself but exactly how is unclear. Here, we used a realistic model of a neuronal membrane and performed molecular dynamics simulations to show various lipid-protein interactions that are dependent on the channel state. Our work also reveals previously unconsidered protein-lipid interactions at a key junction of the channel known to be critical for the transmission of the opening process. We also demonstrate that cholesterol interacts with the protein at a site already known to bind to another compound that modulates the channel, called ivermectin. The work should be useful for future drug design.

A review of traditional and emerging methods to characterize lipid–protein interactions in biological membranes

2015 ◽  
Vol 7 (17) ◽  
pp. 7076-7094 ◽  
Author(s):  
Chih-Yun Hsia ◽  
Mark J. Richards ◽  
Susan Daniel
Keyword(s):  
Plasma Membrane ◽  
Membrane Protein ◽  
Protein Interactions ◽  
Protein Structures ◽  
Biological Membranes ◽  
Biological Functions ◽  
Cell Plasma Membrane ◽  
Lipid Interactions ◽  
Cell Plasma ◽  
Lipid Protein Interactions

Lipid–protein interactions are essential for modulating membrane protein structures and biological functions in the cell plasma membrane. In this review we describe the salient features of classical and emerging methodologies for studying protein–lipid interactions and their limitations.

Membrane Protein–Lipid Interactions Probed Using Mass Spectrometry

2019 ◽  
Vol 88 (1) ◽  
pp. 85-111 ◽  
Author(s):  
Jani Reddy Bolla ◽  
Mark T. Agasid ◽  
Shahid Mehmood ◽  
Carol V. Robinson
Keyword(s):  
Mass Spectrometry ◽  
Membrane Protein ◽  
Lipid Bilayers ◽  
Protein Interactions ◽  
Native Mass Spectrometry ◽  
Lipid Interactions ◽  
X Ray Crystallography ◽  
Native Ms ◽  
Molecular Aspects ◽  
Lipid Protein Interactions

Membrane proteins that exist in lipid bilayers are not isolated molecular entities. The lipid molecules that surround them play crucial roles in maintaining their full structural and functional integrity. Research directed at investigating these critical lipid–protein interactions is developing rapidly. Advancements in both instrumentation and software, as well as in key biophysical and biochemical techniques, are accelerating the field. In this review, we provide a brief outline of structural techniques used to probe protein–lipid interactions and focus on the molecular aspects of these interactions obtained from native mass spectrometry (native MS). We highlight examples in which lipids have been shown to modulate membrane protein structure and show how native MS has emerged as a complementary technique to X-ray crystallography and cryo–electron microscopy. We conclude with a short perspective on future developments that aim to better understand protein–lipid interactions in the native environment.

scholarly journals Unroofing site-specific α-synuclein–lipid interactions at the plasma membrane

2020 ◽  
Vol 117 (32) ◽  
pp. 18977-18983 ◽  
Author(s):  
Upneet Kaur ◽  
Jennifer C. Lee
Keyword(s):  
Protein Interactions ◽  
Lifetime Distributions ◽  
Biophysical Characterization ◽  
Biologically Relevant ◽  
Lipid Interactions ◽  
C Terminus ◽  
Liquid Ordered ◽  
Lipid Environment ◽  
Lipid Protein Interactions ◽  
Synaptic Vesicle Fusion

Parkinson’s disease is associated with α-synuclein (α-syn), a cytosolic protein enriched in presynaptic terminals. The biological function of α-syn remains elusive; however, increasing evidence suggests that the protein is involved in the regulation of synaptic vesicle fusion, signifying the importance of α-syn–lipid interactions. We show that α-syn preferentially binds to GM1-rich, liquid-ordered lipid domains on cytoplasmic membranes by using unroofed cells, which encapsulates lipid complexity and cellular topology. Moreover, proteins (Rab3a, syntaxin-1A, and VAMP2) involved in exocytosis also localize with α-syn, supporting its proposed functional role in exocytosis. To investigate how these lipid/protein interactions influence α-syn at the residue level, α-syn was derivatized with an environmentally sensitive fluorophore (7-nitrobenz-2-oxa-1,3-diazol-4-yl [NBD]) at different N- and C-terminal sites. Measurements of NBD fluorescence lifetime distributions reveal that α-syn adopts a multitude of membrane-bound conformations, which were not recapitulated in simple micelle or vesicle models, indicating an exquisite sensitivity of the protein to the complex lipid environment. Interestingly, these data also suggest the participation of the C terminus in membrane localization, which is generally overlooked and thus emphasize the need to use cellularly derived and biologically relevant membranes for biophysical characterization. Collectively, our results demonstrate that α-syn is more conformationally dynamic at the membrane interface than previously appreciated, which may be important for both its physiological and pathological functions.

scholarly journals Application of electron spin resonance for investigating peptide-lipid interactions, and correlation with thermodynamics

2001 ◽  
Vol 29 (4) ◽  
pp. 582-589 ◽  
Author(s):  
D. Marsh
Keyword(s):  
Electron Spin Resonance ◽  
Membrane Proteins ◽  
Electron Spin ◽  
Protein Interactions ◽  
Surface Binding ◽  
Lipid Interactions ◽  
Peripheral Membrane Proteins ◽  
Spin Resonance ◽  
Surface Active ◽  
Lipid Protein Interactions

Peptide-lipid interactions can be investigated with spin-labelled lipid probes by using electron spin resonance (ESR) methods that have been developed for studying lipid-protein interactions with both integral and peripheral membrane proteins and also with surface-binding proteins that additionally penetrate the membrane. This approach has the advantage that a direct comparison can be made with the databank of ESR results from the various types of membrane protein. The appropriateness of the peptides as models for membrane proteins, or for their specific segments, can then be assessed. Further, differences in behaviour can be readily identified, as for example in the case of surface-active cytolytic or fusogenic peptides. Comparison with thermodynamic predictions for membrane insertion provides a useful adjunct to the spin-label method.

Sign in / Sign up

Export Citation Format

Share Document