Fluorinated Interfaces Drive Self-Association of Transmembrane α Helices in Lipid Bilayers

2006 ◽  
Vol 118 (16) ◽  
pp. 2650-2653 ◽  
Author(s):  
Natascha Naarmann ◽  
Başar Bilgiçer ◽  
He Meng ◽  
Krishna Kumar ◽  
Claudia Steinem
Keyword(s):  
Lipid Bilayers ◽  
Self Association

Viral Fusion Peptides: A Tool Set to Disrupt and Connect Biological Membranes

2000 ◽  
Vol 20 (6) ◽  
pp. 501-518 ◽  
Author(s):  
Lukas K. Tamm ◽  
Xing Han
Keyword(s):  
Lipid Bilayers ◽  
Biological Membrane ◽  
Membrane Curvature ◽  
Current Evidence ◽  
Viral Fusion ◽  
Fusion Peptides ◽  
Membrane Surfaces ◽  
Self Association ◽  
Α Helix ◽  
And Function

The structure and function of viral fusion peptides are reviewed. The fusion peptides of influenza virus hemagglutinin and human immunodeficiency virus are used as paradigms. Fusion peptides associated with lipid bilayers are conformationally polymorphic. Current evidence suggests that the fusion-promoting state is the obliquely inserted α-helix. Fusion peptides also have a tendency to self-associate into γ-sheets at membrane surfaces. Although the conformational conversion between α- and γ-states is reversible under controlled conditions, its physiological relevance is not yet known. The energetics of peptide insertion and self-association could be measured recently using more soluble “second generation” fusion peptides. Fusion peptides have been reported to change membrane curvature and the state of hydration of membrane surfaces. The combined results are built into a model for the mechanism by which fusion peptides are proposed to assist in biological membrane fusion.

scholarly journals Synaptotagmin 1 oligomerization via the juxtamembrane linker regulates spontaneous and evoked neurotransmitter release

2021 ◽  
Author(s):  
Kevin C Courtney ◽  
Yueqi Li ◽  
Jason D Vevea ◽  
Zhenyong Wu ◽  
Zhao Zhang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Lipid Bilayers ◽  
Force Microscopy ◽  
Anionic Phospholipids ◽  
Synaptic Vesicle Exocytosis ◽  
Lysine Residues ◽  
Vesicle Exocytosis ◽  
Synaptotagmin 1 ◽  
Self Association ◽  
Aqueous Conditions

Synaptotagmin-1 (syt1) is a Ca2+ sensor that regulates synaptic vesicle exocytosis. Cell-based experiments suggest that syt1 functions as a multimer, however biochemical and electron microscopy studies have yielded contradictory findings regarding putative self-association. Here, we performed dynamic light scattering on syt1 in solution, followed by electron microscopy, and used atomic force microscopy to study syt1 self-association on supported lipid bilayers under aqueous conditions. Ring-like multimers were clearly observed. Multimerization was enhanced by Ca2+ and required anionic phospholipids. Large ring-like structures (~180 nm) were reduced to smaller rings (~30 nm) upon neutralization of a cluster of juxtamembrane lysine residues; further substitution of residues in the second C2-domain completely abolished self-association. When expressed in neurons, syt1 mutants with graded reductions in self-association activity exhibited concomitant reductions in: a) clamping spontaneous release, and b) triggering and synchronizing evoked release. Thus, the juxtamembrane linker of syt1 plays a crucial role in exocytosis by mediating multimerization.

scholarly journals β-Glutamine-mediated self-association of transmembrane β-peptides within lipid bilayers

2016 ◽  
Vol 7 (9) ◽  
pp. 5900-5907 ◽  
Author(s):  
U. Rost ◽  
C. Steinem ◽  
U. Diederichsen
Keyword(s):  
Hydrogen Bonds ◽  
Lipid Bilayers ◽  
Rational Design ◽  
Secondary Structures ◽  
Design And Synthesis ◽  
Self Association

The rational design and synthesis of novel transmembrane β-peptides forming stable secondary structures in a membrane environment are described. Their state of aggregation within the membrane is controlled by hydrogen bonds.

scholarly journals Synaptotagmin 1 oligomerization via the juxtamembrane linker regulates spontaneous and evoked neurotransmitter release

2021 ◽  
Vol 118 (48) ◽  
pp. e2113859118
Author(s):  
Kevin C. Courtney ◽  
Jason D. Vevea ◽  
Yueqi Li ◽  
Zhenyong Wu ◽  
Zhao Zhang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Lipid Bilayers ◽  
Force Microscopy ◽  
Anionic Phospholipids ◽  
Synaptic Vesicle Exocytosis ◽  
Lysine Residues ◽  
Vesicle Exocytosis ◽  
Synaptotagmin 1 ◽  
Self Association ◽  
Aqueous Conditions

Synaptotagmin 1 (syt1) is a Ca2+ sensor that regulates synaptic vesicle exocytosis. Cell-based experiments suggest that syt1 functions as a multimer; however, biochemical and electron microscopy studies have yielded contradictory findings regarding putative self-association. Here, we performed dynamic light scattering on syt1 in solution, followed by electron microscopy, and we used atomic force microscopy to study syt1 self-association on supported lipid bilayers under aqueous conditions. Ring-like multimers were clearly observed. Multimerization was enhanced by Ca2+ and required anionic phospholipids. Large ring-like structures (∼180 nm) were reduced to smaller rings (∼30 nm) upon neutralization of a cluster of juxtamembrane lysine residues; further substitution of residues in the second C2-domain completely abolished self-association. When expressed in neurons, syt1 mutants with graded reductions in self-association activity exhibited concomitant reductions in 1) clamping spontaneous release and 2) triggering and synchronizing evoked release. Thus, the juxtamembrane linker of syt1 plays a crucial role in exocytosis by mediating multimerization.

Topological Stability and Self-Association of a Completely Hydrophobic Model Transmembrane Helix in Lipid Bilayers†

Biochemistry ◽  
2002 ◽  
Vol 41 (9) ◽  
pp. 3073-3080 ◽  
Author(s):  
Yoshiaki Yano ◽  
Tomokazu Takemoto ◽  
Satoe Kobayashi ◽  
Hiroyuki Yasui ◽  
Hiromu Sakurai ◽  
...  
Keyword(s):  
Lipid Bilayers ◽  
Transmembrane Helix ◽  
Topological Stability ◽  
Self Association

Fluorinated Interfaces Drive Self-Association of Transmembrane α Helices in Lipid Bilayers

2006 ◽  
Vol 45 (16) ◽  
pp. 2588-2591 ◽  
Author(s):  
Natascha Naarmann ◽  
Başar Bilgiçer ◽  
He Meng ◽  
Krishna Kumar ◽  
Claudia Steinem
Keyword(s):  
Lipid Bilayers ◽  
Self Association
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