scholarly journals Membrane protein channels equipped with a cleavable linker for inducing catalysis inside nanocompartments

2021 ◽  
Author(s):  
Luisa Zartner ◽  
Viviana Maffeis ◽  
Cora-Ann Schoenenberger ◽  
Ionel Adrian Dinu ◽  
Cornelia G. Palivan
Keyword(s):  
Membrane Protein ◽  
Stimuli Responsive ◽  
Protein Channels

Precisely timed initiation of catalysis and stability of the catalytic enzymes provided by stimuli-responsive compartments.

scholarly journals Resolving the Dynamic Non-Covalent Interaction inside Membrane Protein Channel by Single-Molecule Interaction Spectrum

2018 ◽  
Author(s):  
Meng-Yin Li ◽  
Yi-Lun Ying ◽  
Xi-Xin Fu ◽  
Jie Yu ◽  
Shao-Chuang Liu ◽  
...  
Keyword(s):  
Membrane Protein ◽  
Single Molecule ◽  
Ionic Current ◽  
Md Simulations ◽  
Energy Spectra ◽  
Membrane Channels ◽  
Non Covalent Interactions ◽  
Protein Channels ◽  
Covalent Interactions ◽  
Molecule Interaction

Millions of years of evolution have produced membrane protein channels capable of efficiently moving ions across the cell membrane. The underlying fundamental mechanisms that facilitate these actions greatly contribute to the weak non-covalent interactions. However, uncovering these dynamic interactions and its synergic network effects still remains challenging in both experimental techniques and molecule dynamics (MD) simulations. Here, we present a rational strategy that combines MD simulations and frequency-energy spectroscopy to identify and quantify the role of non-covalent interactions in carrier transport through membrane protein channels, as encoded in traditional single channel recording or ionic current. We employed wild-type aerolysin transporting of methylcytosine and cytosine as a model to explore the dynamic ionic signatures with non-stationary and non-linear frequency analysis. Our data illuminate that methylcytosine experiences strong non-covalent interactions with the aerolysin nanopore at Region 1 around R220 than cytosine, which produces characteristic frequency-energy spectra. Furthermore, we experimentally validate the obtained hypothesis from frequency-energy spectra by designing single-site mutation of K238G which creates significantly enhanced non-covalent interactions for the recognition of methylcytosine. The frequency-energy spectrum of ions flowing inside membrane channels constitutes a single-molecule interaction spectrum, which bridges the gap between traditional ionic current recording and the MD simulations, facilitating the qualitative and quantitive description of the non-covalent interactions inside membrane channels.

scholarly journals Resolving the Dynamic Non-Covalent Interaction inside Membrane Protein Channel by Single-Molecule Interaction Spectrum

2018 ◽  
Author(s):  
Meng-Yin Li ◽  
Yi-Lun Ying ◽  
Xi-Xin Fu ◽  
Jie Yu ◽  
Shao-Chuang Liu ◽  
...  
Keyword(s):  
Membrane Protein ◽  
Single Molecule ◽  
Ionic Current ◽  
Md Simulations ◽  
Energy Spectra ◽  
Membrane Channels ◽  
Non Covalent Interactions ◽  
Protein Channels ◽  
Covalent Interactions ◽  
Molecule Interaction

Millions of years of evolution have produced membrane protein channels capable of efficiently moving ions across the cell membrane. The underlying fundamental mechanisms that facilitate these actions greatly contribute to the weak non-covalent interactions. However, uncovering these dynamic interactions and its synergic network effects still remains challenging in both experimental techniques and molecule dynamics (MD) simulations. Here, we present a rational strategy that combines MD simulations and frequency-energy spectroscopy to identify and quantify the role of non-covalent interactions in carrier transport through membrane protein channels, as encoded in traditional single channel recording or ionic current. We employed wild-type aerolysin transporting of methylcytosine and cytosine as a model to explore the dynamic ionic signatures with non-stationary and non-linear frequency analysis. Our data illuminate that methylcytosine experiences strong non-covalent interactions with the aerolysin nanopore at Region 1 around R220 than cytosine, which produces characteristic frequency-energy spectra. Furthermore, we experimentally validate the obtained hypothesis from frequency-energy spectra by designing single-site mutation of K238G which creates significantly enhanced non-covalent interactions for the recognition of methylcytosine. The frequency-energy spectrum of ions flowing inside membrane channels constitutes a single-molecule interaction spectrum, which bridges the gap between traditional ionic current recording and the MD simulations, facilitating the qualitative and quantitive description of the non-covalent interactions inside membrane channels.

Amino-functional polyethers: versatile, stimuli-responsive polymers

2020 ◽  
Vol 11 (24) ◽  
pp. 3940-3950 ◽  
Author(s):  
Patrick Verkoyen ◽  
Holger Frey
Keyword(s):  
Ring Opening ◽  
Review Article ◽  
Stimuli Responsive ◽  
New Class ◽  
Stimuli Responsive Polymers ◽  
Responsive Polymers

Amino-functional polyethers have emerged as a new class of “smart”, i.e. pH- and thermoresponsive materials. This review article summarizes the synthesis and applications of these materials, obtained from ring-opening of suitable epoxide monomers.

TMCC3 localizes at the three-way junctions for the proper tubular network of the endoplasmic reticulum

2019 ◽  
Vol 476 (21) ◽  
pp. 3241-3260
Author(s):  
Sindhu Wisesa ◽  
Yasunori Yamamoto ◽  
Toshiaki Sakisaka
Keyword(s):  
Endoplasmic Reticulum ◽  
Membrane Proteins ◽  
Membrane Protein ◽  
Mammalian Cells ◽  
Coiled Coil ◽  
Transmembrane Domains ◽  
Domain Family ◽  
Coiled Coil Domain ◽  
U2os Cells ◽  
Er Membrane

The tubular network of the endoplasmic reticulum (ER) is formed by connecting ER tubules through three-way junctions. Two classes of the conserved ER membrane proteins, atlastins and lunapark, have been shown to reside at the three-way junctions so far and be involved in the generation and stabilization of the three-way junctions. In this study, we report TMCC3 (transmembrane and coiled-coil domain family 3), a member of the TEX28 family, as another ER membrane protein that resides at the three-way junctions in mammalian cells. When the TEX28 family members were transfected into U2OS cells, TMCC3 specifically localized at the three-way junctions in the peripheral ER. TMCC3 bound to atlastins through the C-terminal transmembrane domains. A TMCC3 mutant lacking the N-terminal coiled-coil domain abolished localization to the three-way junctions, suggesting that TMCC3 localized independently of binding to atlastins. TMCC3 knockdown caused a decrease in the number of three-way junctions and expansion of ER sheets, leading to a reduction of the tubular ER network in U2OS cells. The TMCC3 knockdown phenotype was partially rescued by the overexpression of atlastin-2, suggesting that TMCC3 knockdown would decrease the activity of atlastins. These results indicate that TMCC3 localizes at the three-way junctions for the proper tubular ER network.

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