Planar Bilayer Measurements of Alamethicin and Gramicidin Reconstituted in Biomimetic Block Copolymers

Martin, Michael; Dubbs, Timothy; Fried, Joel

doi:10.1021/acs.langmuir.6b03309

Cited by 7 publications

(7 citation statements)

References 59 publications

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“…70 In another approach, planar membranes with synthetic AB and ABA block copolymers of PMOXA and PDMS were used to study the reconstitution of alamethicin and gA and compared with their reconstitution in lipid bilayers. 73 Alamethicin was successfully inserted and showed gating properties similar to those found in diphytanoyl phosphocholine lipid bilayers, whereas gA behavior in polymer membranes was different then in lipid bilayers: the conductance was significantly lower and there was no evidence of conductance-state switching. An amazing breakthrough in the field was the functional pore formation of peptides in solid-supported planar membranes showed by the Meier group.…”

Section: Reconstitution Of Peptides In Planarmentioning

confidence: 89%

“…When gA peptide was added to polymer membranes, it was able to adopt distinct conformations in different environments: inside membrane arrays made of PMOXA-PDMS-PMOXA, it preserved its functionality, indicating a high potential for high-throughput screening applications . In another approach, planar membranes with synthetic AB and ABA block copolymers of PMOXA and PDMS were used to study the reconstitution of alamethicin and gA and compared with their reconstitution in lipid bilayers . Alamethicin was successfully inserted and showed gating properties similar to those found in diphytanoyl phosphocholine lipid bilayers, whereas gA behavior in polymer membranes was different then in lipid bilayers: the conductance was significantly lower and there was no evidence of conductance-state switching.…”

Section: Reconstitution Of Peptides In Planar Polymer Membranesmentioning

confidence: 99%

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Amphiphilic Peptide Self-Assembly: Expansion to Hybrid Materials

et al. 2017

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The design of functional systems with sizes in the nanometer range is a key challenge in fields such as biomedicine, nanotechnology, and engineering. Some of the most promising materials nowadays consist of self-assembling peptides or peptide-polymer hybrid materials because of their versatility and the resulting properties that can be achieved with these structures. Self-assembly of pure amphiphilic peptides or in combination with block copolymers results in a large variety of nanostructures (micelles, nanoparticles (NPs), compartments, planar membranes) each with different characteristics and tunable properties. Here, we describe such novel peptide- or peptide-polymer-based supramolecular nanostructures and emphasize their functionality and various promising applications.

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Section: Reconstitution Of Peptides In Planarmentioning

confidence: 89%

Section: Reconstitution Of Peptides In Planar Polymer Membranesmentioning

confidence: 99%

Amphiphilic Peptide Self-Assembly: Expansion to Hybrid Materials

et al. 2017

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“…Membranes formed by pure diblock copolymers are bilayered [29] while monolayered, bilayered, or mixed membranes can be developed by triblock copolymers [30,31]. It is known that A x B y A x triblock copolymers can exhibit two possible conformations, U-(loop) or I-(bridge) shape, in the polymer membrane [32][33][34][35][36]. The triblock copolymer is termed the loop-conformation as its two hydrophilic moieties are on the same side of the membrane, while a copolymer is called a bridge-shape copolymer when its two hydrophilic blocks situate on the opposite sides of the membrane.…”

Section: Introductionmentioning

confidence: 99%

Formation of Asymmetric and Symmetric Hybrid Membranes of Lipids and Triblock Copolymers

et al. 2020

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Hybrid membranes formed by co-assembly of AxByAx (hydrophilic-hydrophobic-hydrophilic) triblock copolymers into lipid bilayers are investigated by dissipative particle dynamics. Homogeneous hybrid membranes are developed as lipids and polymers are fully compatible. The polymer conformations can be simply classified into bridge- and loop-structures in the membranes. It is interesting to find that the long-time fraction of loop-conformation ( f L ) of copolymers in the membrane depends significantly on the hydrophilic block length (x). As x is small, an equilibrium f L * always results irrespective of the initial conformation distribution and its value depends on the hydrophobic block length (y). For large x, f L tends to be time-invariant because polymers are kinetically trapped in their initial structures. Our findings reveal that only symmetric hybrid membranes are formed for small x, while membranes with stable asymmetric leaflets can be constructed with large x. The effects of block lengths on the polymer conformations, such as transverse and lateral spans ( d ⊥ and d ‖ ) of bridge- and loop-conformations, are discussed as well.

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“…Different from typical bilayer membranes associated with lipids, the ABA polymersome has a mixed monolayer/bilayer structure. In this membrane, there are two possible conformations of triblock copolymers: the bridge (I) and loop (U) structures. − The bridge-shaped copolymer forms a monolayer-like configuration and the two hydrophilic moieties of the polymer are located at the opposite sides of the polymeric membrane. In contrast, the loop-shaped copolymer results in a bilayer-like structure and the two hydrophilic moieties are at the same side of the membrane.…”

Section: Introductionmentioning

confidence: 99%

Floating and Diving Loops of ABA Triblock Copolymers in Lipid Bilayers and Stability Enhancement for Asymmetric Membranes

et al. 2020

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Hybrid membranes of lipids and A x B y A z triblock copolymers can possess better biocompatibility and mechanical stability. In this work, triblock copolymer conformations and stability of asymmetric membranes are explored by dissipative particle dynamics. The triblock copolymers in the membranes exhibit either the bridge or loop conformation. As hydrophobic B-blocks interact attractively with lipid heads, bridge-shaped copolymers are significantly inhibited and loop-shaped copolymers prefer to stay at the interface between hydrophilic and hydrophobic layers. This floating loop has a flattened conformation, consistent with the experimental findings. In contrast, for repulsive interactions between B-blocks and lipid heads, bridge-shaped copolymers are abundant and loop-shaped copolymers tend to plunge into the hydrophobic layer. This diving loop displays a random coil conformation. The asymmetric membrane in which the fractions of loop-shaped copolymers in the upper and lower leaflets are different is thermodynamically unstable. Two approaches are proposed to acquire kinetically stable asymmetric membranes. First, membrane symmetrization is arrested by eliminating bridge-shaped copolymers, which is achieved by B-block/lipid head attraction and B-block/lipid tail repulsion. Second, asymmetric triblock copolymers (x ≠ z) are used to prevent the passage of the long A-block through the hydrophobic layer.

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Planar Bilayer Measurements of Alamethicin and Gramicidin Reconstituted in Biomimetic Block Copolymers

Cited by 7 publications

References 59 publications

Amphiphilic Peptide Self-Assembly: Expansion to Hybrid Materials

Amphiphilic Peptide Self-Assembly: Expansion to Hybrid Materials

Formation of Asymmetric and Symmetric Hybrid Membranes of Lipids and Triblock Copolymers

Floating and Diving Loops of ABA Triblock Copolymers in Lipid Bilayers and Stability Enhancement for Asymmetric Membranes

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