Two-Dimensional Ordered β-Sheet Lipopeptide Monolayers

Abstract

A series of amphiphilic lipopeptides, ALPs, consisting of an alternating hydrophilic and hydrophobic amino acid residue sequence coupled to a phospholipid tail, was designed to form supramolecular assemblies composed of beta-sheet monolayers decorated by lipid tails at the air-water interface. A straightforward synthetic approach based on solid-phase synthesis, followed by an efficient purification protocol was used to prepare the lipid-peptide conjugates. Structural insight into the organization of monolayers was provided by surface pressure versus area isotherms, circular dichroism, Fourier transform infrared spectroscopy, and Brewster angle microscopy. In situ grazing-incidence X-ray diffraction (GIXD) revealed that lipopeptides six to eight amino acids in length form a new type of 2D self-organized monolayers that exhibit beta-sheet ribbons segregated by lipid tails. The conclusions drawn from the experimental findings were supported by a representative model based on molecular dynamics simulations of amphiphilic lipopeptides at the vacuum-water interface.

Amyloids: Not Only Pathological Agents but Also Ordered Nanomaterials

“…Consequently, the formed layer exhibited exceptional one-dimensional elastic characteristics, [83] providing a planar scaffold pertinent for a wide range of potential applications on a nanometer scale. Potential applications were recently illustrated by Cavalli et al by the formation of ordered b-sheet lipopeptide monolayers, [84] serving as a template for the biomineralization of calcium carbonate. [85] Schneider et al [86] have designed 20-residue amphiphilic sequences that fold into b-hairpins in aqueous solution and further self-assemble into a network of fibrils, leading to the formation of a hydrogel.…”

Challenges and breakthroughs in recent research on self-assembly

“…Also, Tour and coworkers investigated the structures of SAMs and pointed out the possibilities of multilayer formation, based on experiments using thiol-terminated fullerene derivatives (figure 107) [905]. Various polymeric units such as oligo (phenyleneethynylene) [906,907], oligothiophene [908], polyelectrolyte brushes [909,910], polyaniline [911], poly(ethylene glycol) [912], peptide [913], protein [914], DNA [915], nucleotide [916], carbon nanotubes [917,918], coordination cages [919] have been immobilized in SAM structures. SAMs with cyclodextrin [920,921] and calixarene [922] can be used for material sensing through inclusion complex formation.…”

Scope and Applications of Amphiphilic Alkyl‐ and Lipopeptides

“…2e-i). [22] These molecules were composed of an amphiphilic oligopeptide domain, (Leu-Glu) n , interlinked by a succinyl moiety to the phospholipid 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE). The ALPs were designed to form supramolecular assemblies composed of b-sheet arrays decorated by hydrophobic lipid tails.…”