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Sheet Peptide (sheet + peptide)

Distribution by Scientific Domains
Chemistry42%

Selected Abstracts

Bioinspired Materials: Oligothiophene Versus , -Sheet Peptide: Synthesis and Self-Assembly of an Organic Semiconductor-Peptide Hybrid (Adv. Mater.

ADVANCED MATERIALS, Issue 16 2009
16/2009)
A first representative of a novel class of bioinspired materials, a fully symmetric hybrid between an oligothiophene and a , -sheet peptide, is introduced in work by Peter Bäuerle and co-workers on p. 1562. The conjugate can be synthesized via click-chemistry and employs a switch-peptide segment to gain control over the self-assembly motif of the peptide part. [source]

Oligothiophene Versus , -Sheet Peptide: Synthesis and Self-Assembly of an Organic Semiconductor-Peptide Hybrid

ADVANCED MATERIALS, Issue 16 2009
Eva-Kathrin Schillinger
A first representative of a novel class of bioinspired materials is introduced, a fully symmetric hybrid between an oligothiophene and a , -sheet peptide. The conjugate is synthesized via "click chemistry", and employs a switch-peptide segment to gain control over the self-assembly motif of the peptide part. The self-organization properties of the hybrid are investigated. [source]

Self-Replicating Amphiphilic ,-Sheet Peptides,

ANGEWANDTE CHEMIE, Issue 36 2009
Boris Rubinov
Einfache Peptide können das auch: Synthetische amphiphile Peptide 1, die aus elektrophilen (E) und nucleophilen (N) Vorstufen entstehen, sind nahe mit Glu-(Phe-Glu)n -Molekülen verwandt. Die Peptide bilden in Wasser lösliche eindimensionale ,-Faltblatt-Aggregate (siehe Bild), und sie beschleunigen die chemische Ligation sowie die Selbstreplikation erheblich. [source]

Bioinspired Materials: Oligothiophene Versus , -Sheet Peptide: Synthesis and Self-Assembly of an Organic Semiconductor-Peptide Hybrid (Adv. Mater.

ADVANCED MATERIALS, Issue 16 2009
16/2009)
A first representative of a novel class of bioinspired materials, a fully symmetric hybrid between an oligothiophene and a , -sheet peptide, is introduced in work by Peter Bäuerle and co-workers on p. 1562. The conjugate can be synthesized via click-chemistry and employs a switch-peptide segment to gain control over the self-assembly motif of the peptide part. [source]

Oligothiophene Versus , -Sheet Peptide: Synthesis and Self-Assembly of an Organic Semiconductor-Peptide Hybrid

ADVANCED MATERIALS, Issue 16 2009
Eva-Kathrin Schillinger
A first representative of a novel class of bioinspired materials is introduced, a fully symmetric hybrid between an oligothiophene and a , -sheet peptide. The conjugate is synthesized via "click chemistry", and employs a switch-peptide segment to gain control over the self-assembly motif of the peptide part. The self-organization properties of the hybrid are investigated. [source]

4-Fluorophenylglycine as a Label for 19F NMR Structure Analysis of Membrane-Associated Peptides

CHEMBIOCHEM, Issue 11 2003
Sergii Afonin
Abstract The non-natural amino acid 4-fluorophenylglycine (4F-Phg) was incorporated into several representative membrane-associated peptides for dual purpose. The 19F-substituted ring is directly attached to the peptide backbone, so it not only provides a well-defined label for highly sensitive 19F NMR studies but, in addition, the D and L enantiomers of the stiff side chain may serve as reporter groups on the transient peptide conformation during the biological function. Besides peptide synthesis, which is accompanied by racemisation of 4F-Phg, we also describe separation of the epimers by HPLC and removal of trifluoroacetic acid. As a first example, 18 different analogues of the fusogenic peptide "B18" were prepared and tested for induction of vesicle fusion; the results confirmed that hydrophobic sites tolerated 4F-Phg labelling. Similar fusion activities within each pair of epimers suggest that the peptide is less structured in the fusogenic transition state than in the helical ground state. In a second example, five doubly labelled analogues of the antimicrobial peptide gramicidin S were compared by using bacterial growth inhibition assays. This cyclic ,-sheet peptide could accommodate both L and D substituents on its hydrophobic face. As a third example, we tested six analogues of the antimicrobial peptide PGLa. The presence of d- 4F-Phg reduced the biological activity of the peptide by interfering with its amphiphilic ,-helical fold. Finally, to illustrate the numerous uses of l- 4F-Phg in 19F NMR spectroscopy, we characterised the interaction of labelled PGLa with uncharged and negatively charged membranes. Observing the signal of the free peptide in an aqueous suspension of unilamellar vesicles, we found a linear saturation behaviour that was dominated by electrostatic attraction of the cationic PGLa. Once the peptide is bound to the membrane, however, solid-state 19F NMR spectroscopy of macroscopically oriented samples revealed that the charge density has virtually no further influence on the structure, alignment or mobility of the peptide. [source]

Self-Assembly of Amylin(20,29) Amide-Bond Derivatives into Helical Ribbons and Peptide Nanotubes rather than Fibrils

CHEMISTRY - A EUROPEAN JOURNAL, Issue 14 2006
Ronald C. Elgersma
Abstract Uncontrolled aggregation of proteins or polypeptides can be detrimental for normal cellular processes in healthy organisms. Proteins or polypeptides that form these amyloid deposits differ in their primary sequence but share a common structural motif: the (anti)parallel , sheet. A well-accepted approach for interfering with ,-sheet formation is the design of soluble ,-sheet peptides to disrupt the hydrogen-bonding network; this ultimately leads to the disassembly of the aggregates or fibrils. Here, we describe the synthesis, spectroscopic analysis, and aggregation behavior, imaged by electron microscopy, of several backbone-modified amylin(20,29) derivatives. It was found that these amylin derivatives were not able to form fibrils and to some extent were able to inhibit fibril growth of native amylin(20,29). However, two of the amylin peptides were able to form large supramolecular assemblies, like helical ribbons and peptide nanotubes, in which ,-sheet formation was clearly absent. This was quite unexpected since these peptides have been designed as soluble ,-sheet breakers for disrupting the characteristic hydrogen-bonding network of (anti)parallel , sheets. The increased hydrophobicity and the presence of essential amino acid side chains in the newly designed amylin(20,29) derivatives were found to be the driving force for self-assembly into helical ribbons and peptide nanotubes. This example of controlled and desired peptide aggregation may be a strong impetus for research on bionanomaterials in which special shapes and assemblies are the focus of interest. [source]