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Peptide Conformation

About: Peptide Conformation is a(n) research topic. Over the lifetime, 814 publication(s) have been published within this topic receiving 28496 citation(s). more


Open accessJournal ArticleDOI: 10.1016/S0005-2736(99)00198-4
Richard M. Epand1, Hans J. Vogel2Institutions (2)
Abstract: Antimicrobial peptides encompass a wide variety of structural motifs. Many peptides have alpha-helical structures. The majority of these peptides are cationic and amphipathic but there are also hydrophobic alpha-helical peptides which possess antimicrobial activity. In addition, some beta-sheet peptides have antimicrobial activity and even antimicrobial alpha-helical peptides which have been modified to possess a beta-structure retain part of their antimicrobial activity. There are also antimicrobial peptides which are rich in a certain specific amino acid such as Trp or His. In addition, antimicrobial peptides exist with thio-ether rings, which are lipopeptides or which have macrocyclic Cys knots. In spite of the structural diversity, a common feature of the cationic antimicrobial peptides is that they all have an amphipathic structure which allows them to bind to the membrane interface. Indeed, most antimicrobial peptides interact with membranes and may be cytotoxic as a result of disturbance of the bacterial inner or outer membranes. Alternatively, a necessary but not sufficient property of these peptides may be to be able to pass through the membrane to reach a target inside the cell. The interaction of these peptides with biological membranes is not just a function of the peptide but is also modulated by the lipid components of the membrane. It is not likely that this diverse group of peptides has a single mechanism of action, but interaction of the peptides with membranes is an important requirement for most, if not all, antimicrobial peptides. more

Topics: Antimicrobial peptides (74%), Beta defensin (60%), Membrane permeability (54%) more

1,227 Citations

Journal ArticleDOI: 10.1016/J.PEPTIDES.2003.08.023
01 Nov 2003-Peptides
Abstract: Cationic antimicrobial peptides are a class of small, positively charged peptides known for their broad-spectrum antimicrobial activity. These peptides have also been shown to possess anti-viral and anti-cancer activity and, most recently, the ability to modulate the innate immune response. To date, a large number of antimicrobial peptides have been chemically characterized, however, few high-resolution structures are available. Structure-activity studies of these peptides reveal two main requirements for antimicrobial activity, (1) a cationic charge and (2) an induced amphipathic conformation. In addition to peptide conformation, the role of membrane lipid composition, specifically non-bilayer lipids, on peptide activity will also be discussed. more

Topics: Antimicrobial peptides (70%), Peptide Conformation (65%), Beta defensin (60%) more

793 Citations

Journal ArticleDOI: 10.1038/NCHEM.1062
01 Jul 2011-Nature Chemistry
Abstract: Peptide macrocycles have found applications that range from drug discovery to nanomaterials. These ring-shaped molecules have shown remarkable capacity for functional fine-tuning. Such capacity is enabled by the possibility of adjusting the peptide conformation using the techniques of chemical synthesis. Cyclic peptides have been difficult, and often impossible, to prepare using traditional synthetic methods. For macrocyclization to occur, the activated peptide must adopt an entropically disfavoured pre-cyclization conformation before forming the desired product. Here, we review recent solutions to some of the major challenges in this important area of contemporary synthesis. more

Topics: Peptide Conformation (63%)

712 Citations

Journal ArticleDOI: 10.1021/BI0011330
14 Oct 2000-Biochemistry
Abstract: The seven-residue peptide N-acetyl-Lys-Leu-Val-Phe-Phe-Ala-Glu-NH(2), called A beta(16-22) and representing residues 16-22 of the full-length beta-amyloid peptide associated with Alzheimer's disease, is shown by electron microscopy to form highly ordered fibrils upon incubation of aqueous solutions. X-ray powder diffraction and optical birefringence measurements confirm that these are amyloid fibrils. The peptide conformation and supramolecular organization in A beta(16-22) fibrils are investigated by solid state (13)C NMR measurements. Two-dimensional magic-angle spinning (2D MAS) exchange and constant-time double-quantum-filtered dipolar recoupling (CTDQFD) measurements indicate a beta-strand conformation of the peptide backbone at the central phenylalanine. One-dimensional and two-dimensional spectra of selectively and uniformly labeled samples exhibit (13)C NMR line widths of <2 ppm, demonstrating that the peptide, including amino acid side chains, has a well-ordered conformation in the fibrils. Two-dimensional (13)C-(13)C chemical shift correlation spectroscopy permits a nearly complete assignment of backbone and side chain (13)C NMR signals and indicates that the beta-strand conformation extends across the entire hydrophobic segment from Leu17 through Ala21. (13)C multiple-quantum (MQ) NMR and (13)C/(15)N rotational echo double-resonance (REDOR) measurements indicate an antiparallel organization of beta-sheets in the A beta(16-22) fibrils. These results suggest that the degree of structural order at the molecular level in amyloid fibrils can approach that in peptide or protein crystals, suggest how the supramolecular organization of beta-sheets in amyloid fibrils can be dependent on the peptide sequence, and illustrate the utility of solid state NMR measurements as probes of the molecular structure of amyloid fibrils. A beta(16-22) is among the shortest fibril-forming fragments of full-length beta-amyloid reported to date, and hence serves as a useful model system for physical studies of amyloid fibril formation. more

637 Citations

01 Jan 2001-Biopolymers
Abstract: The preferred conformations of peptides heavily based on the currently extensively exploited achiral and chiral α-amino acids with a quaternary α-carbon atom, as determined by conformational energy computations, crystal-state (x-ray diffraction) analyses, and solution (1H-NMR and spectroscopic) investigations, are reviewed. It is concluded that 310/α-helical structures and the fully extended (C5) conformation are preferentially adopted by peptide sequences characterized by this family of amino acids, depending upon overall bulkiness and nature (e.g., whether acyclic or C ↔ C cyclized) of their side chains. The intriguing relationship between α-carbon chirality and bend/helix handedness is also illustrated. γ-Bends and semiextended conformations are rarely observed. Formation of β-sheet structures is prevented. © 2002 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 60: 396–419, 2001 more

556 Citations

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Topic's top 5 most impactful authors

Claudio Toniolo

31 papers, 1.3K citations

Fernando Formaggio

22 papers, 818 citations

Marco Crisma

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Padmanabhan Balaram

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Cristina Peggion

10 papers, 127 citations

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