Design of a novel tryptophan-rich membrane-active antimicrobial peptide from the membrane-proximal region of the HIV glycoprotein, gp41

• Evan F. Haney,
• Leonard T. Nguyen,
• David J. Schibli and
• Hans J. Vogel

Beilstein J. Org. Chem. 2012, 8, 1172–1184, doi:10.3762/bjoc.8.130

• , while the band at ~230 nm can be attributed to stacking interactions between nearby aromatic rings [17]. This is in agreement with the fluorescence results and suggests that the gp41w backbone adopts a regular secondary structure when oligomerized in solution. The addition of SDS or DPC micelles to

• to the formation of insoluble peptide–lipid complexes. Unfortunately, due to the loss of CD signal in these samples, it is impossible to determine what type of secondary structure is present in these aggregates. NMR solution structure All the gp41w derivatives were examined by nuclear magnetic

Partial thioamide scan on the lipopeptaibiotic trichogin GA IV. Effects on folding and bioactivity

• Marta De Zotti,
• Barbara Biondi,
• Cristina Peggion,
• Matteo De Poli,
• Haleh Fathi,
• Simona Oancea,
• Claudio Toniolo and
• Fernando Formaggio

Beilstein J. Org. Chem. 2012, 8, 1161–1171, doi:10.3762/bjoc.8.129

• ], backbone amide surrogates have attracted remarkable attention from organic and medicinal chemists. Not only may these modifications impart to a peptide an increased resistance to enzymatic hydrolysis as well as higher receptor affinity and specificity, but they may also influence its preferred secondary

• structure. A ψ[CS-NH] thioamide group is one of the closest mimics of an amide (peptide) linkage. However, it exhibits significantly different chemical and physical properties, some of which are of great potential interest to peptide chemists [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19

Similarity analysis, synthesis, and bioassay of antibacterial cyclic peptidomimetics

• Workalemahu M. Berhanu,
• Mohamed A. Ibrahim,
• Girinath G. Pillai,
• Alexander A. Oliferenko,
• Levan Khelashvili,
• Farukh Jabeen,
• Bushra Mirza,
• Farzana Latif Ansari,
• Ihsan ul-Haq,
• Said A. El-Feky and
• Alan R. Katritzky

Beilstein J. Org. Chem. 2012, 8, 1146–1160, doi:10.3762/bjoc.8.128

• peptides are more stable to proteolysis due to the lack of free N- and C-termini, as well as reduced conformational freedom. Stability can also be achieved by modifying peptides into “peptidomimetics” that mimic and/or stabilize the secondary structure that modifies associated biological processes, thus

Parallel solid-phase synthesis of diaryltriazoles

• Matthias Wrobel,
• Jeffrey Aubé and
• Burkhard König

Beilstein J. Org. Chem. 2012, 8, 1027–1036, doi:10.3762/bjoc.8.115

• protein–protein interactions. Keywords: chemical diversity; Huisgen cycloaddition; library synthesis; peptidomimetics; solid phase synthesis; triazole; Introduction The α-helix was the first-described secondary structure of peptides discovered by Linus Pauling in 1951 [1]. With about 30% of the amino

• acids in proteins being part of α-helices [2], it is the most common secondary structure found in proteins [3]. Protein–protein as well as protein–DNA and protein–RNA interactions often involve α-helices as recognition motifs on protein surfaces [4]. These helices are important targets for new drugs

Asymmetric synthesis of quaternary aryl amino acid derivatives via a three-component aryne coupling reaction

• Elizabeth P. Jones,
• Peter Jones,
• Andrew J. P. White and
• Anthony G. M. Barrett

Beilstein J. Org. Chem. 2011, 7, 1570–1576, doi:10.3762/bjoc.7.185

• . Incorporation of such units into peptidomimetics, not only affects lipophilicity, but also the secondary structure and hence the conformational rigidity, which can increase the resistance to enzymatic degradation [15][16][17][18][19]. Such units are also found in biologically interesting natural products, such

(Pseudo)amide-linked oligosaccharide mimetics: molecular recognition and supramolecular properties

• José L. Jiménez Blanco,
• Fernando Ortega-Caballero,
• Carmen Ortiz Mellet and
• José M. García Fernández

Beilstein J. Org. Chem. 2010, 6, No. 20, doi:10.3762/bjoc.6.20

• interaction with a receptor [20]. As a consequence, a wide variety of methods to restrict the conformational freedom has been developed. One approach to get round this problem is the isosteric replacement of the amide bond in the peptide with a suitable mimetic to induce a specific secondary structure. Recent

• (THF) amino acids were optimised in order to study the influence of ring configuration and protecting groups on the secondary structure in these carbopeptoids. Short oligomeric chains of C-glycosyl β-D-arabino THF amino acids 14 and 15 (where the C-2 and C-5 substituents of the THF ring are cis to each

• other) exhibit a well defined repeating turn secondary structure stabilised by inter-residual hydrogen bonds, whereas the epimeric α-D-arabinofuranose oligomer 12 (with the C-2 and C-5 substituents in trans relative disposition) do not show any secondary structure in solution [34]. NMR and IR studies on

Synthesis and binding studies of two new macrocyclic receptors for the stereoselective recognition of dipeptides

• Ana Maria Castilla,
• M. Morgan Conn and
• Pablo Ballester

Beilstein J. Org. Chem. 2010, 6, No. 5, doi:10.3762/bjoc.6.5

• commonly found in the secondary structure of many biologically relevant proteins. We start from a schematic termolecular complex mimicking a three-stranded β-sheet in which the central strand corresponds to the target guest peptide and the two outer strands constitute the structure of the host (Figure 1

• of dipeptides on the basis of the interactions that occur in the β-sheets commonly found in the secondary structure of many biologically relevant proteins. The geometry of the putative complex used in the design of the receptors implies the threading of the dipeptide guest through the macrocyclic

Synthesis of new C^α-tetrasubstituted α-amino acids

• Andreas A. Grauer and
• Burkhard König

Beilstein J. Org. Chem. 2009, 5, No. 5, doi:10.3762/bjoc.5.5

• ; Introduction The secondary structure of an amino acid sequence is of key importance for the biological activity of proteins [1][2]. In most cases short natural peptide sequences containing L α-amino acids are very flexible and do not show a distinct secondary structure in aqueous solution. Therefore small

• Andreas A. Grauer Burkhard Konig Institute for Organic Chemistry, University of Regensburg, Universitätsstrasse 31, 93040 Regensburg, Germany 10.3762/bjoc.5.5 Abstract Cα-Tetrasubstituted α-amino acids are important building blocks for the synthesis of peptidemimetics with stabilized secondary

• structure, because of their ability to rigidify the peptide backbone. Recently our group reported a new class of cyclic Cα-tetrasubstituted tetrahydrofuran α-amino acids prepared from methionine and aromatic aldehydes. We now report the extension of this methodology to aliphatic aldehydes. Although such