171856-09-0Relevant articles and documents
Peptide/peptoid hybrid oligomers: The influence of hydrophobicity and relative side-chain length on antibacterial activity and cell selectivity
Frederiksen, Nicki,Hansen, Paul R.,Bj?rkling, Fredrik,Franzyk, Henrik
, (2019/12/26)
Previous optimisation studies of peptide/peptoid hybrids typically comprise comparison of structurally related analogues displaying different oligomer length and diverse side chains. The present work concerns a systematically constructed series of 16 closely related 12-mer oligomers with an alternating cationic/hydrophobic design, representing a wide range of hydrophobicity and differences in relative side-chain lengths. The aim was to explore and rationalise the structure-activity relationships within a subclass of oligomers displaying variation of three structural features: (i) cationic side-chain length, (ii) hydrophobic side-chain length, and (iii) type of residue that is of a flexible peptoid nature. Increased side-chain length of cationic residues led to reduced hydrophobicity till the side chains became more extended than the aromatic/hydrophobic side chains, at which point hydrophobicity increased slightly. Evaluation of antibacterial activity revealed that analogues with lowest hydrophobicity exhibited reduced activity against E. coli, while oligomers with the shortest cationic side chains were most potent against P. aeruginosa. Thus, membrane-disruptive interaction with P. aeruginosa appears to be promoted by a hydrophobic surface of the oligomers (comprised of the aromatic groups shielding the cationic side chains). Peptidomimetics with short cationic side chains exhibit increased hemolytic properties as well as give rise to decreased HepG2 (hepatoblastoma G2 cell line) cell viability. An optimal hydrophobicity window could be defined by a threshold of minimal hydrophobicity conferring activity toward E. coli and a threshold for maximal hydrophobicity, beyond which cell selectivity was lost.
Antimicrobial activity of peptidomimetics against multidrug-resistant Escherichia coli: A comparative study of different backbones
Jahnsen, Rasmus D.,Frimodt-M?ller, Niels,Franzyk, Henrik
, p. 7253 - 7261 (2012/11/07)
Novel remedies in the battle against multidrug-resistant bacterial strains are urgently needed, and one obvious approach involves antimicrobial peptides and mimics hereof. The impact of α- and β-peptoid as well as β3-amino acid modifications on the activity profile against β-lactamase-producing Escherichia coli was assessed by testing an array comprising different types of cationic peptidomimetics obtained by a general monomer-based solid-phase synthesis protocol. Most of the peptidomimetics possessed high to moderate activity toward multidrug-resistant E. coli as opposed to the corresponding inactive peptides. Nevertheless, differences in hemolytic activities indicate that a careful choice of backbone design constitutes a significant parameter in the search for effective cationic antimicrobial peptidomimetics targeting specific bacteria.
Solid-phase syntheses of peptoids using Fmoc-protected N-substituted glycines: The synthesis of (retro)peptoids of leu-enkephalin and substance P
Kruijtzer, John A.W.,Hofmeyer, Lovina J.F.,Heerma, Wigger,Versluis, Cornelis,Liskamp, Rob M.J.
, p. 1570 - 1580 (2007/10/03)
A particularly interesting class of oligomeric peptidomimetics is formed by the peptoids, which consist of N-substituted glycine residues. A solid- phase synthesis method for peptoids is presented in which these residues are introduced using their Fmoc derivatives. This 'monomer' method allowed the monitored synthesis of relatively large quantities of pure peptoids as well as the translation of, in principle, any peptide into the corresponding peptoid. The required Fmoc-substituted glycines were accessible by convenient synthesis, and a number of monomers including those containing side chains with functional groups have been synthesized. The use of Fmoc monomers also allowed implementation of a solid-phase synthesis protocol on a commercial peptide synthesizer. The method was exempli- fled by the solid-phase syntheses of the (retro)peptoids of Leu-enkephalin and substance P. Mass spectrometric studies of (retro)peptoids were essential for their characterization, and the presence of the B- and Y'- type ions allows sequence analysis. Substance P (retro)peptoids were biologically active. HPLC analysis showed an increased hydrophobicity, and pepsin treatment resulted in greatly reduced degradation compared with the corresponding peptide.
Building Units for N-Backbone Cyclic Peptides. 3. Synthesis of Protected Nα-(ω-Aminoalkyl)amino Acids and Nα-(ω-Carboxyalkyl)amino Acids
Muller, Dan,Zeltser, Irena,Bitan, Gal,Gilon, Chaim
, p. 411 - 416 (2007/10/03)
An improved synthesis of a family of amino acids that contain ω-aminoalkyl groups and of a new family containing ω-carboxyalkyl groups linked to the α-amine is described. The synthesis was performed by alkylation of suitably monoprotected alkylenediamines and protected ω-amino acids with triflates of α-hydroxy acid esters. The reaction proceeded with inversion of configuration yielding optically pure products. The Nα-(ω-aminoalkyl)amino acids and Nα-(ω-carboxyalkyl)amino acids were orthogonally protected to allow their incorporation into peptides by solid-phase peptide synthesis (SPPS) methodology.
