Arginine | EPFL Graph Search

L'arginine (abréviations IUPAC-IUBMB : Arg et R) est un acide . La molécule est caractérisée par la présence d'un groupe guanidine à l'extrémité de sa chaîne latérale, ce qui en fait un résidu très basique, chargé positivement dans les protéines, et dont le point isoélectrique vaut 10,76. Elle n'est pas considérée comme essentielle pour l'homme mais peut être produite en quantité insuffisante par l'organisme selon l'état de santé des individus, nécessitant alors un apport alimentaire. Historique L'arginine fut isolée pour la première fois à partir de plants de lupin en 1886 par le chimiste suisse Ernst Schultze. Elle est également dérivée de la guanidine, produite à partir du guano. Caractéristiques physiques et structure chimique L'énantiomère L est l'un des aminés protéinogènes, encodé sur les ARN messagers par les codons CGU, CGC, CGA, CGG, AGA et AGG. Son rayon de van der Waals est égal à (14,8 nm). La chaîne latérale de l'arginine est constituée d'un

Arginine-Based Biodegradable Ether–Ester Polymers with Low Cytotoxicity as Potential Gene Carriers

Lucia Baldi Unser, Sagar Shashidhar Manoli, Tamar Memanishvili, Christine Wandrey, Nino Zavradashvili

The success of gene therapy depends on safe and effective gene carriers. Despite being widely used, synthetic vectors based on poly(ethylenimine) (PEI), poly(l-lysine) (PLL), or poly(l-arginine) (poly-Arg) are not yet fully satisfactory. Thus, both improvement of established carriers and creation of new synthetic vectors are necessary. A series of biodegradable arginine-based ether–ester polycations was developed, which consists of three main classes: amides, urethanes, and ureas. Compared to that of PEI, PLL, and poly-Arg, much lower cytotoxicity was achieved for the new cationic arginine-based ether–ester polymers. Even at polycation concentrations up to 2 mg/mL, no significant negative effect on cell viability was observed upon exposure of several cell lines (murine mammary carcinoma, human cervical adenocarcinoma, murine melanoma, and mouse fibroblast) to the new polymers. Interaction with plasmid DNA yielded compact and stable complexes. The results demonstrate the potential of arginine-based ether–ester polycations as nonviral carriers for gene therapy applications.

Amer Chemical Soc2014

A releasable disulfide-linked peptide tag facilitates the synthesis and purification of short peptides

Christian Heinis, Jack Peter Christopher Williams, Yu Teng Wu, Alessandro Zorzi

Combinatorial cyclization of hundreds to thousands of random linear peptides by structurally diverse chemical linkers offers access to large macrocyclic compound libraries. A bottleneck in the development of such libraries is the preparation of large numbers of short random linear peptides. Herein, we present a tag-based strategy that is not dependent on a throughput-limiting chromatographic purification step and thus enables parallel production of short peptides. In brief, peptides are synthesized on solid phase as conjugates with a disulfide-linked Cys-Gly-Arg-Trp tetra-peptide tag. The charged arginine residue in the tag allows for purification of the peptides by diethyl ether-precipitation and the tryptophan allows for quantification of the product by absorption measurement. Addition of a reducing agent releases the short peptides from the tag. The released sulfhydryl group in the peptide can readily be used for cyclization of the peptide library with bis-electrophilic linker reagents.

2020

Cell Compatible Arginine Containing Cationic Polymer: One-Pot Synthesis and Preliminary Biological Assessment

Lucia Baldi Unser, Tamar Memanishvili, Xiao Shen, Christine Wandrey, Nino Zavradashvili

Synthetic cationic polymers are of interest as both nonviral vectors for intracellular gene delivery and antimicrobial agents. For both applications synthetic polymers containing guanidine groups are of special interest since such kind of organic compounds/polymers show a high transfection potential along with antibacterial activity. It is important that the delocalization of the positive charge of the cationic group in guanidine significantly decreases the toxicity compared to the ammonium functionality. One of the most convenient ways for incorporating guanidine groups is the synthesis of polymers composed of the amino acid arginine (Arg) via either application of Arg-based monomers or chemical modification of polymers with derivatives of Arg. It is also important to have biodegradable cationic polymers that will be cleared from the body after their function as transfection or antimicrobial agent is fulfilled. This chapter deals with a two-step/onepot synthesis of a new biodegradable cationic polymer-poly(ethylene malamide) containing L-arginine methyl ester covalently attached to the macrochains in beta-position of the malamide residue via the alpha-amino group. The goal cationic polymer was synthesized by in situ interaction of arginine methyl ester dihydrochloride with intermediary poly(ethylene epoxy succinimide) formed by polycondensation of di-p-nitrophenyl-trans-epoxy succinate with ethylenediamine. The cell compatibility study with Chinese hamster ovary (CHO) and insect Schneider 2 cells (S2) within the concentration range of 0.02-500 mg/mL revealed that the new polymer is not cytotoxic. It formed nanocomplexes with pDNA (120-180 nm in size) at low polymer/DNA weight ratios (WR = 5-10). A preliminarily transfection efficiency of the Arg-containing new cationic polymer was assessed using CHO, S2, H5, and Sf9 cells.

Springer India2014

Cell Compatible Arginine Containing Cationic Polymer: One-Pot Synthesis and Preliminary Biological Assessment

Lucia Baldi Unser, Tamar Memanishvili, Xiao Shen, Christine Wandrey, Nino Zavradashvili

Springer India2014