title: Design, solid phase synthesis and evaluation of cationic ferrocenoyl peptide bioconjugates as potential antioxidant enzyme mimics.
abstract: Synthetic C-terminal amidated cationic ferrocenoyl peptide bioconjugates Fc-Orn-Orn-Orn (1) and Fc-Tyr-Orn-Orn-Orn (2) were rationally designed as superoxide dismutase (SOD) mimics based on the structure of the iron SOD from Escherichia coli. Ferrocenoyl peptide bioconjugates 1, 2 and ferrrocenecarboxylic acid (4) were subsequently evaluated as SOD mimics and as inhibitors of peroxynitrite-mediated tyrosine nitration. Due to their cationic character, ferrocenoyl peptide bioconjugates 1 and 2 exerted an acceptable SOD activity (EC(50)=575 microM and 310 microM, respectively) in comparison with 4 (EC(50)=1.4mM). The C-terminal amidated cationic peptide Ac-Tyr-Orn-Orn-Orn (3), designed as marker of peroxynitrite, was used to evaluate the inhibitory activity of 1 and 4 towards peroxynitrite-mediated tyrosine nitration. Both compounds proved to inhibit the nitration especially the cationic ferrocenoyl peptide bioconjugates 1. The ferrocene moiety of conjugate 2 displayed a strong inhibitory activity of peroxynitrite-mediated nitration of the neighboring tyrosine.
authors.affiliation: INSA Lyon, Institut de Chimie et Biochimie Moléculaires et Supramoléculaires, Laboratoire de Chimie Organique, Bât J. Verne, 20 avenue Albert Einstein, F-69621 Villeurbanne Cedex, France. laurent.soulere@insa-lyon.fr
authors.forename: Laurent
authors.initials: L
authors.lastname: Soulère
authors.forename: Julien
authors.initials: J
authors.lastname: Bernard
mesh_terms: D000975:Antioxidants / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D015195:Drug Design; D004926:Escherichia coli / Q000201:enzymology*; D005296:Ferrous Compounds / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D009842:Oligopeptides / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D011487:Protein Conformation; D013482:Superoxide Dismutase / Q000737:chemistry* / Q000378:metabolism
chemical_list: D000975:Antioxidants; C538882:Fc-Orn-Orn-Orn; C538883:Fc-Tyr-Orn-Orn-Orn; D005296:Ferrous Compounds; D009842:Oligopeptides; D013482:Superoxide Dismutase