2311-26-4Relevant articles and documents
Intramolecular Photoreaction of Synthetic Oligopeptide-Linked Anthraquinone Molecules
Maruyama, Kazuhiro,Hashimoto, Masakazu,Tamiaki, Hitoshi
, p. 6143 - 6150 (1992)
Photoreaction of (N-acetylglycyl)oligopeptide-linked anthraquinone molecules was investigated.In an acetonitrile solution, the photoexcited anthraquinone moiety abstracted intramolecularly the hydrogen atom of the methylene site of glycine residue.The biradical formed was followed by the formation of C-O bonding via radical recombination to produce ring-closure products in high yields (23-58percent).A variety of oligopeptide spacers between acetylglycine and anthraquinone moieties were systematically changed, and their photoreactivities were investigated.The isolated ring-closure products showed a site-selectivity in the photoreaction; one of the carbonyl groups of anthraquinone moiety coupled with the methylene group predominantly (the selectivity was 88/12-100/0).The efficiency of the photocyclization was dependent upon the size and the sequence of the oligopeptide spacer.These results showed that the oligopeptide spacer might control the distance and the orientation among the reaction sites, glycine methylene, and anthraquinone carbonyl groups.
Rapid and Selective Chemical Editing of Ribosomally Synthesized and Post-Translationally Modified Peptides (RiPPs) via CuII-Catalyzed β-Borylation of Dehydroamino Acids
de Vries, Reinder H.,Viel, Jakob H.,Kuipers, Oscar P.,Roelfes, Gerard
supporting information, p. 3946 - 3950 (2020/12/25)
We report the fast and selective chemical editing of ribosomally synthesized and post-translationally modified peptides (RiPPs) by β-borylation of dehydroalanine (Dha) residues. The thiopeptide thiostrepton was modified efficiently using CuII-catalysis under mild conditions and 1D/2D NMR of the purified product showed site-selective borylation of the terminal Dha residues. Using similar conditions, the thiopeptide nosiheptide, lanthipeptide nisin Z, and protein SUMO_G98Dha were also modified efficiently. Borylated thiostrepton showed an up to 84-fold increase in water solubility, and minimum inhibitory concentration (MIC) assays showed that antimicrobial activity was maintained in thiostrepton and nosiheptide. The introduced boronic-acid functionalities were shown to be valuable handles for chemical mutagenesis and in a reversible click reaction with triols for the pH-controlled labeling of RiPPs.
Oxidative Damage in Aliphatic Amino Acids and Di- and Tripeptides by the Environmental Free Radical Oxidant NO3?: the Role of the Amide Bond Revealed by Kinetic and Computational Studies
Nathanael, Joses G.,Wille, Uta
, p. 3405 - 3418 (2019/03/11)
Kinetic and computational data reveal a complex behavior of the important environmental free radical oxidant NO3? in its reactions with aliphatic amino acids and di- and tripeptides, suggesting that attack at the amide N-H bond in the peptide backbone is a highly viable pathway, which proceeds through a proton-coupled electron transfer (PCET) mechanism with a rate coefficient of about 1 × 106 M-1 s-1 in acetonitrile. Similar rate coefficients were determined for hydrogen abstraction from the α-carbon and from tertiary C-H bonds in the side chain. The obtained rate coefficients for the reaction of NO3? with aliphatic di- and tripeptides suggest that attack occurs at all of these sites in each individual amino acid residue, which makes aliphatic peptide sequences highly vulnerable to NO3?-induced oxidative damage. No evidence for amide neighboring group effects, which have previously been found to facilitate radical-induced side-chain damage in phenylalanine, was found for the reaction of NO3? with side chains in aliphatic peptides.
