title: Mechanisms of action of peptide inhibitors of mammalian ribonucleotide reductase targeting quaternary structure.
abstract: Mammalian ribonucleotide reductase (mRR) is a chemotherapeutic target. The enzyme is composed of 2 subunits (mR1 and mR2) and is inhibited by Ac-FTLDADF (denoted P7), corresponding to the C-terminus of mR2, which competes with mR2 for binding to mR1. mRR has 2 physiologically important active forms, mR12mR22 and mR16(mR22)j (j = 1-3). Here we report on the mechanism of action of recently identified peptide derivatives having higher activities than P7 toward inhibition of one or both active forms. A significant feature of both P7 and these new inhibitors is that they are more potent vs. mR12mR22 than mR16(mR22)j. For some of these peptides, this is due in part to their preferential binding to the mR1 monomer. The possible application of these peptide derivatives in cancer chemotherapy is discussed.
authors.affiliation: Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104-6323, USA.
authors.forename: Ying
authors.initials: Y
authors.lastname: Gao
authors.forename: Ossama B
authors.initials: OB
authors.lastname: Kashlan
authors.forename: Jaskiran
authors.initials: J
authors.lastname: Kaur
authors.forename: Chiheng
authors.initials: C
authors.lastname: Tan
authors.forename: Barry S
authors.initials: BS
authors.lastname: Cooperman
mesh_terms: D000818:Animals; D019281:Dimerization; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D007700:Kinetics; D008322:Mammals; D008962:Models, Theoretical; D009690:Nucleic Acid Conformation; D009842:Oligopeptides / Q000737:chemistry / Q000494:pharmacology; D010455:Peptides / Q000737:chemistry* / Q000494:pharmacology*; D012264:Ribonucleotide Reductases / Q000037:antagonists & inhibitors* / Q000737:chemistry; D012542:Scattering, Radiation
chemical_list: D004791:Enzyme Inhibitors; D009842:Oligopeptides; D010455:Peptides; D012264:Ribonucleotide Reductases