Biomaterial Database

Inhibition of OH radical-induced strand break formation of poly(U) by Ru(bpy)32+ or Ru(phen)32+ attached to the polynucleotide. 1995

A B Tossi, and L Sun, and H Görner, and D Schulte-Frohlinde

Max-Planck-Institut für Strahlenchemie, Mülheim, Ruhr, Germany.

Reactions of OH radicals with poly(U) (polyuridylic acid) in the presence of Ru(bpy)32+ or Ru(phen)32+ in aqueous solutions were studied. OH radicals were produced by pulse radiolysis and their reactions with ruthenium complexes were measured spectrophotometrically under conditions were the complexes are attached to the polynucleotide. The OH radical adds to either the uracil moiety or the ruthenium complexes. The ratio of the radicals produced depends only on the ratio of their rate constants and the concentrations of poly(U) and ruthenium complexes. Similar results were obtained with uridine-5'-monosphosphate, where the ruthenium complexes are not attached to the nucleotide. Surprisingly, the yield of single-strand break formation from the OH adducts of uracil in poly(U) is much smaller than that expected on the basis of the yield measured in the absence of ruthenium complexes. Possible reasons for this behaviour are discussed.

UI	MeSH Term	Description	Entries
D009942	Organometallic Compounds	A class of compounds of the type R-M, where a C atom is joined directly to any other element except H, C, N, O, F, Cl, Br, I, or At. (Grant & Hackh's Chemical Dictionary, 5th ed)	Metallo-Organic Compound,Metallo-Organic Compounds,Metalloorganic Compound,Organometallic Compound,Metalloorganic Compounds,Compound, Metallo-Organic,Compound, Metalloorganic,Compound, Organometallic,Compounds, Metallo-Organic,Compounds, Metalloorganic,Compounds, Organometallic,Metallo Organic Compound,Metallo Organic Compounds
D010618	Phenanthrolines		Phenanthroline
D011072	Poly U	A group of uridine ribonucleotides in which the phosphate residues of each uridine ribonucleotide act as bridges in forming diester linkages between the ribose moieties.	Polyuridylic Acids,Uracil Polynucleotides,Poly(rU),Acids, Polyuridylic,Polynucleotides, Uracil
D004249	DNA Damage	Injuries to DNA that introduce deviations from its normal, intact structure and which may, if left unrepaired, result in a MUTATION or a block of DNA REPLICATION. These deviations may be caused by physical or chemical agents and occur by natural or unnatural, introduced circumstances. They include the introduction of illegitimate bases during replication or by deamination or other modification of bases; the loss of a base from the DNA backbone leaving an abasic site; single-strand breaks; double strand breaks; and intrastrand (PYRIMIDINE DIMERS) or interstrand crosslinking. Damage can often be repaired (DNA REPAIR). If the damage is extensive, it can induce APOPTOSIS.	DNA Injury,DNA Lesion,DNA Lesions,Genotoxic Stress,Stress, Genotoxic,Injury, DNA,DNA Injuries
D015082	2,2'-Dipyridyl	A reagent used for the determination of iron.	2,2-Bipyridine,Bipyridyl,alpha,alpha-Dipyridyl,2,2 Dipyridyl,2,2' Dipyridyl,2,2'-Bipyridine,2,2-Bipyridyl,2,2-Dipyridyl,2,2 Bipyridine,2,2 Bipyridyl,2,2' Bipyridine,Dipyridyl, 2,2,Dipyridyl, 2,2',alpha,alpha Dipyridyl
D016166	Free Radical Scavengers	Substances that eliminate free radicals. Among other effects, they protect PANCREATIC ISLETS against damage by CYTOKINES and prevent myocardial and pulmonary REPERFUSION INJURY.	Free Radical Scavenger,Radical Scavenger, Free,Scavenger, Free Radical,Scavengers, Free Radical
D017319	Photosensitizing Agents	Drugs that are pharmacologically inactive but when exposed to ultraviolet radiation or sunlight are converted to their active metabolite to produce a beneficial reaction affecting the diseased tissue. These compounds can be administered topically or systemically and have been used therapeutically to treat psoriasis and various types of neoplasms.	Photosensitizer,Photosensitizers,Photosensitizing Agent,Photosensitizing Effect,Photosensitizing Effects,Agent, Photosensitizing,Agents, Photosensitizing,Effect, Photosensitizing,Effects, Photosensitizing
D017665	Hydroxyl Radical	The univalent radical OH. Hydroxyl radical is a potent oxidizing agent.
D056831	Coordination Complexes	Neutral or negatively charged ligands bonded to metal cations or neutral atoms. The number of ligand atoms to which the metal center is directly bonded is the metal cation's coordination number, and this number is always greater than the regular valence or oxidation number of the metal. A coordination complex can be negative, neutral, or positively charged.	Metal Complexes,Complexes, Coordination,Complexes, Metal