Biomaterial Database

Role of thiols in radioprotection: radiation chemical aspects. 1989

M Tamba

Istituto F.R.A.E. del C.N.R., Bologna, Italy.

Using the technique of pulse radiolysis, it has been demonstrated that thiyl radicals (RS.) derived from glutathione (GSH), cysteine (CYSH), penicillamine (PnSH) and 2-mercaptoethanol (ME) interact with oxygen at a high rate. The resulting transient absorption, with a maximum around 540-560 nm, is characteristic of the sulphur peroxyl radical (RSOO.). The yield and the kinetic of formation of RSOO. further support our previous suggestion that thiyl/O2 reaction is an equilibrium. The redox properties of RSOO. are discussed on the basis of the interaction with reductants. Studies on the radio-induced enzyme inactivation in the presence of thiols seem to suggest a damaging role for RSOO. radicals.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D009113	Muramidase	A basic enzyme that is present in saliva, tears, egg white, and many animal fluids. It functions as an antibacterial agent. The enzyme catalyzes the hydrolysis of 1,4-beta-linkages between N-acetylmuramic acid and N-acetyl-D-glucosamine residues in peptidoglycan and between N-acetyl-D-glucosamine residues in chitodextrin. EC 3.2.1.17.	Lysozyme,Leftose,N-Acetylmuramide Glycanhydrolase,Glycanhydrolase, N-Acetylmuramide,N Acetylmuramide Glycanhydrolase
D010396	Penicillamine	3-Mercapto-D-valine. The most characteristic degradation product of the penicillin antibiotics. It is used as an antirheumatic and as a chelating agent in Wilson's disease.	Dimethylcysteine,Mercaptovaline,beta,beta-Dimethylcysteine,Copper Penicillaminate,Cuprenil,Cuprimine,D-3-Mercaptovaline,D-Penicillamine,Metalcaptase,D 3 Mercaptovaline,D Penicillamine,Penicillaminate, Copper,beta,beta Dimethylcysteine
D011837	Radiation-Protective Agents	Drugs used to protect against ionizing radiation. They are usually of interest for use in radiation therapy but have been considered for other purposes, e.g. military.	Radiation Protectant,Radiation Protective Agent,Radiation-Protective Agent,Radiation-Protective Drug,Radioprotective Agent,Radioprotective Agents,Radioprotective Drug,Agents, Radiation-Protective,Radiation Protectants,Radiation Protective Agents,Radiation-Protective Drugs,Radiation-Protective Effect,Radiation-Protective Effects,Radioprotective Drugs,Agent, Radiation Protective,Agent, Radiation-Protective,Agent, Radioprotective,Agents, Radiation Protective,Agents, Radioprotective,Drug, Radiation-Protective,Drug, Radioprotective,Drugs, Radiation-Protective,Drugs, Radioprotective,Effect, Radiation-Protective,Effects, Radiation-Protective,Protectant, Radiation,Protectants, Radiation,Protective Agent, Radiation,Protective Agents, Radiation,Radiation Protective Drug,Radiation Protective Drugs,Radiation Protective Effect,Radiation Protective Effects
D003545	Cysteine	A thiol-containing non-essential amino acid that is oxidized to form CYSTINE.	Cysteine Hydrochloride,Half-Cystine,L-Cysteine,Zinc Cysteinate,Half Cystine,L Cysteine
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
D004307	Dose-Response Relationship, Radiation	The relationship between the dose of administered radiation and the response of the organism or tissue to the radiation.	Dose Response Relationship, Radiation,Dose-Response Relationships, Radiation,Radiation Dose-Response Relationship,Radiation Dose-Response Relationships,Relationship, Radiation Dose-Response,Relationships, Radiation Dose-Response
D005609	Free Radicals	Highly reactive molecules with an unsatisfied electron valence pair. Free radicals are produced in both normal and pathological processes. Free radicals include reactive oxygen and nitrogen species (RONS). They are proven or suspected agents of tissue damage in a wide variety of circumstances including radiation, damage from environment chemicals, and aging. Natural and pharmacological prevention of free radical damage is being actively investigated.	Free Radical
D005978	Glutathione	A tripeptide with many roles in cells. It conjugates to drugs to make them more soluble for excretion, is a cofactor for some enzymes, is involved in protein disulfide bond rearrangement and reduces peroxides.	Reduced Glutathione,gamma-L-Glu-L-Cys-Gly,gamma-L-Glutamyl-L-Cysteinylglycine,Glutathione, Reduced,gamma L Glu L Cys Gly,gamma L Glutamyl L Cysteinylglycine
D013438	Sulfhydryl Compounds	Compounds containing the -SH radical.	Mercaptan,Mercapto Compounds,Sulfhydryl Compound,Thiol,Thiols,Mercaptans,Compound, Sulfhydryl,Compounds, Mercapto,Compounds, Sulfhydryl