Biomaterial Database

DNA strand scission by the novel antitumor antibiotic leinamycin. 1990

M Hara, and Y Saitoh, and H Nakano

Tokyo Research Laboratories, Kyowa Hakko Kogyo Ltd., Japan.

Leinamycin is a recently discovered antitumor antibiotic with an unusual 1,3-dioxo-1,2-dithiolane structure. It preferentially inhibits the incorporation of [3H]thymidine into the acid-insoluble fraction of Bacillus subtilis. In vitro, leinamycin causes single-strand cleavage of supercoiled double-helical pBR322 DNA in the presence of thiol cofactors. Scavengers of oxygen radical did not supress the DNA-cleaving activity. Thiol-activated leinamycin binds calf thymus DNA at 4 degrees C and thermal treatment of the leinamycin-DNA adduct released a chemically modified leinamycin from the complex. The lack of cytotoxicity and DNA-cleaving activity for S-deoxyleinamycin indicates that the 1,3-dioxo-1,2-dithiolane moiety is essential for the activity of leinamycin. Thus, the primary cellular target of leinamycin appears to be DNA. It binds DNA and causes single-strand break at low concentrations, which may account for the potent antitumor activity.

UI	MeSH Term	Description	Entries
D007769	Lactams	Cyclic AMIDES formed from aminocarboxylic acids by the elimination of water. Lactims are the enol forms of lactams.	Lactam,Lactim,Lactims
D004229	Dithiothreitol	A reagent commonly used in biochemical studies as a protective agent to prevent the oxidation of SH (thiol) groups and for reducing disulphides to dithiols.	Cleland Reagent,Cleland's Reagent,Sputolysin,Clelands Reagent,Reagent, Cleland,Reagent, Cleland's
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
D004269	DNA, Bacterial	Deoxyribonucleic acid that makes up the genetic material of bacteria.	Bacterial DNA
D004277	DNA, Single-Stranded	A single chain of deoxyribonucleotides that occurs in some bacteria and viruses. It usually exists as a covalently closed circle.	Single-Stranded DNA,DNA, Single Stranded,Single Stranded DNA
D000903	Antibiotics, Antineoplastic	Chemical substances, produced by microorganisms, inhibiting or preventing the proliferation of neoplasms.	Antineoplastic Antibiotics,Cytotoxic Antibiotics,Antibiotics, Cytotoxic
D001407	Bacillus	A genus of BACILLACEAE that are spore-forming, rod-shaped cells. Most species are saprophytic soil forms with only a few species being pathogenic.	Bacillus bacterium
D013302	Streptomyces	A genus of bacteria that form a nonfragmented aerial mycelium. Many species have been identified with some being pathogenic. This genus is responsible for producing a majority of the ANTI-BACTERIAL AGENTS of practical value.
D013844	Thiazoles	Heterocyclic compounds where the ring system is composed of three CARBON atoms, a SULFUR and NITROGEN atoms.	Thiazole
D013871	Thiones	Sulfur-containing compounds also known as thioketones of general formula R2C	Thioketone,Thione,Thioketones