Abstract:
:Evidence for the reversible binding of paraquat to calf thymus DNA has been obtained using equilibrium dialysis and thermal melting point determinations. The data indicated the presence of at least two populations of binding site with affinity constants of 6.2 X 10(4) and 7.1 X 10(3) M-1, respectively. The binding capacities of DNA for paraquat were 66 and 480 nmol/mumol DNA nucleotide, respectively, and were equivalent to one ligand bound per 2 DNA phosphate groups. Putrescine inhibited paraquat binding to the low affinity sites without altering binding to the high affinity sites. Scatchard plots of paraquat binding characteristics indicated the presence of positive cooperativity between the compound and DNA. Thermal melting curves of DNA in the presence of paraquat and the endogenous amines putrescine, spermidine and spermine, provided evidence that paraquat cross-linked to DNA with a similar affinity as spermidine. The thermal melting point data also suggested the presence of positive cooperativity between ligand and macromolecule that possibly resulted from a conformation change in the structure of the DNA molecule. Paraquat competitively inhibited the binding of ethidium bromide to DNA and this effect was reversed by Na+. From the data, it is suggested that paraquat binds primarily to the negatively charged phosphates on the DNA backbone but is displaced into the interbase region occupied by the intercalator ethidium bromide. DNA binding of paraquat may, in part, account for its weak mutagenic activity.
journal_name
Chem Biol Interactjournal_title
Chemico-biological interactionsauthors
Minchin RFdoi
10.1016/0009-2797(87)90035-4subject
Has Abstractpub_date
1987-02-01 00:00:00pages
139-49issue
2eissn
0009-2797issn
1872-7786pii
0009-2797(87)90035-4journal_volume
61pub_type
杂志文章abstract::Human leukocyte endothelial adhesion and transmigration occur in the early stage of the pathogenesis of atherosclerosis. Vascular endothelial cells are targeted by pro-inflammatory cytokines modulating many gene proteins responsible for cell adhesion, thrombosis and inflammatory responses. This study examined the pote...
journal_title:Chemico-biological interactions
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journal_title:Chemico-biological interactions
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journal_title:Chemico-biological interactions
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journal_title:Chemico-biological interactions
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journal_title:Chemico-biological interactions
pub_type: 杂志文章
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journal_title:Chemico-biological interactions
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journal_title:Chemico-biological interactions
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journal_title:Chemico-biological interactions
pub_type: 杂志文章
doi:10.1016/0009-2797(91)90104-f
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journal_title:Chemico-biological interactions
pub_type: 杂志文章,评审
doi:10.1016/s0009-2797(99)00065-4
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abstract::Resveratrol (3,4',5-trans-trihydroxystilbene) and other hydroxystilbenes exhibit in vitro antioxidant as well as prooxidant effects. The antioxidant properties are assumed to enable these compounds to protect cells from oxidative damage. The prooxidant effects are held likely to be responsible for their cytotoxic, ant...
journal_title:Chemico-biological interactions
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journal_title:Chemico-biological interactions
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journal_title:Chemico-biological interactions
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journal_title:Chemico-biological interactions
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更新日期:2019-04-25 00:00:00
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journal_title:Chemico-biological interactions
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journal_title:Chemico-biological interactions
pub_type: 杂志文章
doi:10.1016/0009-2797(78)90041-8
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journal_title:Chemico-biological interactions
pub_type: 杂志文章
doi:10.1016/0009-2797(79)90089-9
更新日期:1979-06-01 00:00:00
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journal_title:Chemico-biological interactions
pub_type: 杂志文章
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journal_title:Chemico-biological interactions
pub_type: 杂志文章
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journal_title:Chemico-biological interactions
pub_type: 杂志文章
doi:10.1016/j.cbi.2018.05.013
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journal_title:Chemico-biological interactions
pub_type: 杂志文章
doi:10.1016/0009-2797(78)90108-4
更新日期:1978-03-01 00:00:00
abstract::The metabolism of radiolabelled benz(j)aceanthrylene (B(j)A) was studied by high performance liquid chromatography (HPLC) using suspensions of hepatocytes and liver microsomes from control- or Aroclor 1254 (PCB)-treated rats, or with human liver microsomes (five different donors) as activation systems. The major metab...
journal_title:Chemico-biological interactions
pub_type: 杂志文章
doi:10.1016/s0009-2797(98)00037-4
更新日期:1998-06-05 00:00:00
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journal_title:Chemico-biological interactions
pub_type: 杂志文章
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