Linked Life Data

3130095

Source:http://linkedlifedata.com/resource/pubmed/id/3130095

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1988-6-14
pubmed:abstractText
Flow linear dichroism (LD) of different benzo[a]pyrene diol epoxide (BPDE) isomers covalently bound to calf thymus DNA or poly(dG-dC) provides information about binding geometry and DNA perturbation. With anti-BPDE the apparent angle between the long axis (z) of the pyrene chromophore and the DNA helix axis is approximately 30 degrees as evidenced from the LD of z-polarized absorption bands in the pyrenyl chromophore at 252 and 346 nm. The corresponding angle for the in-plane short axis (y) is determined to be approximately 70 degrees from a y-polarized band at 275 nm. The binding of (+)-anti-BPDE to DNA is found to cause a considerable reduction of the DNA orientation. This is ascribed to a decreased persistence length of DNA, owing either to increased flexibility ("flexible joints") or to permanent kinks at the points of binding. The reduced linear dichroism (LDr), i.e., the ratio between LD and isotropic absorbance, of the long-wavelength absorption band system of BPDE bound to DNA exhibits a wavelength dependence that indicates a relatively wide orientational distribution of the z axis of pyrene. Fluorescence data support the conclusion of a heterogeneous distribution, and a very low polarization anisotropy indicates a mobility between the different orientational states, which is rapid compared to the fluorescence lifetime (nanosecond time scale). Attempts are made to simulate the observed LDr features of the (+)-anti-BPDE-poly(dG-dC) complex using different distribution models on the assumption that the angular dependence of the spectral perturbation is due to dispersive interactions with DNA bases.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
23
pubmed:volume
27
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1213-21
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
Binding geometries of benzo[a]pyrene diol epoxide isomers covalently bound to DNA. Orientational distribution.
pubmed:affiliation
Department of Physical Chemistry, Chalmers University of Technology, Göteborg, Sweden.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't