Interaction of benz[a]pyrene diol epoxide with chromatin studied by flow linear dichroism.
Chromatin isolated from Ehrlich ascites cells was incubated with the tumourigenic compound (+)-7 beta,8 alpha-dihydroxy-9 alpha,10 alpha-epoxy-7,8,9,10- tetrahydrobenz[a]pyrene [(+)-anti-BPDE] at low ionic strength and the modified chromatin was analysed using flow linear dichroism (LD). The results confirm that (+)-anti-BPDE preferentially binds to the DNA in the linker regions, and furthermore show that the long axis of the bound pyrenyl chromophore is oriented parallel or close to parallel to the average orientation of the chromatin fiber axis. The data indicate that the binding geometry of (+)-anti-BPDE in chromatin is similar to that in pure DNA and deoxyguanosine-containing double-helical oligonucleotides.
Eriksson
S
S
Department of Physical Chemistry, Chalmers University of Technology, Gothenburg, Sweden.
Jernström
B
B
Nielsen
P E
PE
Nordén
B
B
D001580:Benzopyrenes / Q000032:analysis*; D002843:Chromatin / Q000032:analysis*; D002942:Circular Dichroism; D005434:Flow Cytometry
D001580:Benzopyrenes; D002843:Chromatin