title: Effect of 5-bromodeoxyuridine on deoxyribonucleic acid-protein adducts induced by ultraviolet light on chromatin cells.
abstract: The formation of DNA-protein adducts induced by ultraviolet irradiation (254-nm. wavelength) has been analyzed by cesium chloride equilibrium sedimentation. The formation of ultraviolet-induced DNA-protein adducts is increased in 5-bromodeoxyuridine-substituted chromatin. Cross-linking is dependent in part upon the extent of 5-bromodeoxyuridine substitution, and is detectable either in chromatin irradiated in vitro or in chromatin from cells irradiated in vivo prior to the isolation of chromatin. As much as 80% of the DNA can be cross-linked to proteins by ultraviolet irradiation of 5-bromodeoxyuridine-substituted chromatin at a fluence of 2,928 Jm-2. In unsubstituted chromatin 11,712 Jm-2 are required to obtain to obtain the same effect. Under the same conditions of 5-bromodeoxyuridine replacement and ultraviolet irradiation only 10% of the total chromosomal proteins can be cross-linked to DNA, whether in vivo or in vitro. Approximately two-thirds of the cross-linked proteins chromatograph as nonhistone proteins, the remaining one-third as histones.
mesh_terms: D001973:Bromodeoxyuridine / Q000494:pharmacology*; D002460:Cell Line; D002499:Centrifugation, Density Gradient; D002843:Chromatin / Q000302:isolation & purification / Q000528:radiation effects; D002868:Chromosomal Proteins, Non-Histone / Q000528:radiation effects*; D004247:DNA / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D005467:Floxuridine / Q000494:pharmacology; D006657:Histones / Q000528:radiation effects*; D008722:Methods; D014466:Ultraviolet Rays; D014529:Uridine / Q000494:pharmacology
chemical_list: D002843:Chromatin; D002868:Chromosomal Proteins, Non-Histone; D006657:Histones; D005467:Floxuridine; D004247:DNA; D001973:Bromodeoxyuridine; D014529:Uridine