Urea-induced structural changes in chromatin obtained by sedimentation.
Sedimentation coefficients have been determined for fractionated preparations of whole and stripped (depleted of very lysine-rich histones and non-histone proteins) chicken erythrocyte chromatin fragments in 0-10 M urea. Significant differences in urea effects are observed between these preparations; differences which can be interpreted structurally by use of Kirkwood's dynamical theory of the translational frictional coefficient. This type of analysis implies that urea-induced chain-swelling in stripped chromatin is due largely to the urea effect upon the constituent nu-bodies, whereas the much larger swelling observed in whole chromatin appears to involve also the effect of urea upon the region between adjacent nu-bodies.
D000818:Animals; D002499:Centrifugation, Density Gradient; D002645:Chickens; D002843:Chromatin / Q000187:drug effects* / Q000648:ultrastructure; D004912:Erythrocytes / Q000648:ultrastructure; D009690:Nucleic Acid Conformation / Q000187:drug effects; D011487:Protein Conformation / Q000187:drug effects; D014508:Urea / Q000494:pharmacology*
D002843:Chromatin; D014508:Urea