[Optical and hydrodynamic properties of DNA complexes with histones H1 from the calf thymus and sea urchin sperm].
A comparative study of the complexes between DNA and H1 histones from calf thymus (H1-T) and sea urchin sperm (H1-S) has been performed using methods of flow birefringence, viscometry and circular dichroism (CD). Both nucleohistone complexes undergo a conformational transition with the increase of protein content. A two-fold drop of intrinsic viscosity was observed when the histone content in the complex increased up to 9-12%. The transition is not accompanied by essential changes in the nucleohistone anisotropy, the latter coincides with the anisotropy of DNA in H1-T containing complexes and is close to that in H1-S containing complexes. CD spectra of the two types of complexes are not the same. For the H1-S containing complexes the decrease of the amplitude of the CD positive band and the shift of its maximum to the longwave region are observed while the spectrum of H1-T containing complex coincides with that of DNA. The spectral changes are partly due to slight aggregation of the H1-S containing complexes. It is also possible that changes in the local structure of DNA within the H1-S containing nucleohistone complexes take place.
D000818:Animals; D002417:Cattle; D002942:Circular Dichroism; D004247:DNA / Q000032:analysis*; D006657:Histones / Q000032:analysis*; D046911:Macromolecular Substances; D008297:Male; D008970:Molecular Weight; D009994:Osmolar Concentration; D012617:Sea Urchins; D013053:Spectrophotometry; D013094:Spermatozoa / Q000032:analysis*; D013950:Thymus Gland / Q000032:analysis*; D014783:Viscosity
D006657:Histones; D046911:Macromolecular Substances; D004247:DNA
Issledovanie opticheskikh i gidrodinamicheskikh svo'istv kompleksov DNK s gistonami H1 is timusa telenka i spermiev morskogo ezha.