Ionic strength induced structure in histone H4 and its fragments.
The salt-induced folding and self-association of histone H4 and its fragments (1-23), (25-67), (69-84), and (69-102) have been studied at the same molar concentration (1 mM) by nuclear magnetic resonance (NMR), circular dichroism (CD), and ir spectroscopy. Byeach of these techniques intact histone H4 exhibited a fast structural change, involving the formation of alphaR helix and aggregation, and also a slow change involving beta-structure formation. Fragment (25-67) was found to behave in a manner similar to the intact molecule for the fast change, showing both helix formation and aggregation but exhibited no time-dependent effects. All the other fragments were found to be essentially noninteracting. It is concluded that (25-67) contains the rgion critical for the folding and self-association of histone H4. On the basis of these results a model is proposed for the self-association of histone H4 in which helix is located between residues 49 and 73, while the beta structure lies between 74 and the C-terminus.
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001665:Binding Sites; D002417:Cattle; D002850:Chromatography, Gel; D002942:Circular Dichroism; D006657:Histones; D009682:Magnetic Resonance Spectroscopy; D008970:Molecular Weight; D009994:Osmolar Concentration; D010446:Peptide Fragments / Q000032:analysis; D011485:Protein Binding; D011487:Protein Conformation; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet; D013950:Thymus Gland
D000596:Amino Acids; D006657:Histones; D010446:Peptide Fragments