Isolation and characterisation of five histone H1 subtypes from adult rat liver.
A procedure is described for quantitative purification of H10 and five H1-1 subtypes--named H1-1a to e--from adult rat liver by reverse-phase high-pressure liquid chromatography. Milligram amounts of each fraction have been obtained. The H1-1a subtype shows a very high lysine content (34%) and H1-1d subtype has an amino-acid composition close to that of H10, but its electrophoretic mobility is different. Salt dependent folding of these subtypes has been studied by circular dichroism. In the presence of 2 or 10 mM sodium phosphate buffers at pH 7.5, H1-1a shows the lowest alpha-helix content. In phosphate-buffer containing 1 M NaCl the number of residues in alpha-helix for all the subtypes rises to 9-10%. Partial cleavage of these subtypes by endoproteinase Glu-C produce three main peptides arising from C-terminal domains. The interaction of the H1-1 subtypes with 196 basepairs linear DNA, purified from rat liver chromatin by high-pressure ion-exchange liquid chromatography, has for consequences a modification of the patterns of digestion: partial proteolysis of the H1-1a and H1-1b subtypes shows differences in the presence or in absence of DNA; on the contrary, H1-1c and H1-1d seem to have the same organization. So these subtypes may play a role in the differential packing of specific region of chromatin.
Tchouatcha-Tchouassom
J C
JC
Laboratoire de Physico-Chimie Biologique - LBTM CNRS Université Claude Bernard Lyon I, Villeurbann, France.
Julliard
J H
JH
Roux
B
B
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D002942:Circular Dichroism; D004247:DNA / Q000302:isolation & purification / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D006657:Histones / Q000302:isolation & purification* / Q000378:metabolism; D008099:Liver / Q000032:analysis*; D008970:Molecular Weight; D009707:Nucleosomes / Q000032:analysis; D010446:Peptide Fragments / Q000302:isolation & purification; D011487:Protein Conformation; D051381:Rats; D012697:Serine Endopeptidases / Q000378:metabolism
D000596:Amino Acids; D006657:Histones; D009707:Nucleosomes; D010446:Peptide Fragments; D004247:DNA; D012697:Serine Endopeptidases; C028344:glutamyl endopeptidase