title: Mg2+-, Ca2+-dependent unwinding of DNA by poly-L-glutamic acid.
abstract: In order to examine a possibility that the high acidic amino acid region in the nonhistone protein HMG(1+2) is concerned with the Mg2+-, or Ca2+-dependent unwinding of DNA by the HMG(1+2) (1,2), poly-L-glutamic acid was employed as an acidic model peptide for thermal melting temperature analysis. The poly-L-glutamic acid bound to DNA either in the presence or absence of Mg2+. The poly-L-glutamic acid unwound DNA double-helix to a similar extent to HMG(1+2) in the presence of Mg2+ or Ca2+, but not in the absence of them. These results may suggest that the high acidic amino acid region in HMG(1+2) participates in Mg2+-, Ca2+-dependent unwinding of DNA double-helix.
mesh_terms: D000818:Animals; D002118:Calcium / Q000502:physiology; D002868:Chromosomal Proteins, Non-Histone / Q000502:physiology*; D004247:DNA; D006609:High Mobility Group Proteins; D006358:Hot Temperature; D008274:Magnesium / Q000502:physiology; D008954:Models, Biological; D009690:Nucleic Acid Conformation / Q000187:drug effects*; D009691:Nucleic Acid Denaturation; D010455:Peptides / Q000494:pharmacology*; D011099:Polyglutamic Acid / Q000494:pharmacology*; D013552:Swine
chemical_list: D002868:Chromosomal Proteins, Non-Histone; D006609:High Mobility Group Proteins; D010455:Peptides; D011099:Polyglutamic Acid; D004247:DNA; D008274:Magnesium; D002118:Calcium