[The effect of hydrogen ions on the B-A transition in DNA].
The effects of hydrogen ions binding to DNA on its secondary structure and B to A transition were studied by methods of X-ray diffraction and infrared spectroscopy. Helical parameters of DNA molecules with different degrees of protonation were determined. It was shown that H+-ions binding stabilize the B form of DNA in fibers in the wide range of water and inorganic salt content. Only 0.03 H+-ions bound to each nucleotide are sufficient to prevent B to A transition caused by a relative humidity decrease in DNA fibers, containing 4% of NaCl. The effective stabilization of the DNA B form by H+-ions binding is explained by modifications in DNA - solvent molecules interactions, especially in the major groove of double helices.
M M
MM
Montrel'
B I
BI
Sukhorukov
D000818:Animals; D004247:DNA; D005399:Fishes; D006859:Hydrogen; D007477:Ions; D009690:Nucleic Acid Conformation; D013055:Spectrophotometry, Infrared; D014961:X-Ray Diffraction
D007477:Ions; D006859:Hydrogen; D004247:DNA
Vliianie vodorodnykh ionov na B-A perekhod v DNA.