Acoustical investigation of poly(dA).poly(dT), poly[d(A-T)], poly(A).poly(U) and DNA hydration in dilute aqueous solutions.
Apparent molar adiabatic compressibilities and apparent molar volumes of poly[d(A-T)].poly[d(A-T)], poly(dA).poly(dT), DNA and poly(A).poly(U) in aqueous solutions were determined at 1 degree C. The change of concentration increment of the ultrasonic velocity upon replacing counter ion Cs+ by the Mg2+ ion was also determined for these polymers. The following conclusions have been made: (1) the hydration of the double helix of poly(dA).poly(dT) is remarkably larger than that of other polynucleotides; (2) the hydration of the AT pair in the B-form DNA is larger than that of the GC pair; (3) the substitution of Cs+ for Mg2+ ions as counter ions results in a decrease of hydration of the system polynucleotide plus Mg2+, and (4) the magnitude of this dehydration depends on the nucleotide sequence; the following rule is true: the lesser is a polynucleotide hydration, the larger dehydration upon changing Cs+ for Mg2+ ions in the ionic atmosphere of polynucleotide.
Buckin
V A
VA
Institute of Biological Physics, USSR Academy of Sciences, Moscow.
Kankiya
B I
BI
Sarvazyan
A P
AP
Uedaira
H
H
D001482:Base Composition; D002586:Cesium; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D008274:Magnesium; D009690:Nucleic Acid Conformation; D009994:Osmolar Concentration; D011063:Poly A-U; D011067:Poly dA-dT; D011089:Polydeoxyribonucleotides; D012996:Solutions; D014465:Ultrasonics; D014867:Water
D011089:Polydeoxyribonucleotides; D012996:Solutions; D014867:Water; D002586:Cesium; D011063:Poly A-U; D011067:Poly dA-dT; D008274:Magnesium