Differential Hydration of dA•dT Base Pairing and dA and dT Bulges in Deoxyoligonucleotides

Krzyztof Zieba, Luis A. Marky, Tram M. Chu, Donald W. Kupke

Research output: Contribution to journalArticle

62 Citations (Scopus)

Abstract

The role of water in the formation of stable duplexes of nucleic acids is being studied by determining the concurrent volume change, heats, and counterion uptake that accompany the duplexation process. The variability of the volume contraction that we have observed in the formation of a variety of homoduplexes suggests that sequence and conformation acutely affect the degree of hydration. We have used a combination of densimetric and calorimetric techniques to measure the change in volume and enthalpy resulting from the mixing of two complementary strands to form (a) fully paired duplexes with 10 or 11 base pairs and (b) bulged decameric duplexes with an extra dA or dT unmatched residue. We also monitored absorbance vs temperature profiles as a function of strand and salt concentration for all four duplexes. Relative to the decamer duplex, insertion of an extra dA•dT base pair to form an undecamer duplex results in a favorable enthalpy of −5.6 kcal/mol that is nearly compensated by an unfavorable entropy term of −5.1 kcal/mol. This enthalpy difference correlates with a differential uptake of water molecules, corresponding to an additional hydration of 16 mol of water molecules/mol of base pair. Relative to the fully paired duplexes, both bulged duplexes are 12-16 °C less stable and exhibit marginally larger counterion uptake on forming the duplex. The enthalpy change is slightly lower for the T-bulge duplex and less still for the A-bulge duplex. The volume change results indicate that an unmatched residue increases the amount of coulombic and/or structural hydration. The combined results strongly suggest that the destabilizing forces in bulged duplexes are partially compensated by an increase in hydration levels.

Original languageEnglish (US)
Pages (from-to)8018-8026
Number of pages9
JournalBiochemistry
Volume30
Issue number32
DOIs
StatePublished - Aug 1 1991

Fingerprint

Base Pairing
Hydration
Enthalpy
Water
Entropy
Nucleic Acids
Molecules
Salts
Hot Temperature
Conformations
Temperature

ASJC Scopus subject areas

  • Biochemistry

Cite this

Differential Hydration of dA•dT Base Pairing and dA and dT Bulges in Deoxyoligonucleotides. / Zieba, Krzyztof; Marky, Luis A.; Chu, Tram M.; Kupke, Donald W.

In: Biochemistry, Vol. 30, No. 32, 01.08.1991, p. 8018-8026.

Research output: Contribution to journalArticle

Zieba, Krzyztof ; Marky, Luis A. ; Chu, Tram M. ; Kupke, Donald W. / Differential Hydration of dA•dT Base Pairing and dA and dT Bulges in Deoxyoligonucleotides. In: Biochemistry. 1991 ; Vol. 30, No. 32. pp. 8018-8026.
@article{1ec9f40e569f425da76bd77cbb61cf1b,
title = "Differential Hydration of dA•dT Base Pairing and dA and dT Bulges in Deoxyoligonucleotides",
abstract = "The role of water in the formation of stable duplexes of nucleic acids is being studied by determining the concurrent volume change, heats, and counterion uptake that accompany the duplexation process. The variability of the volume contraction that we have observed in the formation of a variety of homoduplexes suggests that sequence and conformation acutely affect the degree of hydration. We have used a combination of densimetric and calorimetric techniques to measure the change in volume and enthalpy resulting from the mixing of two complementary strands to form (a) fully paired duplexes with 10 or 11 base pairs and (b) bulged decameric duplexes with an extra dA or dT unmatched residue. We also monitored absorbance vs temperature profiles as a function of strand and salt concentration for all four duplexes. Relative to the decamer duplex, insertion of an extra dA•dT base pair to form an undecamer duplex results in a favorable enthalpy of −5.6 kcal/mol that is nearly compensated by an unfavorable entropy term of −5.1 kcal/mol. This enthalpy difference correlates with a differential uptake of water molecules, corresponding to an additional hydration of 16 mol of water molecules/mol of base pair. Relative to the fully paired duplexes, both bulged duplexes are 12-16 °C less stable and exhibit marginally larger counterion uptake on forming the duplex. The enthalpy change is slightly lower for the T-bulge duplex and less still for the A-bulge duplex. The volume change results indicate that an unmatched residue increases the amount of coulombic and/or structural hydration. The combined results strongly suggest that the destabilizing forces in bulged duplexes are partially compensated by an increase in hydration levels.",
author = "Krzyztof Zieba and Marky, {Luis A.} and Chu, {Tram M.} and Kupke, {Donald W.}",
year = "1991",
month = "8",
day = "1",
doi = "10.1021/bi00246a020",
language = "English (US)",
volume = "30",
pages = "8018--8026",
journal = "Biochemistry",
issn = "0006-2960",
publisher = "American Chemical Society",
number = "32",

}

TY - JOUR

T1 - Differential Hydration of dA•dT Base Pairing and dA and dT Bulges in Deoxyoligonucleotides

AU - Zieba, Krzyztof

AU - Marky, Luis A.

AU - Chu, Tram M.

AU - Kupke, Donald W.

PY - 1991/8/1

Y1 - 1991/8/1

N2 - The role of water in the formation of stable duplexes of nucleic acids is being studied by determining the concurrent volume change, heats, and counterion uptake that accompany the duplexation process. The variability of the volume contraction that we have observed in the formation of a variety of homoduplexes suggests that sequence and conformation acutely affect the degree of hydration. We have used a combination of densimetric and calorimetric techniques to measure the change in volume and enthalpy resulting from the mixing of two complementary strands to form (a) fully paired duplexes with 10 or 11 base pairs and (b) bulged decameric duplexes with an extra dA or dT unmatched residue. We also monitored absorbance vs temperature profiles as a function of strand and salt concentration for all four duplexes. Relative to the decamer duplex, insertion of an extra dA•dT base pair to form an undecamer duplex results in a favorable enthalpy of −5.6 kcal/mol that is nearly compensated by an unfavorable entropy term of −5.1 kcal/mol. This enthalpy difference correlates with a differential uptake of water molecules, corresponding to an additional hydration of 16 mol of water molecules/mol of base pair. Relative to the fully paired duplexes, both bulged duplexes are 12-16 °C less stable and exhibit marginally larger counterion uptake on forming the duplex. The enthalpy change is slightly lower for the T-bulge duplex and less still for the A-bulge duplex. The volume change results indicate that an unmatched residue increases the amount of coulombic and/or structural hydration. The combined results strongly suggest that the destabilizing forces in bulged duplexes are partially compensated by an increase in hydration levels.

AB - The role of water in the formation of stable duplexes of nucleic acids is being studied by determining the concurrent volume change, heats, and counterion uptake that accompany the duplexation process. The variability of the volume contraction that we have observed in the formation of a variety of homoduplexes suggests that sequence and conformation acutely affect the degree of hydration. We have used a combination of densimetric and calorimetric techniques to measure the change in volume and enthalpy resulting from the mixing of two complementary strands to form (a) fully paired duplexes with 10 or 11 base pairs and (b) bulged decameric duplexes with an extra dA or dT unmatched residue. We also monitored absorbance vs temperature profiles as a function of strand and salt concentration for all four duplexes. Relative to the decamer duplex, insertion of an extra dA•dT base pair to form an undecamer duplex results in a favorable enthalpy of −5.6 kcal/mol that is nearly compensated by an unfavorable entropy term of −5.1 kcal/mol. This enthalpy difference correlates with a differential uptake of water molecules, corresponding to an additional hydration of 16 mol of water molecules/mol of base pair. Relative to the fully paired duplexes, both bulged duplexes are 12-16 °C less stable and exhibit marginally larger counterion uptake on forming the duplex. The enthalpy change is slightly lower for the T-bulge duplex and less still for the A-bulge duplex. The volume change results indicate that an unmatched residue increases the amount of coulombic and/or structural hydration. The combined results strongly suggest that the destabilizing forces in bulged duplexes are partially compensated by an increase in hydration levels.

UR - http://www.scopus.com/inward/record.url?scp=0025896047&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0025896047&partnerID=8YFLogxK

U2 - 10.1021/bi00246a020

DO - 10.1021/bi00246a020

M3 - Article

C2 - 1868075

AN - SCOPUS:0025896047

VL - 30

SP - 8018

EP - 8026

JO - Biochemistry

JF - Biochemistry

SN - 0006-2960

IS - 32

ER -