Journal
JOURNAL OF PHYSICAL CHEMISTRY B
Volume 124, Issue 27, Pages 5614-5625Publisher
AMER CHEMICAL SOC
DOI: 10.1021/acs.jpcb.0c04065
Keywords
-
Categories
Funding
- NIH [GM23509, GM34469, CA47995]
Ask authors/readers for more resources
Knowledge of differences in heat capacity changes (Delta C-p) between biopolymer states provides essential information about the temperature dependence of the thermodynamic properties of these states, while also revealing insights into the nature of the forces that drive the formation of functional and dysfunctional biopolymer order. In contrast to proteins, for nucleic acids there is a dearth of direct experimental determination of this information-rich parameter, a deficiency that compromises interpretations of the ever-increasing thermodynamic analyses of nucleic acid properties; particularly as they relate to differential nucleic acid (meta)stability states and their potential biological functions. Here we demonstrate that such heat capacity differences, in fact, exist not only between traditionally measured native to fully unfolded (assumed random coil) DNA states, but also between competing order-to-order transformations. We illustrate the experimental approach by measuring the heat capacity change between native/ordered, sequence homologous, isomeric DNA states that differ in conformation but not sequence. Importantly, these heat capacity differences occur within biologically relevant temperature ranges. In short, we describe a new and general method to measure the value of such heat capacity differences anywhere in experimentally accessible conformational and temperature space; in this case, between two metastable bulge loop states, implicated in DNA expansion diseases, and their competing, fully paired, thermodynamically more stable duplex states. This measurement reveals a Delta C-p of 61 +/- 7 cal moI(bp)(-1) K-1. Such heat capacity differences between competing DNA native ensemble states must be considered when evaluating equilibria between different DNA ordered conformations, including the assessment of the differential stabilizing forces and potential biological functions of competing DNA structured motifs.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available