Search results
Results from the WOW.Com Content Network
In biochemistry, denaturation is a process in which proteins or nucleic acids lose folded structure present in their native state due to various factors, including application of some external stress or compound, such as a strong acid or base, a concentrated inorganic salt, an organic solvent (e.g., alcohol or chloroform), agitation and radiation, or heat. [3]
where , and indicate the enthalpy, entropy and Gibbs free energy of unfolding under a constant pH and pressure. The temperature, T {\displaystyle \ T} is varied to probe the thermal stability of the system and T d {\displaystyle \ T_{d}} is the temperature at which half of the molecules in the system are unfolded.
Except for the C/G initiation term, the first term represents the free energy of the first base pair, CG, in the absence of a nearest neighbor. The second term includes both the free energy of formation of the second base pair, GC, and stacking interaction between this base pair and the previous base pair. The remaining terms are similarly defined.
Denaturation midpoint of a protein is defined as the temperature (T m) or concentration of denaturant (C m) at which both the folded and unfolded states are equally populated at equilibrium (assuming two-state protein folding). T m is often determined using a thermal shift assay.
where ln denotes the natural logarithm, is the thermodynamic equilibrium constant, and R is the ideal gas constant.This equation is exact at any one temperature and all pressures, derived from the requirement that the Gibbs free energy of reaction be stationary in a state of chemical equilibrium.
The diagram sketches how proteins fold into their native structures by minimizing their free energy. The folding funnel hypothesis is a specific version of the energy landscape theory of protein folding, which assumes that a protein's native state corresponds to its free energy minimum under the solution conditions usually encountered in cells.
In thermodynamics, the thermodynamic free energy is one of the state functions of a thermodynamic system (the others being internal energy, enthalpy, entropy, etc.).The change in the free energy is the maximum amount of work that the system can perform in a process at constant temperature, and its sign indicates whether the process is thermodynamically favorable or forbidden.
Folded, 3-D structure of ribonuclease A. Anfinsen's dogma, also known as the thermodynamic hypothesis, is a postulate in molecular biology.It states that, at least for a small globular protein in its standard physiological environment, the native structure is determined only by the protein's amino acid sequence. [1]