Thermodynamic hypothesis

In 1999, the Klemperer group published experimental results from a dispersed fluorescence study of the linear and T-shaped Ar l2(X, v = 0) conformers to obtain information about the X- and B-state potentials of the complex and to gain insight into the photodissociation dynamics in the B electronic state [65]. In carrying out their analysis, they assumed that the linear and T-shaped conformers existed in a thermodynamic equilibrium, with the abundance of the linear conformer being three times that of the T-shaped conformer. In an effort to test the validity of the thermodynamic hypothesis Bastida, et al. [66], performed a... 

Anfinsen s thermodynamic hypothesis, which states that the native state for a protein in its physiological milieu is the one of lowest Gibbs free energy (Anfinsen, 1973). 

This criterion is good for establishish whether a process is under thermodynamic control. Care should be taken however to understand the term reversibility in this case. The folding of a protein is generally per se a chemically irreversible process, in the sense that the chemical equilibrium is overwhelmingly shifted towards the folded form - there is not a low activation energy barrier between the native folded and the unfolded form and a corresponding chemical equilibrium in the native state between the two forms. Thus, in the case of the thermodynamic hypothesis of... 

In a strict self-assembly process, the final product is produced entirely spontaneously when the components are mixed together in the correct ratios under a given set of conditions of temperature, pH, concentration etc. The product formation must be completely reversible and represent the thermodynamic minimum for the system. In essence, all the information necessary for the assembly to occur is coded into the constituent parts. The concept of strict self-assembly is rooted in the Thermodynamic Hypothesis of Afinison who suggested that under physiological conditions the native structure of a protein is... 

Anfinsen [7] proposed the thermodynamic hypothesis , asserting that proteins fold to a conformation in which the free energy of the molecule is minimized. This hypothesis is commonly accepted and provides the basis for most of the methods for protein structure prediction. 

The PPR has also implications in conjunction with the thermodynamic hypothesis [86,87], the Levinthal paradox [88], the use of redundant conformations in conformational searches, and the possibility of an enhanced search procedure (projected angle method). These points lie outside the scope of the present work and will be discussed in detail in future work [89]. 

Assuming that the activities of C03 and C02 are independent of the anion composition of the ionic melt, there may be formulated a non-thermodynamic hypothesis that the changes of the equilibrium constant of equation (1.3.29) in various melts are caused only by the difference in their oxoacidic properties. 

The thermodynamic hypothesis [1,7] that native proteins are in a global minimum of free energy is now generally accepted. Since the native state... 

As will be discussed later, in many ways, strict self-assembly is a restatement of Afinison s Thermodynamic Hypothesis and encompasses all processes in which components assemble reversibly. The archetype of strict self-assembly is tobacco mosaic virus (TMV). The TMV particles consist of a single helical strand of RNA embedded in a right-handed helix composed of identical coat protein subunits. The TMV particles will dissociate into their component parts by changes in pH, temperature, or even pressure. However, once the correct conditions are again attained, protein subunits and RNA spontaneously reassemble into virus particles that are indistinguishable from the original TMV. 

Many experiment of Harcourt and Esson was also considered by Van t Hoff and they correlated their law with his thermodynamic hypothesis. They found confirmation also of Van t Hoff parametric formula for nc... 

The native state of a single-domain protein is its tertiary structure, and it is estimated that approximately 1000 different shapes or folds exist in nature. The native state generally adopts a globular three-dimensional shape, stabilized by both covalent (peptide bonds, disulfide bridges) and noncovalent (electrostatic, hydrophobic and hydrogen bonds) interactions. Local structures within the native fold are known as secondary structures, with common motifs including alpha heHces and beta sheets. The classic experiments of Anfinsen et al. su ested a Thermodynamic Hypothesis for folding, in which the... 

A guiding principle in the study of protein folding is the thermodynamic hypothesis (6), established by Christian A. Anfinsen in the 1950s and early 1960s. The thermodynamic hypothesis suggests that a particular three-dimensional structure of a protein occurs because this molecular arrangement is the most stable... 

In vivo protein misfolding in the absence of mutations Single-funnel hypothesis exception to thermodynamics hypothesis Multi-funnel hypothesis non-native funnel selected. 

Direct evidence for kinetic control Single-funnel hypothesis exeeption to thermodynamics hypothesis Multi-funnel hypothesis Folding is kinet-ically controlled. 

Irreversible unfolding in the absence of aggregation, loss of co-factors or chemical modifications Single-funnel hypothesis exception to thermodynamics hypothesis Multi-funnel hypothesis The denatured state wandered too far away from the native funnel and protein fell into a different funnel when native conditions were restored. 

A somewhat simpler, but by no means trivial, task is to find the lowest energy state of the model polypeptide. Due to the thermodynamic hypothesis [158], which postulates that native proteins are in the global minimum of the conformational energy, the minimum energy state of a properly designed protein... 

Structure prediction of polypeptides and proteins from their amino acid sequences is regarded as a holy grail in the computational chemistry and molecular and structural biology communities. According to the thermodynamic hypothesis the native stracture of a protein in a given environment corresponds to the... 

Some 30 years ago Christian Anfinsens groundbreaking work on the refolding of bovine pancreatic ribonuclease conclusively demonstrated that the information necessary to specify the three-dimensional structure of a folded protein in general is completely specified in the protein s amino acid sequence. Experimentally, the thermodynamic hypothesis of protein folding is now well supported. It states that the native... 

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