Lumry-Eyring model

Evidence for the three-state Lumry-Eyring model... 

In some situations, the three-state Lumry-Eyring model, which includes unfolding and (first-order) denaturation, is insufficient to describe experimental results. A four-state model describes the situation better. Causes necessitating a four-state model can be aggregation of the biocatalyst or folding intermediates between the native and the fully unfolded state. 

If aggregation is important, the Lumry-Eyring model has to be extended by introducing a folding intermediate I, which can lead reversibly either to the native protein N, or the fully unfolded protein U, or irreversibly to a protein aggregate An, assumed catalytically inactive. The kinetic representation is thus expressed by Eq. (17.28). 

Commonly, the thermal denaturation of proteins is often discussed in terms of the Lumry-Eyring model, which involves two steps reversible unfolding and irreversible alteration of the unfolded state to produce the final denatured state, which is unable to fold back to the native protein. 

In general, the heating rate dependence of protein thermal structural perturbations can be understood in terms of the Lumry-Eyring model [38], as shown below. According to this framework, a reversible unfolding step is followed by an irreversible event ... 

This scheme represents the limiting case of the Lumry-Eyring model consisting of only two populated states, the native (N) and the final aggregated state (A). This scheme predicts that k is a first-order kinetic constant that varies with temperature, as given by the Arrhenius equation. Based on this simple kinetic model, T should vary with heating rate (v) according to the equation ... 

Roberts CJ. Kinetics of irreversible protein aggregation analysis of extended Lumry-Eyring models and implications for predicting protein shelf life. J Phys Chem B 2003 107 1194-1207. 

Their simple model assumes that each denatured protein molecule transforms irreversibly in a first order reaction into a species from which the native form cannot be recovered. This model is called Lumry-Eyring model [55] since Lumry and Eyring were among the first to propose that proteins unfold in two steps, a reversible unfolding equilibrium of the tertiary structure followed by a first order, irreversible step involving secondary structure unfolding. 

Three-State Model Lumry-Eyring Equation 1493... 

Li, Y., Roberts, C.J. (2009) Lumry-Eyring nucleated-polymeiization model of protein aggregation kinetics. 2. Competing growth via condensation and chain polymerization. J Phys Chem S, 113 (19), 7020-7032. 

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