Phi Value Analysis - Variants of -value Analysis

Variants of -value Analysis

Other kinetic-perturbation techniques for analyzing the folding transition state have been developed in recent years. The most well-known variant is the -value, in which two metal-binding residues such as histidine are engineered into a protein; the folding kinetics are then studied as a function of the metal ion concentration. However, Fersht has illustrated some difficulties with this approach. An alternative "cross-linking" variant of the -value was developed in the course of studying the association of segments in the folding transition state through the introduction of covalent crosslinks such as disulfide bonds.