Oxidized RNase as a protein model having no contribution to the hydrogen exchange rate from conformational restrictions.

As oxidized RNase is a model for the random conformation state of RNase, the hydrogen exchange kinetics of oxidized RNase approximate the intrinsic conformation-independent chemical exchange rate of the native protein. The energy of activation, the pH(min), and the k(min) of oxidized RNase exchange rates are similar to those reported for amino acid homopolymers. However, unlike the exchange from homopolymers, the exchange from oxidized RNase is characterized by a distribution of first-order rates. This distribution is important to the analysis of exchange from native proteins in terms of classes of sites which share common structural properties.