[Study of cytochrome c refolding kinetics by the "stopped flow" method at acid pH]

It is shown that refolding of horse cytochrome c at pH 2.0 induced by an increase of ionic strength occurs in three kinetic phases with the rate constants similar to those observed for the refolding of this protein into the native state. The rate constants and amplitudes of these phases do not depend on the final ionic strength and phase amplitudes are not temperature-dependent. Reasons for the complex kinetics of the cytochrome c refolding at acid pH are discussed. A description of a "stopped-flow" attachment compatible with different commercial optical devices is provided.