Reactivation and Refolding of a Partially Folded Creatine Kinase Modified by 5,5′-Dithio-bis(2-nitrobenzoic Acid)

Abstract

Creatine kinase with its thiol groups modified by 5,5′-dithio-bis(2-nitrobenzoic acid) has been shown to be partially folded in a monomeric state using fluorescence, circular dichroism, proteolysis, and size exclusion chromatography studies. In the presence of DTT, the partially folded modified creatine kinase can be reactivated and refolded following a biphasic course, suggesting the existence of a monomeric intermediate during the refolding of CK. The results provide evidence for our previously suggested model of the refolding pathway of urea-denatured creatine kinase.