Chaperone‐Like Activity of Protein Disulfide‐Isomerase in the Refolding Of Rhodanese

Abstract

Protein disulfide‐isomerase (PDI) in near stoichiometric concentrations promotes reactivation and prevents aggregation of guanidine‐hydrochloride‐denatured rhodanese during refolding upon dilution. PDI also suppresses aggregation of rhodanese during thermal inactivation. The above‐mentioned properties displayed by PDI completely satisfy the definition of chaperone and provide additional evidence to confirm the hypothesis proposed previously [Wang, C. C. & Tsou, C. L. (1993) FASEB J. 7, 1515–1517] that PDI is both an enzyme and a chaperone. Since rhodanese contains no disulfide bonds, the chaperone‐like activity of PDI acting on rhodanese is independent of its disulfide‐isomerase activity. Copyright © 1995, Wiley Blackwell. All rights reserved