DOES DSBA HAVE CHAPERONE-LIKE ACTIVITY

DsbA showed chaperone-like activity similar to but weaker than that of protein disulfide isomerase in increasing reactivation and decreasing aggregation during the refolding of guanidine hydrochloride-denatured D-glyceraldehyde-3-phosphate dehydrogenase and rhodanese. The fact th at both enzymes are devoid of disulfide bonds indicates the independen ce of the chaperone-like activity of DsbA from its thiol-protein oxido reductase activity. The increased reactivation of D-glyceraldehyde-3-p hosphate dehydrogenase by DsbA can be suppressed with increasing conce ntrations of a peptide of 21 amino acid residues, suggesting that the peptide binding ability of DsbA is responsible for its chaperone-like activity. (C) 1997 Academic Press