A chaperone-mimetic effect of serum albumin on rhodanese.
Reactivation of denatured rhodanese (thiosulfate:cyanide sulfurtransferase, EC 2.8.1.1) was found to be aided by the presence of serum albumin. Both the rate and the extent of reactivation of the urea-denatured enzyme were optimal at low rhodanese and moderate serum albumin concentrations. Similarly, stabilization of the sulfurtransferase activity of rhodanese that had been partially unfolded at 40 degrees C was aided by the presence of serum albumin. All the observations are in accord with a model in which enzyme that has been partially refolded from the urea-denatured state or partially unfolded thermally interacts directly with serum albumin in a way that prevents rhodanese self-association. Serum albumin thus acts as a molecular chaperone in these systems.
Jarabak
R
R
Department of Biochemistry and Molecular Biology, University of Chicago, IL 60637.
Westley
J
J
Dungan
J M
JM
Horowitz
P
P
D000818:Animals; D002021:Buffers; D002417:Cattle; D004793:Enzyme Reactivators / Q000494:pharmacology*; D006358:Hot Temperature; D007700:Kinetics; D011489:Protein Denaturation / Q000187:drug effects; D017510:Protein Folding; D012710:Serum Albumin, Bovine / Q000494:pharmacology*; D013455:Sulfur / Q000737:chemistry; D013884:Thiosulfate Sulfurtransferase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D014508:Urea / Q000494:pharmacology
D002021:Buffers; D004793:Enzyme Reactivators; D012710:Serum Albumin, Bovine; D013455:Sulfur; D014508:Urea; D013884:Thiosulfate Sulfurtransferase