GroEL and protein disulfide isomerase each binds with folding intermediates of D-glyceraldehyde-3-phosphate dehydrogenase released from complexes formed with the other.
Simultaneous presence of two chaperones, GroEL and protein disulfide isomerase (PDI), assists the reactivation of denatured D-glyceraldehyde-3-phosphate dehydrogenase (GAPDH) in an additive way. Delayed addition of chaperones to the refolding solution after dilution of denatured GAPDH indicates an interaction with intermediates formed mainly in the first 5 min for PDI and formed within a longer time period for GroEL-ATP. The above indicate that the two chaperones interact with different folding intermediates of GAPDH. After delayed addition of one chaperone to the refolding mixture containing the other at 4 degrees C, GroEL binds with all GAPDH intermediates dissociated from PDI, and PDI interacts with the intermediates released from GroEL during the first 10-20 min. It is suggested that the GAPDH folding intermediates released from the chaperone-bound complex are still partially folded so as to be rebound by the other chaperone. The above results clearly support the network model of GroEL and PDI.
National Laboratory of Biomacromolecules, Institute of Biophysics, Academia Sinica, Beijing, China.
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Zhang
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Li
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Wang
D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D002417:Cattle; D018834:Chaperonin 60 / Q000378:metabolism*; D004357:Drug Synergism; D005986:Glyceraldehyde 3-Phosphate / Q000378:metabolism; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism*; D008956:Models, Chemical; D018832:Molecular Chaperones / Q000378:metabolism / Q000494:pharmacology; D011485:Protein Binding; D019704:Protein Disulfide-Isomerases / Q000378:metabolism* / Q000494:pharmacology; D017510:Protein Folding; D020673:Protein Renaturation / Q000187:drug effects; D011817:Rabbits; D013997:Time Factors
D018834:Chaperonin 60; D018832:Molecular Chaperones; D005986:Glyceraldehyde 3-Phosphate; D000255:Adenosine Triphosphate; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases; D019704:Protein Disulfide-Isomerases