Effects of macromolecular crowding on the unfolding and the refolding of D-glyceraldehyde-3-phosophospate dehydrogenase.
The effects of crowding agents, polyethylene glycol (PEG 20K), Dextran 70, and bovine serum albumin, on the denaturation of homotetrameric D-glyceraldehyde-3-phosphate dehydrogenase (GAPDH, EC 1.2.1.12) in 0.5 M guanidine hydrochloride and the reactivation of the fully denatured enzyme have been examined quantitatively. Increasing the concentration of PEG 20K to 225 mg/ml decreases the rate constant of slow phase of GAPDH inactivation to 5% but with no change for the fast phase. Chaperone GroEL assists GAPDH refolding greatly and shows even higher efficiency under crowding condition. Crowding mainly affects refolding steps after the formation of the dimeric folding intermediate.
Ren
Guoping
G
National Laboratory of Biomacromolecules, Institute of Biophysics, Academia Sinica, Beijing 100101, China.
Lin
Zong
Z
Tsou
Chen-lu
CL
Wang
Chih-chen
CC
D000818:Animals; D018834:Chaperonin 60 / Q000378:metabolism; D019281:Dimerization; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000737:chemistry* / Q000378:metabolism*; D019791:Guanidine / Q000494:pharmacology; D007700:Kinetics; D011489:Protein Denaturation / Q000187:drug effects; D017510:Protein Folding; D020673:Protein Renaturation / Q000187:drug effects; D020836:Protein Structure, Quaternary; D011817:Rabbits; D013696:Temperature
D018834:Chaperonin 60; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases; D019791:Guanidine