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Misfolded forms of glyceraldehyde‐3‐phosphate dehydrogenase interact with GroEL and inhibit chaperonin‐assisted folding of the wild‐type enzyme
Author(s) -
Polyakova Oxana V.,
Roitel Olivier,
Asryants Regina A.,
Poliakov Alexei A.,
Branlant Guy,
Muronetz Vladimir I.
Publication year - 2005
Publication title -
protein science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.353
H-Index - 175
eISSN - 1469-896X
pISSN - 0961-8368
DOI - 10.1110/ps.041211205
Subject(s) - groel , chaperonin , glyceraldehyde 3 phosphate dehydrogenase , protein folding , glyceraldehyde , biochemistry , dehydrogenase , mutant , chemistry , groes , enzyme , biology , escherichia coli , gene
We studied the interaction of chaperonin GroEL with different misfolded forms of tetrameric phosphorylating glyceraldehyde‐3‐phosphate dehydrogenase (GAPDH): (1) GAPDH from rabbit muscles with all SH‐groups modified by 5,5′‐dithiobis(2‐nitrobenzoate); (2) O‐R ‐type dimers of mutant GAPDH from Bacillus stearothermophilus with amino acid substitutions Y283V, D282G, and Y283V/W84F, and (3) O‐P ‐type dimers of mutant GAPDH from B. stearothermophilus with amino acid substitutions Y46G/S48G and Y46G/R52G. It was shown that chemically modified GAPDH and the O‐R ‐type mutant dimers bound to GroEL with 1:1 stoichiometry and dissociation constants K d of 0.4 and 0.9 μM, respectively. A striking feature of the resulting complexes with GroEL was their stability in the presence of Mg‐ATP. Chemically modified GAPDH and the O‐R ‐type mutant dimers inhibited GroEL‐assisted refolding of urea‐denatured wild‐type GAPDH from B. stearothermophilus but did not affect its spontaneous reactivation. In contrast to the O‐R ‐dimers, the O‐P ‐type mutant dimers neither bound nor affected GroEL‐assisted refolding of the wild‐type GAPDH. Thus, we suggest that interaction of GroEL with certain types of misfolded proteins can result in the formation of stable complexes and the impairment of chaperonin activity.