TY - JOUR
T1 - Dissecting the Thermodynamics of ATP Binding to GroEL One Nucleotide at a Time
AU - Walker, Thomas
AU - Sun, He Mirabel
AU - Gunnels, Tiffany
AU - Wysocki, Vicki
AU - Laganowsky, Arthur
AU - Rye, Hays
AU - Russell, David
N1 - Funding Information:
Funding for this work was provided by the National Institutes of Health (Grants P41GM128577 to D.H.R. and V.W. and R01GM138863 to D.H.R. and A.L.).
Publisher Copyright:
© 2023 The Authors. Published by American Chemical Society.
PY - 2023/3/22
Y1 - 2023/3/22
N2 - Variable-temperature electrospray ionization (vT-ESI) native mass spectrometry (nMS) is used to determine the thermodynamics for stepwise binding of up to 14 ATP molecules to the 801 kDa GroEL tetradecamer chaperonin complex. Detailed analysis reveals strong enthalpy-entropy compensation (EEC) for the ATP binding events leading to formation of GroEL-ATP7 and GroEL-ATP14 complexes. The observed variations in EEC and stepwise free energy changes of specific ATP binding are consistent with the well-established nested cooperativity model describing GroEL-ATP interactions, viz., intraring positive cooperativity and inter-ring negative cooperativity ( Dyachenko, A. ; Proc. Natl. Acad. Sci. U.S.A. 2013, 110, 7235−7239 ). Entropy-driven ATP binding is to be expected for ligand-induced conformational changes of the GroEL tetradecamer, though the magnitude of the entropy change suggests that reorganization of GroEL-hydrating water molecules and/or expulsion of water from the GroEL cavity may also play key roles. The capability for determining complete thermodynamic signatures (ΔG, ΔH, and −TΔS) for individual ligand binding reactions for the large, nearly megadalton GroEL complex expands our fundamental view of chaperonin functional chemistry. Moreover, this work and related studies of protein-ligand interactions illustrate important new capabilities of vT-ESI-nMS for thermodynamic studies of protein interactions with ligands and other molecules such as proteins and drugs.
AB - Variable-temperature electrospray ionization (vT-ESI) native mass spectrometry (nMS) is used to determine the thermodynamics for stepwise binding of up to 14 ATP molecules to the 801 kDa GroEL tetradecamer chaperonin complex. Detailed analysis reveals strong enthalpy-entropy compensation (EEC) for the ATP binding events leading to formation of GroEL-ATP7 and GroEL-ATP14 complexes. The observed variations in EEC and stepwise free energy changes of specific ATP binding are consistent with the well-established nested cooperativity model describing GroEL-ATP interactions, viz., intraring positive cooperativity and inter-ring negative cooperativity ( Dyachenko, A. ; Proc. Natl. Acad. Sci. U.S.A. 2013, 110, 7235−7239 ). Entropy-driven ATP binding is to be expected for ligand-induced conformational changes of the GroEL tetradecamer, though the magnitude of the entropy change suggests that reorganization of GroEL-hydrating water molecules and/or expulsion of water from the GroEL cavity may also play key roles. The capability for determining complete thermodynamic signatures (ΔG, ΔH, and −TΔS) for individual ligand binding reactions for the large, nearly megadalton GroEL complex expands our fundamental view of chaperonin functional chemistry. Moreover, this work and related studies of protein-ligand interactions illustrate important new capabilities of vT-ESI-nMS for thermodynamic studies of protein interactions with ligands and other molecules such as proteins and drugs.
UR - http://www.scopus.com/inward/record.url?scp=85148896055&partnerID=8YFLogxK
U2 - 10.1021/acscentsci.2c01065
DO - 10.1021/acscentsci.2c01065
M3 - Article
AN - SCOPUS:85148896055
SN - 2374-7943
VL - 9
SP - 466
EP - 475
JO - ACS Central Science
JF - ACS Central Science
IS - 3
ER -