TY - JOUR
T1 - Designing protein dimerizers
T2 - The importance of ligand conformational equilibria
AU - Carlson, Jonathan C.T.
AU - Kanter, Aaron
AU - Thuduppathy, Guruvasuthevan R.
AU - Cody, Vivian
AU - Pineda, Pamela E.
AU - Mc Ivor, R S
AU - Wagner, Carston R
PY - 2003/2/12
Y1 - 2003/2/12
N2 - In an effort to elucidate the role of ligand conformation in induced protein dimerization, we synthesized a flexible methotrexate (MTX) dimer, demonstrated its ability to selectively dimerize Escherichia coli dihydrofolate reductase (DHFR), and evaluated the factors regulating its ability to induce cooperative dimerization. Despite known entropic barriers, bis-MTX proved to possess substantial conformational stability in aqueous solution (-3.8 kcal/mol ≥ ΔGfold ≥ -4.9 kcal/mol), exerting a dominant influence on the thermodynamics of dimerization. To dimerize DHFR, bis-MTX must shift from a folded to an extended conformation. From this conclusion, the strength of favorable protein-protein interactions in bis-MTX-E. coli DHFR dimers (-3.1 kcal/mol ≥ ΔGc ≥ -4.2 kcal/mol), and the selectivity of dimerization for E. coli DHFR relative to mouse DHFR (>107) could be determined. The crystal structure of bis-MTX in complex with E. coli DHFR confirms the feasibility of a close-packed dimerization interface and suggests a possible solution conformation for the induced protein dimers. Consequently, the secondary structure of this minimal foldamer regulates its ability to dimerize dihydrofolate reductase in solution, providing insight into the complex energy landscape of induced dimerization.
AB - In an effort to elucidate the role of ligand conformation in induced protein dimerization, we synthesized a flexible methotrexate (MTX) dimer, demonstrated its ability to selectively dimerize Escherichia coli dihydrofolate reductase (DHFR), and evaluated the factors regulating its ability to induce cooperative dimerization. Despite known entropic barriers, bis-MTX proved to possess substantial conformational stability in aqueous solution (-3.8 kcal/mol ≥ ΔGfold ≥ -4.9 kcal/mol), exerting a dominant influence on the thermodynamics of dimerization. To dimerize DHFR, bis-MTX must shift from a folded to an extended conformation. From this conclusion, the strength of favorable protein-protein interactions in bis-MTX-E. coli DHFR dimers (-3.1 kcal/mol ≥ ΔGc ≥ -4.2 kcal/mol), and the selectivity of dimerization for E. coli DHFR relative to mouse DHFR (>107) could be determined. The crystal structure of bis-MTX in complex with E. coli DHFR confirms the feasibility of a close-packed dimerization interface and suggests a possible solution conformation for the induced protein dimers. Consequently, the secondary structure of this minimal foldamer regulates its ability to dimerize dihydrofolate reductase in solution, providing insight into the complex energy landscape of induced dimerization.
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U2 - 10.1021/ja026264y
DO - 10.1021/ja026264y
M3 - Article
C2 - 12568609
AN - SCOPUS:0037433202
SN - 0002-7863
VL - 125
SP - 1501
EP - 1507
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 6
ER -