Binding of Natively Unfolded HIF-1α ODD Domain to p53 Nuria Sánchez-Puig, Dmitry B. Veprintsev, Alan R. Fersht  Molecular Cell  Volume 17, Issue 1, Pages 11-21 (January 2005) DOI: 10.1016/j.molcel.2004.11.019

Figure 1 Hydrodynamic Characterization of HIF-1α 530–698 and HIF-1α 403–603 (A) Size-exclusion chromatography elution profile of HIF-1α 530–698 (circles) and HIF-1α 403–603 (triangles) monitored at 220 nm. Asterisks denote the positions of the molecular weight standards, from left to right: ferritin (440 kDa), catalase (232 kDa), aldolase (158 kDa), albumin (67 kDa), ovoalbumin (43 kDa), chymotrypsinogen (25 kDa). (Inset) Purified recombinant HIF-1α 530–698 and HIF-1α 403–603. 10% SDS-PAGE stained with Coomassie Brilliant Blue R-250. Lane 1, molecular weight markers (kDa); lane 2, HIF-1α 530–698; lane 3, HIF-1α 403–603. (B) Equilibrium sedimentation experiments of HIF-1α 530–698 at 10°C and 30,000 rpm. Residuals correspond to the fitting of the data to a single exponential model to deduce the molecular weight. Molecular Cell 2005 17, 11-21DOI: (10.1016/j.molcel.2004.11.019)

Figure 2 Secondary Structure Analysis of HIF-1α 530–698 and HIF-1α 403–603 by CD (A) Far-UV CD spectra of HIF-1α 530–698 at different temperatures. (B) Temperature dependence of the molar ellipticity of HIF-1α 530–698 followed at 222 nm. (C) Far-UV CD spectra of HIF-1α 403–603 at different temperatures. All spectra were recorded in 25 mM NaPi (pH 7.2), 150 mM KCl, and 1 mM DTE. Molecular Cell 2005 17, 11-21DOI: (10.1016/j.molcel.2004.11.019)

Figure 3 Effect of the Solution Environment on the CD Spectra of HIF-1α 530–698 (A) TFE. (B) SDS. (C) pH in the absence of salt. (D) pH in the presence of salt. All spectra were recorded in 25 mM NaPi (pH 7.2), 150 mM KCl, 1 mM DTE, except for those studying the effect of pH without salt. Molecular Cell 2005 17, 11-21DOI: (10.1016/j.molcel.2004.11.019)

Figure 4 Equilibrium Sedimentation Analysis of the Interaction of HIF-1α 530–698 and HIF-1α 403–603 with p53 Core (A and B) HIF-1α 530–698 with p53 core at I 150 and 200 mM, respectively. (C and D) HIF-1α 403–603 with p53 core at I 150 and 200 mM, respectively. Upper panels show concentration distribution plots. Continuous lines correspond to the fit assuming two species of unknown mass in equilibrium, except for (B), where data best described a single species present. Lower panels show the plots of residual deviations. Molecular Cell 2005 17, 11-21DOI: (10.1016/j.molcel.2004.11.019)

Figure 5 Binding of HIF-1α 530–698 and HIF-1α 403–603 with p53 Core Examined by Fluorescence Anisotropy (A and B) HIF-1α 530–698 with p53 core at I 20 and 56 mM, respectively. (C and D) HIF-1α 403–603 with p53 core at I 20 and 56 mM, respectively. (Inset in [C]) Hill plot of HIF-1α 403-603 with p53 core at I 20 mM. The Hill coefficient (slope) value corresponds to 1.9 ± 0.06. The continuous line in each plot corresponds to a single site binding model fit, except for plot (C), where data were fitted to a two nonidentical, noninteracting binding site model. Molecular Cell 2005 17, 11-21DOI: (10.1016/j.molcel.2004.11.019)

Figure 6 Binding of HIF-1α ODD and Inhibitory Domain to Full-Length p53 (A) Binding of HIF-1α 530–698 and HIF-1α 403–603 to p53 flQM examined by fluorescence anisotropy. Binding of HIF-1α 403–603 to p53 flQM at (•) 150 and (▴) 200 mM ionic strength. Solid lines represent the fitting to a single binding site model with a drift. Binding of HIF-1α 530–698 to p53 flQM at (○) 150 and (▵) 200 mM ionic strength. (B) Fluorescence anisotropy competition assay between unlabeled p53 consensus DNA and fluorescein-labeled HIF-1α 403–603 for p53 flQM. Unlabeled DNA was added to a solution containing a preformed complex of 0.1 μM fluorescein-labeled HIF-1α 403–603 and 10 μM p53 flQM (initial anisotropy ∼0.1; see [A]). Consecutive additions of unlabeled DNA resulted in the displacement of the fluorescein-labeled HIF-1α 403–603 and formation of a new complex between p53 flQM and DNA. As more DNA is added, free HIF-1α 403–603 is generated until anisotropy reaches a value corresponding to that of the free molecule. Molecular Cell 2005 17, 11-21DOI: (10.1016/j.molcel.2004.11.019)