Fig. 2: Effects of chirality on protein interactions.
From: Stereochemistry in the disorder–order continuum of protein interactions
a, ProTα and the H1155–175 peptide remain disordered during their interaction. b, Far-UV CD spectra of l-H1155–175 and d-H1155–175 peptides and their sum. MRE, mean residue ellipticity (cm2 dmol−1 residue−1; n = 1). c,d, CSP (c) and ΔCSPl-d (n = 1) (d) caused by the addition of l-H1 or d-H1 (500 µM) to ProTα (50 µM). e, ITC of interactions of ProTα with l-H1155–175 and d-H1155–175. Raw ITC thermograms (left) and fitted one-site binding isotherms (right). DP, differential power. f, smFRET of l-H1155–175 or d-H1155–175 with ProTα, fitting FRET efficiency (⟨E⟩) as a function of ligand concentration to obtain Kd values. g, MCL1 is folded and interacts with the disordered PUMA peptide, which forms an α-helix upon interaction via induced fit. h, Far-UV CD spectra of l-PUMA and d-PUMA peptides, and their sum. i, ITC performed under the same conditions for both l-PUMA and d-PUMA (n = 3, figure is representative). N/A, not applicable. j, ITC performed using higher concentrations of both MCL1 and d-PUMA (70 µM and 700 µM, respectively; n = 3, figure is representative). k, CSPs induced by the interaction of MCL1 (50 µM) with l-PUMA and d-PUMA at equal (90%) saturation (n = 1). l, Changes in NMR peak intensities upon addition of l-PUMA or d-PUMA to MCL1 at 90% saturation (n = 1). In all panels, l-peptides are represented in grey, and d-peptides are in orange. Blue diamonds indicate missing assignments, assigned residues that could not be tracked, or prolines.
