CD spectra of LC4.

<p>(1) 50 µM LC4 in phosphate buffer at pH 7.4; (2) as in (1) but at pH 4.5; (3) 50 µM LC4 in SDS micelles at pH 7.4; (4) as in (3) but at pH 4.5. The experiments were carried out at room temperature in 80 mM phosphate buffer or 80 mM phosphate buffer containing 10 mM SDS.</p

Patterns of sequential and medium range NOE cross-peaks of LC4 in SDS micelles.

<p>The NOEs for 2 mM LC4 were derived from the NOESY spectrum with a mixing time of 150 ms in the presence of 200 mM d₂₅-SDS micelles. The NOE patterns are used to characterize the region of the helical structure <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0020452#pone.0020452-Wthrich1" target="_blank">[28]</a>.</p

Chemical shift differences of H^α between the experimental values and random coil values.

<p>The experimental values were observed as the H^α chemical shift for 2 mM LC4 in the presence of 200 mM d₂₅-SDS micelles. The random coil values were obtained from Chemical Shift Index <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0020452#pone.0020452-Wishart1" target="_blank">[30]</a>. The negative Δδ values showed the presence of the helical conformation.</p

Summary of Structure Statistics of LC4 in SDS micelles^a.

a<p>Except for the number of constraints, average values given for the set of 20 conformers with the lowest CYANA target function value.</p>b<p>The values were calculated for residues 157–172.</p

Possible docking positions of LC4 and LC5 calculated using the program ZDOCK.

<p>The NMR structure of LC5 was determined in the previous study <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0020452#pone.0020452-Miyamoto1" target="_blank">[10]</a>. The docking positions were calculated using the program ZDOCK and then the energy-minimization calculations were performed using the program Discovery Studio. (A) Ribbon diagrams of the 5 lowest energy structures (residues Val157–Glu172 of LC4; residues Lys229–Thr239 of LC5) (B) close-up view of the binding interface of the lowest energy structure, showing the heavy atoms of the side chains.</p

Overall structure of LC4 in SDS micelles at pH 4.5 by ¹H-NMR.

<p>(A) Stereoview illustrating a trace of the backbone atoms for the ensemble of the 20 lowest energy structures, showing the heavy atoms of the side chains (residues Val157-Leu174). The structures in the well-ordered region (residues Val157-Glu172) was superimposed over the backbone atoms. (B) Surface representation and ribbon diagram of LC4 showing the side chains (residues Val157-Glu172). The helical regions (α1 and α2) are shown in red.</p