Unspecific interaction of Skp with LPS-preaggregates. (A) δ1[15N]-1D cross-sections from 2D [15N,1H]-TROSY spectra of a titration of [U-15N,2H]-Skp (200 μM trimer concentration) in NMR buffer with variable LPS concentration, as indicated by the color gradient. The red and blue dashed lines indicate the integration limits for folded Skp and all protein signals, respectively. (B) NMR signal intensity of the spectra in A as a function of the LPS concentration. Values for the complete spectrum are shown in blue and for the β-sheet region in red. (C) Measurement of effective molecular diffusion constants of Skp in the presence of 1.8 mM LPS by a 15N-filtered diffusion bipolar pulse pairs-LED NMR experiment (44). The blue circles are measurements of the signal intensity as a function of the field gradient strength. The black line represents the linear fit to the measured data. To see this figure in color, go online.