(A) H2-Db (10 µM) loaded with a photo-cleavable peptide (RGPGRAFJ*TI, J* denotes photocleavable amino acid) was irradiated with UV light in the presence of TAPBPRwt (3 µM, red), TAPBPRTsn-SL (blue), or TAPBPRΔSL (yellow) and subsequently analyzed by SEC. The different elution volumes of the first main peak, marked by dashed lines, already hint at different complex stabilities. (B) Deconvolution of size-exclusion chromatogram from TAPBPRwt complex formation (experiment independent of the sample shown in (A)). The experimental chromatogram (red) was deconvoluted using three Gaussian functions (gray) that can be ascribed to the TAPBPR-H2-Db complex (1.06 mL), free TAPBPR (1.12 mL), and free H2-Db (1.20 mL). The sum of the three Gaussians is shown as dotted curve. The residual plot depicted beneath the main panel shows the difference between the experimental data and the sum. (C) Stability of complexes formed by TAPBPRwt, TAPBPRTsn-SL, and TAPBPRΔSL, respectively, as judged by the area of the complex peak obtained by deconvolution. Data represent mean ± SD (n = 2).