Volume 108, Issue 3, Pages 666-677 (February 2015) Alteration of the Langerin Oligomerization State Affects Birbeck Granule Formation  Eric Chabrol, Michel Thépaut, Colette Dezutter-Dambuyant, Corinne Vivès, Julien Marcoux, Richard Kahn, Jenny Valladeau-Guilemond, Patrice Vachette, Dominique Durand, Franck Fieschi  Biophysical Journal  Volume 108, Issue 3, Pages 666-677 (February 2015) DOI: 10.1016/j.bpj.2014.10.075 Copyright © 2015 Biophysical Society Terms and Conditions

Figure 1 Electron microscopy pictures of transfected COP5 cells. (A, B, and D–F) Cells transfected with: langerinWT gene (A and B), langerinF241L gene (D and E), and langerinW264R gene (F). (C) Cells not transfected. The characteristic BG structure is shown in (A and B). Arrows point to CMS (observed with langerinWT) or superimposed and thickened membranes (observed with langerinF241L). Comparison of (B) with (E) shows the structural modification of CMS caused by the F241L mutation (substitution of the double layers with an inner striation with short, curved, and irregularly thickened double layers without inner electron-dense bodies), whereas panel (F) shows the loss of CMS with the W264R mutation. Biophysical Journal 2015 108, 666-677DOI: (10.1016/j.bpj.2014.10.075) Copyright © 2015 Biophysical Society Terms and Conditions

Figure 2 Functional characterization of Lg-CRDs. (A) Delayed elution of Lg-CRDs and BSA in Mannan-Agarose affinity column. BSA, used as a negative control (dotted-dashed line), Lg-CRDWT (solid line), Lg-CRDF241L (dotted line), and Lg-CRDW264R (gray dashed line). (B and C) Sensorgrams of the interaction of Lg-CRDs with gp120. B: Lg-CRDWT. C: Lg-CRDF241L. Both proteins were injected in series of twofold dilutions over the concentration range [12.5 μM, 400 μM]. Biophysical Journal 2015 108, 666-677DOI: (10.1016/j.bpj.2014.10.075) Copyright © 2015 Biophysical Society Terms and Conditions

Figure 3 Structural characterization of Lg-CRDs. (A) CD spectra of Lg-CRDWT (solid line), Lg-CRDF241L (dotted line), and Lg-CRDW264R (gray dashed line). (B) Thermal shift assay of Lg-CRDWT (solid line), Lg-CRDF241L (dotted line), and Lg-CRDW264R (gray dashed line) as a function of temperature. Biophysical Journal 2015 108, 666-677DOI: (10.1016/j.bpj.2014.10.075) Copyright © 2015 Biophysical Society Terms and Conditions

Figure 4 Crystallographic structures of Lg-CRDWT (orange) and Lg-CRDF241L (blue). (A) Superimposition of both structures. (B) Focus on F241 and F202 π-orbital stacking in Lg-CRDWT structure. (C) Same focus as C with both superimposed structures. Biophysical Journal 2015 108, 666-677DOI: (10.1016/j.bpj.2014.10.075) Copyright © 2015 Biophysical Society Terms and Conditions

Figure 5 Sensorgrams of the interaction of Lg-ECDs with gp120. (A) Lg-ECDWT; concentrations used are 5, 10, 50, 100, 200, 500, 750, and 1000 nM. (B) Lg-ECDF241L; black lines correspond to concentrations of 62.5, 250, 500, and 1000 nM and dotted lines correspond to additional concentrations used, 2, 4, and 6.6 μM. Biophysical Journal 2015 108, 666-677DOI: (10.1016/j.bpj.2014.10.075) Copyright © 2015 Biophysical Society Terms and Conditions

Figure 6 Oligomeric state of Lg-ECD assessed by cross-linking and MALDI-MS analysis. Top to bottom panel correspond to MALDI-MS spectra of Lg-ECDWT, Lg-ECDWT cross-linked with EGS, Lg-ECDF241L, Lg-ECDF241L cross-linked with EGS, respectively. Biophysical Journal 2015 108, 666-677DOI: (10.1016/j.bpj.2014.10.075) Copyright © 2015 Biophysical Society Terms and Conditions

Figure 7 SAXS-coupled SE-HPLC elution profiles of Lg-ECDs. Lg-ECDWT (continuous line) and Lg-ECDF241L (dashed line). The light blue rectangle corresponds to the elution of the WT protein. Biophysical Journal 2015 108, 666-677DOI: (10.1016/j.bpj.2014.10.075) Copyright © 2015 Biophysical Society Terms and Conditions

Figure 8 SAXS analysis. (A) Model of Lg-ECDWT trimer from (30) after incorporation of the trimeric head and proximal coiled-coil region from 3KQG. (B) Comparison of the distance distribution function of Lg-ECDWT model shown in A (cyan line), with that derived from the experimental curve for Lg-ECDWT (red curve). (C) Disorder prediction using PondR (30) in the range 68–198 (neck). (D) Prediction of secondary structure in the same range. Only helices are predicted. (E) Prediction of coiled coil using Logicoil (31). (F) Variation along the SEC elution profile of the protein concentration c (black dashed line), radius of gyration Rg (red diamonds), and I(0)/c (blue squares). Each frame corresponds to a 2 s SAXS pattern. (G) Comparison of the distance distribution functions of the WT trimer (red line) and of the trimer of F241L mutant (purple line). (H) Comparison of the distance distribution functions of the WT trimer (red line) and of the dimer of F241L mutant (green line). (I) Two 90° rotation views of a typical model obtained with SASREF for the dimer of F241L mutant. (J) Black dots: SAXS experimental data for the dimer of F241L mutant with error bars (gray lines); for q < 0.17 Å−1 error bars are smaller than the black dots; green line: calculated curve using CRYSOL from the model shown in Fig. 8 I. Biophysical Journal 2015 108, 666-677DOI: (10.1016/j.bpj.2014.10.075) Copyright © 2015 Biophysical Society Terms and Conditions

Figure 9 F241 and K200 are central residues of the interface between CRD of one protomer and C-terminal neck end of the neighboring one. (A). Top view. (B) Top view with a zoom over the square in panel A. (C) Lateral view. (D) Lateral view with a zoom over the square in (C). Biophysical Journal 2015 108, 666-677DOI: (10.1016/j.bpj.2014.10.075) Copyright © 2015 Biophysical Society Terms and Conditions