Fig 2: Immunohistochemical analysis of ABCA1 and SR-BI at the maternal-fetal interface (including the anti-mesometrial side and mesometrial side of the uterus) during the peri-implantation period in Meishan pigs.(A) Images stained with ABCA1 and SR-BI antibodies on Days 12, 15 and 18 of pregnency in Meishan pigs. The expression patterns of ABCA1 and SR-BI both in Meishan pigs and Yorkshire pigs were similar. (B) Quantitative analysis of ABCA1 and SR-BI by measuring the average integrated optical density (IOD) in LE. Asterisks indicate significant differences (mean ± SD) between breeds (**P < 0.01), P value was determined by Student’s t test. Legend: Tr, trophoblast; LE, endometrial luminal epithelium; GE, glandular epithelium; D, day of pregnancy; Scale bars = 100 μm or 20 μm (amplification).

Fig 3: PMPC free chain binding to SRB1, CD36, and CD81 receptors. Autodock vina estimated relative binding affinities are shown as swarm plots at increasing number of PMPC chains (NPC) for SRB1, CD36, and CD81 (a). All-atom depiction of the PMPC free chain (for NPC with highest affinity) binding site, shown as VDW surface in magenta. For CD36 and SRB1, glycans are shown as licorice and their VDW surface is also overlay. The secondary structure of the three receptors is shown as a cartoon in silver. Cellular membrane is indicated in gray. In the CD81 case, two binding modes are depicted (b). PMPC free chain binding site inside CD36 and SRB1 (c). PMPC free chain docking pose versus MD stable pose onto CD81 (d).

Fig 4: Scavenger receptor class B, type I partially colocalized with UGGT1 and calnexin. (A) Colocalization of SR-BI with calnexin-Flag in Huh7.5.1 cells. Huh7.5.1 cells transfected with calnexin-Flag construct were fixed by methanol, permealized by 0.5% Triton X-100 and immunofluorescently labeled for SR-BI antibody (green) and Flag antibody (red). DAPI marked nucleus (blue). Scale bar, 15 μm. (B) Colocalization of SR-BI with UGGT1-Flag in Huh7.5.1 cells. Huh7.5.1 cells transfected with UGGT1-Flag construct were fixed by methanol, permealized by 0.5% Triton X-100 and immunofluorescently labeled for SR-BI antibody (green) and Flag antibody (red). DAPI marked nucleus (blue). Scale bar, 15 μm.

Fig 5: Influence of glycans on Psome binding. Lectin binding assay to assess the amount of glycans on FaDu, HDF, and THP-1 cells (a). 3D heat maps showing the Psome surface coverage in the three cell lines analyzed, FaDu, HDF, and THP1, as a function of the Psome radius, R, and the PMPC degree of polymerization, NPC. The different panels correspond to different glycan compositions: from top to bottom, the polymerization degree of the branches is increased (b). 100 snapshots taken at 10 ns intervals for glycans depicted as sticks are superimposed onto the van der Waals surface representation of the receptor. The volume occupied by the glycans is highlighted as a semitransparent surface. 100 snapshots of the bound PMPC free chain (NPC = 4) are also depicted as magenta sticks in the binding site. Front and top views of the receptor-free chain complex are provided for SRB1 and CD36. In the bottom panel, a schematic representation of the DNeup5Aca2–6DGalpb1–4DGlcpNAcb1–2DManpa1–6[DNeup5Aca2–6DGalpb1–4DGlcpNAcb1–2DManpa1–3]DManpb1–4DGlcpNAcb1–4DGlcpNAcb1 complex glycans used in the MD simulations together with its all-atom representation and VDW surface (c). Scattered plot of the percentage of the receptor solvent accessible surface area (SASA) hidden by glycans as a function of the glycan radius of gyration for CD36 (blue) and SRB1 (orange). In the mirror axis, the receptor SASA is reported as a solid line (left). The probability density function (PDF) of the receptor volume and the receptor plus glycans extracted from a 1 μs molecular dynamics simulation is reported for CD36 (blue) and SRB1 (orange) (right) (d).