Corresponding conformation at the 3F5-recognized epitope in α₁PI and CD4-complexed HIV-1 gp120.

<p>HIV-1 gp120 is depicted from two perspectives (<b>A,B</b>) with green representing two α-helices (aa 100–115 and 476–484). The gp120 peptide immunogen used to raise 1C1 and 3F5 (aa 471–490) is located at the C-terminus of gp120, and the linear segment ⁴⁸⁶YKVV⁴⁸⁹ is depicted in red along with Met95 and the oligosaccharide-linked segment ²³⁴NGT²³⁶, all of which are within 8 Å of the conformational epitope. The gp120-homologous domain in α₁PI is also located at the C-terminus of the protein, and is depicted from two perspectives (<b>C,D</b>) with violet representing the antiparallel β-sheet strand at the base of the cleft (aa 369–389), and green representing the α-helices that form the mouth of the cleft (aa 27–44 and 259–277). Met-385, which distinguishes human from chimpanzee α₁PI, is depicted in red along with the segment ³⁸⁶GKVV³⁸⁹, the oligosaccharide, and oligosaccharide-linked segment ⁴⁶NST⁴⁸. The HLE_G-reactive site Met-358, is depicted in yellow for orientation. Structures for human α₁PI (1HP7) and CD4-complexed HIV-1 gp120 (1RZJ) from the NCBI Molecular Modeling Database (MMDB) were analyzed using Cn3D software. Small carbohydrate structures, depicted in multiple colors, were associated with 1RZJ in MMDB, and the three associated with 1HP7 were added using Adobe Photoshop.