This IgG1 model is described in Fig. 1 in Anatomy of the Antibody Molecule by Eduardo A. Padlan, Mol. Immunol. 31:169-217, 1994. Atomic coordinate files are available here both for the entire molecule (IGG1-ALL.PDB, 10,401 atoms, 700 Kbytes) and for the alpha carbons only (IGG1-CAC.PDB, 1,336 atoms, 100 Kbytes). Both files are compressed into the 200 Kbyte self-unzipping file IGG1-EAP.EXE. (When the program IGG1-EAP.EXE is run under DOS, it will generate the two PDB files.) For Mac users, the uncompressed files are provided: IGG1-ALL.PDB and IGG1-CAC.PDB.
N.B.: Improvements in these PDB files were made on February 7, 1996. The versions provided originally were concatenations of separate PDB files each of which had independent numbering of the atoms. This produced redundant numbers and confused RasMol. Also some of the chains had no chain designation letters. These have been provided, and all atoms in each file are now numbered sequentially.