The following jpeg encoded image files are the models of human IgG1 where various residues have been
marked in a different colour to illustrate features of the molecule. These IgG models are based on some
model structures which I have been using in my undergraduate teaching. These other models are stored in a
different location and can be accessed from my main menu. To
download higher resolution jpeg encoded files just click on the gif images below
IgG1 allotypes. The yellow residues are those residues which differ by allotype in
human IgG1. There is a Lys (G1m(17)) for Arg (G1m(3)) change at 214 in the CH1, an Asp 356 Leu 358
(G1m(1)) for Glu 356 Met 358 (nG1m(1)) in the CH3 and an Gly 431 (G1m(2)) for Ala (nG1m(2)) also in
the CH3. The carbohydrate shown in purple is attached to residue Asn 297 in the CH2.
IgG1 vs IgG4. The residues which differ between IgG1 and IgG4 are indicated in yellow.
The hinge region is also indicated in grey as this is not highly conserved between isotypes. The
carbohydrate shown in purple is attached to residue Asn 297 in the CH2.
IgG1 vs IgG3. The residues which differ between IgG1 and IgG3 are indicated in yellow.
The hinge region is also indicated in grey as this is not highly conserved between isotypes. The
carbohydrate shown in purple is attached to residue Asn 297 in the CH2.
IgG1 functions. This model highlights the residues thought to be of some functional
significance in the binding of complement and FcR. The Duncan & Winter C1q binding motif is shown in
yellow Glu 318, Lys 320, Lys 322, these residues are however identical in all four human IgG isotypes.
Residues in the lower hinge encoded at the N-terminal end of the CH2 domain are thought to be important
in FcR binding (these residues are not resolved in the crystal structures). The two important residues which
seem to determine the difference between human IgG1 and IgG4 in complement lysis and ADCC through
activated K-cells are marked in white. These residues are Ala 330 Pro 331 in IgG1 and Ser 330 Ser 331 in
IgG4. As before the carbohydrate shown in purple is attached to residue Asn 297 in the CH2.
Composite image. This is a composite image of all four of the above models together. It allows
the different residues to be compared side by side.
This page is from 
Mike Clark
"An antibody engineer who also enjoys the mountains."
mrc7@cam.ac.uk
Mike's home-page
11th June 1997
Go to BSI 95 talk Abstract
Go to Mike's immunoglobulin home page
IgG1 allotypes. The yellow residues are those residues which differ by allotype in
human IgG1. There is a Lys (G1m(17)) for Arg (G1m(3)) change at 214 in the CH1, an Asp 356 Leu 358
(G1m(1)) for Glu 356 Met 358 (nG1m(1)) in the CH3 and an Gly 431 (G1m(2)) for Ala (nG1m(2)) also in
the CH3. The carbohydrate shown in purple is attached to residue Asn 297 in the CH2.
IgG1 vs IgG4. The residues which differ between IgG1 and IgG4 are indicated in yellow.
The hinge region is also indicated in grey as this is not highly conserved between isotypes. The
carbohydrate shown in purple is attached to residue Asn 297 in the CH2.
IgG1 vs IgG3. The residues which differ between IgG1 and IgG3 are indicated in yellow.
The hinge region is also indicated in grey as this is not highly conserved between isotypes. The
carbohydrate shown in purple is attached to residue Asn 297 in the CH2.
IgG1 functions. This model highlights the residues thought to be of some functional
significance in the binding of complement and FcR. The Duncan & Winter C1q binding motif is shown in
yellow Glu 318, Lys 320, Lys 322, these residues are however identical in all four human IgG isotypes.
Residues in the lower hinge encoded at the N-terminal end of the CH2 domain are thought to be important
in FcR binding (these residues are not resolved in the crystal structures). The two important residues which
seem to determine the difference between human IgG1 and IgG4 in complement lysis and ADCC through
activated K-cells are marked in white. These residues are Ala 330 Pro 331 in IgG1 and Ser 330 Ser 331 in
IgG4. As before the carbohydrate shown in purple is attached to residue Asn 297 in the CH2. 
Composite image. This is a composite image of all four of the above models together. It allows
the different residues to be compared side by side.