3QNX
Orthorhombic form of human IgA1 Fab fragment, sharing same Fv as IgG
Summary for 3QNX
| Entry DOI | 10.2210/pdb3qnx/pdb |
| Related | 3M8O 3QNY 3QNZ 3QO0 3QO1 |
| Descriptor | Fab fragment of IMMUNOGLOBULIN A1 LIGHT CHAIN, Fab fragment of IMMUNOGLOBULIN A1 HEAVY CHAIN, GLYCEROL, ... (4 entities in total) |
| Functional Keywords | immunoglobulin fold, immune system |
| Biological source | Homo sapiens (human) More |
| Total number of polymer chains | 2 |
| Total formula weight | 47792.28 |
| Authors | Trajtenberg, F.,Correa, A.,Buschiazzo, A. (deposition date: 2011-02-09, release date: 2012-02-15, Last modification date: 2024-10-30) |
| Primary citation | Correa, A.,Trajtenberg, F.,Obal, G.,Pritsch, O.,Dighiero, G.,Oppezzo, P.,Buschiazzo, A. Structure of a human IgA1 Fab fragment at 1.55 angstrom resolution: potential effect of the constant domains on antigen-affinity modulation Acta Crystallogr.,Sect.D, 69:388-397, 2013 Cited by PubMed Abstract: Despite being the most abundant class of immunoglobulins in humans and playing central roles in the adaptive immune response, high-resolution structural data are still lacking for the antigen-binding region of human isotype A antibodies (IgAs). The crystal structures of a human Fab fragment of IgA1 in three different crystal forms are now reported. The three-dimensional organization is similar to those of other Fab classes, but FabA1 seems to be more rigid, being constrained by a hydrophobic core in the interface between the variable and constant domains of the heavy chain (VH-CH1) as well as by a disulfide bridge that connects the light and heavy chains, influencing the relative heavy/light-chain orientation. The crystal structure of the same antibody but with a G-isotype CH1 which is reported to display different antigen affinity has also been solved. The differential structural features reveal plausible mechanisms for constant/variable-domain long-distance effects whereby antibody class switching could alter antigen affinity. PubMed: 23519414DOI: 10.1107/S0907444912048664 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.2 Å) |
Structure validation
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