1Q0X

Anti-morphine Antibody 9B1 Unliganded Form

Summary for 1Q0X

• Entry DOI: 10.2210/pdb1q0x/pdb
• Descriptor: Fab 9B1, light chain, Fab 9B1, heavy chain, SULFATE ION, ... (5 entities in total)
• Functional Keywords: anti-morphine antibody, fab fragment, immune system
• Biological source: Mus musculus (house mouse); More
• Total number of polymer chains: 2
• Total formula weight: 46669.95

Authors

Pozharski, E.,Wilson, M.A.,Hewagama, A.,Shanafelt, A.B.,Petsko, G.,Ringe, D. (deposition date: 2003-07-17, release date: 2004-04-20, Last modification date: 2024-10-30)

Primary citation

Pozharski, E.,Wilson, M.A.,Hewagama, A.,Shanafelt, A.B.,Petsko, G.,Ringe, D.
Anchoring a cationic ligand: the structure of the Fab fragment of the anti-morphine antibody 9B1 and its complex with morphine
J.Mol.Biol., 337:691-697, 2004

PubMed Abstract: The crystal structures of an anti-morphine antibody 9B1 (to 1.6A resolution) and its complex with morphine (to 2.0 A resolution) are reported. The morphine-binding site is described as a shallow depression on the protein surface, an unusual topology for a high-affinity ( Ka approximately 10(9) M(-1)) antibody against a small antigen. The polar part of the ligand is exposed to solvent, and the cationic nitrogen atom of the morphine molecule is anchored at the bottom of the binding site by a salt-bridge to a glutamate side-chain. Additional affinity is provided by a double cation-pi interaction with two tryptophan residues. Comparison of the morphine complex with the structure of the free Fab shows that a domain closure occurs upon binding of the ligand.

PubMed: 15019787
DOI: 10.1016/j.jmb.2003.12.084

Experimental method

X-RAY DIFFRACTION (1.6 Å)