1q0x
From Proteopedia
Anti-morphine Antibody 9B1 Unliganded Form
Overview
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.
About this Structure
1Q0X is a Single protein structure of sequence from Mus musculus. Full crystallographic information is available from OCA.
Reference
Anchoring a cationic ligand: the structure of the Fab fragment of the anti-morphine antibody 9B1 and its complex with morphine., Pozharski E, Wilson MA, Hewagama A, Shanafelt AB, Petsko G, Ringe D, J Mol Biol. 2004 Mar 26;337(3):691-7. PMID:15019787 Page seeded by OCA on Sat May 3 05:43:56 2008
