4ckd

Publication Abstract from PubMed

Binding of a single-chain Fv antibody to Escherichia coli beta-galactosidase (beta-gal) is known to stabilize the enzyme and activate several inactive point mutants, historically called antibody-mediated enzyme formation mutants. To understand the nature of this activation, we have determined by electron cryo-microscopy the structure of the complex between beta-gal and the antibody scFv13R4. Our structure localizes the scFv13R4 binding site to the crevice between domains 1 and 3 in each beta-gal subunit. The mutations that scFv13R4 counteracts are located between the antibody binding site and the active site of beta-gal, at one end of the TIM-barrel that forms domain 3 where the substrate lactose is hydrolyzed. The mode of binding suggests how scFv stabilizes both the active site of beta-gal and the tetrameric state.

Molecular Mechanism of Antibody-Mediated Activation of beta-galactosidase.,Vinothkumar KR, McMullan G, Henderson R Structure. 2014 Mar 4. pii: S0969-2126(14)00039-2. doi:, 10.1016/j.str.2014.01.011. PMID:24613486^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.