United Kingdom (UK)
Recombinant monoclonal antibody to Sag1. Manufactured using AbAb’s Recombinant Platform with variable regions (i.e. specificity) from the hybridoma 4F11E12.
UniProt Accession Number of Target Protein: C7E5U4
Alternative Name(s) of Target: P30
Immunogen: 4F11E12 was generated by intraperitoneal infection of mice with cysts from the 76 K T. gondii strain and was selected for its ability to inhibit efficiently the recognition of SAG1 by sera from infected patients. The 4F11E12 Fab fragment was created by digestion with papain
Specificity: 4F11E12 recognises a highly conserved conformational epitope on the surface of the D1 domain in both native and recombinant SAG1, located within the N-terminal domain; the binding site does not overlap with the proposed ligand-binding pocket or homodimerization site. The eptiope is an immunodominant area and includes residues from 2 long loops located at one exteremity. SAG1 is a GPI-anchored cell surface protein predicted to act as an adhesin during host-cell attachment through its binding to proteoglycans. SAG1 recognizes ligands such as glucosamide moieties, which are expressed in a broad range of host cell types. T. gondii is a protozoan parasite capable of causing chronic infections resulting in congenital disease and has the ability to evade natural host defences.
Application Notes: F411E12 can be co-crystallized with SAG1, which enables the mode of binding to be elucidated.
Antibody first published in:
Graille et al. Crystal structure of the complex between the monomeric form of Toxoplasma gondii surface antigen 1 (SAG1) and a monoclonal antibody that mimics the human immune response. J Mol Biol. 2005 Nov 25;354(2):447-58. Epub 2005 Sep 30. PMID:16242717
Note on publication:
Describes the generation of F411E12 Fab and its co-crystallization with SAG1. The epitope binding site was determined and it was found that netiher homodimerization or prevents access to the ligand binding site (which are necessary to neutralize parasite entry into host cells).