title: New variation on a theme: structure and mechanism of action of hydrolytic antibody 7F11, an aspartate rich relation of catalytic antibodies 17E8 and 29G11.
abstract: A computer model, based on homology, of the catalytic antibody 7F11 that catalyses the decomposition of the benzoate ester of a dioxetane resulting in chemiluminescence is reported. Antibody 7F11 has 89% identity in the V(L) domain, and 72% identity in the V(H) domain with hydrolytic antibodies 17E8 and 29G11 previously reported by Scanlan et al. These were also raised against a phosphonate containing hapten. The antigen-binding site of antibody 7F11 whilst similar to that of 17E8 has aspartic acids at positions 33H and 35H, reminiscent in position of the catalytic residues found in aspartate proteinases such as pepsin. AutoDock 3.0 has been used to identify the best binding mode for the hapten. Molecular dynamic simulations have also been undertaken to examine any major conformational changes induced by hapten binding. A mechanism for benzoate ester hydrolysis involving the aspartic acid side-chains is proposed. Construction of a single-chain variable fragment (scFv) of 7F11 is also reported.
authors.affiliation: School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
authors.forename: Simon S J
authors.initials: SS
authors.lastname: Cross
authors.forename: Kevin
authors.initials: K
authors.lastname: Brady
authors.forename: James D
authors.initials: JD
authors.lastname: Stevenson
authors.forename: Jenny R
authors.initials: JR
authors.lastname: Sackin
authors.forename: Nigel
authors.initials: N
authors.lastname: Kenward
authors.forename: Anja
authors.initials: A
authors.lastname: Dietel
authors.forename: Neil R
authors.initials: NR
authors.lastname: Thomas
mesh_terms: D017151:Antibodies, Catalytic / Q000737:chemistry*; D001224:Aspartic Acid; D003198:Computer Simulation; D015870:Gene Expression; D006868:Hydrolysis; D007128:Immunoglobulin Fragments / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D007143:Immunoglobulin Heavy Chains / Q000737:chemistry; D007147:Immunoglobulin Light Chains / Q000737:chemistry; D007135:Immunoglobulin Variable Region / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D007700:Kinetics; D008958:Models, Molecular; D013329:Structure-Activity Relationship
chemical_list: D017151:Antibodies, Catalytic; D007128:Immunoglobulin Fragments; D007143:Immunoglobulin Heavy Chains; D007147:Immunoglobulin Light Chains; D007135:Immunoglobulin Variable Region; C055966:immunoglobulin Fv; D001224:Aspartic Acid