title: The functional effects of biotinylation of anti-angiotensin-converting enzyme monoclonal antibody in terms of targeting in vivo.
abstract: The effect of modification with biotin N-hydroxysuccinimide ester of mouse monoclonal antibody to angiotensin-converting enzyme, anti-ACE Mab 9B9, on its targeting to endothelial cells has been studied in vitro and in vivo. By in vitro assay, Mab 9B9 biotinylated at a biotin/IgG molar ratio in reaction mixture (B/IgG ratio) of 0.7-2.2 bound streptavidin monovalently and retained antigen-binding capacity. Mab 9B9 biotinylated at a B/IgG ratio of 20 and higher bound streptavidin polyvalently. Extensive biotinylation (B/IgG ratio of 60 and higher) led to dramatic reduction of Mab 9B9 Ag-binding capacity and to reduction of Mab 9B9 recognition by goat polyclonal antibody to mouse IgG. Radiolabeled Mab 9B9 biotinylated at a B/IgG ratio of 6 (b6-Mab 9B9) bound effectively to cultured vascular endothelium, with affinity characteristics similar to nonbiotinylated Mab 9B9. Endothelial cells internalized both Mab 9B9 and b6-Mab 9B9 to the same extent (60% internalization at 3 h incubation at 37 degrees C). Degradation of cell surface-associated Mab 9B9 or b6-Mab 9B9 was very low (< 1% as measured by TCA solubility of radiolabel). In contrast, degradation of internalized b6-Mab 9B9 was more profound than that of Mab 9B9 (20 +/- 3% vs 6 +/- 1%, P < 0.01). After injection in rats, radiolabeled b6-Mab 9B9 had a biodistribution pattern similar to that of radiolabeled Mab 9B9. Both preparations effectively accumulated in the lung (15-20% of injected dose/g of tissue vs 2% of injected dose/g of blood).(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Institute for Environmental Medicine, University of Pennsylvania School of Medicine, Philadelphia 19104, USA.
authors.forename: V R
authors.initials: VR
authors.lastname: Muzykantov
authors.forename: V D
authors.initials: VD
authors.lastname: Gavriluk
authors.forename: A
authors.initials: A
authors.lastname: Reinecke
authors.forename: E N
authors.initials: EN
authors.lastname: Atochina
authors.forename: A
authors.initials: A
authors.lastname: Kuo
authors.forename: E S
authors.initials: ES
authors.lastname: Barnathan
authors.forename: A B
authors.initials: AB
authors.lastname: Fisher
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology / Q000378:metabolism* / Q000493:pharmacokinetics; D000937:Antigen-Antibody Reactions; D001426:Bacterial Proteins / Q000378:metabolism; D001710:Biotin / Q000031:analogs & derivatives* / Q000378:metabolism; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000378:metabolism; D006801:Humans; D008168:Lung / Q000378:metabolism*; D008657:Metabolic Clearance Rate; D051379:Mice; D007703:Peptidyl-Dipeptidase A / Q000276:immunology*; D009195:Peroxidase / Q000378:metabolism; D011485:Protein Binding; D011489:Protein Denaturation; D051381:Rats; D017207:Rats, Sprague-Dawley; D019809:Streptavidin; D013388:Succinimides / Q000378:metabolism*; D014018:Tissue Distribution
chemical_list: D000911:Antibodies, Monoclonal; D001426:Bacterial Proteins; D013388:Succinimides; C033788:biotinyl N-hydroxysuccinimide ester; D001710:Biotin; D019809:Streptavidin; D009195:Peroxidase; D007703:Peptidyl-Dipeptidase A