title: Effect of acetylation on monoclonal antibody ZCE-025 Fab': distribution in normal and tumor-bearing mice.
abstract: Studies were performed to determine in vitro and in vivo effects of acetylation on Fab' fragments of ZCE-025, a monoclonal anti-CEA antibody. Isoelectric focusing revealed a drop in isoelectric point of 1.7 pI units following acetylation. Biodistribution studies of acetylated and nonacetylated [111In]Fab' were performed in normal BALB/c mice and in nude mice bearing the T-380 CEA-producing human colon tumor. The acetylated fragments remained in the vascular compartment longer and had significantly diminished renal uptake of 111In compared to controls. While acetylation itself effected a 50% drop in immunoreactivity, tumor uptake of the acetylated and nonacetylated 111In-labeled Fab' fragments was comparable, with the exception of one data point, through 72 h.
authors.affiliation: Department of Nuclear Medicine, Veterans Administration Medical Center, San Diego, CA 92161.
authors.forename: J P
authors.initials: JP
authors.lastname: Tarburton
authors.forename: S E
authors.initials: SE
authors.lastname: Halpern
authors.forename: P L
authors.initials: PL
authors.lastname: Hagan
authors.forename: E
authors.initials: E
authors.lastname: Sudora
authors.forename: A
authors.initials: A
authors.lastname: Chen
authors.forename: D M
authors.initials: DM
authors.lastname: Fridman
authors.forename: A E
authors.initials: AE
authors.lastname: Pfaff
mesh_terms: D000107:Acetylation; D000818:Animals; D000911:Antibodies, Monoclonal / Q000493:pharmacokinetics*; D002272:Carcinoembryonic Antigen / Q000276:immunology*; D007140:Immunoglobulin Fab Fragments / Q000493:pharmacokinetics*; D007205:Indium Radioisotopes / Q000008:administration & dosage / Q000378:metabolism; D007525:Isoelectric Focusing; D007668:Kidney / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009374:Neoplasms, Experimental / Q000378:metabolism*; D014018:Tissue Distribution
chemical_list: D000911:Antibodies, Monoclonal; D002272:Carcinoembryonic Antigen; D007140:Immunoglobulin Fab Fragments; D007205:Indium Radioisotopes