title: Low immunoreactivity of canine cholecystokinin-58.
abstract: The immunoreactivity of intact and trypsinized canine cholecystokinin-58 was examined using five C-terminally directed cholecystokinin antisera. Cholecystokinin-58 was nearly as immunoreactive as sulfated, amidated cholecystokinin-8 with one cholecystokinin-specific antiserum and an antiserum with moderate (18%) gastrin cross-reactivity, but two to four times less immunoreactive than the octapeptide with two other cholecystokinin-specific antisera and an antiserum with full cross-reactivity with cholecystokinin and gastrin. The cross-reactivity of cholecystokinin-58 with all antisera was increased by trypsinization, and the magnitude of the increase was related to the degree of trypsinization. These results suggest that it is not possible to measure absolute cholecystokinin levels in tissue and blood with antisera reported to date and that cholecystokinin-58 has a tertiary structure that influences its binding to cholecystokinin antibodies.
authors.affiliation: Research Service, Veterans Administration Medical Center, Kansas City, Missouri.
authors.forename: C M
authors.initials: CM
authors.lastname: Turkelson
authors.forename: J R
authors.initials: JR
authors.lastname: Reeve
authors.forename: T E
authors.initials: TE
authors.lastname: Solomon
mesh_terms: D000818:Animals; D002766:Cholecystokinin / Q000276:immunology* / Q000302:isolation & purification; D003429:Cross Reactions / Q000276:immunology; D004285:Dogs; D007106:Immune Sera / Q000276:immunology; D011487:Protein Conformation; D011863:Radioimmunoassay; D014357:Trypsin
chemical_list: D007106:Immune Sera; C038823:cholecystokinin 58; D002766:Cholecystokinin; D014357:Trypsin