title: Arginine carboxypeptidase (CPR) in human plasma determined with sandwich ELISA.
abstract: There are two types of carboxypeptidases present in human blood, carboxypeptidase N (CPN) and arginine carboxypeptidase (CPR). CPR is generated during coagulation from a precursor (proCPR) which can be converted to the active form by trypsin in vitro. Since it is difficult to distinguish the two types of carboxypeptidases in human blood by the measurement of enzyme activity, we established a quantitative sandwich ELISA by which CPR can be quantitated. The amount of CPR in plasma, fresh serum and heated serum were essentially the same. Therefore the ELISA assay does not distinguish proCPR, activated CPR and inactivated CPR. With the ELISA method, CPR was quantitated in plasma from fifty patients with rheumatoid arthritis and eleven patients with severe hepatitis as well as healthy individuals. The amount of CPR in plasma obtained from patients with rheumatoid arthritis was not found to be lower than that of normal subjects. Furthermore, the patients who suffered severe hepatitis and had very low levels of CPR-total were fatal. This suggests that a decrease of CPR level might be a good indication of a patient's prognosis to death by hepatitis.
authors.affiliation: Department of Molecular Biology, Nagoya City University School of Medicine, Aichi, Japan.
authors.forename: X
authors.initials: X
authors.lastname: Guo
authors.forename: A
authors.initials: A
authors.lastname: Morioka
authors.forename: Y
authors.initials: Y
authors.lastname: Kaneko
authors.forename: N
authors.initials: N
authors.lastname: Okada
authors.forename: K
authors.initials: K
authors.lastname: Obata
authors.forename: T
authors.initials: T
authors.lastname: Nomura
authors.forename: W
authors.initials: W
authors.lastname: Campbell
authors.forename: H
authors.initials: H
authors.lastname: Okada
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology; D015153:Blotting, Western; D004591:Electrophoresis, Polyacrylamide Gel; D004792:Enzyme Precursors / Q000097:blood* / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D006801:Humans; D001121:Lysine Carboxypeptidase / Q000097:blood* / Q000276:immunology; D012967:Sodium Dodecyl Sulfate
chemical_list: D000911:Antibodies, Monoclonal; D004792:Enzyme Precursors; D012967:Sodium Dodecyl Sulfate; D001121:Lysine Carboxypeptidase