Enzyme-linked immunosorbent assay for the detection of cathepsin-kininogen complexes in human plasma.
A simple and sensitive enzyme-linked immunosorbent assay (ELISA) for the determination of cathepsins B-, H- and L-kininogen (B-KG, H-KG, and L-KG) complexes was constructed using a microtiter plate based sandwich technique. The assay range was 7.5-480 ng/ml with three cross-linked cathepsin-kinin-free low molecular weight KG (LMWKGf) complexes. The average within-run coefficients of variation (CV) using three concentrations were 7.5, 7.2 and 9.9% for B-LMWKGf, H-LMWKGf, and L-LMWKGf complexes, respectively. The between-run CV values indicated satisfactory reproducibility for the method. Recoveries of cross-linked B-LMWKGf, H-LMWKGf, and L-LMWKGf complexes from negative control plasma were 127 +/- 7.1, 112 +/- 5.8 and 102 +/- 8.8% (n = 10, mean +/- SD), respectively, whereas the average recovery from phosphate buffer (pH 7.2) containing 0.15 M NaCl, 0.05% Tween-20 and 0.1% bovine serum albumin was 93.1 +/- 8.2% (n = 10, mean +/- SD). It was possible to detect B-KG and H-KG complexes in the plasma of 5/280 and 14/280 patients manifesting acute phase responses. Levels in plasma from healthy individuals were negligible. This ELISA should permit the study of cathepsin metabolism in acute phase disorders.
Takeda
A
A
Department of Clinical Pathology, Fujigaoka Hospital, Showa University School of Medicine, Kanagawa, Japan.
Nakamura
Y
Y
Aoki
Y
Y
D000210:Acute-Phase Reaction / Q000097:blood; D000818:Animals; D002401:Cathepsin B / Q000097:blood*; D056655:Cathepsin H; D002403:Cathepsins / Q000097:blood*; D003546:Cysteine Endopeptidases; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D006801:Humans; D005779:Immunodiffusion; D007704:Kininogens / Q000097:blood*; D011817:Rabbits; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D007704:Kininogens; D002403:Cathepsins; D003546:Cysteine Endopeptidases; D002401:Cathepsin B; C534126:CTSH protein, human; D056655:Cathepsin H