Alpha-fetoprotein antibody-lectin enzyme immunoassay to characterize sugar chains for the study of liver diseases.
An antibody-lectin enzyme immunoassay (EIA) technique was developed for the analysis of sugar chains of serum alpha-fetoprotein in various liver diseases. The anti-'alpha-fetoprotein'-IgG was coated on a microtiter plate and then treated with periodic acid. A serum sample was added to the plate and then a 'peroxidase'-conjugated lectin was added. The amount of lectin bound to the sugar chain of the 'alpha-fetoprotein' was estimated from the 'peroxidase' activity. The 'peroxidase' activities of 4 different lectins, LCA, Con A, LCA and EPHA, were compared. The LCA/'wheat germ agglutinin' activity ratio and LCA/EPHA activity ratio were increased in liver diseases and LCA/'wheat germ agglutinin' ratio showed a statistically significant difference between the chronic hepatitis and the liver cirrhosis groups (p less than 0.05). Furthermore, when serum samples were pretreated with sialidase, a statistically significant difference was observed in the LCA/EPHA and LCA/Con A ratios between the chronic hepatitis and the hepatoma groups (p less than 0.05). These results indicated that low sialylation at the non-reduced end of the sugar chains of 'alpha-fetoprotein' occurs in liver cirrhosis and that high fucosylation at the reduced end of N-acetylglucosamine residue of 'alpha-fetoprotein' occurs in hepatomas.
Kinoshita
N
N
Department of Biochemistry, Osaka University Medical School, Japan.
Suzuki
S
S
Matsuda
Y
Y
Taniguchi
N
N
D000906:Antibodies / Q000032:analysis*; D015415:Biomarkers / Q000032:analysis*; D002241:Carbohydrates / Q000032:analysis*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D037102:Lectins; D008107:Liver Diseases / Q000175:diagnosis* / Q000378:metabolism; D000509:alpha-Fetoproteins / Q000032:analysis* / Q000276:immunology
D000906:Antibodies; D015415:Biomarkers; D002241:Carbohydrates; D037102:Lectins; D000509:alpha-Fetoproteins