Characterization of gamma-glutamyltranspeptidase from human pancreatic cancer.
To elucidate the specific changes of pancreatic gamma-glutamyl-transpeptidase (gamma-GTP) associated with malignant transformation, some properties of gamma-GTP purified from pancreatic cancer were compared with those of gamma-GTPs from normal pancreas and other tissues. Four of five pancreatic cancer gamma-GTPs showed distinctly slower electrophoretic mobility than normal pancreatic enzymes. Isoelectric points of pancreatic cancer gamma-GTPs varied in each case, but they were all higher than those of normal pancreatic enzymes. This difference in isoelectric points of gamma-GTPs between cancerous tissue and normal tissue was reduced by neuraminidase treatment. Lectin affinity chromatography revealed two of five pancreatic cancer gamma-GTPs with a greater affinity to concanavalin A (Con A) than normal pancreas gamma-GTPs. Four of five pancreatic cancer gamma-GTPs had a greater affinity to Lens culinaris agglutinin (LCA) than normal pancreas gamma-GTPs. Normal pancreas gamma-GTPs had little affinity to Phaseolus vulgaris erythroagglutinating (E-PHA), but two of five pancreatic cancer gamma-GTPs had an apparent affinity to E-PHA and one of them had a slight affinity to E-PHA. These results indicate that the transformational changes of pancreatic cancer gamma-GTP are mainly induced in the sugar chains of the enzyme molecule, resulting in lower content of sialic acid and higher content of fucose and bisecting GlcNAc residue (the beta-N-acetylglucosamine residue linked at the C-4 of the beta-mannosyl residue of the trimannosyl core of the asparagine-linked sugar chain) as compared with the normal pancreatic enzyme.
Ohta
H
H
Department of Internal Medicine, School of Medicine, Kanazawa University, Japan.
Sawabu
N
N
Odani
H
H
Kawakami
H
H
Watanabe
H
H
Toya
D
D
Ozaki
K
K
Hattori
N
N
D006528:Carcinoma, Hepatocellular / Q000201:enzymology; D002846:Chromatography, Affinity; D006031:Glycosylation; D006801:Humans; D007526:Isoelectric Point; D007668:Kidney / Q000201:enzymology; D037102:Lectins; D008099:Liver / Q000201:enzymology; D008113:Liver Neoplasms; D010179:Pancreas / Q000201:enzymology; D010190:Pancreatic Neoplasms / Q000201:enzymology*; D005723:gamma-Glutamyltransferase / Q000378:metabolism*
D037102:Lectins; D005723:gamma-Glutamyltransferase