Localization of Phosphate Dependent Glutaminase in Ascites Fluid of Ovarian Cancer Patient


Department of Metabolic Regulation, Chittaranjan National Cancer Institute, Calcutta, India


Phosphate dependent glutaminase was purified from ascites fluid of ovarian cancer patients. The purified enzyme showed a final specific activity of 110 unit / mg protein with 72 fold purification and 21% yield. Purified enzyme gives one dark band of Mr ~65.5 KD and two light bands of Mr ~47.5 KD and ~45 KD respectively on 10% SDS-PAGE. One major immunoreactive band was found in trans-immunoblot analysis using antibodies against rat kidney and ascites fluid glutaminase raised in rabbit and mice respectively. Phosphate dependent glutaminase enzyme purified from mitochondria of malignant and non malignant ovarian tissue also showed bands of same molecular weight on 10% SDS-PAGE and gave same immunoreactive bands in trans-immunoblot like the purified glutaminase from ascites fluid. This result was confirmed by using the specific activity stain for glutaminase, which indicates that same enzyme activity is probably due to leakage of the same enzyme from malignant tissue into the ascites fluid. The purified enzyme from human peritoneal fluid showed a high specificity toward glutamine, therefore is a true glutaminase. Moreover, ascites fluid taken from patients of different age group with different stages of ovarian carcinoma revealed the presence of same glutaminase on 10% SDS-PAGE, and exhibited immunoreaction on ELISA, trans-immunoblot and dot immunoblot analysis. Pathology & Oncology Research, Vol 6, Nr 3, 217-223, 2000

Key words: Ovarian cancer; ascites fluid; glutaminase

Received: Apr 17, 2000; accepted: May 18, 2000
Correspondence: Putul MAITY, Department of Metabolic Regulation, Chittaranjan National Cancer Institute, 37, S. P. Mukherjee Road, 16 Calcutta 700 026, India; Tel: 475-9313/7606, Fax: 91-33-475-7606

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