A quantitative and qualitative study of the transglutaminase-mediated insertion of polyamines into plasma proteins from patients with bronchopulmonary cancer.

The transglutaminase-mediated incorporation of putrescine into proteins of plasma derived from 44 patients with histologically defined bronchopulmonary cancer was compared with that from an age-matched group of 18 patients hospitalized with non-malignant diseases. Two types of kinetic data were obtained over a range of putrescine concentrations 0.09 mM to 0.6 mM. Whereas the plasma from all the patients of the control group showed linear kinetics, that from only 24 patients of the cancer group showed linear kinetics. The remaining 20 showed kinetics typical of inhibition by excess substrate. PAGE analysis of [14C] putreascine-bound plasma proteins showed around 15 different bands. Among these putrescine-binding proteins, we identified, with the help of corresponding specific antisera, four protease inhibitors: alpha 2-macroglobulin, alpha I-antitrypsin, alpha I-antichymotrypsin and antithrombin III.