Three ammonia-producing enzymes were selected for study, namely adenosine deaminase (adenosine aminohydrolase, EC 3.5.4.4), AMP deaminase (AMP aminohydrolase, EC 3.5.4.6) and urease (urea amidohydrolase, EC 3.5.1 3). Activities were detected after each enzyme preparation was subjected to electrophoresis on both starch gel and cellulose acetate strips. Adenosine deaminase activity had been detec...

In view of the 20to 80-fold elevation of deoxycytidine-5'phosphate (dCMP) deaminase in many human malignant tumors, we have utilized 5-fluorodeoxycytidine (FdCyd) (»administered with tetrahydrouridine (H4Urd) as a combination of antitumor agents against two murine solid tumors which possess high levels of dCMP deaminase. This approach is based on our past studies in which we demonstrated that ...

Homogeneous adenylate deaminase from snail foot muscle deaminated 5'-AMP, 5'-ADP, 5'-ATP and NADH with similar velocity and affinity to all substrates. At millimolar concentration NAD+ was also deaminated to a comparable extent, but NADP+, NADPH and FAD were not substrates for the snail enzyme. The amount of deaminase activity per g of fresh tissue is 5-10 times greater than in the muscle of an...

Extracts of solid mouse tumors were examined for deoxycytidine kinase and deaminase activities. 1beta-D-Arabinofuranosylcytosine nucleotide was formed at a rate of 45 nmoles/hr by Glioma 26/57 and only 14 nmoles/hr by Ridgway osteogenic sarcoma. Deaminase activity was highest in Lewis lung (114 nmoles of 1-Beta-D-arabinofurano-syluridine formed per hr) and in CaD2 (104 nmoles of u-beta-D-arabin...

Adenylate deaminase (AMP deaminase, EC 3.5.4.6) of a high substrate specificity was purified from pig heart by chromatography on cellulose phosphate. The enzyme shows a co-operative binding of AMP [h (Hill coefficient) 2.35, with SO.5 (half-saturating substrate concentration) 5mM]. ATP and ADP act as positive effectors, lowering h to 1.55 and SO.5 to 1 mM. The addition of liposomes (phospholipi...

The rise in adenosine deaminase (ADA) activity in the pleural fluid of tuberculous pleurisy patients, though used for diagnosis, is of unknown origin. In this work, we determined ADA activity and the activities of 2'-deoxyadenosine deaminase and ADA-2 in 350 patients. We also considered whether the results throw light on the origin of high pleural fluid ADA in tuberculous pleurisy and estimated...

Effects of dioctyltin oxide (DOTO) tricyclohexyltin hydroxide (TCHTOH) and tributyltin oxide (TBTO) were examined on some enzymic activities in liver and kidney and biogenic amines level in brain of rats at 24 hours after single subcutaneous administration (25 ƒÊmole/100 g B. Wt.). All the organotin compounds produced a significant increase in the activity of alkaline phosphatase and adenosin t...

Every minute, the world’s population grows, and in order to feed them, crop output agricultural productivity must be improved by adding crucial microorganisms that boost plant yields various ways through nitrogen fixation, secretion of both growth regulators 1-aminocyclopropane 1-carboxylate deaminase, as well some antimicrobial agents. Numerous endophytic bacteria have recently been used incre...