In the light of the kinetic studies reported in this paper, the nucleoside phosphotransferase of carrot is considered as an enzyme possessing two hydrolytic sites, binding the phosphate donor, and one transfer site, engaging the nucleoside acceptor. The purification of the protein used in these studies, with phenylphosphate as the donor and uridine as the acceptor, is described. In addition to ...

IN a previous communication [Martland and Robison, 1924] it was shown that after blood has been laked with distilled water a rapid increase in the amount of inorganic phosphate occurs even at room temperature. The change is still more rapid at 370 but is entirely inhibited when the blood is laked with 1 00 trichloroacetic acid, which indicates that it is due to the enzymic hydrolysis of phospho...

Many food raw materials contain natural antioxidants which exert control of oxidative processes in the living cells. Among antioxidative agents are found enzymes such as superoxide dismutase, glutathione peroxidase and glucose oxidase-catalase. Among naturally occurring non-enzymic antioxidants are carotenoids, especially astaxanthin (e.g. in fish), tocopherols in oils and other phenolic compou...

Epithelial cells from hamster small intestine, in short term culture, incorporated [carbinol-14C]retinol into a compound that is identical to synthetic retinyl phosphate, as judged by chromatography on DEAE-cellulose, silicic acid, and thin layers of silica gel. The biological compound displays the same absorption spectrum as does synthetic retinyl phosphate with a maximum at 325 nm. Hydrolysis...

We describe a mechanized method for determining total estrogens in plasma during the last trimester of pregnancy. This method involves rapid enzymic hydrolysis, automatic extraction (in a tube) with cyclohexane/ethyl acetate, purification of the extracted material by anion-exchange chromatography on a disposable "mini-column" of Dowex AG1 X 2 (acetate form), and continuous-flow fluorometric qua...

Ten murine monoclonal antibodies have been produced that are specific for bovine milk lipoprotein lipase. One monoclonal antibody, bLPL-mAb-7, inhibited completely the apolipoprotein C-II (apo-C-II)-dependent enzymic hydrolysis of trioleoylglycerol in a phospholipid-stabilized emulsion, but had no effect on the hydrolysis of the water-soluble substrate p-nitro-phenylacetate. Four times more bLP...

One of the more prominent characteristics of intracellular peptidases is their remarkable susceptibility to the presence in the hydrolysis mixture of specific activators and inhibitors. The present investigation was undertaken to determine whether these relationships would remain unchanged if the activator or inhibitor were injected into the intact animal prior to the removal of the tissue to b...