Plasminogen activator: Isolation and purification from lymphosarcoma of ascites bearing mice.

Plasminogen activator secreted by lymphosarcoma (ascites) of mice was purified up to 163-fold by ammonium sulphate fractionation at 35% saturation and chromatography on p-aminobenzamidine-Sepharose 4B. The purified activator contained specific activity of 9980 IU/mg. The plasminogen activator displayed homogeneity by polyacrylamide slab gel electrophoresis and high performance liquid chromatography. The activator consisted of a single polypeptide chain with an apparent molecular weight of 66,000 daltons as determined by sodium dodecyl sulphate-polyacrylamide gel electrophoresis under reducing conditions as well as gel filtration on Sephadex G-100. Distinct differences between this activator and urokinase were discernible in respect of specific activities, fibrin affinity and immunochemical properties. The lymphosarcoma activator appears to be of tissue-type origin since it showed gross similarity to standard tissue plasminogen activator in terms of modes of binding to fibrin and immunological attributes.

Effects of heavy water on mitochondrial respiration and oxidative phosphorylation.

Studies on the influence of heavy water on mitochondrial respiration and oxidative phosphorylation revealed that both isotope and solvent effects, may be responsible for the observed changes. Although the two types of effects could not be totally delineated from each other by the experimental approaches employed, the isotope effect appeared to be primarily responsible for the uncoupling of oxidative phosphorylation, while the inhibition of respiration in the presence of ADP (State 3 respiration) could be a manifestation of the solvent effect.