Biochemical evaluations of the effects of the sulfhydryl-containing angiotensin-converting enzyme inhibitor (captopril) on the nephrotoxicity induced by doxorubicin in normal rats were carried out. A single dose of doxorubicin (15 mg kg-1) which caused nephrotoxicity was manifested biochemically by the elevation of serum urea after 24 and 48 h of administration. Also a severe decrease in total ...

Primary explants of P388, EL-4, and L1210 murine leukemia cells and of normal mouse bone marrow are shown to require sulfhydryl compounds for proliferation in vitro. Nine extablished cell lines show no stimulation by these compounds. Leukemia cells can lose the sulfhydryl dependence after various periods of adaptation to in vitro culture. Various sulfhydryl compounds have widely differing poten...

An endopeptidase preparation from germinated barley Hordeum vulgare L., cv. Trophy, purified by affinity chromatography and density-gradient electrofocusing, consisted of three or four components. The preparation was only partly resolved by electrofocusing, with evidence of three possible components (pI 4.15, 4.28, and 4.37). Gel filtration on Sephadex G-75 yielded an asymmetrical peak, the maj...

The effect of regucalcin, a regulatory protein in the intracellular signaling process, on superoxide dismutase (SOD) activity in the cytosol of rat liver was investigated. The presence of zinc sulfate (10(-6) or 10(-5) m) or cupric sulfate (10(-6) m) in the enzyme reaction mixture caused a significant increase in SOD activity, indicating that Cu/Zn-SOD may be present in the liver cytosol. SOD a...

The autodigestive proteolytic activity of extracts of cotyledons of mung beans (Phaseolus aureus Roxb.) increased 4- to 5-fold during germination. A similar increase was found in the ability of these extracts to digest added casein or mung bean globulins. The increase occurred after a 2-day lag during the next 2 to 3 days of germination and coincided with the period of rapid storage protein bre...

The occurrence of succinic dehydrogenase [succinic:(acceptor) oxidoreductase, EC 1.3.99.1] in membrane fractions of Micrococcus lysodeikticus was investigated. The enzyme could be purified 10-fold, by deoxycholate treatment. Butanol extraction of membranes yielded an active fraction, nonsedimentable at 130,000 x g for 2 hr and altered in its phospholipid content relative to membranes. The activ...

RNA template-polymerase complex, influenza virus, complementary RNA (synthesis in vitro) The enzyme-template complex of influenza RNA polymerase (fowl plague virus) was purified 200-fold. The sole virus component found in this preparation was RNP-antigen. All attempts to remove the internal template led to an irreversible loss of enzyme activity. The complex was essentially free of nucleases. I...

The sulfhydryl enzyme malate synthase was shown to undergo an X-ray induced aggregation and inactivation in solution (Zipper and Durchschlag, Radiat. Environ. Biophys. 18, 99-121 (1980). Further evidence for the occurrence of aggregation and inactivation and also of fragmentation and partial unfolding of the enzyme upon X-irradiation was obtained by chemical and electrophoretic studies. Irradia...

Histidine decarboxylase from fetal rat liver was purified to near-homogeneity. The purified enzyme has a molecular weight of 210,000, and appears to contain two subunits with molecular weights of 145,000 and 66,000, respectively. The enzyme is inhibited by heavy metals such as Hg2+ and Zn2+ and sulfhydryl-reactive compounds such as 5,5'-dithiobis-2-nitrobenzoic acid. The enzyme is partially dep...