Subcellular distribution of N-ethylmaleimide-stimulatable glutathione S-transferase activity in rat liver. Evidence of localization of glutathione S-transferase in peroxisomal membrane

Subcellular distribution of glutathione S-transferase activity was investigated as stimulated form by N-ethylmaleimide in rat liver. The stimulated glutathione S-transferase activity was localized in mitochondrial and lysosomal fractions besides microsomes. Among N-ethylmaleimide-treated submitochondrial fractions, glutathione S-transferase activity was stimulated only in outer mitochondrial membrane fraction. In lysosomal fraction, it was suggested that glutathione S-transferase activity in peroxisomes, which is immunochemically related to microsomal transferase, was also stimulated, but not in lysosomes.     

Activation of human plasma prekallikrein by Pseudomonas aeruginosa elastase in vitro

Human plasma prekallikrein, precursor of the bradykinin-generating enzyme, was activated in a purified system under a near physiological condition (pH 7.8, ionic strength I = 0.14, 37 degrees C) by Pseudomonas aeruginosa elastase which is a tissue-destructive metalloproteinase. Compared with that, Pseudomonas aeruginosa alkaline proteinase poorly activated it with a rate as low as less than one-twentieth of that of elastase. The activation by elastase was blocked with a specific inhibitor of elastase, HONHCOCH(CH2C6H5)CO-Ala-Gly-NH2 (10 microM). Generation of kallikrein-like amidolytic activity was also observed in plasma deficient in Hageman factor by treatment with elastase, but was not in plasma deficient in prekallikrein. The kallikrein-like activity generated in Hageman factor deficient plasma as well as the generation process itself was indeed inhibited by anti-human prekallikrein goat antibody. These results suggest that the pathological activation of the kallikrein-kinin system might occur under certain clinical conditions in pseudomonal infections.     

Structure-activity relationships of analogs of the aphid alarm pheromone, (E)-β-farnesene

The structural components essential for activity of the aphid alarm pheromone, (E)-β-farnesene were determined through the synthesis of related farnesene and nor-farnesene analogs. Biological activity was determined with three aphid species belonging to the subfamily Aphidinae. Structural requirements determined to be important for alarm pheromone activity are: The presence of a π-bond (1.34 to 1.39 Å) adjacent to a special free rotational single bond, a (E)-configurational double bond in the central position of the molecule, and a third double bond in the terminal isoprene end of the compound.