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M L Salin

Publications and source records attributed to M L Salin.

40 records · Page 3Linked to original sources
PubMed1974

Superoxide dismutases in polymorphonuclear leukocytes.

Isolated human polymorphonuclear leukocytes were found to contain two distinct superoxide dismutases, electrophoretically identical to the superoxide dismutases found in other human tissues. One is inhibited by cyanide and is located in the cytosol. The other is not inhibited by cyanide and is mitochondrial. These findings disagree with reports by other laboratories, which did not find the cyanide-sensitive cytoplasmic enzyme. The superoxide dismutase-containing preparation of leukocytes released large amounts of superoxide into the medium when the cells were phagocytizing, suggesting that, if the cell population is homogeneous, superoxide production probably takes place on the outer surface of the cell membrane, in addition to inside the phagocytic vacuole.

Cyanides↗
PubMed1973

Oxaloacetate as the hill oxidant in mesophyll cells of plants possessing the c(4)-dicarboxylic Acid cycle of leaf photosynthesis.

Isolated mesophyll cells from leaves of plants that use the C(4) dicarboxylic acid pathway of CO(2) fixation have been used to demonstrate that oxaloacetic acid reduction to malic acid is coupled to the photochemical evolution of oxygen through the presumed production of NADPH. The major acid-stable product of light-dependent CO(2) fixation is shown to be malic acid. In the presence of phosphoenolpyruvate and bicarbonate the stoichiometry of CO(2) fixation into acid-stable products to O(2) evolution is shown to be near 1.0. Thus oxaloacetic acid acts directly as the Hill oxidant in mesophyll cell chloroplasts. The experiments are taken as a firm demonstration that the C(4) dicarboxylic acid cycle of photosynthesis is the major pathway for the fixation of CO(2) in mesophyll cells of plants having this pathway.

Journal Article↗
PubMed1971

Changes of photorespiratory activity with leaf age.

We have discovered that younger leaves do not exhibit the same large increase in photosynthesis as do older ones when the oxygen tension is lowered. This phenomenon was observed in various tobacco and citrus species and indicated less photo-respiration in young leaves. Activities of glycolate oxidase and of glyoxylate reductase were found to be significantly lower in younger leaves than in more mature ones from the same plant. Assays of glycolate content revealed the same trend. Levels of phosphoenolpyruvate carboxylase were only slightly higher in the younger leaves. This finding lessens the possibility of differing enzymatic pathways for CO(2) fixation. It is concluded that the small photorespiratory activity of young leaves can be attributed to a lower activity of the photorespiratory enzymes and perhaps also to a slightly higher rate of internal recycling of CO(2).

Journal Article↗