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Biomedical subjects

J H Cherry

Publications and source records attributed to J H Cherry.

At least 55 records · Page 3Linked to original sources
PubMed1968

De Novo Synthesis of Isocitritase in Peanut (Arachis hypogaea L.) Cotyledons.

Germination of peanut seed is accompanied by a rapid increase in isocitritase (isocitrate lyase, EC 4.1.3.1) during the first 4 days. The presence of cycloheximide (50 mug/ml) during water imbibition inhibited the increase in isocitritase activity. Actinomycin D conversely did not inhibit isocitritase activity until the second day of imbibition while RNA synthesis was inhibited. Germination of peanut seed in (14)C-reconstituted amino acids followed by fractionation of a 20 to 35% ammonium sulfate preparation on a Sephadex G-200 column (57-fold purification) showed that the active enzymic fraction coincided with a large peak of radioactivity. Germination of peanut seed in 45% D(2)O followed by enzyme purification and CsCl equilibrium centrifugation revealed that all the enzyme from D(2)O seed had a higher density than normal isocitritase. These data indicate that isocitritase in peanut seed is synthesized de novo.

Journal Article↗
PubMed1966

Effect of 4,6-Dinitro-o-sec-butylphenol on Phosphorus Accumulation and Incorporation in Tomato Leaf Disks.

The accumulation and incorporation of externally applied P(32) into ATP and the effect of 4,6-dinitro-o-sec-butylphenol (DNBP) on these processes was studied, using tomato (Lycopersicon esculentum Mill.) leaf disks.P(32) was, in most part, actively accumulated into leaf disks with time and was incorporated into ATP and other organic phosphates. DNBP inhibited both P(32) accumulation and ATP generation. The amount of inhibition increased with time of incubation.It is concluded that P(32) accumulation is related to ATP generation. Even though DNBP greatly inhibits phosphorus accumulation, there is little or no effect on its retention.DNBP has the ability to uncouple oxidative phosphorylation. Therefore, it is assumed that its inhibitory effect on phosphate accumulation and generation of high-energy phosphorus esters is related to its inhibition of oxidative phosphorylation.A method is described which appears to be satisfactory to determine the relative amounts of ATP and ADP in leaf disks labeled with P(32).

Journal Article↗
PubMed1966

Effects of protein inhibitors and auxin on nucleic Acid metabolism in peanut cotyledons.

The accumulation of labeled phosphorus into newly synthesized nucleic acids or peanut cotyledon slices incubated with chloramphenicol, puromycin, or 2,4-dichlorophenoxyacetic acid (2,4-D) was reduced. Promotion of nucleic acid synthesis was not noted by any of these chemicals. Chloramphenicol completely inhibited the synthesis of the DNA-RNA fraction at 1.25 x 10(-3)m while soluble and ribosomal RNA was inhibited by 70% and 80%, respectively. At the same concentration messenger RNA was inhibited by only 40%. These effects suggest that chloramphenicol inhibit nucleic acid synthesis in peanut cotyledons in a differential manner. Similar results were noted for DNA at low concentrations of 2,4-D. However, at high concentrations of 2,4-D, DNA as well as RNA fractions were inhibited in a similar manner at a given concentration. Puromycin did not differentially inhibit nucleic acid synthesis except at 2 x 10(-3)m where DNA was least inhibited.Nondifferential inhibition suggests that a common site or precursor pool essential for the synthesis of all nucleic acid fractions is altered. Differential inhibition may be due to the interference with a specific rate-limiting step, directly or indirectly, in the formation of a particular nucleic acid.

Journal Article↗
PubMed1965

Comparison of messenger RNA in photoperiodically induced and noninduced Xanthium buds.

In response to the floral stimulus, Xanthium buds synthesize relatively more messenger RNA than do vegetative buds. This is demonstrated by fractionation, on methylated albumin-kieselguhr columns, of a mixture of nucleic acids from vegetative and induced buds, one being labeled with uridine-H(3) and the other with uridine-2-C(14). While floral induction stimulates a small increase in messenger RNA synthesis as revealed by labeling intact plants, this difference can be magnified by labeling excised buds in solution. From experiments with excised buds from Xanthium plants, it is concluded that buds from photoperiodically induced plants contain more messenger RNA than buds from noninduced ones do.

Carbon Isotopes↗