Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “PENTOSES”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,045 records · Page 58Linked to original sources
PubMed1973

Activities of enzymes of the oxidative and the reductive pentose phosphate pathways in heterocysts of a blue-green alga.

Preparations of heterocysts of Anabaena cylindrica Lemm. had 7- to 8-fold higher activities of glucose 6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase, 2-fold more hexokinase activity, and 0.02 to 0.06 times as much ribulose diphosphate carboxylase and glyceraldehyde 3-phosphate dehydrogenase activities as did whole filaments per milligram soluble protein in cell-free extracts. Time courses of solubilization of glucose 6-phosphate dehydrogenase activity indicated that heterocysts contain 74 to 80% of the total activity of this enzyme in filaments.

Journal Article↗
PubMed1978

Isoenzymes of the Glycolytic and Pentose Phosphate Pathways in Proplastids from the Developing Endosperm of Ricinis communis L.

Two isoenzymes each of hexose-P isomerase, aldolase and 6-P-gluconate dehydrogenase have been found in the endosperm of developing castor beans (Ricinus communis L.). One isoenzyme for each activity is present in the proplastid fraction. Only one form of glucose-6-P dehydrogenase was found. It is suggested that the partition of an enzyme activity between cytosol and plastid is regulated by the synthesis of isoenzymes which are subcellular site specific. In addition, this report describes the use of diethylaminoethyl-Sephadex A-25 sievorptive chromatography for the preparation of plant enzymes.

Journal Article↗
PubMed1982

The involvement of the pentose shunt in thyroid metabolism after stimulation with TSH or with immunoglobulins from patients with thyroid disease. 1. The generation of NADPH in relation to stimulation of thyroid growth.

It has been shown previously that both thyrotrophin (TSH), and also immunoglobulins (Ig) derived from patients with goitrous Graves' disease, stimulate DNA-synthesis in guinea-pig thyroid tissue maintained in vitro. Here we describe the use of the same in vitro system and methods of quantitative cytochemistry to test the effect of these substances on the generation of NADPH, which is another indicator of the potential for growth. As could be predicted by its trophic action, TSH stimulated the generation of NADPH by glucose 6-phosphate dehydrogenase. The Ig-fraction from normal subjects depressed this activity. The Ig-fraction from Graves' disease patients with goitres stimulated the generation of NADPH, whereas the Ig from patients with Graves' disease but with minimal enlargement of the thyroid gland behaved like normal Ig. A similar lack of stimulation was found with Ig from patients with Pendred's syndrome, other dyshormonogenetic goitres, and autonomous single adenomas. In all specimens tested, there was good correlation between the amount of DNA-synthesis, measured by Feulgen cytophotometry, and the activity of glucose 6-phosphate dehydrogenase activity that generated NADPH. These results support the concept that there is a distinct type of autoantibody that influences thyroid growth.

Animals↗
PubMed1982

The involvement of the pentose shunt in thyroid metabolism after stimulation with TSH or with immunoglobulins from patients with thyroid disease. II. The reoxidation of NADPH and stimulation of hormone synthesis.

Reducing equivalents derived from the tissue re-oxidation of NADPH (NADPH-diaphorase) have been implicated in the peroxidation that is involved in the organification of iodine in the production of thyroid hormones. Immunoglobulin (Ig) fractions from patients with thyroid diseases and from normal controls, in a standard dose of 125 micrograms/ml and 0.3 microunits/ml thyrotrophin (TSH) were incubated with segments of guinea-pig thyroid gland maintained in vitro. A quantitative cytochemical study was made on how these fractions influenced the enzyme activity. A good correlation was found between the ability of such Ig fractions to stimulate the NADPH-diaphorase activity and (1) the degree of hyperthyroidism in the patients and (2) the amount of T3 secreted by the thyroid segments in vitro.

Animals↗
PubMed1980

Biochemical genetics of the pentose phosphate cycle: human ribose 5-phosphate isomerase (RPI) and ribulose 5-phosphate 3-epimerase (RPE).

1. Staining procedures are described for the detection after starch-gel electrophoresis of ribose-5-phosphate isomerase (RPI) and ribulose 5-phosphate 3-epimerase (RPE). 2. Both RPI and RPE were detected in all human tissues including red cells, lymphocytes and fibroblasts. 3. No evidence was found for more than one structural gene locus for either enzyme. 4. No allelic variants of either enzyme were found in erythrocyte lysates from over 200 unrelated individuals. 5. Preliminary data are presented which suggest that differences in tissue RPE isozyme patterns may be due to endogenous proteolytic activity. 6. Electrophoretic analysis of RPE and RPI isozyme patterns in extracts of man/mouse hybrid cells indicates that RPE is probably a dimer and RPI may also be polymeric.

Animals↗