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W H TAYLOR

Publications and source records attributed to W H TAYLOR.

At least 19 recordsLinked to original sources
PubMed1964

ENZYMES OF THE PYRIMIDINE PATHWAY IN ESCHERICHIA COLI. II. INTRACELLULAR LOCALIZATION AND PROPERTIES OF DIHYDROOROTIC DEHYDROGENASE.

Taylor, W. Herman (Portland State College, Portland, Ore.), and Mary L. Taylor. Enzymes of the pyrimidine pathway in Escherichia coli. II. Intracellular localization and properties of dihydroorotic dehydrogenase. J. Bacteriol. 88:105-111. 1964.-Intracellular localization of three enzymes of the pyrimidine pathway in Escherichia coli was studied. Dihydroorotic dehydrogenase was found to be associated with the membrane portion of lysed spheroplasts. Centrifugal fractionation of cell-free extracts showed all the dihydroorotic dehydrogenase activity to be associated with large structures, probably cell wall-membrane fragments. In contrast, all orotidylic decarboxylase activity was found in the cytoplasm in both lysed spheroplasts and cell-free extracts. Aspartate transcarbamylase activity appeared to be particulate in repressed cells, but only 25% was particulate in derepressed cells. Dihydroorotic dehydrogenase was shown to be bound to oxidative particles by oxygen uptake and orotate production from dihydroorotate. A ferricyanide reduction assay, suitable for measuring soluble and particulate enzyme, was devised for dihydroorotic dehydrogenase. Soluble dihydroorotic dehydrogenase was prepared by use of deoxycholate. A 20-fold purification of the enzyme compared to whole-cell activity was achieved by ammonium sulfate fractionation of the deoxycholate-soluble enzyme. Although cytochromes were implicated by cyanide inhibition of aerobic orotate production by particles, the purified enzyme appeared to be separated from the cytochromes, as shown by lack of cyanide inhibition in the ferricyanide assay. The purified soluble enzyme did not react in the aerobic assay previously used by others for assay of this enzyme. In contrast to the degradative dihydroorotic dehydrogenases reported by other workers, the biosynthetic dihydroorotic dehydrogenase of E. coli did not link to pyridine nucleotides.

Carboxy-Lyases↗
PubMed1964

ENZYMES OF THE PYRIMIDINE PATHWAY IN ESCHERICHIA COLI. I. SYNTHESIS BY CELLS AND SPHEROPLASTS.

Taylor, W. Herman (Portland State College, Portland, Ore.), and G. David Novelli. Enzymes of the pyrimidine pathway in Escherichia coli. I. Synthesis by cells and spheroplasts. J. Bacteriol. 88:99-104. 1964.-Upon release from repression, cells and spheroplasts of two mutants of Escherichia coli efficiently synthesized aspartate transcarbamylase and ornithine transcarbamylase, whereas only cells synthesized dihydroorotic dehydrogenase. Ethylenediaminetetraacetate treatment and sucrose incubation of cells were found to be responsible for the loss of dihydroorotic dehydrogenase synthesis. Spheroplasts required the addition of amino acids and an energy source for the synthesis of aspartate transcarbamylase. Uracil repressed synthesis of aspartate transcarbamylase in spheroplasts as well as in cells. Chloramphenicol inhibition and amino acid requirement for increased aspartate transcarbamylase activity in spheroplasts indicated de novo protein synthesis. E. coli 15, R185-482, and E. coli K-12, 496, were used to study the effect of carbon source and stimulation by orotate and dihydroorotate on synthesis of dihydroorotic dehydrogenase. Only E. coli 15, R185-482, showed any stimulation of dihydroorotic dehydrogenase synthesis. When glucose was the carbon source, orotate but not dihydroorotate stimulated; with glycerol as carbon source, dihydroorotate stimulated and orotate acted as a repressor. These results are discussed in terms of induction and pyrimidine supply to the cells.

Amino Acids↗
PubMed1962

Hypernatraemia in cerebral disorders.

Six patients are described in whom cerebral damage was associated with raised plasma sodium and chloride concentrations and with extremely low urinary outputs of sodium and chloride. The patients were not clinically dehydrated and direct determinations showed that the blood and plasma volumes, the endogenous creatinine clearance, and the urinary output of antidiuretic hormone were normal. For these and other reasons it is concluded that the metabolic picture results not from diminished circulatory volume, water deficiency, sodium deficiency, undetected diabetes insipidus or osmotic diuresis, but from the cerebral damage itself. In these and other cited cases, the cerebral damage was localized chiefly in the frontal lobes, hypothalamus or lower brain-stem, thus suggesting a descending pathway, the relationship of which to the pineal area controlling aldosterone secretion requires clarification.

Brain Injuries↗
PubMed1960

Gastric proteolysis in disease. 4. Proteinase activity of extracts of human gastric adenocarcinomata.

Resting gastric juice and extracts of uninvaded gastric mucosa from the stomachs of patients with gastric adenocarcinomata digest plasma protein with either two or three maxima below pH 5. Egg albumen is digested with one or two maxima below pH 5, for the maximum found near pH 3.5 with plasma protein is absent. These properties do not differ significantly from those described in normal subjects. Extracts of gastric adenocarcinomatous tissue from the same patients differ in that plasma protein is digested with only one maximum, at pH 3.2 to 3.4, and egg albumen is not digested at all. The proteinase activity of the carcinomatous tissue probably arises from adenocarcinomatous cells and not from invaded muscle cells or reactive fibrous tissue. These results could be explained either (a) if gastric adenocarcinomatous cells synthesized a quite different proteinase from those of normal gastric mucosa, or (b) if they synthesized a proteinase, which resembled those of normal mucosa in possessing the active centre responsible for maximal activity near pH 3.5 but in which the centre or centres responsible for maximal activity below pH 3, were missing.

Adenocarcinoma↗