UNT Theses and Dissertations - 2 Matching Results

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NAD+-Dependent 15-Hydroxyprostaglandin Dehydrogenase from Swine Kidney: Characterization and Kinetic Mechanism

Description: Cytoplasmic 15-hydroxyprostaglandin dehydrogenase from swine kidney was purified to specific activity of 1.2 U per mg protein, by chromatographic techniques. Native molecular weight of enzyme was estimated at 45,000. Enzyme was inhibited by sulfhydryls, diuretics, and various fatty acids. Substrate studies indicated NAD+ specificity and ability to catabolize prostaglandins, except prostaglandin B and thromboxane B. Initial velocity studies gave intersecting plots conforming to a sequential mechanism. 15-keto-prostaglandin exhibited linear noncompetitive production inhibition with respect to either prostaglandin or NAD+; NAD yielded linear competitive production inhibition with respect to NADH. Results, and those of dead-end inhibition and alternated substrate studies, are consistent with an ordered Bi-Bi mechanism: NAD+ is added first, then prostaglandin; then 15-keto-rostaglandin is released, then NADH.
Date: December 1979
Creator: Kung-Chao, Diana T.-Y.
Partner: UNT Libraries

A Quantitative Radioimmunoassay for Phosphoglucose Isomerase and Its Utilization in Detecting Cross-Reactive Material in Variant Forms of Phosphoglucose Isomerase and in Human Tissues

Description: A method for purification and radiolabelling phosphoglucose isomerase was devised in order to develop a sensitive quantitative radioimmunoassay for the detection of the enzyme irrespective of its catalytic activity. For four genetic variants of PGI no difference in the molecular specific activity was observed. In one variant (PGI-Denton), liver and heart tissue extracts, and in mature erythrocytes (as compared to normal erythrocytes), a decreased molecular specific activity was observed which initially may imply that these samples contain cross-reactive material which is not catalytically active.
Date: May 1979
Creator: Purdy, Kimberly L.
Partner: UNT Libraries