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Articles 1 - 7 of 7

Full-Text Articles in Biochemistry, Biophysics, and Structural Biology

Metabolism Of Arachidonate-Containing Phospholipid Molecular Species In The Murine Macrophage-Like Cell Line, P388d1, Crystal R. Waites May 1991

Metabolism Of Arachidonate-Containing Phospholipid Molecular Species In The Murine Macrophage-Like Cell Line, P388d1, Crystal R. Waites

Electronic Theses and Dissertations

Glycerophospholipids of mammalian cells exist as chemically diverse structures with various fatty acids at the sn-1 and sn-2 positions. Arachidonic acid, a polyunsaturated fatty acid, which may be converted to biologically active eicosanoids such as prostaglandins, thromboxanes, and leukotrienes, is found predominantly in the sn-2 position of glycerophospholipids. The purpose of this study was to examine, at the level of the individual molecular species, the incorporation of arachidonate into phospholipids and its release from phospholipids during stimulation. In this way, the specificity of the enzymes controlling arachidonate metabolism could be examined in order to clarify the processes that control the ...


Nitrogen Dioxide Reaction With Proteins: Evidence For Peptide Bond Cleavage At Lysine Residues, Darryl B. Hood May 1991

Nitrogen Dioxide Reaction With Proteins: Evidence For Peptide Bond Cleavage At Lysine Residues, Darryl B. Hood

Electronic Theses and Dissertations

Nitrogen dioxide (NO$\sb2$), an air pollutant produced by burning fossil fuels and a component of cigarette smoke, is thought to contribute to the pathogenesis of pulmonary diseases, such as emphysema. To gain information on the mechanism by which NO$\sb2$ damages the lung, in vitro exposures of $\alpha\sb1$-proteinase inhibitor ($\alpha\sb1$-PI), elastin, bovine serum albumin (BSA), human serum albumin (HSA) and synthetic poly-L-lysine were performed. A genetic deficiency of $\alpha\sb1$-PI predisposes humans to emphysema and NO$\sb2$ has been hypothesized to damage $\alpha\sb1$-PI, which would leave proteases such as human neutrophil elastase ...


Mouse Mast Cell Proteases: Induction, Molecular Cloning, And Characterization, Wei Chu May 1991

Mouse Mast Cell Proteases: Induction, Molecular Cloning, And Characterization, Wei Chu

Electronic Theses and Dissertations

Tryptase, a mast cell-specific serine protease with trypsin-like specificity, has been identified in a mouse mast cell line (ABFTL-6) based on it's enzymatic activity, inhibition properties, and cross-reactivity to a human mast cell tryptase antibody. The effects of fibroblast-conditioned medium and sodium butyrate on ABFTL-6 mast cell differentiation and tryptase expression have been examined. ABFTL-6 mouse mast cells undergo phenotypic changes upon culturing in media supplemented with fibroblast-conditioned media at 50% or 1 mM sodium butyrate. The induced cells increased in size, had larger and more metachromatic cytoplasmic granules, and increased their total cellular protein about four-fold. Tryptase activity ...


Effects Of Oxysterols On Acyl-Coa: Cholesterol Acyltranferase , Meiling Shih Jan 1991

Effects Of Oxysterols On Acyl-Coa: Cholesterol Acyltranferase , Meiling Shih

Retrospective Theses and Dissertations

Two oxysterols, 20(R and S)-20,25-dihydroperoxy-5-cholesten-3[beta]-ol (HPs) isolated from the mixture of cholesterol autoxidation products have been found to reduce effectively cholesteryl ester accumulation in mouse peritoneal macrophages. The effect of HPs was associated with inhibition of cholesterol esterification by suppressing acyl-CoA:cholesterol acyltransferase activity, and by interruption of acetylated low-density-lipoprotein metabolism. The mechanism by which HPs inhibit ACAT activity is investigated in detail in the present study. With reconstituted liposomes, I demonstrated that an increase in cholesterol concentration did not prevent the inhibitory effect of HPs. On the other hand, inactivated ACAT activity was partially ...


Characterization Of The Mitogen Regulated Protein Receptor , Joseph T. Nelson Jan 1991

Characterization Of The Mitogen Regulated Protein Receptor , Joseph T. Nelson

Retrospective Theses and Dissertations

Mitogen regulated protein (MRP) is a glycoprotein synthesized in murine placenta and secreted into the maternal bloodstream during gestation. The temporal profile of MRP concentration in the plasma during gestation, its synthesis in an organ known to secrete other lactogenic hormones, and its homology to prolactin suggest an hormonal role;A requisite characteristic of a polypeptide hormone is to have a receptor on the plasma membrane of another tissue separate from its site of synthesis. The receptor then mediates the functional effects by binding the hormone. I discovered and characterized a receptor for MRP from murine uterine membrane preparations. The ...


Characterization Of A Potato Proteinase Inhibitor Ii Gene Whose Expression In Not Wound-Responsive , Sanggyu Park Jan 1991

Characterization Of A Potato Proteinase Inhibitor Ii Gene Whose Expression In Not Wound-Responsive , Sanggyu Park

Retrospective Theses and Dissertations

A potato Proteinase Inhibitor II gene (pin2T) was isolated and characterized both at the molecular level and the functional level. The open reading frame as well as the 5[superscript]' and 3[superscript]' flanking regions were sequenced. The coding region and 3[superscript]' flanking region showed 86% and 87% identity with those of the previously isolated wound-inducible potato Proteinase Inhibitor IIK gene (pin2K) sequence, respectively. However, the 5[superscript]' flanking region of the pin2T is highly homologous (91% identity) with that of pin2K from -767 to +29, relative to the transcription start site of the wound-inducible pin2K. The 5[superscript ...


Studies On The Active Site Of Escherichia Coli Adenylosuccinate Synthetase By Chemical Modification And Site-Directed Mutagenesis , Qun Dong Jan 1991

Studies On The Active Site Of Escherichia Coli Adenylosuccinate Synthetase By Chemical Modification And Site-Directed Mutagenesis , Qun Dong

Retrospective Theses and Dissertations

Reaction of E. coli adenylosuccinate synthetase with thiol reagents leaded to modification of one cysteine residue per subunit without significant loss of enzyme activity. Modification of a second cysteine residue occurred under 3.4 M urea and resulted in complete loss of enzyme activity. The remaining two cystein residues were modified only after treatment with 8 M urea. The reactive cystein had been identified as Cys[superscript]291, and the thiol exposed with 3.5 M urea is Cys[superscript]344. When Cys[superscript]344 was replaced by either serine or alanine, the mutant enzymes were as active as the ...