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Articles 1 - 4 of 4

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

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 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 ...


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 ...