Detail Mass-spectrometric investigations of the biochemistry pertaining to lipid peroxidation Bibliografi Author: Baker, Andrew G. ; Novotny, Milos (Advisor) Topik: CHEMISTRY; ANALYTICAL|CHEMISTRY; BIOCHEMISTRY Bahasa: (EN )    ISBN: 0-599-66859-8     Penerbit: Indiana University     Tahun Terbit: 2000     Jenis: Theses - Dissertation Fulltext: 9962758.pdf (0.0B; 0 download) Abstract Lipid peroxidation has been widely implicated in a number of different pathophysiological conditions and disease states. Diabetes is one such disease where several of the associated complications are either caused by, or exacerbated by lipid peroxidation. Several experiments utilizing mass spectroometry were used to study different aspects of lipid peroxidation in relation to diabetes. Using the C57BL/Ks db/db mouse as an animal model of the human Type II diabetes, metabolic profiling experiments were performed, with the levels of lipid peroxidation-related compounds monitored as a function of dietary fat or antioxidant intake. In another model system, the red blood cells from either the db/db or db/+ (non-diabetic) mouse were investigated. Lipid peroxidation-related compounds were extracted from the erythrocyte membrane using supercritical fluid extraction and analyzed through gas chromatography coupled with mass spectrometry. The erythrocyte fatty acid composition was strongly influenced by either disease state or the dietary intake of fat. Levels of lipid peroxidation-related compounds were elevated in diabetic erythrocytes. A dietary supplement with menhaden oil altered the levels of such compounds originating from the n-3 fatty acids. A supplementation with vitamin E resulted in a marked reduction in the levels of lipid peroxidation-related volatile compounds. Interactions between protein amino groups and alkenals formed as a result of lipid peroxidation were subsequently studied. Using model proteins and a peptide with only one reactive lysine, the heterogeneous products formed during the reaction were investigated using mass spectrometry and nuclear magnetic resonance spectroscopy. A rapid Schiff-base condensation was followed by further reactions, resulting in the formation of variously substituted pyridinium derivatives and pyridinium crosslink species. Tandem mass spectrometry experiments were performed to explore the dissociation behavior for the peptides containing pyridinium-derivatized lysine moieties. Diagnostic ions specific to the derivatized lysine were observed. Decomposition pathways have been proposed for the formation of these ions. In addition, a novel method for performing collisional activation using an ion trap mass spectrometer was developed. The signal from a random-noise generator was multiplied with a single-frequency excitation signal and the resultant waveform was applied to the endcap electrodes of the ion trap to collisionally activate precursor ions during the tandem mass spectrometry experiments. The advantages of this novel activation method were demonstrated using peptide and carbohydrate ions. Opini Anda Klik untuk menuliskan opini Anda tentang koleksi ini! Lihat Sejarah Pengadaan  Konversi Metadata   Kembali

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