Detail Analysis of biomolecules using matrix-assisted laser desorption/ionization mass spectrometry Bibliografi Author: Williams, Peter (Advisor); Firestine, Jennifer Ann Topik: CHEMISTRY; ANALYTICAL|CHEMISTRY; BIOCHEMISTRY Bahasa: (EN )    ISBN: 0-599-67383-4     Penerbit: Arizona State University     Tahun Terbit: 2000     Jenis: Theses - Dissertation Fulltext: 9963137.pdf (0.0B; 2 download) Abstract The use of matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry to probe the structure of biomolecules has continued to grow in recent years. Here the use of bioreactive mass spectrometer probes is used to investigate protein conformations. Currently, nuclear magnetic resonance (NMR) and X-ray crystallography are the prime methods for this type of analysis. Both NMR and X-ray studies require large samples and many months to acquire structural data. However, bioreactive probes, coupled to the MALDI-TOF, require small samples and are a rapid, inexpensive method of investigating protein structures. The calcium-binding proteins, calmodulin and alpha-lactalbumin, were examined. Calmodulin has two identical domains connected by a long-central helix. As each of the domains binds two calcium ions the domains become more resistant to proteolytic cleavage. Our data suggests that as calmodulin binds calcium, the central helix folds and has greater stability and higher resistance to cleavage. The analysis of α-lactalbumin, is not only a proof of the ability to detect conformational differences within a protein, but it also contains four disulfide linkages. These linkages prove to have a steric on the ability to obtain excellent results with the bioreactive probes. While the previous proteins undergo a large conformational change, the oxidized and reduced forms of cytochrome c look almost identical in the X-ray crystal structure. The subtle differences in structure are easily and rapidly detected using bioreactive probes and MALDI-TOF mass spectrometry. The reduced form of cytochrome c is more solvent accessible and therefore produced more cleavage patterns early in the digestion. Lastly, the MALDI-TOF is also an ideal method for looking at lipids. The lipid content of adult Drosophila melanogaster from populations which exhibit postponed senescence were compared to control populations of flies. While the lipid quantity of these flies has been examined the lipid content has not. With the use of MALDI-TOF MS it is possible to quickly and accurately examine both of these factors simultaneously. A comparison of the lipid type and quantity of flies undergo early reproduction and those which have delayed reproduction as well as the differences between the sexes, was examined. Opini Anda Klik untuk menuliskan opini Anda tentang koleksi ini! Lihat Sejarah Pengadaan  Konversi Metadata   Kembali

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