The thesis consists of two parts targeting the characterization of chromatographic behavior of linear tryptic and cyclic peptides containing oxidized methionine (Met) in reversed-phased chromatography. The retention order of methionine-containing peptide analogues was observed to be the same in both studies: Met oxide < Met dioxide < Met. For linear tryptic peptides, the magnitude of the retention time shift may vary dramatically: from –9 % to +0.36 % acetonitrile. Particularly, large negative retention time shifts are found mostly associated with methionine being in the hydrophobic face of an amphipathic helix. Contrary to previously reported observations, I demonstrate for the first time that methionine oxidation may increase peptide hydrophobicity, this occurs only when methionine is in the N3 position of the N-capping stabilization motif preceding an amphipathic helix. In the second study, the effect of peak splitting was observed for some Met oxide-containing cyclolinopeptides, which most likely appear due to diastereomerization.
| Identifer | oai:union.ndltd.org:MANITOBA/oai:mspace.lib.umanitoba.ca:1993/30202 |
| Date | January 2014 |
| Creators | Lao, Ying |
| Contributors | Krokhine, Oleg (Chemistry), Perreault, Helene (Chemistry) O'Neil, Joe (Chemistry) Aliani, Michel (Human Nutritional Science) |
| Publisher | Elsevier, John Wiley and Sons |
| Source Sets | University of Manitoba Canada |
| Detected Language | English |
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