Summary: | 碩士 === 國立中正大學 === 化學暨生物化學研究所 === 102 === Overexpression of histone deacetylase (HDACs) was observed in many cancer types. In red blood cells, HDAC6 was found and was related to lung cancer. The purpose of this study is to identify sites of acetylation in human hemoglobin and measure the extent of acetylation in each site by using nanoflow liquid chromatography−nanospray ionization tandem mass spectrometry (nanoLC-NSI/MS/MS). Among the 22 lysine residues in human hemoglobin, we found that acetylation took place at 7 sites. Semiquantification showed that the extents of modification at these sites for smokers and nonsmokers. According to the result, it has no difference in the extents of acetylation between smoker and nonsmoker.
Nitration of proteins is related to inflammation, neurological disease and cancer. We analyzed 15 salivary samples from smokers, nonsmokers and oral cancer patients by immunoaffinity column coupled with nanoLC-NSI/MS/MS. So far, we identified 134 nitroproteins and 105 nitrosoproteins in these samples.
Dried blood spot (DBS) is an emerging microsampling technology for bioanalysis. It remains unknown whether nitration and oxidation in hemoglobin can form artifactually during storage of DBS in air. Therefore, we analyzed hemoglobin extracted from DBS cards and evaluate the stability of its modifications. After placing the DBS cards at 4°C and at room temperature, we isolated hemoglobin from these cards and compared the extent of nitration and oxidation with direct extract hemoglobin. The extents of eleven modifications, including nitration and nitrosylation of tyrosine as well as oxidation of cysteine and methionine residues, in human hemoglobin were measured in the trypsin digest by nanoLC-NSI/MS/MS under the selected reaction monitoring (SRM) mode. The extents of all PTMs are stable up to 14 days at all conditions.
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