CAJ | 학술논문

对蛋白质样品制备中引入的氨基酸残基的一种现象--蛋白质酶切肽段氨基端的环化修饰现象的初步研究结果显示,很多以谷氨酰胺(Q)或氨乙酰化修饰的半胱氨酸(CAM_C)残基起始的肽段会发生氨基端的环化修饰,且修饰反应不完全,在同一样本中修饰与非修饰两种状态常同时存在,并且环化修饰后的肽段的反相色谱保留时间发生延迟.在数据库检索时添加环化修饰,可以提高蛋白质的鉴定成功率.本研究结果为大规模的蛋白质质谱数据解析提供了有价值的参考.
대단백질양품제비중인입적안기산잔기적일충현상--단백질매절태단안기단적배화수식현상적초보연구결과현시,흔다이곡안선알(Q)혹안을선화수식적반광안산(CAM_C)잔기기시적태단회발생안기단적배화수식,차수식반응불완전,재동일양본중수식여비수식량충상태상동시존재,병차배화수식후적태단적반상색보보류시간발생연지.재수거고검색시첨가배화수식,가이제고단백질적감정성공솔.본연구결과위대규모적단백질질보수거해석제공료유개치적삼고.
Biological mass spectrometry has been developed for the largE-scale protein identification. The successful identification of protein in proteomic study is based on an effective match of MS data to the sequence in database. Because of the diversity and heterogeneity of protein modification, the experimental data obtained by mass spectrometry does not match the theoretical value sometimes, which makes about 90 percent or more of the tandem mass spectra not be effectively identified. This has become one of the most important technique issues to be resolved in current proteome research. The N-terminal cyclization of peptides, as one of a variety of modification introduced in sample preparation, has been preliminarily studied in this work. The result showed that N-terminal cyclization occurred at the most of the glutamine(Q) or carbamoylmethyl-cysteine(CAM_C) residues and the reaction is often incomplete or partial, both types of peptides could often exist in its respective state at the same time, and the behavior of modified peptides in revered phase chromatography is also changed. The success rate of protein identification could be obviously improved if adding the N-terminal cyclization modification in the database searching. These results will be very helpful in the mass spectrometric data analysis of proteomic study.