基质辅助激光解吸电离-串联飞行时间质谱鉴定鲨鱼硒结合蛋白  

Identification of Selenium-Binding Protein of Shark by MALDI-TOF/TOF Mass Spectrometry

作　　者：王勇[1] 李水明[1] 何曼文[2] 

机构地区：[1]深圳大学生命科学学院,深圳市海洋生物资源与生态环境重点实验室,广东深圳518060 [2]深圳大学生命科学学院,深圳市微生物基因工程重点实验室,广东深圳518060

出　　处：《质谱学报》2013年第5期257-262,共6页Journal of Chinese Mass Spectrometry Society

基　　金：国家自然科学基金(21271131、31070731);深圳市科技研发资金科技条件平台计划重点实验室项目(CXB201005240008A)资助

摘　　要：利用基质辅助激光解吸电离-串联飞行时间质谱(MALDI-TOF/TOF)高置信度地鉴定了原核表达的白鳍鲨硒结合蛋白。实验表明,硒结合蛋白肽段之一被错误指认为胰酶自水解峰和混合谱是影响其未进行串联质谱分析或不能被数据库搜索匹配的主要原因,同时还发现,虽然赖氨酸结尾肽段在MALDI源中信号强度普遍很低,但对它们进行串联质谱分析也可获得较好的谱图质量,部分数据可用于从头测序。考虑以上因素后,硒结合蛋白鉴定覆盖率由35%增至51%。Prokaryotic expressed selenium-binding protein （SBP） of whitetip reef shark was identified by matrix-assisted laser desorption/ionization tandem time-of-flight mass spec- trometry （MALDI-TOF/TOF） with high confidence. One of the peptides of SBP was judged as the self-hydrolysis peak of trypsin and mixture spectra were the reasons that they can not be selected for MS/MS analysis or can not be matched by database searching. In ad- dition, it was found that despite the weak signal intensity of some lysine-terminated pep- tides in MALDI-TOF spectrum, MALDI-TOF/TOF spectra of them can provide nearly complete sequence information even can be used for de novo sequencing. Taking into ac- count the above factors, the identification coverage of selenium binding protein increased from 35% to 51%.

关 键 词：硒结合蛋白 基质辅助激光解吸电离-串联飞行时间质谱(MALDI-TOF TOF) 蛋白质鉴定 数据库 搜索 手工解析 

分 类 号：O657.63[理学—分析化学]