利用最小二乘法判断同位素标记肽的假阳性  

Evaluation on False-Positive of Isotope-Labeled Peptides Using Least-Square Method

作　　者：宋培明[1,2] 张扬[2] 颜志国[1] 骆建华[1] 刘银坤[2] 杨芃原 陈先[2] 

机构地区：[1]上海交通大学生命科学技术学院,上海200240 [2]复旦大学生物医学研究院,上海200032

出　　处：《上海交通大学学报》2009年第1期15-18,24,共5页Journal of Shanghai Jiaotong University

基　　金：上海市科委国际合作项目(06SR07109);国家(“十五”)科技攻关项目资助(2002BAC11A11,2004BA711A19);国家自然科学基金资助项目(20328508,30670574);国家高科技研究发展计划(863)项目资助(2006AA020805)

摘　　要：提出了1种判别标记肽假阳性的方法,根据同位素分布的概率原理计算出不同标记效率下的理论同位素分布,利用最小二乘法拟合得到标记肽的标记效率,根据标记肽的假阳性阈值来判断标记肽的假阳性,并使用本方法判断了比较蛋白质组试验中的3个标记肽.结果表明,在这3个标记肽中有2个阳性标记肽结果,1个假阳性标记肽,说明此方法简单可靠,可用于判定标记肽的假阳性,衡量标记肽和正常肽之间的相似性,判断质谱峰型的变化,排除标记肽假阳性对蛋白质定量的影响.A simple method to evaluate the false positive of isotope-labeled peptides was designed and developed. Based on the probability model of isotope distribution, the theoretical isotope distribution with different label efficiency were calculated and the label efficiency of peptide labeled was evaluated by comparing the experimental and theoretical isotope distribution using the least-square method. The peptide labeled was determined as false-positive when its label efficiency was below the threshold. The method was employed to evaluate the false positive of three peptides labeled in a comparative proteomics, and two of them were determined as positive while the third was a false positive. This method will facilitate the accurate quantification in comparative proteomies.

关 键 词：最小二乘法 同位素分布 比较蛋白质组 氨基酸同位素标记定量 

分 类 号：Q657.63[生物学—生物物理学]