CAJ | 학술논문

磷酸化修饰的分析一直是蛋白质组学研究的热点之一。在鸟枪法的蛋白质组学研究中，通过在数据库检索中设定磷酸化为可变修饰可以直接鉴定磷酸化修饰的位点。但是翻译后修饰的引入会增加数据检索空间，造成鉴定灵敏度的降低。为了解决这一问题，我们构建了一种位点注释的数据库，这种数据库包含蛋白质的磷酸化位点信息，并开发了一种新的数据库检索策略用于磷酸化肽段的可靠鉴定。用不同类型的数据作为分析对象，通过Mascot检索软件对这种新的数据库检索策略进行了考察，证明了这种方法在保证鉴定结果可靠性的前提下提高了磷酸化肽段鉴定的灵敏度。
린산화수식적분석일직시단백질조학연구적열점지일。재조창법적단백질조학연구중，통과재수거고검색중설정린산화위가변수식가이직접감정린산화수식적위점。단시번역후수식적인입회증가수거검색공간，조성감정령민도적강저。위료해결저일문제，아문구건료일충위점주석적수거고，저충수거고포함단백질적린산화위점신식，병개발료일충신적수거고검색책략용우린산화태단적가고감정。용불동류형적수거작위분석대상，통과Mascot검색연건대저충신적수거고검색책략진행료고찰，증명료저충방법재보증감정결과가고성적전제하제고료린산화태단감정적령민도。
Phosphoproteome analysis is one of the important research fields in proteomics. In shotgun proteomics,phosphopeptides could be identified directly by setting phosphorylation as variable modifications in database search. However,search space increases significantly when variable modifications are set in post-translation modifications( PTMs)analysis,which will decrease the identification sensitivity. Because setting a variable modification on a specific type of amino acid residue means all of this amino acid residues in the database might be modified, which is not consistent with actual conditions. Phosphorylation and dephosphorylation are regu-lated by protein kinases and phosphatases,which can only occur on particular substrates. Therefore only residues within specific sequence are potential sites which may be modified. To address this issue,we extracted the characteristic sequence from the identified phosphorylation sites and created an annotated database containing phosphorylation site information,which allowed the searching engine to set variable modifications only on the serine,threonine and tyrosine residues that were identified to be phosphorylated previously. In this database only annotated serine,threonine and tyrosine can be modified. This strategy significantly reduced the search space. The performance of this new database searching strategy was evaluated by searching different types of data with Mascot,and higher sensitivity for phosphopeptide identifi-cation was achieved with high reliability.