中文摘要：

利用MALDI-TOF质谱结合磺基异硫氰酸苯酯（SPTTC）化学辅助的从头测序（de novo sequencing）方法,将用固相金属离子亲和色谱（immobilized metal affinity chromatography,IMAC）选择性地从混合物中亲和提取的磷酸肽进行磷酸化位点测定,该方法只有肽键断裂产生的带C端的碎片离子系列（y^＋离子系列）出现在质谱图中,图谱背景清晰,信噪比高,单纯的y^＋片段离子系列使得谱图解析变得非常容易,对于多磷酸化肽的磷酸化位点,不需借助于任何软件,只需简单地计算两峰之间的分子量之差即可确定。

英文摘要：

Phosphorylated peptides have been detected and phosphorylation modified sites have been identified very sensitively by combining immobilized metal affinity chromatography （IMAC） affinity capture with chemically assisted de novo sequencing followed 4-sulfophenyl isothiocyanate （SPITC） derivatization by MALDI-TOF mass spectrometry. The N-terminal sulfonation of phosphopeptide by SPITC enhanced MALDI- TOF-PSD fragmentation signals and produced a spectrum containing only y^＋ ions. This method facilitated de novo sequencing and spectrum interpretation. The characterization of phosphorylated sites can simply calculated from mass differences between the adjacent y-ion, and advanced software is not need.