稀土金属元素标记行为考察

The Labeling Behavior Study of Rare Earth Elements

稀土金属元素因其与双功能试剂的螯合效率高、对肽段的反相色谱行为和质谱的离子化效率影响小、检测背景低,以及过量的金属离子在检测时不会产生干扰等优点,近年来在生物标记结合质谱定量分析研究领域引起了关注。选取稀土金属中单同位素铽(Tb)、钇(Y)、铥(Tm)、钬(Ho)和镥(Lu)5种元素,通过双功能试剂二乙三胺五乙酸双酸酐(DTPA双酸酐)对合成肽段及蛋白质酶切产物标记的过程进行研究,包括对标记条件进行优化,对该质量标签的色谱行为和共洗脱、标记稳定性、离子交换、动态范围、质谱检测限等现象进行考察。结果表明:铥和钬两元素结合效率最高,分别达到了92.5%和89.9%;稳定性考察结果表明,质量标签在4℃下放置一周仍可检测到95%,若将标记好的标签用于定量研究,则放置时间不能超过两周;多金属标记质量标签可以共洗脱;两种金属浓度差不超过6倍时,由离子抑制带来的影响较小;离子交换结果表明,只有很少部分发生了离子交换,对标记实验没有影响。

Rare earth element combined with mass spectrometry has received extensive attention in recent years because of their high chelating efficiency, chromatographic behavior, ionization efficiency, low background and no interference of excessive metal ions. Monoiso- topic elements of terbium （Tb）, yttrium （Y）, thulium （Tm）, holmium （Ho） and lutetium （Lu） were selected as model in this research, and the synthesis of peptides and digestion products from proteins through the bifunctional reagent DTPA double anhydride was investigated. The labeling conditions were optimized, followed by the examination of chromatographic behavior, co-elution, stability, ion replacement, dynamic range and mass detection limits. The results show that thulium and holmium have the best binding efficiency of 92.5% and 89.9%, respectively. Stability test results show that 95% of the quality tagshave been detected in a week when stored at 4 ℃. Better linear relationship can be gotten when the concentration of metal particles within 6 times. The ion exchange results show that only a small part of the ion exchange takes place, and it has no effect on the labeling experiments.