Alkylated Trihydroxyacetophenone as a MALDI Matrix for Hydrophobic Peptides
Alkylated Trihydroxyacetophenone as a MALDI Matrix for Hydrophobic Peptides
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DOI：
10.1021/ac4018378
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发表时间：
2013-10-15
影响因子：
7.4
通讯作者：
Tanaka, Koichi
中科院分区：
文献类型：
--
作者：
Fukuyama, Yuko;Nakajima, Chihiro;Tanaka, Koichi
由于常规基质的亲水性和对疏水肽的亲和力较低，在基质辅助激光解吸/电离质谱（MALDI-MS）中很难检测到疏水肽。最近，我们报道了烷基化二羟基苯甲酸（ADHB）作为疏水性肽的基质添加剂；然而，在基质分析物干燥点的边缘检测到肽。在这里，我们报道了一种新的基质，烷基化三羟基苯乙酮（ATHAP），这是一种2,4,6-三羟基苯乙酮衍生物，在乙酰基上含有疏水烷基链，因此预计对疏水肽具有亲和力。与α -氰基-4-羟基肉桂酸（CHCA）相比，ATHAP对疏水肽的敏感性提高了10倍，而CHCA对亲水性肽的检测受到抑制。使用ATHAP在整个基质分析物干燥点检测肽，克服了使用ADHB时寻找“最佳点”的困难。此外，ATHAP作为基质单独发挥作用，不像ADHB作为添加剂。在磷酸化酶b酶切分析中，用该基质检测到1pmol CHCA未检测到的疏水肽，证实了ATHAP增加了序列覆盖范围，并可能扩大MALDI-MS中目标分析物的范围。
Hydrophobic peptides are difficult to detect in matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS), because of the hydrophilic properties of conventional matrices and the low affinity for hydrophobic peptides. Recently, we reported on alkylated dihydroxybenzoic acid (ADHB) as a matrix additive for hydrophobic peptides; however, the peptides were detected in the rim of the matrix-analyte dried spot. Here, we report on a novel matrix, alkylated trihydroxyacetophenone (ATHAP), which is a 2,4,6-trihydroxyacetophenone derivative incorporating a hydrophobic alkyl chain on the acetyl group and thus is expected to have an affinity for hydrophobic peptides. ATHAP increased the sensitivity of hydrophobic peptides 10-fold compared with alpha-cyano-4-hydroxycinnamic acid (CHCA), in which the detection of hydrophilic peptides was suppressed. The peptides were detected throughout the entire matrix-analyte dried spot using ATHAP, overcoming the difficulty of finding a "sweet spot" when using ADHB. In addition, ATHAP functioned alone as a matrix, unlike ADHB as an additive. In phosphorylase b digests analysis, hydrophobic peptides, which were not detected with CHCA for 1 pmol, were detected with this matrix, confirming that ATHAP led to increased sequence coverage and may extend the range of target analytes in MALDI-MS.