Alkylated Dihydroxybenzoic Acid as a MALDI Matrix Additive for Hydrophobic Peptide Analysis

作者：Fukuyama Yuko^*; Tanimura Ritsuko; Maeda Kazuki; Watanabe Makoto; Kawabata Shin Ichirou; Iwamoto Shinichi; Izumi Shunsuke; Tanaka Koichi

来源：Analytical Chemistry, 2012, 84(9): 4237-4243.

DOI：10.1021/ac300540r

Hydrophobic peptides are generally difficult to detect using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) because the majority of MALDI matrixes are hydrophilic and therefore have a low affinity for hydrophobic peptides. Here, we report on a novel matrix additive, o-alkylated dihydroxybenzoic acid (ADHB), which is a 2,5-dihydroxybenzoic acid (DHB) derivative incorporating a hydrophobic alkyl chain on a hydroxyl group to improve its affinity for hydrophobic peptides, thereby improving MALDI-MS sensitivity. The addition of ADHB to the conventional matrix alpha-cyano-4-hyroxyannamic acid (CHCA) improved the sensitivity of hydrophobic peptides 10- to 100 fold The sequence coverage of phosphorylase b digest was increased using ADHB. MS imaging indicated that hydrophobic peptides were enriched in the rim of a matrix/analyte dried spot when ADHB was used. In conclusion, the addition of ADHB to the standard matrix led to improved sensitivity of hydrophobic peptides by MALDI-MS.

• 出版日期2012-5-1