Xu Songyun, Ye Mingliang, Xu Danke, Li Xin, Pan Chensong, Zou Hanfa
National Chromatographic R & A Center, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116011, China.
Anal Chem. 2006 Apr 15;78(8):2593-9. doi: 10.1021/ac051572a.
High concentrations of urea and guanidine hydrochloride are commonly used for the denaturation of protein, which was digested by enzymatic proteolysis for the identification by MS analysis. The presence of these contaminants seriously suppresses the ion signal of analytes in MALDI-TOF MS analysis. Herein, a novel MALDI matrix, 3, 4-diaminobenzophenone (DABP), has been found with high tolerance for these contaminants in MALDI MS analysis. The ion signal of analyte insulin can be detected in the presence of 2 M guanidine hydrochloride and 1.5 M urea using DABP as matrix. The tryptic digest of BSA (400 fmol) in 1 M guanidine hydrochloride or 1 M urea was successfully analyzed without any pretreatment prior to MS analysis. Furthermore, it has been found that this matrix can also effectively suppress the cation ion adduction of the peptides in the presence of high concentrations of metal ions in sample solution.
高浓度的尿素和盐酸胍常用于蛋白质变性，蛋白质经酶解后用于质谱分析鉴定。在基质辅助激光解吸电离飞行时间质谱（MALDI-TOF MS）分析中，这些污染物的存在严重抑制了分析物的离子信号。在此，发现了一种新型的MALDI基质，即3,4-二氨基二苯甲酮（DABP），在MALDI MS分析中对这些污染物具有高耐受性。以DABP为基质，在存在2 M盐酸胍和1.5 M尿素的情况下，可以检测到分析物胰岛素的离子信号。在1 M盐酸胍或1 M尿素中，牛血清白蛋白（400 fmol）的胰蛋白酶消化产物在进行MS分析前无需任何预处理即可成功分析。此外，还发现该基质在样品溶液中存在高浓度金属离子的情况下，也能有效抑制肽的阳离子加合。
