Analysis of oligonucleotide and protein via matrix-assisted laser desorption/ionization time-of-flight mass spectrometry using 2-amino-5-nitrothiazole as an effective matrix

Using 2-amino-5-nitrothiazole as a matrix, the matrix-assisted laser desorption/ionization time-of-flight mass spectrometric study of oligonucleotide and protein was carried out. The results show that 2-amino- 5-nitrothiazole has a high efficiency in desorbing and ionizing oligonucleotide and protein molecules. In the positive-ion mode, resolution over 10 000 of pd(T)(10), pd(C)(10), pd(A)(8), pd(G)(10) and pd(5'ATC GAT CGA T 3') can be obtained; 2-amino- 5-nitrothiazole is as effective as the commonly used matrices such as alpha-cyano-4-hydroxycinnamic acid (HCCA) and 3, 5-dimethoxy-4-hydroxycinnamic acid (SA) for the analysis of proteins. In the negative-ion mode, the molecular ion signal of oligonucleotide with molecular mass of over 7 000 can be recorded at a high signal-to-noise ratio. Moreover, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) analysis by utilizing 2-amino-5-nitrothiazole as a matrix shows the tolerance to alkali metal cations to a certain extent.