Synthesis and Matrix Properties of α-Cyano-5-phenyl-2,4-pentadienic Acid (CPPA) for Intact Proteins Analysis by Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry

Molecules

Antonio Monopoli¹  CosimaD. Calvano²  Angelo Nacci³  TommasoR.I. Cataldi³ 

[1] Agenzia delle Dogane e dei Monopoli, Ufficio delle Dogane di Bari, Corso De Tullio, 70122 Bari, Italy;Centro Interdipartimentale di Ricerca S.M.A.R.T., 70126 Bari, Italy;Dipartimento di Chimica, Università degli Studi di Bari Aldo Moro, Via Orabona, 70126 Bari, Italy;

关键词: MALDI matrix;    mass spectrometry;    proteomics;    bacteria;    hazelnut;    milk;   

DOI  :  10.3390/molecules25246054

来源: DOAJ

【 摘 要 】

The effectiveness of a synthesized matrix, α-cyano-5-phenyl-2,4-pentadienic acid (CPPA), for protein analysis by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) in complex samples such as foodstuff and bacterial extracts, is demonstrated. Ultraviolet (UV) absorption along with laser desorption/ionization mass spectrometry (LDI-MS) experiments were systematically conducted in positive ion mode under standard Nd:YLF laser excitation with the aim of characterizing the matrix in terms of wavelength absorption and proton affinity. Besides, the results for standard proteins revealed that CPPA significantly enhanced the protein signals, reduced the spot-to-spot variability and increased the spot homogeneity. The CPPA matrix was successful employed to investigate intact microorganisms, milk and seed extracts for protein profiling. Compared to conventional matrices such as sinapinic acid (SA), α-cyano-4-hydroxycinnamic acid (CHCA) and 4-chloro-α-cyanocinnamic acid (CClCA), CPPA exhibited better signal-to-noise (S/N) ratios and a uniform response for most examined proteins occurring in milk, hazelnut and in intact bacterial cells of E. coli. These findings not only provide a reactive proton transfer MALDI matrix with excellent reproducibility and sensitivity, but also contribute to extending the battery of useful matrices for intact protein analysis.

【 授权许可】

Unknown