Optimization in Detecting Multiply-charged Protein Ions using MALDI TOF-MS

Jihyeon Lee,Taehee Kim,Jangmi Hong,Jeongkwon Kim

doi:10.5478/msl.2013.4.1.21

Abstract

The effects of trifluoroacetic acid (TFA) were evaluated on the generation of multiply charged ions of cytochrome c in a 2-nitrophloroglucinol (2-NPG) matrix in high-vacuum, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The presence of 1% TFA in the 2-NPG matrix solution was more effective in generating multiply charged protein ions than matrix solutions containing 0.1% or 0% TFA. Regarding the matrix itself, with 1% TFA, 2-NPG was significantly more effective in generating multiply charged ions than 2,5-dihydroxybenzoic acid (2,5-DHB). The maximum charge state of cytochrome c was +8 when using a 2-NPG matrix containing 1% TFA.

Highlights

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a soft ionization technique frequently used for the analysis of proteins
Note that 2-NPG is a novel matrix used to enhance the generation of multiply charged protein ions in high-vacuum MALDI-MS analysis. 2,5-DHB is one of the most commonly used matrix materials in MALDI-MS analyses.[5]
The MALDI mass spectrum of cytochrome c using the 2-NPG matrix without any trifluoroacetic acid (TFA) contains peaks representing three charge states: +1, +2, and +3 (Figure 2(a))

Summary

Introduction

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a soft ionization technique frequently used for the analysis of proteins. Abstract: The effects of trifluoroacetic acid (TFA) were evaluated on the generation of multiply charged ions of cytochrome c in a 2-nitrophloroglucinol (2-NPG) matrix in high-vacuum, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The presence of 1% TFA in the 2-NPG matrix solution was more effective in generating multiply charged protein ions than matrix solutions containing 0.1% or 0% TFA.

Results

Conclusion