Dual quinone tagging for MALDI-TOF mass spectrometric quantitation of cysteine-containing peptide.
Dual quinone tagging for MALDI-TOF mass spectrometric quantitation of cysteine-containing peptide.
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DOI：
10.1021/ac501703d
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发表时间：
2014-08
影响因子：
7.4
通讯作者：
Rongna Ma;Junjie Hu;Z. Cai;H. Ju
中科院分区：
文献类型：
--
作者：
Rongna Ma;Junjie Hu;Z. Cai;H. Ju
A dual quinone tagging strategy is designed for quantitation of cysteine-containing peptide (CCP) with MALDI-TOF mass spectrometry. The quinone compounds can rapidly and specifically bind to the thiol group of cysteine residues by a Michael addition reaction, which is used to identify both CCP and the number of cysteine residues in CCP through the direct observation of untagged and tagged products. After reduced with DL-dithiothreitol, the intramolecular disulfide bond can also be identified. Using benzoquinone (BQ) and methyl-p-benzoquinone (MBQ) as dual tags and a peptide with an amino acid sequence of SSDQFRPDDCT (C-pep1) as a model target, respectively, the quantitation strategy is performed through the intensity ratio of MBQ-tagged C-pep1 to BQ-tagged C-pep1 as the internal standard. The logarithm value of the intensity ratio is proportional to C-pep1 concentration in a range from 5.0 to 5000 nM. The limit of detection is as low as 2.0 nM. The proposed methodology provides a novel tool for rapid characterization, identification, and quantitation of biomolecules containing thiol reactive sites and has a promising application in the large-scale detection and analysis of cysteine-containing biomolecules.
