TY - JOUR
T1 - Cross-linking electrochemical mass spectrometry for probing protein three-dimensional structures
AU - Zheng, Qiuling
AU - Zhang, Hao
AU - Tong, Lingying
AU - Wu, Shiyong
AU - Chen, Hao
N1 - Publisher Copyright:
© 2014 American Chemical Society.
PY - 2014/9/1
Y1 - 2014/9/1
N2 - Chemical cross-linking combined with mass spectrometry (MS) is powerful to provide protein three-dimensional structure information but difficulties in identifying cross-linked peptides and elucidating their structures limit its usefulness. To tackle these challenges, this study presents a novel crosslinking MS in conjunction with electrochemistry using disulfide-bondcontaining dithiobis[succinimidyl propionate] (DSP) as the cross-linker. In our approach, electrolysis of DSP-bridged protein/peptide products, as online monitored by desorption electrospray ionization mass spectrometry is highly informative. First, as disulfide bonds are electrochemically reducible, the crosslinks are subject to pronounced intensity decrease upon electrolytic reduction, suggesting a new way to identify cross-links. Also, mass shift before and after electrolysis suggests the linkage pattern of cross-links. Electrochemical reduction removes disulfide bond constraints, possibly increasing sequence coverage for tandem MS analysis and yielding linear peptides whose structures are more easily determined than their cross-linked precursor peptides. Furthermore, this cross-linking electrochemical MS method is rapid, due to the fast nature of electrochemical conversion (much faster than traditional chemical reduction) and no need for chromatographic separation, which would be of high value for structural proteomics research.
AB - Chemical cross-linking combined with mass spectrometry (MS) is powerful to provide protein three-dimensional structure information but difficulties in identifying cross-linked peptides and elucidating their structures limit its usefulness. To tackle these challenges, this study presents a novel crosslinking MS in conjunction with electrochemistry using disulfide-bondcontaining dithiobis[succinimidyl propionate] (DSP) as the cross-linker. In our approach, electrolysis of DSP-bridged protein/peptide products, as online monitored by desorption electrospray ionization mass spectrometry is highly informative. First, as disulfide bonds are electrochemically reducible, the crosslinks are subject to pronounced intensity decrease upon electrolytic reduction, suggesting a new way to identify cross-links. Also, mass shift before and after electrolysis suggests the linkage pattern of cross-links. Electrochemical reduction removes disulfide bond constraints, possibly increasing sequence coverage for tandem MS analysis and yielding linear peptides whose structures are more easily determined than their cross-linked precursor peptides. Furthermore, this cross-linking electrochemical MS method is rapid, due to the fast nature of electrochemical conversion (much faster than traditional chemical reduction) and no need for chromatographic separation, which would be of high value for structural proteomics research.
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U2 - 10.1021/ac501526n
DO - 10.1021/ac501526n
M3 - Article
C2 - 25141260
AN - SCOPUS:84913553474
SN - 0003-2700
VL - 86
SP - 8983
EP - 8991
JO - Analytical Chemistry
JF - Analytical Chemistry
IS - 18
ER -