A facile microdialysis interface for on-line desalting and identification of proteins by nano-electrospray ionization mass spectrometry.
The adverse effect of salts, especially inorganic salts, on electrospray ionization mass spectrometry (ESI-MS) is one of the most serious obstacles that might limit its application. Among the numerous desalting approaches, the microdialysis technique is favorable for large molecules, such as proteins. In this work, employing a hollow fiber membrane of cellulose acetate (MWCO 3000 Da), a simple, facile and efficient microdialysis interface with the dead volume of less than 1 microL was constructed for the on-line desalting and identification of proteins dissolved in high salt concentration buffer by nano-ESI-MS. Furthermore, with counterflow added, the desalting procedure was accelerated, and could be finished within 1 min. This system was successfully applied to the analysis of myoglobin dissolved in either high concentration ammonium acetate or sodium chloride buffer. The experimental results showed that, by using such a microdialysis interface, the salt concentration, even as high as 1 M, could be decreased by at least 2 orders of magnitude, while sample loss was less than 10%, demonstrating the potential of such an interface in broadening the application of nano-ESI-MS in the analysis of large molecules.
Sun
Liangliang
L
National Chromatographic Research and Analysis Center, Dalian Institute of Chemical Physics, Chinese Academy of Science, 457 Zhongshan Road, Dalian 116023, China.
Duan
Jicheng
J
Tao
Dingyin
D
Liang
Zhen
Z
Zhang
Weibing
W
Zhang
Lihua
L
Zhang
Yukui
Y
D002021:Buffers; D002482:Cellulose / Q000031:analogs & derivatives / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D008567:Membranes, Artificial; D017551:Microdialysis / Q000295:instrumentation / Q000379:methods*; D008970:Molecular Weight; D009211:Myoglobin / Q000032:analysis; D036103:Nanotechnology; D009862:Online Systems; D011506:Proteins / Q000032:analysis*; D012965:Sodium Chloride / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013997:Time Factors
D002021:Buffers; D008567:Membranes, Artificial; D009211:Myoglobin; D011506:Proteins; C005062:acetylcellulose; D012965:Sodium Chloride; D002482:Cellulose