Complementary MALDI MS and SALD ICP MS detection of a single separation record for metalloprotein analaysis
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| Year of publication | 2013 |
| Type | Conference abstract |
| MU Faculty or unit | |
| Citation | |
| Description | Metals play a crucial role in physiology and pathology of biological systems. It has been estimated that the metalloproteins encompass about one third of all proteins. A novel method for comprehensive multidimensional analysis of metalloproteins is presented here. This approach is based on an off-line coupling of a single micro-column separation run to both substrate-assisted laser desorption (SALD) inductively coupled plasma (ICP) mass spectrometry (MS) and matrix-assisted laser desorption/ionization mass spectrometry (MALDI) MS. The effluent fractions are collected on a custom-designed Au-coated polyethylene terephthalate glycol (PETG) sample target that is compatible to both MS methods. The whole concept is demonstrated on analysis of rabbit-liver metallothionein (MT) isoform mixture. The MTs are separated by capillary electrophoresis (CE) coupled to MALDI MS/SALD ICP MS via a liquid junction interface and a sub-atmospheric deposition chamber. MALDI MS and SALD ICP MS provide information about both molecular mass of present proteins and metal distribution and quantity, respectively. We believe the presented method is a viable alternative to on-line coupling employing electrospray ionization and nebulizer ICP MS. The off-line hyphenation allows decoupling separation and both detection processes in time and space and offers further options, e.g. re-analysis or archiving of the separation record, laser-induced fluorescence detection or on target protein digestion. |
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