A Multidetection Platform for Proteome Analysis
| Authors | |
|---|---|
| Year of publication | 2008 |
| Type | R&D Presentation |
| MU Faculty or unit | |
| Citation | |
| Description | An instrumentation platform based on a universal interface for deposition of CE or microLC eluent on a target of a MALDI mass spectrometer will be described. The deposited fractions of proteins or peptides may be analyzed in off-line mode using MALDI mass or tandem mass spectrometry (MS or MS/MS) and native laser-induced fluorescence (LIF) detection or subjected to on-target reactions, such as digestion for protein identification. An additional detection mode is inductively coupled plasma mass spectrometry (ICP MS), nature of which is complementary to soft MALDI MS. We propose substrate assisted laser desorption (SALD) of sample from the target and sample transfer to ICP. Thus, both information about protein identity and content of elements, such as metals or phosphorus are available from a single separation record. Using the platform, sub-picomolar quantities of proteins are detected, digested and identified directly on MALDI target. LIF detection of protein bands is found to be sensitive, fast and generally useful for tryptophan-containing proteins. Although not as sensitive as the on-column LIF detection, on-target LIF detection may be used to select fractions containing proteins. Consequently on-target peptide mass fingerprinting is carried out to identify protein in the selected fractions. For the SALD ICP MS detection, influence of desorption laser fluence, presence of additives or role of substrate is discussed. Selected metals are detected in sub-picomolar amounts. MALD-ICP MS analysis of chromium species (Cr3+ and CrO42-) will be shown to demonstrate the coupling for metal analysis. High separation efficiency is maintained due to the employed liquid junction and fraction deposition. |
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