A Novel Approach to in situ Proteome Analysis Using Chemical Inkjet Printing Technology and MALDI-QIT-TOF Tandem Mass Spectrometer

Abstract

Proteomics data obtained by mass spectrometry are now being combined with spatial information. This report outlines a digestion procedure for tissue sections on polyvinylidenfluoride membrane and results of a direct tandem mass spectrometry of mouse brain sections in situ. We succeeded in sequencing the digested peptides such as myelin basic protein, histon H2A, and tubulin β4 directly from tissue sections and transferred membrane. Protein blotting method can provide protein denaturation during the transfer process with electrode heat and with detergent contained in a transfer buffer. In addition to denaturing proteins, chemical inkjet printing technology and a highly sensitive matrix-assisted laser desorption/ionization quadrupole-ion-trap time-of-flight tandem mass spectrometer enabled us to print solutions of enzyme in micro-scale areas on the membranes and obtain high quality data in mass spectrometry/mass spectrometry. This analytical methodology will provide an innovative approach to in situ proteome analysis.