Oscar Yanes1, Francesc X. Avilés1, Ryan Wenzel2, Alexis Nazabal2, Renato Zenobi2, and Juan J. Calvete3
- Institut de Biotecnologia i Biomedicina and Departament de Bioquimica i Biol. Mol., Universitat Autònoma de Barcelona, Bellaterra (Barcelona), Spain
- Department of Chemistry and Applied Biosciences, Swiss Federal Institute of Technology (ETH), Zürich, Switzerland
- Instituto de Biomedicina de Valencia, C.S.I.C, Valencia, Spain
Proteomic profiling involves identification and quantification of protein components in complex biological systems. Most of the mass profiling studies performed with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) have been restricted to peptides and small proteins (<20 kDa) because the sensitivity of the standard ion detectors decreases with increasing ion mass. Here we perform a protein profiling study of the snake venom Sistrurus miliarius barbouri, comparing 2D gel electrophoresis and reversed-phase high-performance liquid chromatography (HPLC) with a high mass cryodetector MALDI-TOF instrument (Macromizer), whose detector displays an uniform sensitivity with mass. Our results show that such MS approach can render superior analysis of protein complexity compared with that obtained with the electrophoretic and chromatographic approaches. The summation of ion impacts allows relative quantification of different proteins, and the number of ion counts correlates with the peak areas in the reversed-phase HPLC. Furthermore, the sensitivity reached with the high mass cryodetection MS technology clearly exceeds the detection limit of standard high-sensitivity staining methods.