Shotgun proteomics: a qualitative approach applying isoelectric focusing on immobilized pH gradient and LC-MS/MS.

Shotgun proteomics is a rapid and near universal strategy to identify proteins in complex protein mixtures. After protein digestion, the resulting peptide mixture is submitted to two orthogonal techniques: peptides are first separated according to their isoelectric point (pI) by isoelectric focusing (IEF) on immobilized pH gradient (IPG); after peptide extraction, they are then separated in the second dimension according to their hydrophobic properties by reverse phase liquid chromatography (RPLC). Finally, they are detected by tandem mass spectrometry (MS/MS) and proteins are matched by means of bioinformatics software.

History of Biochemistry at the University of Geneva From the Boulevard des Philosophes to Quai Ernest-Ansermet.

A brief account of the developments in biochemistry at the Faculty of Science of the University of Geneva is given from its emergence from organic chemistry at the Ancienne Ecole de chimie to today's Department of Biochemistry at the Section de chimie et biochimie.

Accelerated digestion for high-throughput proteomics analysis of whole bacterial proteomes.

In bottom-up proteomics, rapid and efficient protein digestion is crucial for data reliability. However, sample preparation remains one of the rate-limiting steps in proteomics workflows. In this study, we compared the conventional trypsin digestion procedure with two accelerated digestion protocols based on shorter reaction times and microwave-assisted digestion for the preparation of membrane-enriched protein fractions of the human pathogenic bacterium Staphylococcus aureus.

PICarver: a software tool and strategy for peptides isoelectric focusing.

The use of isoelectric focusing as first dimension of separation is a new trend in shotgun proteomics. In all applications using this approach, peptides are separated into equitable fractions, whereas theoretical distribution of peptides according to p I is heterogeneous. We present the development of a new tool and strategy that generates a fractionation scheme resulting in almost even distribution of peptides per fraction, based on theoretical and experimental data.

Imaging mass spectrometry using peptide isoelectric focusing.

Imaging Mass Spectrometry (IMS) has emerged as a powerful technique in the field of proteomics. The use of Immobilized pH Gradient-IsoElectric Focusing (IPG-IEF) is also a new trend, as the first dimension of separation, in shotgun proteomics. We report a combination of these two outstanding technologies.