Protein Cleavage Disulfide Bonds Reduction Metabolite Synthesis and Much More Using Electrochemistry/MS

摘要

Recently, the scope of Electrochemistry (EC) upfront MS has been extended from mimicking drug metabolism towards new applications such as: protein/peptide cleavage, disulfide bonds reduction, covalent drug-protein binding, etc. In this presentation we will show the application of on-line EC/MS as a powerful tool to simulate various oxidation and reduction processes in life sciences. A specially designed μ-preparative electrochemical flow cell will be presented. The cell allows the synthesis of sufficient amounts of metabolites in a few minutes for subsequent use as reference material (e.g. NMR or MS). New scanning method was applied for oxidation of the highly concentrated samples (mM range) to achieve high yield in the metabolites formation. Stable oxidation conditions were obtained without the need of any cell maintenance for a prolonged period of time. Electrochemistry up front MS can be applied for protein and peptide cleavage (as a promising new approach to enzymatic digestion). Electrochemical cleavage of proteins and peptides occurs very specifically at C-terminal of the Tyrosine and Tryptophan peptide bonds. Examples of oxidative cleavage will be presented. Disulfide bonds are one of the most important post-translational modifications for proteins. In this poster we present the structural analysis of biologically active peptides and proteins containing disulfide bonds (e.g., somatostatin, insulin, etc) using electrochemistry (EC) combined with mass spectrometry. Therefore the sample undergoes electrolytic disulfide cleavage in the electrochemical flow cell followed by online MS analysis. Based on the intact protein mass and the resulting fragments and the MS/MS data unambiguous assignment of the disulfide bonds becomes possible. All these applications illustrate the tremendous power and broad applicability of electrochemistry as a tool to mimic nature's Redox reactions within a few seconds or minutes.