An electrophoretic approach to screen for glutamine deamidation

Abstract Protein deamidation is a posttranslational modification with important implications in physiology and medicine. There is, however, no simple technique for a rapid screening of protein deamidation. The deamidating activity of transglutaminase was applied to establish a simple method for the screen of protein deamidation using recombinant human growth hormone, a rat hippocampal membrane fraction, and a cell homogenate enriched in 5-hydroxytryptamine-1A receptor as model systems. Here we report a simple, economic, and fast approach to assess protein deamidation by two electrophoretic methods: differential cleavage on sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS–PAGE) via in situ V8 protease digestion and the principle of spot shifting via blue native (BN)–PAGE/two-dimensional (2D)–SDS–PAGE/immunoblotting.