Development and application of a method for identification of isothiocyanate-targeted molecules in colon cancer cells.

In this study, we have developed a novel method to identify isothiocyanate (ITC)-targeted molecules using two well-studied ITCs: benzyl ITC (BITC) and phenethyl ITC (PEITC). The principle of this method is based on identifying a pattern of differences between BITC and PEITC given that they show similar chemical and biological behaviors. For method validation, dithiothreitol-reduced bovine insulin as a model molecule was incubated with either BITC or PEITC, and digested peptides were analyzed by ultra-performance liquid chromatography time-of-flight mass spectrometry (UPLC–TOF–MS) and liquid chromatography quadrupole TOF–MS (LC–Q–TOF–MS). Three peptides—NYCN, FVNQHLCGSHLVE, and ALYLVCGE—were identified as being adducted with BITC or PEITC on their cysteine residues. Each set of peptides adducted with either BITC or PEITC showed retention times (RTBITCMore