Straightforward proteomic analysis reveals real dynamics of proteins in cells

To reveal real dynamics of proteins in cells, we have developed a novel type of straightforward proteomic analysis named FD-LC-MS/MS. This technique consists of fluorogenic derivatization (FD) of intact proteins, followed by high performance liquid chromatographic (LC) separation, detection and quantification of the derivatized proteins, isolation of the subject proteins, enzymatic digestion of the isolated proteins, and identification of the proteins using HPLC and MS/MS with a database-searching algorithm. The method is uncomplicated, sensitive, reproducible, and easily quantifies and identifies intact proteins in tissues and cells. Additionally, in contrast to other proteomic approaches, our method does not require any pretreatment steps, such as precipitation and clean-up, except for the derivatization, resulting in high reproducibility and the same or higher detectability than that of other methods. In this article, after a brief review of other types of proteomic analyses, we introduce the development and application of the FD-LC-MS/MS method. We also discuss the features and perspectives of this method.