Targeted quantitation of HMGB1 protein by label-free Mass Spectrometry technique

— Mass spectrometry (MS)-based methods have become popular in recent years for the quantitation of biomolecules, especially peptides and proteins. High Mobility Group Box-1 protein (HMGB1) is a nuclear DNA-binding protein that resides inside the nucleus and can be released to the extracellular space under specific conditions. HMGB1 has been reported as circulating mechanistic indicators of cell death mode in animal models and in clinical studies. There is accumulating evidence that HMGB1 contributes to the pathogenesis of inflammatory and autoimmune diseases. Moreover, HMGB1 has been found to play an important role in tumor development, growth, and spread. Circulating HMGB1 level could be a useful and specific marker for evaluating different disease status and predicting prognosis in patients. The label-free quantitative comparison without any standard reference or normalization of the target peptide signal is the simplest Liquid ChromatographicMS (LC-MS) method for the quantitation of a protein. The aim of the research was the development of an analytical method for the quantitation of HMGB1 by a label-free Mass Spectrometry technique. In this paper are presented the preliminary results: the quantitation of HMGB1 was assessed in a cell lysate sample through the use of the standard concentration curve of purified HMGB1 protein.