Stability and splitting produces revealed by matrix-assisted laser desorption ionization-time of flight-mass Spectrometry in human serum transferrin

Abstract

Human serum transferrin (HTF) with purity of mass spectrometry were prepared for the analysis of molecular structure. Here, several analytical techniques, such as SDS-PAGE, enzymolysis out-gel, MALDI-TOF mass spectrometry, database search, and comparison approach were employed to identify the stability and splitting produces among iron-saturated HTF, HTF-2Fe(3+), HTF-Fe3+ and apoHTF. Using acetomtrile as a component of eluant for RP-HPLC separation, it was found that the eluarit enabled to decompose HTF into peptides, which indicated that the structural stability of HTF was tightly relative to the iron numbers binding to the protein, and the iron played an important role in improving the stability. The regulation and pathway of forming various peptides from the HTF treated with acetonitrile directly, were studied for revealing the splitting mechanism. The acetonitrile resulted in the unfolding of HTF for forming various different polymers splitting products of the protein. It could be presumed that the reason for the low reliability of diagnosis both congenital disorder of glycosylation and chronic alcohol abuse in clinic is the interferential factors of aplittying products in HTF.