Identification of human basic fetoprotein as glucose-6-phosphate isomerase by using N- and C-terminal sequence tags and terminal tag database

•Both termini of basic fetoprotein (BFP) were sequenced by MALDI mass spectrometry.•For identifying BFP, a terminal tag database, ProteinCarta, was employed.•BFP was first identified as glucose-6-phosphate isomerase (G6PI_HUMAN).

Human basic fetoprotein (BFP), found in fetal serum and tissue extracts as well as in extracts of various cancer tissues, has long been known as a marker protein for cancers; however, the primary sequence has not yet been reported. This paper describes the identification of BFP using the N- and C-terminal amino acid sequence tags (Ac-AALTRDPQFQ and QQREARVQ, respectively) clarified by mass spectrometry-based methods, and a terminal tag database (ProteinCarta). In this study, BFP was identified as glucose-6-phosphate isomerase (G6PI_HUMAN).

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slide