We have been applied current MS techniques to detect and characterize aberrant proteins and to determine modified proteins from 1994. Two simple methods were devised to prepare proteins in these projects. One was immunoprecipitation with antisera against target protein, followed by LC-ESIMS and the other was 2-dimensional LC connected to ESIMS. Using these procedures, we detected more than 40 cases (10 different types) of transthyretins (TTRs), 5 cases (5 different types) of Cu/Zn superoxide dismutases and 60 cases (29 different types) of hemoglobins (Hbs) for 8 years. TTR has several isoforms in serum, most of which are caused by disulfide linkage with cysteine residue at position 10. We found an ion peak 80 Da larger than unmodified TTR by MS, assigned it to
S-sulfonated TTR and the modified TTR can be used as a diagnostic marker for molybdenum cofactor deficiency. We also measured glycated β-globin N-terminus hexapeptide (HbAlc) by immobilized endoproteinase Glu-C digestion and measured these digests by LC-ESIMS technique, proposed by Kobold
et al. and calculated the values of HbA1c by weighted sum of singly and doubly charged ions of these hexapeptides. Finally we describe identifications of Burkitt lymphoma BL60 cell line proteins catalogues by radical-free/high reduction two-dimensional gel electrophoretically separation and a high sensitive nanoflow-electrospray ion trap mass spectrometry.
抄録全体を表示