This study evaluates the nature of glycated human insulin formed following exposure to
hyperglycemic conditions in vitro. Glycated insulin was purified by RP-HPLC and its
molecular mass (5971.3 Da) determined by plasma desorption mass spectrometry (MS). The
difference in mass (163.7 Da) from nonglycated insulin (5807.6 Da) corresponds to a single
reduced glucose (glucitol) residue. Following reduction of insulin disulfide bridges, MS
confirmed that the B-chain was glycated. Enzymatic digestions with trypsin, endoproteinase …