Novel assay system for acidic Peptide:<i>N</i>-glycanase (aPNGase) activity in crude plant extract

<p>Acidic peptide:<i>N</i>-glycanase (aPNGase) plays a pivotal role in plant glycoprotein turnover. For the construction of aPNGase-knockout or -overexpressing plants, a new method to detect the activity in crude plant extracts is required because endogenous peptidases present in the extract hamper enzyme assays using fluorescence-labeled <i>N</i>-glycopeptides as a substrate. In this study, we developed a new method for measuring aPNGase activity in crude extracts from plant materials.</p>