Peptide N-Glycosidase F (PNGase F) Treatment Urine aliquots (supernatant fraction, 20 mL) were subject to deglycosylation reaction using PNGase F (Cat No. P0704S, New England Biolabs, Ipswich, MA, USA). Deglycosylated urinary ACE2 protein fragments were detected by western analysis. Details of the assays can be found in Text S1.