Truncated and GPS site mutated forms of Fc-CD97 ECD. (A) Schematic overview of CD97ECD-hFc fusion proteins. Circle, EGF-like domain; Rectangle, GAIN domain; Lollipop, potential N-glycosylation sites; Arrow, GPS auto-proteolytic site. (B and C) Purified Fc-CD97ECD fragments analyzed by Western blot (B) or Coomassie brilliant blue staining (C). Blots were probed with anti-human IgG Fc mAb, followed by horseradish peroxidase (HRP)-conjugated Ab.