Ptrg is a highly N-glycosylated protein. A Western blot analysis revealed that Prtg purified from an E10.5 mandible is a protein with a molecular mass of approximately 180 kDa (lane #2). The molecular mass is much larger than that calculated from the predicted amino acid sequences. N-glycosidase F reduces the size of the proteins to approximately 130 kDa (lane #3). The purified proteins were separated and stained with Coomassie brilliant Blue dye (lane #1). The amount of the loaded protein is 10 μg in each lane.