Figure 2 - Release of the sperm-surface glycopeptides by proteolytic treatments. Sperm were suspended in PBS (for autoproteolysis), trypsin (0.8 mg/ml PBS), activated papain (0.8 mg/ml PBS), or pronase (160 g/ml PBS containing 4 mM CaCl2), and then incubated at 37oC. Aliquots were removed at 1 h (open squares), 2 h (filled squares), and 4 h (hatched squares), and then assayed for carbohydrates and proteins, as described in Material and Methods. Data are reported as g carbohydrate released per mg sperm protein as sperm substrate at t = 0.