FIG. 5.

Effect of papain digestion on decapsidation of purified OSU virions neutralized by MAb 1C10, directed against VP7. Purified OSU (10 μl; 200 μg/ml) virions were mixed with purified MAb 1C10 (2 μl; 2,640 μg/ml) and incubated for 1 h at room temperature. Virus-antibody mixtures were treated with papain (0.8 mg/ml) for 3 h at room temperature in the presence or absence of a reducing agent (10 mM cysteine). After the reaction was stopped with iodoacetamide (1.5 mM), the mixtures were added to a stirred cuvette containing 1.1 ml of EGTA-Ca-EGTA buffers adjusted to 150 nM Ca²⁺ and were maintained at 25°C. The MAb and digestion conditions used are indicated. Results of one experiment from a series of two are shown.