FIGURE 6.

AEBSF inhibits trypsin digestion after 15 min. Shown is a Tris-Tricine SDS-PAGE of Cp183-EEE of Cp183-WT capsids digested for 15 min and 3 h with trypsin. After 15 min, either the sample was boiled (−) or 0.2 mm AEBSF was added (+). The samples with added inhibitor were incubated for 3 h. Control samples had no AEBSF added prior to a 3-h incubation. All samples were analyzed by SDS-PAGE. Note that treatment with AEBSF essentially blocked trypsin cleavage. This allowed trypsin cleavage to be halted at specific time points so that samples could then be studied by cryo-EM.