Figure 3.

Peptidase activity profile and anti–HA-Doa4 immunoblot analysis of yeast extracts fractionated by Sephacryl S-400 gel filtration. (A) Cleavage of suc-LLVY-AMC in fractions collected from an S-400 column fractionation of extracts from doa4Δ cells carrying pDOA4–8(HA). Protein concentration is also plotted. Dextran blue was used to determine the exclusion volume, V_o, and purified 20S proteasomes and aldolase (molecular mass 158 kDa) were used to calibrate the column. (B) Anti-HA immunoblot analysis of HA-Doa4 protein. C, crude lysate.