FIG. 2.

Analysis of precursors and products detected in MHV-infected cells by using replicase-specific antisera anti-D11 and anti-D12. (A) Pulse-chase analysis. Lysates prepared from MHV-infected cells were pulse-labeled with Tran³⁵S-label from 4.5 to 5.0 hpi and chased with medium containing excess methionine for the times indicated. Lysates were prepared and subjected to immunoprecipitation with anti-D11 serum and analyzed as described in the legend to Fig. 1. The p150 and p44 products are indicated by arrows. (B) Inhibition of 3CLpro-mediated proteolytic processing by E64d. MHV-infected HeLa-MHVR cells were labeled with Tran³⁵S-label from 5 to 7 hpi in either the absence (−) or presence (+) of 400 μg of protease inhibitor E64d per ml and subjected to immunoprecipitation with anti-D11 and anti-D12 sera.