Figure 4

EGCG binds to the ATPase domain of HSP70 and HSP90. (A) Whole cell lysates were incubated with EGCG-conjugated Sepharose 4B. After precipitation, the levels of bound HSP70 or HSP90 were monitored by Western blot analysis. (B) Whole cell lysates were incubated with EGCG-Sepharose 4B in the absence or presence of ATP. The levels of bound HSP70 or HSP90 in precipitates were monitored by Western blot analysis.