Fig. 1

CDK4-binding activity of soluble AK2 in E. coli HB2151 culture supernatant. Coating of microtiter plates was conducted using equal concentrations of rhCDK4 or irrelevant antigens (rhPHD2, rhCOX-2, or BSA). Next, plates were incubated sequentially with culture supernatants of either IPTG-induced or uninduced E. coli AK2/HB2151 cells followed by incubation with anti-V5 tag monoclonal antibody then HRP-conjugated anti-mouse IgG. The group incubated with supernatant of E. coli HB2151 served as the negative control (NC) group. (*** P < 0.001 vs. corresponding irrelevant proteins controls or NC group, # P > 0.05 vs. corresponding irrelevant proteins controls, & represents P > 0.05). Abbreviations: rhCDK, recombinant human cyclin-dependent kinase; rhPHD, recombinant human prolyl hydroxylase; rhCOX, recombinant human cyclooxygenase; BSA, bovine serum albumin; IPTG, isopropyl β-D-1- thiogalactopyranoside