FIG. 4.

Western blot analysis of the APF proteins of L. gasseri Agg⁻ (lane 1), JA11 (apf1 knockout; lane 2), JA12 (apf2 knockout; lane 3), 4B2(pVM23) (APF1 overproducer; lane 4), 4B2(pVM24) (APF2 overproducer; lane 5), 4B2(pVM25) (with APF down-regulated; lane 6), 4B2(pVM25) (wild-type-looking revertant; lane 7), and 4B2(pNZ124) (control; lane 8). The crude extracts from L. gasseri 4B2 cells grown on agar plates were separated on sodium dodecyl sulfate-polyacrylamide gel electrophoresis and blotted onto a nitrocellulose membrane. The APF proteins were recognized with polyclonal anti-APF antibodies. k.o., knockout; o.p., overproduction; d.r., down regulation; rev., revertants; wt, wild type.