Figure 4.

Recombinant SpTransformer protein, rSpTransformer-E1 (rSpTrf-E1), monomers and the rHis-rich fragment induce luminal content leakage from the large unilamellar vesicles (LUVs). (A) A Western blot evaluated with anti-SpTrf antisera shows dimers and monomers of rSpTrf-E1, unknown proteins from non-induced bacteria (Non-induced) that were processed following the same sample preparation as the recombinant proteins, and natSpTrf proteins isolated from two sea urchins by nickel affinity according to Sherman et al. (16). (B) A Western blot evaluated with anti-SpTrf antisera shows the rGly-rich and rHis-rich fragments expressed in E. coli and isolated by nickel affinity. The rHis-rich fragment shows partial degradation from 20 to 15 kDa as reported previously (12). (C) LUVs incubated with rSpTrf-E1 monomers and the rHis-rich fragment (both at 10 µM) induce fluorescent dye leakage. The other protein isolates are not active.