Figure 2.

Screening of the SLT-1 A subunit library yielded a toxin variant, SLT-1A^IYSNKLM, displaying cytotoxicity towards human melanoma cell lines. (A) Dose-response curves illustrating the specific cytotoxicity of SLT-1A^IYSNKLM (black diamonds, black triangles, black squares, black circles) compared to wt SLT-1A (white diamonds, white triangles, white squares, white circles) for the 518-A2 human melanoma cell line (black squares, white circles). The carcinoma cell lines CAMA-1 (black diamonds, white diamonds; human breast), HepG2 (black triangles, white triangles; human liver), and PC-3 (black squares, white squares; human prostate) are insensitive to SLT-1A^IYSNKLM. (B) Dose-response curves illustrating the cytotoxicity profile of SLT-1A^IYSNKLM towards 8 different human melanoma cell lines: 518-A2 (black circles), A-375 (black inverted triangles), SK-Mel-28 (white circles), MeWo (black squares), A-2058 (white inverted triangles), MALME-3 M (white triangles), SK-Mel-2 (white squares), and C-32 (black triangles) as well as human melanocytes (white diamonds). Error bars represent s.e.m. for experiments performed in quadruplicate.