Fig. 4.

KST peptide can carry into cells a multimolar complex containing antiHsp70 antibody and thus block the protective effect of Hsp70 in SK-N-SH cells containing different amounts of the chaperone. a SK-N-SH cells were transfected with plasmid containing the hsp70 gene under control of metallothionein promoter (SK-N-SH–Hsp70 cells) and incubated with 25 or 75 μM ZnSO₄ to induce Hsp70 synthesis. Cells were investigated with Western blotting. An antibody to GAPDH was used as a loading control. b SK-N-SH–Hsp70 cells were inducted with 75 μM ZnSO₄ and incubated with the macromolecular complex KST–Av–αHsp70Ab overnight, then fixed, permeabilized, and stained with secondary anti-mouse antibody conjugated with Cy3 (red). Avidin was labeled with FITC (green). Nuclei were stained with DAPI (blue). Scale bar 1 μm. c SK-N-SH–Hsp70 cells were inducted with 25 or 75 μM of ZnSO₄ for 18 h and incubated with KST–Av–αHsp70 complex overnight and then treated with 1 μM staurosporine to induce apoptosis. After 24 h, the amount of living cells was determined with an MTT assay