Fig. 6.

The region inserted into POPS liposomes was different between DnaK and Hsp70. Recombinant DnaK (2 μg) or recombinant human Hsp70 (2 μg) were incubated with POPS liposomes (400 μg) in 50-mM Tris buffer pH 7.4 for 30 min at 25 °C. The liposomes were centrifuged at 100,000×g for 40 min at 4 °C. Pellets were resuspended in Na₂CO₃ buffer (pH 11.5) and centrifuged again. The resulting proteoliposomes were incubated with proteinase K (50 μg/ml) for 30 min at 37 °C, and the liposomes were centrifuged at 100,000×g for 40 min at 4 °C and washed again. The liposome pellet was analyzed by mass spectroscopy. DnaK (a) and Hsp70 (b) peptides that are protected from proteinase K digestion are highlighted in grey. Similarity between DnaK and Hsp70 peptide mapping is shown in the pairwise alignment of DnaK and Hsp70 sequences (c)