Fig 1.

 Blocking the N-terminus of Hsp22 with a histidine tag reduces its efficiency to prevent citrate synthase (CS) heat-induced aggregation. CS (0.1 μM) was incubated at 42°C for 90 minutes either alone (open lozenge) or in the presence of 0.1 μM of His-Hsp22 purified under native conditions (A and B, open triangle) or purified with urea (A, open circle) or of untagged-Hsp22 purified under native conditions (B, closed triangle). Protein aggregation was determined by the light-scattering assay at 320 nm. Data are representative of 6 trials and are expressed as the mean ± standard deviation