Class A -Lactamases as Versatile Scaffolds to Create Hybrid Enzymes: Applications from Basic Research to Medicine
Figure 7
Model polyQ proteins using BlaP to investigate the amyloid fibril formation. The advantage of using BlaP as a scaffold to create polyQ proteins are highlighted in red. Left side panel: schematic representation of the polyQ-BlaP hybrid protein. Middle panel: kinetics of aggregation of BlaP197(Gln)55 and BlaP197(Gln)79 at 110 μM under the following conditions of incubation: (i) PBS, pH 7.5 and 0 M urea at 37°C (pink), (ii) PBS, pH 7.5, and 1.85 M urea at 25°C (blue) and (iii) PBS, pH 7.5, and 3.5 M urea at 25°C (green). BlaP197(Gln)55 does not form amyloid fibrils under native conditions, in contrast to BlaP197(Gln)79. Under native conditions, the threshold value is therefore comprised between 55 and 79Q. Under denaturing conditions, it is comprised between 30 and 55Q. Moreover, the kinetics of aggregation are faster with longer polyQ tracts. Right side panel: schematic pathway of aggregation for BlaP197(Gln)55 and BlaP197(Gln)79. N, native state; U, unfolded state; F, amyloid fibril. The native conformation of BlaP imposes constraints to the 55Q tract that prevent it to trigger the formation of amyloid fibrils. Figure adapted from Scarafone et al. [16].
