Figure 3. Brichos interacts with fibrillar but not monomeric Aβ42.

(a) Images using TEM with a nano-gold conjugated secondary antibody against anti-Brichos antibodies show that the chaperone binds to Aβ42 fibrils. (b) SPR analysis verifies the specific binding to fibrils and allows determination of the association (k_on ≈ 5.1 × 10³ M⁻¹s⁻¹) and dissociation (k_off ≈ 2.1 × 10⁻⁴ s⁻¹) rate constants, implying an apparent equilibrium dissociation constant K_D ≈ 40 nM. No binding was observed to the monomer or to control in the absence of Aβ42.