Effect of basement membrane components on assembly of 3‐pyroglutamylamyloid β‐protein

Abstract

Abstract3‐pyroglutamyl amyloid β‐protein is major component of senile plaques in Alzheimer’s disease. Basement membrane (BM) components co‐localize with amyloid in the plaque. We investigated the potential of BM components, such as type IV collagen (collagen IV), laminin and entactin, to prevent assembly of 3‐pyroglutamyl amyloid β‐protein 3‐42 (Aβ3pE‐42) and to induce a disassembly of Aβ3pE‐42 fibril. For this we used thioflavin T fluorometric assays. All BM components significantly inhibited Aβ3pE‐42 fibril formation (Molar ratio; Aβ:collagen IV = 136:1, Aβ:laminin = 180:1, Aβ:enactin = 20:1). The inhibitory effect of BM components was in a dose‐dependent manner. Collagen IV and laminin significantly disrupted pre‐formed AβpE‐42 fibril, whereas enactin without effect. We propose that BM components may be involved in senile plaque formation by regulating both AβpE‐42 fibril formation and disassembly of the fibril.