40] Probing conformations of amyloidogenic proteins by hydrogen exchange and mass spectrometry

Abstract

Evidence has suggested that the formation of amyloid fibrils may involve the structural rearrangement of native monomeric protein through partially folded intermediates. For example, the kinetics of amyloid fibril formation in vitro is most favorable for wild-type transthyretin under solution conditions that destabilize the native state tetramer of the protein. Furthermore, naturally occurring variants of human lysozyme, transthyretin, and immunoglobulin light chain VL domain have been shown to destabilize the native states of these proteins. Destabilization allows these proteins to unfold more readily, generating partially folded states that are proposed as amyloidogenic intermediates. These aggregation-prone intermediates are difficult to study by classical structural biology techniques as they are too dynamic for X-ray crystallography and are not amenable to nuclear magnetic resonance (NMR) measurements directly because the concentration necessary for their study promotes aggregation. In this article, hydrogen exchange measured by electrospray (ES) mass spectrometry (MS) is used to probe the solution dynamics of amyloidogenic proteins.