Electrophoresis- and FRET-Based Measures of Serpin Polymerization

Many serpinopathies, including alpha-1 antitrypsin (A1AT) deficiency, are associated with the formation of unbranched polymer chains of mutant serpins. In vivo, this deficiency is the result of mutations that cause kinetic or thermodynamic destabilization of the molecule. However, polymerization can also be induced in vitro from mutant or wild-type serpins under destabilizing conditions. The characteristics of the resulting polymers are dependent upon induction conditions. Due to their relationship to disease, serpin polymers, mainly those formed from A1AT, have been widely studied. Here, we describe Förster resonance energy transfer (FRET) and gel-based approaches for their characterization.