The amyloidogenic SEVI precursor, PAP248-286, is highly unfolded in solution despite an underlying helical tendency

► PAP248-286 folds into a disordered structure upon binding to SDS micelles. ► PAP248-286 is significantly unfolded in solution. ► PAP248-286 adopts helical structures in TFE solutions. ► Disordered structure of PAP248-286 in SDS results from electrostatic interactions. ► Unusual degree of disorder of PAP248-286 may account for its unusual properties.