sentence: AFM and NS-TEM images showed that WT α - syn formed a mixture of three polymorphs including straight polymorph ( ~ 93 % ) , and two left-handed twist polymorphs ( ~ 3.6 % and ~ 2.6 % , respectively ) in PB buffer , which are all distinct from the right-handed twist morphology of the G51D fibril formed under the same condition ( Supplementary Fig. 2 ) .