title: Detection of prion protein oligomers by single molecule fluorescence imaging.
abstract: The degree of polymerization of PrP has a close relationship with the pathological mechanisms of prion diseases. We examined, at the molecular level, the polymerization state of PrP in lysates of prion-infected cells using total internal reflection fluorescence microscopy (TIRFM). The crude lysates were fractionated by gel-filtration spin columns according to their molecular size. Both the oligomer-rich and the monomer-rich fractions were probed with fluorescein-labeled anti-PrP antibodies (mAb SAF70 and mAb 8G8). Fluorescent spots of varying intensity were detected, with the ratio of intense fluorescent spots being greater in the oligomer fraction samples with mAb SAF70 than those with 8G8, the specific epitope of which is thought to be buried in abnormal PrP molecules. The results indicated that PrP oligomers could be specifically detected and conformational changes of abnormal PrP molecules observed. Imaging by TIRFM may aid in determining the polymerization state and properties of PrP oligomers in pathological processes.
authors.affiliation: Department of Neuropathology, Graduate School of Medical Sciences Division of Biomolecular Chemistry, Institute for Materials Chemistry and Engineering, Kyushu University, Fukuoka, Japan.
authors.forename: Satoko
authors.initials: S
authors.lastname: Shibano
authors.forename: Kensuke
authors.initials: K
authors.lastname: Sasaki
authors.forename: Satoru
authors.initials: S
authors.lastname: Kidoaki
authors.forename: Toru
authors.initials: T
authors.lastname: Iwaki
mesh_terms: D000818:Animals; D051379:Mice; D061848:Optical Imaging / Q000379:methods*; D017096:Prion Diseases / Q000378:metabolism*; D011328:Prions / Q000032:analysis*
chemical_list: D011328:Prions