Prion Protein-Antibody Complexes Characterized by Chromatography-Coupled Small-Angle X-Ray Scattering.
Aberrant self-assembly, induced by structural misfolding of the prion proteins, leads to a number of neurodegenerative disorders. In particular, misfolding of the mostly α-helical cellular prion protein (PrP(C)) into a β-sheet-rich disease-causing isoform (PrP(Sc)) is the key molecular event in the formation of PrP(Sc) aggregates. The molecular mechanisms underlying the PrP(C)-to-PrP(Sc) conversion and subsequent aggregation remain to be elucidated. However, in persistently prion-infected cell-culture models, it was shown that treatment with monoclonal antibodies against defined regions of the prion protein (PrP) led to the clearing of PrP(Sc) in cultured cells. To gain more insight into this process, we characterized PrP-antibody complexes in solution using a fast protein liquid chromatography coupled with small-angle x-ray scattering (FPLC-SAXS) procedure. High-quality SAXS data were collected for full-length recombinant mouse PrP [denoted recPrP(23-230)] and N-terminally truncated recPrP(89-230), as well as their complexes with each of two Fab fragments (HuM-P and HuM-R1), which recognize N- and C-terminal epitopes of PrP, respectively. In-line measurements by fast protein liquid chromatography coupled with SAXS minimized data artifacts caused by a non-monodispersed sample, allowing structural analysis of PrP alone and in complex with Fab antibodies. The resulting structural models suggest two mechanisms for how these Fabs may prevent the conversion of PrP(C) into PrP(Sc).
Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California.
Lester
L
Carter
Department of Bioengineering and Therapeutic Sciences and Department of Pharmaceutical Chemistry and California Institute for Quantitative Biosciences (QB3), University of California San Francisco, San Francisco, California.
Seung Joong
SJ
Kim
Department of Bioengineering and Therapeutic Sciences and Department of Pharmaceutical Chemistry and California Institute for Quantitative Biosciences (QB3), University of California San Francisco, San Francisco, California.
Dina
D
Schneidman-Duhovny
Institute for Neurodegenerative Diseases, University of California San Francisco, San Francisco, California; Department of Neurology, University of California San Francisco, San Francisco, California.
Jan
J
Stöhr
Institute for Neurodegenerative Diseases, University of California San Francisco, San Francisco, California.
Guillaume
G
Poncet-Montange
Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California.
Thomas M
TM
Weiss
Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California.
Hiro
H
Tsuruta
Institute for Neurodegenerative Diseases, University of California San Francisco, San Francisco, California; Department of Neurology, University of California San Francisco, San Francisco, California. Electronic address: stanley@ind.ucsf.edu.
Stanley B
SB
Prusiner
Department of Bioengineering and Therapeutic Sciences and Department of Pharmaceutical Chemistry and California Institute for Quantitative Biosciences (QB3), University of California San Francisco, San Francisco, California. Electronic address: sali@salilab.org.
Andrej
A
Sali
D000818:Animals; D061067:Antibodies, Monoclonal, Humanized / Q000378:metabolism*; D002853:Chromatography, Liquid; D051379:Mice; D008958:Models, Molecular; D018621:PrPC Proteins / Q000737:chemistry* / Q000235:genetics / Q000276:immunology*; D018620:PrPSc Proteins / Q000737:chemistry* / Q000235:genetics; D011994:Recombinant Proteins / Q000737:chemistry; D053838:Scattering, Small Angle; D012996:Solutions; D014961:X-Ray Diffraction
D061067:Antibodies, Monoclonal, Humanized; D018621:PrPC Proteins; D018620:PrPSc Proteins; D011994:Recombinant Proteins; D012996:Solutions