Directed selection of a conformational antibody domain that prevents mature amyloid fibril formation by stabilizing Aβ protofibrils

doi:10.1073/pnas.0703793104

Directed selection of a conformational antibody domain that prevents mature amyloid fibril formation by stabilizing Aβ protofibrils

^†Leibniz Institut für Altersforschung, Fritz-Lipmann-Institut, 07745 Jena, Germany;
*Leibniz Institut für Naturstoff-Forschung und Infektionsbiologie, Hans-Knöll-Institut, 07745 Jena, Germany;
^¶Friedrich-Schiller-Universität Jena, Institut für Pathologie, 07740 Jena, Germany;
^‖Brain and Mind Research Institute, Alzheimer's and Parkinson's Disease Laboratory, University of Sydney, Camperdown NSW 2050, Australia;
**Friedrich-Schiller-Universität Jena, Institut für Anatomie II, 07743 Jena, Germany; and
^††Institut für Pathologie, Charité Universitätsmedizin, 10117 Berlin, Germany

Edited by David S. Eisenberg, University of California, Los Angeles, CA, and approved October 24, 2007 (received for review April 25, 2007)

Abstract

The formation of amyloid fibrils is a common biochemical characteristic that occurs in Alzheimer's disease and several other amyloidoses. The unifying structural feature of amyloid fibrils is their specific type of β-sheet conformation that differentiates these fibrils from the products of normal protein folding reactions. Here we describe the generation of an antibody domain, termed B10, that recognizes an amyloid-specific and conformationally defined epitope. This antibody domain was selected by phage-display from a recombinant library of camelid antibody domains. Surface plasmon resonance, immunoblots, and immunohistochemistry show that this antibody domain distinguishes Aβ amyloid fibrils from disaggregated Aβ peptide as well as from specific Aβ oligomers. The antibody domain possesses functional activity in preventing the formation of mature amyloid fibrils by stabilizing Aβ protofibrils. These data suggest possible applications of B10 in the detection of amyloid fibrils or in the modulation of their formation.

Footnotes

^‡‡To whom correspondence should be addressed. E-mail: fandrich{at}enzyme-halle.mpg.de
Author contributions: G.H. and C.H. contributed equally to this work; K.-J.H., U.H., and M.F. designed research; G.H., C.H., R.F., P.H., C.S., J.M., K.W., G.G., and M.B. performed research; J.G. and C.R. contributed new reagents/analytic tools; C.H., U.H., and M.F. analyzed data; and C.H., U.H., and M.F. wrote the paper.
↵ ^‡Present address: Max-Planck Research Unit for Enzymology of Protein Folding and Martin-Luther University Halle-Wittenberg, Biozentrum, Weinbergweg 22, D-06120 Halle (Saale), Germany.
↵ ^§Present address: Neuroscience Discovery Research, Abbott GmbH and Co. KG, Knollstrasse 67061 Ludwigshafen, Germany.
The authors declare no conflict of interest.
This article is a PNAS Direct Submission.
This article contains supporting information online at www.pnas.org/cgi/content/full/0703793104/DC1.