The metabolic pathway generating p3, an A beta-peptide fragment, is probably non-amyloidogenic.
The Alzheimer a beta amyloid precursor protein is metabolized by at least two secretory pathways. One generates the A beta peptide and the other a N-terminally truncated A beta fragment termed p3 that is considered non-amyloidogenic. However, direct evidence is missing. We have undertaken to synthesize and purify p3. Pure p3 polymerizes in vitro, forming a lattice with an ultrastructure distinct from the linear fibrils of A beta. In contrast to amyloid, polymerized p3 does not bind thioflavine T. It is therefore concluded that amino acids in the N-terminal part of the A beta molecule are required for formation of typical amyloid fibrils and that the metabolic pathway generating p3 probably is non-amyloidogenic
Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden.
J
J
Näslund
M
M
Jensen
L O
LO
Tjernberg
J
J
Thyberg
L
L
Terenius
C
C
Nordstedt
D000595:Amino Acid Sequence; D016564:Amyloid beta-Protein Precursor / Q000737:chemistry / Q000378:metabolism*; D008854:Microscopy, Electron; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000378:metabolism*
D016564:Amyloid beta-Protein Precursor; D010446:Peptide Fragments