Identification of synaptic plasma membrane proteins co-precipitated with fibrillar beta-amyloid peptide.
The beta-amyloid peptide that is overproduced in Alzheimer's disease rapidly forms fibrils, which are able to interact with various molecular partners. This study aimed to identify abundant synaptosomal proteins binding to the fibrillar beta-amyloid (fAbeta) 1-42. Triton X-100-soluble proteins were extracted from the rat synaptic plasma membrane fraction. Interacting proteins were isolated by co-precipitation with fAbeta, or with fibrillar crystallin as a negative control. Protein identification was accomplished (1) by separating the tryptically digested peptides of the protein pellet by one-dimensional reversed-phase HPLC and analysing them using an ion-trap mass spectrometer with electrospray ionization; and (2) by subjecting the precipitated proteins to gel electrophoretic fractionation, in-gel tryptic digestion and to matrix-assisted laser desorption/ionization time-of-flight mass measurements and post-source decay analysis. Six different synaptosomal proteins co-precipitated with fAbeta were identified by both methods: vacuolar proton-pump ATP synthase, glyceraldehyde-3-phosphate dehydrogenase, synapsins I and II, beta-tubulin and 2',3'-cyclic nucleotide 3'-phosphodiesterase. Most of these proteins have already been associated with Alzheimer's disease, and the biological and pathophysiological significance of their interaction with fAbeta is discussed.
Department of Medical Chemistry, University of Szeged, Szeged, Hungary. yverdier@hotmail.com
Yann
Y
Verdier
Emoke
E
Huszár
Botond
B
Penke
Zsuzsa
Z
Penke
Gary
G
Woffendin
Michaela
M
Scigelova
Lívia
L
Fülöp
Mária
M
Szucs
Katalin
K
Medzihradszky
Tamás
T
Janáky
D016229:Amyloid beta-Peptides / Q000302:isolation & purification / Q000378:metabolism*; D000818:Animals; D001921:Brain / Q000166:cytology / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism* / Q000648:ultrastructure; D011232:Chemical Precipitation; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D008297:Male; D008565:Membrane Proteins / Q000302:isolation & purification*; D046529:Microscopy, Electron, Transmission / Q000379:methods; D009454:Neurofibrils / Q000378:metabolism* / Q000648:ultrastructure; D010446:Peptide Fragments / Q000302:isolation & purification / Q000378:metabolism*; D011485:Protein Binding / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods; D013569:Synapses / Q000378:metabolism* / Q000648:ultrastructure; D013574:Synaptosomes / Q000378:metabolism / Q000648:ultrastructure; D038204:beta-Crystallins / Q000378:metabolism
D016229:Amyloid beta-Peptides; D008565:Membrane Proteins; D010446:Peptide Fragments; C075222:amyloid beta-protein (1-42); D038204:beta-Crystallins