Differential epitope identification of antibodies against intracellular domains of alzheimer's amyloid precursor protein using high resolution affinity-mass spectrometry.
Several polypeptides comprising the carboxy-terminal domain of the 1-amyloid precursor protein (cAPP) were prepared by solid phase peptide synthesis, and employed as antigens for the determination of the epitopes recognised by anti-cAPP antibodies. Selective proteolytic epitope-excision and -extraction on the immobilised immune complexes, in combination with high resolution Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) were used as major methods for epitope identification. The epitope recognised by a polyclonal anti-cAPP antibody (36-BO) was identified as APP(727-737), a sequence close to the APP transmembrane region. In contrast, the epitope recognised by a monoclonal anti-cAPP antibody (Jonas-mAb) was identified at APP(740-747) to be located more remote from the transmembrane region. The two adjacent, yet distinct epitopes recognised by two different antibodies should provide efficient tools for (i), molecular diagnostic applications, and (ii), the study of intracellular processing pathways of APP relevant to Alzheimer's disease, utilising suitable mass spectrometric and molecular imaging approaches.
Tian
Xiaodan
X
Department of Chemistry, Laboratory of Analytical Chemistry and Biopolymer Structure Analysis, University of Konstanz, Germany.
Maftei
Madalina
M
Kohlmann
Markus
M
Allinquant
Bernadette
B
Przybylski
Michael
M
D000544:Alzheimer Disease / Q000276:immunology*; D000595:Amino Acid Sequence; D016564:Amyloid beta-Protein Precursor / Q000737:chemistry / Q000276:immunology*; D000906:Antibodies / Q000276:immunology*; D000939:Epitopes / Q000276:immunology*; D006801:Humans; D008969:Molecular Sequence Data; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D017550:Spectroscopy, Fourier Transform Infrared
D016564:Amyloid beta-Protein Precursor; D000906:Antibodies; D000939:Epitopes