Use of separation and mass spectrometric techniques in the diagnosis of Alzheimer's disease

This thesis focuses on the preparation of covalently cross-linked oligomeric forms of amyloid beta and their analysis by SDS-PAGE and MALDI-TOF. The covalently cross-linked oligomeric forms of Aβ(1-42) were formed by chemical and enzymatic reactions. The chains of amyloid beta are crossed over the amino acid residue of tyrosine to form a covalent bond. Such covalent cross-linking stabilizes the oligomeric structure, which allows for improved analysis of amyloid beta oligomers. The development of methods for the detection and quantification of amyloid beta oligomers may be of considerable benefit for the diagnosis of Alzheimer's disease, as it is the oligomeric forms of amyloid beta that are most strongly associated with Alzheimer's disease pathology. In the theoretical part, Alzheimer's disease is described with the above-mentioned problems in early diagnosis and therapy. In addition, background information on amyloid beta is given, and analytical methods for the separation and detection of amyloid beta used in research are described. The experimental part deals with the optimization of analytical methods MALDI-TOF and SDS-PAGE. In the MALDI-TOF, 2,5-dihydroxybenzoic acid and sinapic acid matrices were selected as suitable matrices for the determination of Aβ(1-42). The most suitable method of..