Amyloid beta peptide, soluble oligomer containing amyloid beta peptide, amyloid beta peptide or soluble oligomer identification method suitable for disease treatment, amyloid beta peptide or soluble oligomer amyloid beta peptide or soluble oligomer Method of selecting binding protein to react, use of amyloid beta peptide or soluble oligomer in the production of pharmaceutical composition, pharmaceutical preparation containing amyloid beta peptide or soluble oligomer, vaccine containing amyloid beta peptide or soluble oligomer, coding for amyloid beta peptide Nucleotide, amyloid beta peptide-co
The invention provides monomeric and oligomeric amyloid beta peptide isomers that are resistant towards fibrillogenesis and their use as screening reagents or antigens in methods and pharmaceutical preparations for the treatment of Alzheimer's disease and other conditions related to protein misfolding. The alanines at positions 21 and 30, in wild type amyloid beta peptide amino acid sequence, are according to the invention replaced by cysteins, which results in an intra molecular disulphide bond. The invention further provides transgenic animals expressing modified amyloid precursor proteins or amyloid beta peptides.