Abstract: The present invention relates to screening assays for the identification of BACE2 inhibitors.

Abstract: The present invention is concerned with a compounds of the general formula wherein R, R?, R?, R??, R??, X and n are as defined in the description and the use of said compound as ionization modifier. The invention further relates to a method for the quantification of a polypeptide or fragments thereof from a source containing said polypeptide in labeled and unlabeled form comprising (a) modifying the isolated polypeptide with said compound as an ionization modifier, (b) analyzing the prepared polypeptide or fragments thereof by mass spectrometry, and thereby determining the amount of polypeptide or fragments thereof that was present in the source of polypeptide or fragments thereof.

Abstract: The present invention relates to an in vitro method for the quantification of beta-amyloid peptide (A&bgr;) in mammalian tissue samples and body fluids comprising spiking of isotope labeled A&bgr; into a sample containing A&bgr; and determining labeled and unlabeled A&bgr; by mass spectrometry. The present invention also relates to the use of the methods of the invention for the determination of the A&bgr; content in tissue sample and body fluid as well as the determination of A&bgr; microheterogeneities.

Abstract: The present invention relates to an assay for identifying inhibitors of beta-secretases comprising the steps of immobilizing a beta-secretase protein on a solid support, contacting it with a test compound in the presence of a tagged beta-secretase inhibitor, and comparing the extent of binding of the tagged beta-secretase inhibitor in the presence and in the absence of the test compound in order to evaluate if the test compound is an inhibitor of beta-secretases. The present invention also relates to a method of screening for inhibitors of beta-secretases, to novel beta-secretase inhibitors and their use as tagged beta-secretase inhibitors for identification of inhibitors of beta-secetase, to a kit for identifying beta-secretase inhibiotrs as well as to novel beta-secretase inhibitors for use in the treatment of Alzheimer's disease and other cerebrovascular amyloidosis.