The fibrils in the plaques formed in the brains of patients with Alzheimer?s disease contain significant amounts of truncated Abeta proteins. This fragments contain an N-terminal pyroglutamic acid. The g-carboxy group of glutamic acid forms a cyclic bond with the free N-terminal amino group to form pyroglutamateONE-LETTER SEQUENCE: Glp-FRHDSGYEVHHQKLVFFAEDVGSNKGAIIGLMVGGVVMOLECULAR FORMULA: CHNOSMOLECULAR WEIGHT:4125.68STORAGE CONDITIONS: -20 5C, CAS REGISTRY NUMBER: [161818-04-8], SYNONYMS: (Pyr)-Amyloid β-Protein (3-40) RESEARCH AREA: Alzheimer's DiseaseREFERENCES: Mok, SS. et al. J. Neurosci. Res. 61, 449 (2000); Russo, C. et al. Nature. 405, 531 (2000)