%0 Journal Article
%T Concerted action of dipeptidyl peptidase IV and glutaminyl cyclase results in formation of pyroglutamate-modified amyloid peptides in vitro.
%A Antonyan A
%A Schlenzig D
%A Schilling S
%A Naumann M
%A Sharoyan S
%A Mardanyan S
%A Demuth HU
%J Neurochem Int
%V 113
%N 0
%D 02 2018
%M 29224965
%F 4.297
%R 10.1016/j.neuint.2017.12.001
%X Compelling evidence suggests a crucial role of amyloid beta peptides (Aβ(1-40/42)) in the etiology of Alzheimer's disease (AD). The N-terminal truncation of Aβ(1-40/42) and their modification, e.g. by glutaminyl cyclase (QC), is expected to enhance the amyloid toxicity. In this work, the MALDI-TOF mass spectrometry application proved N-terminal cleavage of Aβ(1-40/42) by purified dipeptidyl peptidase IV (DPPIV) in vitro observed earlier. The subsequent transformation of resulted Aβ(3-40/42) to pE-Aβ(3-40/42) in QC catalyzed glutamate cyclization was manifested. Hence, consecutive conversion of Aβ(1-40/42) by DPPIV and QC can be assumed as a potential mechanism of formation of non-degrading pyroglutamated pE-Aβ(3-40/42), which might accumulate and contribute to AD progression. The in vitro acceleration of Aβ(1-40) aggregation in the simultaneous presence of DPPIV and QC was shown also.