Previously, we hypothesized that aminopeptidase-catalyzed proteolysis may limit the rate of β-amyloid catabolism in brain and that reduction of a certain aminopeptidase activity may lead to deposition of peptidic metabolites represented by β-amyloid and thus to Alzheimer's disease (AD). To explore this possibility in clinical situations and to seek a possible biochemical marker for the disease, we quantitated four classes of aminopeptidase activities in cerebrospinal fluids and heparinized plasma from sporadic AD patients and age-matched controls collected in two independent medical institutions. We found that only plasma glutamyl aminopeptidase activity was significantly and consistently lower in AD patients. Although the mechanism leading to such a biochemical change in plasma remains to be elucidated, the results provide support for the aminopeptidase hypothesis and indicate that the enzyme activity may potentially be used as a diagnostic/predictive marker for AD.
|ジャーナル||Biochemical and biophysical research communications|
|出版ステータス||Published - 1997 2月 24|
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