TITLE:
Copper Ions Enhance Signal Intensity of Sandwich ELISA for Amorphous Aggregates of Amyloid-β42
AUTHORS:
Akira Itakura, Yoshio F. Kanematsu, Ryoko Suzuki, Hideki Kohno, Kazuaki Yoshimune
KEYWORDS:
Amyloid-β42, Soluble Aggregates, Antibody, ELISA
JOURNAL NAME:
Advances in Bioscience and Biotechnology,
Vol.7 No.9,
August
22,
2016
ABSTRACT: Amyloid-β42 (Aβ42) accumulates within senileplaque, a pathological hall mark of
Alzheimer’s disease (AD). Our previous reports showed that the monoclonal antibodies
37-11 and 77-3 react with conformational epitopes on the surface of the soluble
aggregates of Aβ42 and that sandwich ELISA using these two monoclonal antibodies
yields high reactivity to detect soluble aggregates of Aβ42. Here, the reactivity of the
sandwich ELISA was shown to increase in the presence of 50 μM Cu2+. However, the
addition of Cu2+ had only a small effect on the reactivity of a direct ELISA using antibody
37-11 or 77-3, suggesting that Cu2+ has a small effect on the number of epitopes
on the surface of the aggregates. Atomic force microscopy images showed that
larger aggregates were formed in the presence of Cu2+, as shown in the other reports.
Cu2+ may gather the aggregates with distinct epitopes recognized by antibodies 37-11
and 77-3, leading to increased signal intensity of the sandwich ELISA.