TY - JOUR
T1 - Biochemical evidence for the long-tail form (Aβ1-42/43) of amyloid β protein as a seed molecule in cerebral deposits of alzheimer′s disease
AU - Tamaoka, A.
AU - Kondo, T.
AU - Odaka, A.
AU - Sahara, N.
AU - Sawamura, N.
AU - Ozawa, K.
AU - Suzuki, N.
AU - Shoji, S.
AU - Mori, H.
PY - 1994/11/30
Y1 - 1994/11/30
N2 - We measured the amounts of total Aβ, Aβ1-40, and Aβ1-42/43 in brain tissues using a newly developed ELISA assay and found that the amounts of insoluble Aβ1-42/43 and insoluble Aβ1-40) were linearly related to the amount of Aβ deposits or total insoluble Aβ at their lower and higher concentrations, respectively. In an experiment to characterize the Aβ species in brain homogenates with buffered saline, we unexpectedly detected soluble Aβ which was derived from the insoluble amyloid deposits in brain tissue, indicating reversible depolymerisation of Aβ from insoluble amyloid deposits. To confirm this finding, we performed 5 consecutive washes of insoluble precipitates of AD brains with buffered saline. Both species of Aβ were found in all 5 supernatant fractions and their amounts were gradually decreased. The ratio of Aβ1-42/43/43 to Aβ1-40 was increased with the numbers of washes, indicating that Aβ1-40 existed in an exposed manner as compared to Aβ1-42/43. Thus the present finding is the first biochemical evidence that Aβ1-40 was the predominant species involved in the reversible exchanging reaction on seeding Aβ1-42/43 between the soluble and the insoluble forms (amyloid fibrils).
AB - We measured the amounts of total Aβ, Aβ1-40, and Aβ1-42/43 in brain tissues using a newly developed ELISA assay and found that the amounts of insoluble Aβ1-42/43 and insoluble Aβ1-40) were linearly related to the amount of Aβ deposits or total insoluble Aβ at their lower and higher concentrations, respectively. In an experiment to characterize the Aβ species in brain homogenates with buffered saline, we unexpectedly detected soluble Aβ which was derived from the insoluble amyloid deposits in brain tissue, indicating reversible depolymerisation of Aβ from insoluble amyloid deposits. To confirm this finding, we performed 5 consecutive washes of insoluble precipitates of AD brains with buffered saline. Both species of Aβ were found in all 5 supernatant fractions and their amounts were gradually decreased. The ratio of Aβ1-42/43/43 to Aβ1-40 was increased with the numbers of washes, indicating that Aβ1-40 existed in an exposed manner as compared to Aβ1-42/43. Thus the present finding is the first biochemical evidence that Aβ1-40 was the predominant species involved in the reversible exchanging reaction on seeding Aβ1-42/43 between the soluble and the insoluble forms (amyloid fibrils).
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U2 - 10.1006/bbrc.1994.2740
DO - 10.1006/bbrc.1994.2740
M3 - Article
C2 - 7999120
AN - SCOPUS:0028096692
VL - 205
SP - 834
EP - 842
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
SN - 0006-291X
IS - 1
ER -