Figure 2.

Differential inhibition of Aβ₄₂ and Aβ₄₀ formation. (A) Labeled K695sw cells were chased with the indicated concentrations of MDL 28170 and precipitated with 21F12 (Upper) followed by 1282 (Lower). (B) Quantitation of the effect of 200 μM MDL 28170 on Aβ and p3 by phosphorimaging. The bars show the pixel number relative to an untreated control (200); SDs are indicated. The decreases in Aβ_total and p3_total relative to an untreated control were significant (∗, two-tailed t test, n = 4, P < 0.001) and the decreases in Aβ₄₂ and p3₄₂ upon treatment with MDL 28170 did not reach significance. Moreover, the difference in inhibition of Aβ₄₂ versus total Aβ is significant (two-tailed t test, n = 4, P < 0.01) and the difference in inhibition of p3₄₂ versus total p3 is also significant (two-tailed t test, n = 4, P < 0.05).