Table 1. Fragments of Aβ42 Resulting from Initial Cleavages by IDE at pH 7.4, 4 °C and Substrate-to-Enzyme Molar Ratio of 100:1.

fragments	observed m/z ratio	charge z	observed mass (Da)	theoretical mass (Da)	δ (Da)a	initial cleavage site
D1–F19	463.83	5	2314.15	2314.50	–0.35	Phe19–Phe20
	579.53	4	2314.12		–0.38
	772.37	3	2314.11		–0.39
F20–A42	740.07	3	2217.21	2217.61	–0.40
	1109.60	2	2217.20		–0.41
D1–F20	493.24	5	2461.20	2461.68	–0.48	Phe20–Ala21
	616.30	4	2461.20		–0.48
A21–A42	691.05	3	2070.15	2070.43	–0.28
	1036.07	2	2070.14		–0.29
D1–K28b	653.31	5	3261.55	3262.50	–0.95	Lys28–Gly29
G29–A42b oxidizedc	643.38	2	1284.76	1285.75	–1.01

^aObserved mass–theoretical mass.

^bPrimary fragments observed only in the presence of resveratrol.

^cMet35 oxidized to a sulfoxide.