Table 1. Crystal data and X-ray diffraction data-collection statistics.

Values in parentheses are for the highest resolution bin (approximate interval of 0.1 Å).

Crystal	WO2 Fab, form A	WO2 Fab–Aβ1–16	WO2 Fab–Aβ1–28	WO2 Fab, form B
Crystallization conditions	100 mM MES pH 6.7, 20%(v/v) PEG 550 MME, 10 mM ZnSO4	100 mM MES pH 6.5, 25%(v/v) PEG 400	100 mM bicine pH 9.0, 20%(w/v) PEG 8000, 200 mM MgCl2	100 mM MES pH 6.5, 25%(v/v) PEG 550 MME, Aβ1–42 (equimolar)
Cryoprotectant	100 mM MES pH 6.7, 30%(v/v) PEG 550 MME, 10 mM ZnSO4	Not required	100 mM bicine pH 9.0, 25%(v/v) PEG 8000, 200 mM MgCl2	100 mM MES pH 6.5, 25%(v/v) PEG 550 MME, 20%(v/v) glycerol
X-ray source	14-BMC, APS	14-BM-C, APS	Rotating anode	Rotating anode
X-ray wavelength (Å)	0.99988	0.99988	Cu Kα	Cu Kα
Temperature (K)	100	100	100	100
Space group	P212121	P212121	P212121	P21
Unit-cell parameters
a (Å)	52.4	51.7	51.7	40.4
b (Å)	90.5	66.6	66.4	111.2
c (Å)	123.3	115.2	115.5	53.1
β (°)				103.8
Maximum resolution (Å)	1.6	1.6	1.6	1.9
Total observations	328859	273773	248683	100646
Unique reflections used	76778	53462	53254	33358
Redundancy	4.3 (3.2)	5.1 (3.2)	4.7 (3.1)	3.0 (2.0)
Data completeness (%)	98.0 (87.8)	99.2 (92.2)	99.7 (100)	93.3 (68.1)
Rmerge† (%)	10.1 (28.2)	11.8 (26.3)	7.3 (30.0)	5.8 (16.4)
〈I/σ(I)〉	16.6 (2.3)	14.3 (2.7)	11.4 (3.8)	14.4 (4.8)

^† R _merge = , where I _i(hkl) is the intensity of the ith measurement of an equivalent reflection with indices hkl.