Table 4.

Effect of urea on model parameters

	Urea concentration
	0.4 M	2 M	4 M	6 M
kM /kI (μM)	80 ± 30	80 ± 30	0	0
kD/kI	0.65 ± 0.15	0.65 ± 0.15	4 ± 0.5	3.6 ± 0.4
KMD (μM−1)	0.64 ± 0.08	0.64 ± 0.08	ND	ND
kpn /kn (μM4)	6 ± 1 × 108a	1.1 ± 0.6	10 ± 9	3.4 ± 2.7
kpf/kn (μM4)	6 ± 1 × 108a	50 ± 20 × 103	40 ± 20 × 103	2 ± 2 × 103
kla (μM−2 h−1)	0.047 ± 0.003	2 ± 1	ND	ND

Number of filaments in fibril, p, number of intermediates I in nucleus N, n, and reaction order of filaments association into fibrils, q were assumed to be independent of urea concentration.

^a From Pallitto and Murphy (2001). ND, not determined. Fitted values of the model parameters are reported along with their 95% confidence intervals.