TABLE 1.

Impact of I50L substitution on protease susceptibility from patient isolates before and after treatment with ATV^a

Patient protease backbone	I50L Change
	ATV	APV	IDV	LPV	NFV	RTV	SQV
Q7E, L10I, K14R, D30N, L38I, M46I, Q61E, L63P, I72V, V77I, N88D, I93L	7.4	0.65	1.2	0.26	0.24	0.15	0.41
T12D, K14R, V32I, K43T, M46I, I47V, I62V, L63P, V82A, I93L	4.3	0.50	0.14	0.83	0.66	0.33	0.24
L10I, T12P, K14R, K20I, Q61E, I62V, L63P, I64L, A71V, T74P, L90M, I93L	16	1.4	0.27	0.36	0.69	0.23	0.33

^aI50L change (IC₅₀ on treatment [with I50L]/IC₅₀ baseline [no I50L]) was calculated after measuring protease susceptibility by Western blot assays of total cell lysates after transfection of gag-pol expression vectors (n = 3). Primary resistance substitutions are underlined.