Table 2.

Substitution of Trp-631 with a series of hydrophobic amino acids

Peptide	[θ]222, 103 deg cm2 dmol−1	Tm, °C	IC50, viral entry, nM	IC50, cell fusion, nM
Wild-type C34	−31.7	66	1.5  ±  0.2	0.55  ±  0.03
Trp-631 → Nal	−32.0	62	1.4  ±  0.3	0.79  ±  0.08
Trp-631 → Phe	−26.3	59	3.6  ±  0.8	1.6  ±  0.05
Trp-631 → Leu	−26.7	50	5.3  ±  1.0	3.2  ±  0.1
Trp-631 → Val	−23.9	43	13  ±  2.8	4.5  ±  0.09
Trp-631 → Abu	−23.2	43	16  ±  4.8	6.9  ±  0.4
Trp-631 → Ala	−24.9	37	40  ±  4.3	15  ±  0.8
Trp-631 → Gly	−17.1	35	38  ±  6.1	25  ±  3.8

Values were determined as in Table 1. The means and standard errors for the inhibition assays were from triplicate trials.