Table 1.

Dissociation constants of type I homoarginine-equivalent arginine mimetic peptides (hAMI).

		Kd, μM	Error	ΔG, kcal mol−1	ΔΔGaffinity, a kcal mol−1	ΔΔGspecificity, b kcal mol−1
Src	Arg	5.3	0.3	−7.2	0	−1.0
	Dap-Ac	91	5.3	−5.5	1.68	−0.7
	hArg(gGly)	11.1	0.2	−6.7	0.44	−0.9
	hArg(gl-Val)	25.5	1.3	−6.2	0.93	−1.0
	hArg(gd-Val)	22.5	1.1	−6.3	0.86	−1.9
	hArg(gl-Phe)	23.9	1.1	−6.3	0.89	−0.7
	hArg(gd-Phe)	15.9	0.6	−6.5	0.65	−2.0
	hArg(gl-Trp)	31.8	1.5	−6.1	1.07	−0.5
	hArg(gd-Trp)	12.6	1.1	−6.7	0.52	−1.5
Grb	Arg	29	2	−6.2	0
	Dap-Ac	320	104	−4.8	1.42
	hArg(gGly)	50	6	−5.8	0.32
	hArg(gl-Val)	141	12	−5.2	0.93
	hArg(gd-Val)	576	19	−4.4	1.76
	hArg(gl-Phe)	82	7	−5.6	0.61
	hArg(gd-Phe)	451	22	−4.6	1.62
	hArg(gl-Trp)	72	3	−5.6	0.54
	hArg(gd-Trp)	164	7	−5.1	1.02

^aΔΔG_affinity = ΔG (peptide) – ΔG (Arg).

^bΔΔG_specificity = ΔG_Src – ΔG_Grb for a given peptide. All peptides bound poorly to Crk (K_d > 250 μM). All experiments were conducted in PBS at 25 °C.