Molecular modeling and biological effects of peptidomimetic inhibitors of TACE activity

Figures & data

Figure 1.  Chemical structures of lead compound 1 and modified compounds 8a–d with molecular weight (MW), melting point (m.p.), and yield percentage. Ala, l-alanine; Phe, l-3-phenylalanine; Nal, l-3-(2’-naphthyl)alanine.

Figure 2.  Synthesis of 8a–d. Reagents and conditions: (a) i-PrOH; (b) R₁SH/Et₃N, benzene; (c) Z-Cl (PhCH₂OCOCl); (d) Boc-l-AlaOH, HOBt/DCC, H₂NCH₂Ph; (e) TFA, Boc-l-AA-OH, HOBt/DCC/Et₃N; (f) TFA, HOBt/DCC/Et₃N; (g) HONH₂/MeOH.

Table 1.  Effects of inhibitors on LPS-induced sTNF-α secretion by HL-60.

Group	sTNF-α secretion
	OD570 (mean ± SD)	p value	GIR (%)
LPS(–)	0.42 ± 0.034
LPS(+)	0.31 ± 0.026
8a (2 mg/mL)	0.32 ± 0.037	<0.05^a	9.1
8b (1 mg/mL)	0.37 ± 0.036	<0.05^a	54.5
8c (4 mg/mL)	0.34 ± 0.016	<0.05^a	27.3
8d (2 mg/mL)	0.37 ± 0.030	<0.05^a	54.5

^aAll compared with LPS(+) group.

Figure 3.  Content assay of mTNF-α on peritoneal macrophage surfaces of LPS-treated mice by FCM. (A) 0.1 mL PBS (blank control); (B) PBS + Tween-80 (solvent control); (C) Tween-80 containing 1.5 mg of compound 8d; (D) Tween-80 containing 2.5 mg of compound 8d; (A–D) i.p. injection of the above solutions, respectively, followed by intracaudate injection of 0.1 mL solution containing 10 mg d-GalN and 0.4–2 μg LPS; (E) intracaudate injection of 0.1 mL solution containing 10 mg d-GalN and 0.4–2 μg LPS only (positive control).

Figure 4.  Hematoxylin and eosin (HE) staining of liver and kidney before and after injection of LPS, inhibitor 8d (×200). (A) LPS in liver; (B) LPS and 8d (2.5 mg) in liver; (C) LPS in kidney; (D) LPS and 8d (2.5 mg) in kidney.

Figure 5.  Resultant conformation after molecular docking between inhibitor 8c and TACE on SCI Octane 2 graph workstation using advanced Insight II 2003.3L molecular modeling software.

Table 2.  Comparison of nonbonding interaction energies between four inhibitors (8a–d) and TACE with results of cell experiments.

Inhibitor	Nonbonding interaction energy (kcal/mol)			GIR (%)
	van der Waals interaction energy	Electrostatic interaction energy	Total energy
8a	–71	–11	–82	9.1
8b	–94	–25	–119	54.5
8c	–72	–22	–94	27.3
8d	–86	–25	–111	54.5