Table 4.

Binding site residues and docking scores for compounds and known inhibitors of PTP1B (PDB: 1NNY and 1T49) obtained using AutoDock 4.2.

Compounds	Binding Energy 1	Number of H-Bonds	H-Bond Interacting Residues	Hydrophobic Interacting Residues	Electrostatic Interacting Residues
Kuwanon C (1)	−7.54	3	Glu200, Gly277, Ala189	Phe196(Pi-Pi Stacked), Phe280(Pi-Pi Stacked, Pi-Alkyl), Lys197(Alkyl), Leu192(Pi-Alkyl)
Oxyresveratrol (5)	−6.98	6	Asn193, Lys197, GLu200, Glu276, Ala189	Phe280(Pi-Pi Stacked), Phe196(Amide-Pi Stacked), Leu192(Pi-Alkyl)
Kuwanon G (7)	−6.26	7	Ser216, Gln266, Asp48, Met258, Gln262, Tyr46	Tyr46(Pi-Pi Stacked), Ala217(Alkyl), Ile219(Alkyl), Trp179(Pi-Alkyl), Val49(Pi-Alkyl), Arg221(Pi-Alkyl)	Arg221(Pi-Cation)
	−7.11	5	Asn193, Gly277, Phe280, Glu200	Phe196(Pi-Pi Stacked, Pi-Pi T-shaped, Pi-Alkyl), Phe280(Pi-Pi Stacked, Pi-Pi T-shaped, Pi-Alkyl), Ile281(Alkyl), Leu192(Pi-Alkyl)	Lys197(Pi-Cation)
Compound A 2	−10.2	10	Ser216, Ala217, Gly218, Ile219, Gly220,Arg221, Arg254, Asp48	Ala217(Pi-Sigma, Pi-Alkyl), Tyr46(Pi-Sigma, Pi-Pi Stacked), Ala27(Pi-Pi Stacked)
Compound B 3	−9.08	2	Asn193, Glu276	Phe196(Pi-Sigma, Pi-Alkyl), Phe280(Pi-Pi Stacked, Pi-Pi T-shaped, Pi-Alkyl), Ile281(Alkyl), Leu192(Pi-Alkyl), Ala189(Pi-Alkyl)

¹ Estimated binding energy of the ligand–receptor complex (kcal/mol). ² 3-({5-[N-acetyl-3-{4-[(carboxycarbonyl)(2-carboxyphenyl)amino]-1-naphthyl}-l-alanyl)amino]pentyl}oxy)-2-naphthoic acid, a known catalytic inhibitor. ³ 3-(3,5-dibromo-4-hydroxy-benzoyl)-2-ethyl-benzofuran-6-sulfonic acid (4-sulfamoyl-phenyl)-amide, a known allosteric inhibitor.