Molecular modeling of protein tyrosine phosphatase 1B (PTP 1B) inhibitors

Binding modes of a series of aryloxymethylphosphonates and monoanionic biosteres of phosphate group from a series of benzylic alpha,alpha-diflluoro phosphate and its biosteres as protein tyrosine phosphatase 1B (PTP 1B) inhibitors have been identified by molecular modeling techniques. We have performed docking and molecular dynamics simulations of these inhibitors with PTP 1B enzyme. The initial conformation of the inhibitors for docking was obtained from simulated annealing technique. Solvent accessible surface area calculations suggested that active site of PTP 1B is highly hydrophobic. The results indicate that for aryloxymethylphosphonates, in addition to hydrogen bonding interactions, Tyr46, Arg47, Asp48, Val49, Glu115, Lys116, Lys120 amino acid residues of PTP 1B are responsible for governing inhibitor potency of the compounds. The sulfonate and tetrazole functional groups have been identified as effective monoanionic biosteres of phosphate group and biphenyl ring system due to its favorable interactions with Glu115, Lys116, Lys120 residues of PTP 1B found to be more suitable aromatic functionality than naphthalene ring system for benzylic alpha,alpha-diflluoro phosphate and its biosteres. The information generated from the present study should be useful in the design of more potent PTP 1B inhibitors as anti diabetic agents.