title: In silico study on binding specificity of gonadotropins and their receptors: design of a novel and selective peptidomimetic for human follicle stimulating hormone receptor.
abstract: Gonadotropins bind to specific receptors in spite of sharing a high level of sequence and structural similarity. This specific binding is crucial for maintaining the reproductive health of an organism. In this study, residues that dictate the receptor binding specificity of the gonadotropins (FSH and LH) have been identified using combination of in silico methods. Docking studies (ZDOCK), based on the systematic replacement of these residues, confirmed its importance in receptor binding. An interesting observation is that the relative positioning of the residues conferring binding specificity varied for the gonadotropin-receptor complexes. This spatial difference of the key residues could be exploited for design of specific modulators. Based on the identified residues, we have rationally designed a peptidomimetic (FSHP) that displays good binding affinity and specificity for hFSHR. FSHP was developed by screening 3.9 million compounds using pharmacophore-shape similarity followed by fragment-based approach. It was observed that FSHP and hFSHâ can share the same receptor binding site thereby mimicking the native hFSHR-FSH interactions. FSHP also displayed higher binding affinity to hFSHR as compared to two reported hFSHR antagonists. MD simulation studies on hFSHR-FSHP complex revealed that FSHP is conformationally rigid and the intermolecular interactions are maintained during the course of simulation.
authors.affiliation: Biomedical Informatics Center of Indian Council of Medical Research, National Institute for Research in Reproductive Health, Mumbai, India.
authors.forename: Archana
authors.initials: A
authors.lastname: Sonawani
authors.forename: Sarfaraj
authors.initials: S
authors.lastname: Niazi
authors.forename: Susan
authors.initials: S
authors.lastname: Idicula-Thomas
mesh_terms: D020816:Amino Acid Motifs; D005640:Follicle Stimulating Hormone / Q000737:chemistry*; D006062:Gonadotropins / Q000737:chemistry; D006801:Humans; D006860:Hydrogen Bonding; D057927:Hydrophobic and Hydrophilic Interactions; D007986:Luteinizing Hormone / Q000737:chemistry*; D062105:Molecular Docking Simulation; D056004:Molecular Dynamics Simulation; D018716:Molecular Mimicry; D009842:Oligopeptides / Q000737:chemistry*; D011485:Protein Binding; D017433:Protein Structure, Secondary; D011962:Receptors, FSH / Q000737:chemistry*; D011967:Receptors, Gonadotropin / Q000737:chemistry; D013499:Surface Properties; D013816:Thermodynamics
chemical_list: D006062:Gonadotropins; D009842:Oligopeptides; D011962:Receptors, FSH; D011967:Receptors, Gonadotropin; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone