Deciphering the 3D Structural Characterization of Gonadotropin-Releasing Hormone in Tenualosa ilisha Using Homology...

Gonadotropin-Releasing Hormone (GnRH) is a crucial neuropeptide that regulates reproductive functions in vertebrates. The study identifies and characterizes (GnRH) in the brain of Tenualosa ilisha, an iconic and lucrative Clupeiform fish from River Ganga, India. The current study aimed to analyze the GnRH gene in T. ilisha using an in silico study. The GnRH gene of T. ilisha comprises a full-length nucleotide sequence of 605 base pairs with an open reading frame of 312 base pairs, which encodes 103 deduced amino acids (aa), respectively. It was found that leucine (L) is the most abundant amino acid in the GnRH protein. Additionally, the ligand interactions of the GnRH were analyzed using computational approaches. The structural validation showed an excellent stereochemical quality of the GnRH protein sequence, with over 88% of residues in Ramachandran plot-favored regions. The binding site prediction revealed 6 ligand-binding pockets, with the largest pocket containing 12 amino acids. After ADME screening, 16 drug-like compounds were docked to GnRH protein. Top five ligands N-Ac-(4-Cl-Phe)-Trp-Lys-AlaNH2, LHRH_LYS (6), Seabream_GnRH, Leuprolide, and LHRH_Des-tyr (5) had binding affinities ranging from -7.5 to -5.6 kcal/mol. The stable binding site was confirmed by 100 ns molecular dynamics simulations, with RMSD values below 10 Å and key residues retaining ligand contacts. The GnRH-protein resulted in the development of a suitable peptide sequence of T. ilisha, showing similarity with the similar anadromous American shad (Alosa sapidissima). This will certainly aid in future therapeutic and captive breeding advances, thereby fostering the culture and conservation of the wild species.