English

Abstract

Interleukin-2 (IL-2) is an immunoregulatory cytokine whose biological effects are mediated through interaction with specific receptors on the surface of target cells. Due to its presumed role in generating a normal immune response, IL-2 is being evaluated for the treatment of a variety of tumors, in addition to infectious diseases. Main drawback of human IL-2 is that the molecule is relatively unstable. Therefore, with the objective of increasing the stability of the molecule, site directed mutagenesis of human IL-2 gene was carried out. Early studies indicated that mutations at three Cysteine residues (58, 105, 125) which are in the active sites of human IL-2 resulted in the reduced stability as well as the biological activity of the molecule. Therefore, mutations were carried out at the positions of amino acid other than the receptor binding sites at 111Valine to Arginine, 117Lysine to Glutamine and 133 Threonine to Asparagine of the human sequence by comparing it with the bovine sequence which has higher stability than the human counterpart, using SWISS PDB tool. To understand the biological activity of the mutated IL-2, energy minimization studies were carried out using SWISS-PDB. Docking studies were performed to check the reliability of the results using HEX DOCK, ARGUS LAB and PATCH DOCK between the IL-2 receptor and its mutated Ligand. These docking results also confirmed that the reliability of these mutated IL-2 gene. Stability, half life and ADME characteristics of these mutants can be studied in a detailed manner in the in