Mutation studies on transmembrane protein sulphate permease for enhanced biohydrogen production in Chlamydomonas reinhardtii: a molecular dynamics simulation approach.

Abstract

Fossil fuel reserves are rapidly depleting, necessitating the need to find a promising alternative. Hydrogen is a clean and promising energy source with a significant energy yield and water as the only byproduct leading many to view it as a viable source of renewable energy. Despite traditional assessments for the techno-economic feasibility of biohydrogen not supporting its practical implementation, biologically produced hydrogen remains a more environmentally friendly and an efficient energy source. Recent studies have reported that low levels of sulphate permease (SulP) is said to increase hydrogen production. Mutation studies were carried out and molecular docking was performed for wild type and mutated sulphate permease with ligands that dampen its activity as reported in literature. Effect of mutation on SULP1 gene in Chlamydomonas reinhardtii was assessed using PredictSNP, I-Mutant 2.0, and SIFT. Sulphate permease being a transmembrane protein, CHARMM-GUI membrane builder module was used for solvent equilibration, lipid bilayer generation and proteins. Protein structures were harmonically restrained to maintain their initial positions and allow the solvent to equilibrate effectively. Molecular simulations were performed for wild & mutant types with ligands and assessed for RMSD, RMSF, intra- and inter-hydrogen bond interactions, Rg and SASA till 200 ns using GROMACs v.2016. The MMPBSA values were found to be -29.392 +/- 11.753 kJ/mol WT (Wild type) and -34.080 +/- 10.837 kJ/mol MT (Mutant type). Significant structural modification was inferred through the mutation approach.