Computational Modeling and Quality Validation of HMG-CoA Reductase for Drug Design Applications

The enzyme 3-hydroxy-3-methylglutaryl CoA reductase (HMG-CoA reductase or HMGR) catalyzes the conversion of HMG-CoA to mevalonate, which is the rate-limiting step in cholesterol and isoprenoid biosynthesis. HMG-CoA reductase (HMGR) is the main target of statins, which are commonly used medicines to lower cholesterol and prevent heart-related diseases. However, the use of statins may lead to harmful side effects, like muscle pain (myopathy) and muscle breakdown (rhabdomyolysis), creating a demand for alternative therapeutic options. This study aims to analyze and predict the 3D structure of HMGR from 12 different species, such as humans, fruit flies, plants, and protists, using a computer-based method to evaluate their potential for future drug design. Protein sequences were retrieved from the NCBI database and analyzed using various bioinformatics tools. The physicochemical properties and amino acid composition were computed by ExPASy's ProtParam tool, and the secondary structural features were determined by SOPMA and PHD servers. ClustalW, CELLO, and MEME, respectively, predicted the phylogenetic tree, subcellular localization, and structural motifs. Homology modeling was performed using the Swiss-Model Workspace with selected templates and visualized with PyMOL software. The predicted models were evaluated with PROCHECK analysis by Ramachandran plot and VERIFY 3D, and ERRAT values using the SAVES server. The aliphatic index and GRAVY values indicated that most HMGRs were thermally stable and hydrophobic. Among the selected HMG-CoA reductase sequences, the alpha helix dominated over the extended strand, beta turn, and random coil, according to the secondary structural properties. The phylogenetic analysis ensured the relationship among experimental species, and the predicted motifs indicated uniformity in the conserved sequences. The result of the predicted model indicated good quality and high reliability of the protein for most species, particularly for H. sapiens and D. melanogaster. This in silico study provides valuable insights into the structural and functional aspects of HMGR across species, laying a strong foundation for the development of safer and more effective cholesterol-lowering medications in the future.