Protein and enzymes play an important role in practically every aspects of life. An understanding of the mechanism that involves protein and enzymes are crucial for many different purposes. Here in meilerlab we apply and develop multiscale methods to understand the complex mechanism of these biomolecules for many different puroposes including protein - drug interactions as well as unveiling the mechinsm of different enzymatic reactions. We are working to develop a multiscale QM/MM MC method, where QM calculations will be combined with Monte carlo based simulations. Using QM/MM MC the accurate energetics for a biomolecular reaction will be evalutated by applying QM method for the small reactive parts and MC will be applied for the conformational sampling of the biomolecule.