QSite is a new mixed mode QM/MM program by Schrodinger for highly accurate energy calculations of protein-ligand interactions in the active site. The program is specifically designed for proteins and allows a number of different QM/MM boundaries for residues in the active site. QSite uses the power and speed of Jaguar to perform the QM part of the calculations and OPLS-AA to perform the MM part of the calculations.

Features

• Easy set-up through the Maestro interface. Select quantum mechanical region simply by pointing and clicking on screen.
• Ability to treat metals, including all main group and transition metals.
• Reliable ground state convergence for metal-containing systems by applying a unique initial guess wavefunction algorithm.
• Inclusion of solvation effects by applying a continuum solvation model.
• Flexibility in specifying boundaries between the QM and the MM regions, such as backbone, side chain, or full residue selection.
• Different levels of QM theory: Hartree-Fock, Density Functional Theory, Localized Mœller-Plesset second order perturbation theory

13 Dec 2001

Schrodinger is pleased to announce the latest release of QSite, a mixed Quantum Mechanics/Molecular Mechanics (QM/MM) package specially tuned for studying reactive chemistry in large biological systems. QSite allows highly accurate studies of protein-ligand interactions including hydrogen-bonding, proton-transfer, charge-transfer reactions, metal-ligand binding and metalloenzyme catalysis.

Hybrid QM/MM takes advantage of the best of both worlds - the accuracy of quantum mechanics and the efficiency of molecular mechanics. In QSite, the molecular mechanics calculations are performed using the OPLS-AA force field, generally acknowledged to be the most reliable for treating medicinally relevant compounds and proteins. The critical region is treated quantum mechanically using the highest-performance ab initio program, Jaguar. Additionally, QSite benefits from Jaguar's unique initial guess algorithm that ensures convergence to the correct electronic ground state for metal-containing systems. QSite is able to perform full geometry optimizations and incorporate solvation effects using continuum dielectric methods.

For more information please contact us at: mailto:info@schrodinger.com