Structure and Mechanism Analysis of Proteins by Fragment Molecular Orbital Calculations

Abstract

The fragment molecular orbital（FMO）method is a theoretical method that enables quantum chemical calculations of whole bio-macromolecules, such as proteins and nucleic acids, yielding the energies and electron densities of whole molecules as well as interaction energies between fragments. The FMO calculations of protein complexes that have been structurally analyzed experimentally allow for quantitative analysis and physicochemical interpretation of intra- and intermolecular interactions within the complexes. Here we describe the quantitative analysis of structures and interactions using the FMO method, i.e., the “structure and interaction basis” obtained through the complementary use of experimental structure and the FMO calculations.