Graph theory can be applied to proteins to investigate longrange interactions and dynamics. A common approach is to represent the amino acids as nodes connected by edges which are weighted by the distance or other more complex descriptors such as interaction energies or correlated motion. In literature nu-merous examples can be found in which network approaches are used to describe protein dynamics , for the construction of coarse-graining models of proteins , or to partition proteins into fragments for quantum-chemical subsystem methods .