The protein state of matter.

Three ways are generally used to visualize proteins: (1) a static model in which the atomic positions are defined, (2) a dynamic model taking into account fluctuations, and (3) a reactive model that reflects the internal and external electric fields of the molecule. The properties of chromophoric prosthetic groups can be probed by optical spectroscopy, and when high resolution techniques are used, the results reveal information about the local electric fields in proteins, as influenced and determined by atomic positions and dynamics.