Heat capacities of globular proteins

The heat capacities of globular proteins due to residue fluctuations are studied theoretically based on a Gaussian network model. It is found that the heat capacities for globular proteins as a function of a scaled temperature almost follow a universal curve in spite of their different sizes, shapes, and architectures. From the heat capacity curve at low temperatures, we can derive the spectral dimension of globular proteins, which is found to be larger than 2. This result implies that globular proteins behave dynamically as objects with dimension between 2 and 3.