Influence of temperature on the topological features of inner cavities in cytoglobin

Cytoglobin (Cygb) is a novel member of the globin family in man, but there is no clear evidence about its biological function. Cygb exhibits a highly complex ligand rebinding kinetics, which agrees with the structural plasticity of the inner cavities and tunnels found in the protein matrix. In this work we have examined the effect of temperature on the topological features of Cygb. To this end, the structural and dynamical properties of human Cygb are compared with those determined for the Antarctic fish Chaenocephalus aceratus. The results support a distinct temperature-dependence of the topological features in the two proteins, suggesting different adaptations to cold and warm environments.