How do lateral diffusion rates of membrane proteins change?

The lateral diffusion rates of membrane proteins are primarily influenced by their interactions with other proteins or components within the membrane. This means that the presence of other proteins, lipids, and even the cytoskeletal elements can either enhance or hinder the movement of membrane proteins. For instance, if a membrane protein is tethered to the cytoskeleton or interacts with other proteins (forming complexes), its mobility may be restricted, leading to slower lateral diffusion. Conversely, proteins that are not heavily interacting with other components can diffuse more freely.

In contrast, diffusion rates do not remain constant regardless of other components, as interaction dynamics significantly affect the mobility of proteins in the membrane. It is also important to note that the diffusion speed of membrane proteins is generally slower than that of lipids due to their larger size and complexity. Furthermore, the diffusion of membrane proteins can occur in the presence of lipids, as they exist within the lipid bilayer; therefore, the idea that diffusion cannot happen if lipids are present is incorrect. Overall, the interactions of membrane proteins within their environment critically determine their lateral diffusion rates.