What is a characteristic of multipass transmembrane proteins?

Multipass transmembrane proteins are characterized by their ability to span the lipid bilayer of cell membranes multiple times. This structural feature allows them to have various functional domains that can interact with both the extracellular environment and the cytoplasm. The arrangement of these proteins often consists of multiple helical regions or domains that traverse the membrane, facilitating the transport of substances across the membrane or the transmission of signals from the outside to the inside of the cell.

Soluble proteins, which do not interact significantly with membranes, are distinct from multipass transmembrane proteins. Additionally, the interaction of transmembrane proteins with the lipid bilayer is crucial for their function; hence, they cannot be said to not interact with the bilayer. Finally, peripheral proteins differ from multipass transmembrane proteins in that they do not span the membrane and are typically located on the surface of the membrane, interacting with integral membrane proteins or the lipid bilayer indirectly.

Thus, the hallmark feature of multipass transmembrane proteins is their spanning of the membrane several times, which is essential for their diverse roles in cellular function.