Membrane Proteins


Membrane proteins are common proteins that are part of, or interact with, biological membranes. Biological membranes are thin layers of lipids and proteins that separate the interior of a cell or an organelle from the surrounding environment. Membranes are essential for maintaining the structure, function and communication of living systems.

Membrane proteins perform a variety of functions vital to the survival of organisms, such as relaying signals, transporting molecules and ions, catalyzing reactions, and mediating cell adhesion. About a third of all human proteins are membrane proteins, and these are targets for more than half of all drugs.

Membrane proteins can be classified into several broad categories depending on their location and association with the lipid bilayer. Integral membrane proteins are permanently embedded within the lipid bilayer and can either span across the membrane (transmembrane proteins) or associate with one side of the membrane (integral monotopic proteins). Peripheral membrane proteins are temporarily attached to the lipid bilayer or to other integral proteins by non-covalent interactions. Lipid-bound proteins are located entirely within the boundaries of the lipid bilayer.

In this article, we will explore the location, types, features and functions of membrane proteins in more detail. We will also discuss some examples of membrane proteins and their roles in health and disease.