membrane protein complex

Definition

Target type: cellularcomponent

Any protein complex that is part of a membrane. [GOC:dos]

Membrane protein complexes are intricate assemblies of multiple protein subunits, often embedded within cellular membranes. These complexes are essential for a wide array of cellular functions, including signal transduction, transport, and cell adhesion. The cellular component of a membrane protein complex encompasses the specific location and interactions within the membrane environment.

A membrane protein complex can be characterized by its location within the membrane:

* **Integral membrane proteins:** These proteins are embedded within the lipid bilayer, with at least one transmembrane domain that spans the entire membrane. They often play a crucial role in transport and signaling.
* **Peripheral membrane proteins:** These proteins are associated with the membrane surface, either through interactions with lipid head groups or with integral membrane proteins. They are often involved in signaling and cytoskeletal interactions.

The interactions within a membrane protein complex are equally important. Proteins within these complexes can interact through various mechanisms:

* **Hydrophobic interactions:** These interactions are driven by the exclusion of water from non-polar amino acids. They are particularly important for the association of transmembrane domains.
* **Ionic interactions:** These interactions occur between oppositely charged amino acids, contributing to the stability of the complex.
* **Hydrogen bonds:** These interactions form between polar amino acids, further stabilizing the complex.
* **Disulfide bonds:** These covalent bonds form between cysteine residues, providing strong structural support.

The organization and interactions within a membrane protein complex are highly dynamic and regulated. These complexes can undergo conformational changes in response to signals, leading to alterations in their function. The cellular component of a membrane protein complex is therefore a dynamic entity, constantly adapting to the needs of the cell.
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Proteins (2)

Compounds (17)