How do transmembrane protein alpha helixes bind to the membrane?

I would post this in biology but as the question is biochemical in nature I decided this would be a more appropriate platform.


What I'm asking is how exactly does a transmembrane protein bind to the cell membrane? I realize that the transmembrane alpha helix is about 20 amino acids long with mostly hydrophobic amino acids as the inside of the membrane is hydrophobic.


What I don't realize is how exactly this alpha helix binds to the membrane and sticks to it? I've tried searching on the subject but I can't seem to find the answer. I found out that the alpha helix satisfies the hydrogen bonds internally leaving no polar R groups for the membrane as most groups are hydrophobic, but that only explains how it **doesn't** bind to the membrane.




Well, it binds via [hydrophobic interacions](https://en.wikipedia.org/wiki/Hydrophobic_effect) - non-polar R groups are attracted to hydrophobic interior of the membrane via [dispersion forces](https://en.wikipedia.org/wiki/London_dispersion_force), and also don't disrupt the structure of water as if they would outside of membrane. It's the same thing which holds molecules of the membrane together.


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