Integral membrane proteins
Integral membrane proteins are membrane proteins that are partly embedded in a membrane or that penetrate it completely. A distinction is made between transmembrane proteins and monotopic membrane proteins. Integral membrane proteins interact with the hydrophobic inner layer of a membrane in contrast to peripheral membrane proteins .
Transmembrane proteins
Transmembrane proteins are membrane proteins that cross both sheets of the phospholipid bilayer of a biomembrane. A distinction is made between bitopic transmembrane proteins, which only cross the membrane once, and polytopic transmembrane proteins, which cross the membrane several times.
Monotopic membrane proteins
In contrast to transmembrane proteins, monotopic membrane proteins do not completely cross the double lipid layer, only half of it.
Interactions
Integral membrane proteins are amphiphilic and, with their hydrophobic domain, interact with the hydrophobic fatty acids within the membrane. Therefore, they can only be released from a membrane by detergents . Detergents replace the fatty acids, whereby micelles are formed from the detergent and the protein. They are not necessarily firmly anchored in a membrane, but can also be freely movable.
Individual evidence
- ↑ a b Entry on integral membrane proteins. In: Römpp Online . Georg Thieme Verlag, accessed on March 27, 2020.
- ↑ C. Bordier: Phase separation of integral membrane proteins in Triton X-114 solution. In: Journal of Biological Chemistry . Volume 256, Number 4, February 1981, pp. 1604-1607, PMID 6257680 .