Examples of intrinsic proteins are:
- Mammalian major intrinsic protein (MIP), which is the major component of lens fibre gap junctions.
- Mammalian aquaporins, which form water-specific channels.
- Bacterial glycerol facilitator protein, which facilitates the movement of glycerol across the cell membrane.
Word origin: ML intrinsecus inward (adjective), L (adverb), equiv. to intrin- (int(e)r-.