Porins

**Definition:** Porins are protein molecules that were originally found in the outer membrane of GRAM-NEGATIVE BACTERIA and that form multi-meric channels for the passive DIFFUSION of WATER; IONS; or other small molecules. Porins are present in bacterial CELL WALLS, as well as in plant, fungal, mammalian and other vertebrate CELL MEMBRANES and MITOCHONDRIAL MEMBRANES.

**Tree numbers:** - D12.776.157.530.400.500 - D12.776.543.550.450.730 - D12.776.543.585.400.730

**Synonyms:** - Porin