Definition of porin in English:



  • Any of a class of proteins whose molecules can form channels (large enough to allow the passage of small ions and molecules) through cellular membranes.

    • ‘It functions as an anion-selective porin allowing the passage of small molecules through the outer membrane.’
    • ‘Extramembranous loops are crucial in regulating the activity of TonB-dependent receptors and other outer membrane proteins such as porins, by providing suitable sites for substrate recognition, selectivity, or binding.’
    • ‘These molecular sieving properties are due to a major class of proteins called porins that form trimeric channels in the outer membrane.’
    • ‘Bacterial outer membrane porins are classified into channels specific for the uptake of nutrients, such as maltose or sucrose, and unspecific pore proteins.’
    • ‘This function is accomplished by a number of membrane channel proteins called porins, which display a wide range of permeability profiles.’


1970s: from Greek poros ‘pore’ + -in.