Protein K (porin)
Encyclopedia
Protein K is a porin
expressed in some pathogenic strains of E. coli bacteria
. It has a molecular weight of about 40 kDa and is localized to the outer membrane
, through which it allows both inorganic and organic
ion
s to pass.
The strains in which protein K has been identified are encapsulated, or surrounded by a poly-sialic acid
capsule that renders them more resistant to phagocytosis by cells in the immune system
.
Porin
Porin may refer to:* Porin , a transmembrane protein* Porin , a Croatian grand Opera, first performed in 1897* Porin , the Croatian national music industry award, first awarded in 1994 and named after the opera...
expressed in some pathogenic strains of E. coli bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
. It has a molecular weight of about 40 kDa and is localized to the outer membrane
Outer membrane
The bacterial outer membrane is found in Gram-negative bacteria. Its composition is distinct from that of the cytoplasmic membrane - among other things, the outer leaflet of the membrane includes a complex lipopolysaccharide whose lipid portion acts as an endotoxin - and it is linked to the cell's...
, through which it allows both inorganic and organic
Organic chemistry
Organic chemistry is a subdiscipline within chemistry involving the scientific study of the structure, properties, composition, reactions, and preparation of carbon-based compounds, hydrocarbons, and their derivatives...
ion
Ion
An ion is an atom or molecule in which the total number of electrons is not equal to the total number of protons, giving it a net positive or negative electrical charge. The name was given by physicist Michael Faraday for the substances that allow a current to pass between electrodes in a...
s to pass.
The strains in which protein K has been identified are encapsulated, or surrounded by a poly-sialic acid
Sialic acid
Sialic acid is a generic term for the N- or O-substituted derivatives of neuraminic acid, a monosaccharide with a nine-carbon backbone. It is also the name for the most common member of this group, N-acetylneuraminic acid...
capsule that renders them more resistant to phagocytosis by cells in the immune system
Immune system
An immune system is a system of biological structures and processes within an organism that protects against disease by identifying and killing pathogens and tumor cells. It detects a wide variety of agents, from viruses to parasitic worms, and needs to distinguish them from the organism's own...
.