SkQ
Encyclopedia
SkQ stands for a class of organic molecules composed of a large organic cation (often called "penetrating cation" for the ability to penetrate through lipid bilayer
) with antioxidant
plastoquinone
attached to it. When added to a living cell
, penetrating cations are distributed according to the transmembrane electrical potential difference
. They traverse across the cell membrane
(negatively charged from inside) and accumulate in mitochondria (also negatively charged inside). The concentration of a penetrating cation in mitochondria can be more than 1000-fold higher than its extracellular concentration.
production revealed that SkQ is a very efficient antioxidant, even when added to the cells in the nanomolar concentration range.
in mitochondria may contribute to senescence
. Reactive oxygen species
damage mitochondrial DNA
and other important cell component, leading to gradual impairment of cellular function. Antioxidants may slow this damage. Several studies indicate that SkQ can efficiently protect the cell from oxidative damage (see for a review).
Lipid bilayer
The lipid bilayer is a thin membrane made of two layers of lipid molecules. These membranes are flat sheets that form a continuous barrier around cells. The cell membrane of almost all living organisms and many viruses are made of a lipid bilayer, as are the membranes surrounding the cell nucleus...
) with antioxidant
Antioxidant
An antioxidant is a molecule capable of inhibiting the oxidation of other molecules. Oxidation is a chemical reaction that transfers electrons or hydrogen from a substance to an oxidizing agent. Oxidation reactions can produce free radicals. In turn, these radicals can start chain reactions. When...
plastoquinone
Plastoquinone
Plastoquinone is a quinone molecule involved in the electron transport chain in the light-dependent reactions of photosynthesis. Plastoquinone is reduced , forming plastoquinol...
attached to it. When added to a living cell
Cell (biology)
The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos....
, penetrating cations are distributed according to the transmembrane electrical potential difference
Membrane potential
Membrane potential is the difference in electrical potential between the interior and exterior of a biological cell. All animal cells are surrounded by a plasma membrane composed of a lipid bilayer with a variety of types of proteins embedded in it...
. They traverse across the cell membrane
Cell membrane
The cell membrane or plasma membrane is a biological membrane that separates the interior of all cells from the outside environment. The cell membrane is selectively permeable to ions and organic molecules and controls the movement of substances in and out of cells. It basically protects the cell...
(negatively charged from inside) and accumulate in mitochondria (also negatively charged inside). The concentration of a penetrating cation in mitochondria can be more than 1000-fold higher than its extracellular concentration.
SkQ is a mitochondria-targeted antioxidant
It was proposed that penetrating cations can act as "electric locomotive molecules" and target molecules attached to them in mitochondria. Monitoring the distribution of plastoquinonyl-decyl-rhodamine 19 (SkQR1), a fluorescent SkQ, confirmed that it accumulated almost exclusively in mitochondria. Measurements of mitochondrial reactive oxygen speciesReactive oxygen species
Reactive oxygen species are chemically reactive molecules containing oxygen. Examples include oxygen ions and peroxides. Reactive oxygen species are highly reactive due to the presence of unpaired valence shell electrons....
production revealed that SkQ is a very efficient antioxidant, even when added to the cells in the nanomolar concentration range.
SkQ as a potential anti-aging drug
Production of reactive oxygen speciesReactive oxygen species
Reactive oxygen species are chemically reactive molecules containing oxygen. Examples include oxygen ions and peroxides. Reactive oxygen species are highly reactive due to the presence of unpaired valence shell electrons....
in mitochondria may contribute to senescence
Senescence
Senescence or biological aging is the change in the biology of an organism as it ages after its maturity. Such changes range from those affecting its cells and their function to those affecting the whole organism...
. Reactive oxygen species
Reactive oxygen species
Reactive oxygen species are chemically reactive molecules containing oxygen. Examples include oxygen ions and peroxides. Reactive oxygen species are highly reactive due to the presence of unpaired valence shell electrons....
damage mitochondrial DNA
Mitochondrial DNA
Mitochondrial DNA is the DNA located in organelles called mitochondria, structures within eukaryotic cells that convert the chemical energy from food into a form that cells can use, adenosine triphosphate...
and other important cell component, leading to gradual impairment of cellular function. Antioxidants may slow this damage. Several studies indicate that SkQ can efficiently protect the cell from oxidative damage (see for a review).