Sulfur respiration in mammals

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Researchers have gained new insight into the formation of a group of compounds found in almost all organisms, which are reportedly shown to be a powerful antioxidant that protects cells from damage by free radicals. They found that these compounds were also essential in supporting the mitochondrial energy metabolism, which is known as sulfur respiration, and identified it for the first time in humans and other mammals.

Researchers have gained new insight into the formation of a group of compounds found in almost all organisms, which are reportedly shown to be a powerful antioxidant that protects cells from damage by free radicals. They found that these compounds were also essential in supporting the mitochondrial energy metabolism, which is known as sulfur respiration, and identified it for the first time in humans and other mammals.

The compounds, such as cysteine hydropersulfide (CysSSH) and other persulfides, are widely present in the cells of most organisms, from single-celled to humans, and even in the natural environment and foodstuffs. They are believed to act as an antioxidant that protects cells from harmful free radicals, which are byproducts of normal cell activity or pollutants, and can cause various diseases such as cancer. However, how these reactive sulfur molecules are formed, or what role they play exactly within these cells, has not been well understood.

A team of researchers from Tohoku University, working with colleagues in Japan, Hungary, the United Kingdom, and the United States, homed in on one pathway for the formation of CysSSH inside cells, publishing their findings in Nature Communications. They found that the amino acid L-cysteine acted as a starting building block for the synthesis of CysSSH, through a reaction catalyzed by cysteinyl-tRNA synthetases (CARSs), a family of enzymes present in most mammalian cells.

Read more at Tohoku University

Image: Sulfur respiration: oxygen-independent energy production system in mammals.

 Image Credit: Takaaki Akaike / Tohoku University