C6H13NO3S is a molecular formula representing a class of organic compounds composed of six carbon atoms, thirteen hydrogen atoms, one nitrogen atom, three oxygen atoms, and one sulfur atom. This specific elemental composition is characteristic of various biologically relevant molecules, particularly derivatives of amino acids involving sulfur oxidation.
Notable Compounds
The most widely recognized and biologically significant compounds with the molecular formula C6H13NO3S are the methionine sulfoxides. These compounds are oxidized forms of the essential amino acid methionine (C5H11NO2S), where an additional oxygen atom has been incorporated onto the sulfur atom.Methionine Sulfoxides
Methionine sulfoxides are formed through the oxidation of the thioether sulfur atom in methionine, leading to the formation of a sulfoxide group (S=O). This oxidative modification is often catalyzed by reactive oxygen species (ROS) and serves as a significant post-translational modification in proteins.- Stereoisomers: The sulfoxide group introduces a chiral center at the sulfur atom, in addition to the existing chiral alpha-carbon of methionine. Consequently, methionine sulfoxide exists as four stereoisomers: L-methionine-(S)-sulfoxide, L-methionine-(R)-sulfoxide, D-methionine-(S)-sulfoxide, and D-methionine-(R)-sulfoxide. The L-form is predominant in biological systems.
- Biological Significance: Methionine sulfoxides play crucial roles in cellular physiology and pathology:
- Biomarker of Oxidative Stress: The formation of methionine sulfoxide in proteins is a widely accepted indicator and consequence of oxidative stress, reflecting damage caused by reactive oxygen and nitrogen species.
- Enzymatic Repair: Cells possess dedicated enzyme systems, primarily methionine sulfoxide reductases (MsrA and MsrB), that can reduce methionine sulfoxide back to methionine. This enzymatic repair system is vital for restoring the function of oxidatively damaged proteins and for cellular defense against oxidative damage.
- Redox Signaling: The reversible oxidation and reduction of methionine residues, particularly within critical proteins, are thought to contribute to cellular redox signaling pathways, influencing various cellular processes.
General Characteristics
Compounds sharing the molecular formula C6H13NO3S typically exhibit the following general characteristics:- Organic Nature: Containing a carbon backbone with numerous carbon-hydrogen bonds, characteristic of organic chemistry.
- Polarity: The presence of nitrogen, oxygen (especially in the sulfoxide and carboxyl groups), and a sulfur atom contributes to significant polarity, making these compounds generally soluble in water.
- Biochemical Relevance: The combination of carbon, hydrogen, nitrogen, oxygen, and sulfur atoms is fundamental to many biological molecules, including amino acids, peptides, and various metabolites.