Cysteic acid explained

Cysteic acid also known as 3-sulfo--alanine is the organic compound with the formula HO₃SCH₂CH(NH₂)CO₂H. It is often referred to as cysteate, which near neutral pH takes the form ⁻O₃SCH₂CH(NH₃⁺)CO₂⁻.

It is an amino acid generated by oxidation of cysteine, whereby a thiol group is fully oxidized to a sulfonic acid/sulfonate group. It is further metabolized via 3-sulfolactate, which converts to pyruvate and sulfite/bisulfite. The enzyme L-cysteate sulfo-lyase catalyzes this conversion. Cysteate is a biosynthetic precursor to taurine in microalgae.^[1] By contrast, most taurine in animals is made from cysteine sulfinate.^[2]

Notes and References

1. Tevatia . Rahul . Allen . James . Rudrappa . Deepak . White . Derrick . Clemente . Thomas E. . Cerutti . Heriberto . Demirel . Yaşar . Blum . Paul . 2015-05-01 . The taurine biosynthetic pathway of microalgae . Algal Research . en . 9 . 21–26 . 10.1016/j.algal.2015.02.012 . 2211-9264.
2. Dissimilation of C3-Sulfonates. Cook, Alasdair M. . Denger, Karin . Smits, Theo H. M. . Archives of Microbiology. 2006. 185. 2. 83–90. 10.1007/s00203-005-0069-1. 16341843. 28030645.