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Cysteate
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 The enzyme L-cysteate sulfo-lyase (EC 4.4.1.25) catalyzes the reaction :L-cysteate + H2O = hydrogensulfite + pyruvate + NH3 (overall reaction) ::(1a) L-cysteate = hydrogensulfite + 2-aminoprop-2-enoate ::(1b) 2-aminoprop-2-enoate = 2-iminopropan ... catalyzes this conversion. Cysteate is a biosynthetic precursor to taurine in microalgae. By contrast, most taurine in animals is made from cysteine sulfinate. References Sulfur amino acids Sulfonic acids {{organic-compound-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
L-cysteate Sulfo-lyase
The enzyme L-cysteate sulfo-lyase (EC 4.4.1.25) catalyzes the reaction :L-cysteate + H2O = hydrogensulfite + pyruvate + NH3 (overall reaction) ::(1a) L-cysteate = hydrogensulfite + 2-aminoprop-2-enoate ::(1b) 2-aminoprop-2-enoate = 2-iminopropanoate (spontaneous) ::(1c) 2-iminopropanoate + H2O = pyruvate + NH3 (spontaneous) This enzyme belongs to the family of lyase In biochemistry, a lyase is an enzyme that catalyzes the breaking (an elimination reaction) of various chemical bonds by means other than hydrolysis (a substitution reaction) and oxidation, often forming a new double bond or a new ring structure. ...s, specifically the class of carbon-sulfur lyases. The systematic name of this enzyme class is L-cysteate bisulfite-lyase (deaminating; pyruvate-forming). Other names in common use include L-cysteate sulfo-lyase (deaminating), and CuyA. References * EC 4.4.1 Enzymes of unknown structure {{enzyme-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |