Oxidation of Cysteine Sulfur in Vivo

In contrast to the fact that Z-cysteine alone can be utilized for growth, oxidation in the living animal of the sulfur from d- or Z-cysteine seems to proceed equally well. Among the products resulting from this oxidation cystine, sulfate, thiosulfate, and taurine have been identified. 

The oxidation of cyiitaine to cyfitine manifests itself in a particularly striking fashion in individuals suffering from cystinuria. Brand, Cahill, and Harris (27) have stated that 70% of the ingested Z-cysteine sulfur was found in the urine of a cystinuric in the form of cystine. In the normal 

Oxidation of Su lfdr op Vauiouk Z-Cy.steine Debivatives t.i Sulfur in Animals  

Amino acid Animal and path of introduction Sulfate formed Ref. No. 

The oxidation of cysteine sulfur to thiosulfate has been observed in rabbits after intravenous injection of Z-cysteine. Of 338 mg. of Z-cystcine sulfur introduced, 0.8% was recovered in the urine in the form of thiosulfate after a 48-hour interval (49). As in the case of methionine, this amount is very small its slightness is explained in the same way. However, the amount is significant. 

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