La formation enzymatique de l'acide cystéinesulfinique á partir de sulfite par l'embryon de veau

Abstract

Incubation of ground embryonic calf liver under nitrogen at 38°C with 35S-labelled sodium sulphite, pyruvate and glutamic acid, leads to the formation of 35S-cysteinesulphinic acid, isolated as the DNP-derivative. 35S-hypotaurine is also found, but not 35S-taurine or 35S-cystine. The amount of cysteinesulphinic acid present in the medium at the end of the incubation has been measured. In the presence of serine this amount is noticeably less. In the course of the incubation of the sulphine with embryonic calf liver, organic sulphur compounds without amino groups are also formed. Of these, one or more can be transformed, either directly or indirectly, into a product whose properties on paper ionophoresis are the same as those of cysteinesulphinic acid. Finally it has been established that under the conditions employed, cysteinesulphinic acid is not reduced to cystine. In vivo, on the contrary, this reduction is possible 2.