The metabolism of dl-[β-14C] and dl-[35S]cystine by the rat
- 1 September 1953
- journal article
- research article
- Published by Portland Press Ltd. in Biochemical Journal
- Vol. 55 (2), 280-285
- https://doi.org/10.1042/bj0550280
Abstract
The metabolism of DL-cystine by the rat was studied by feeding DL-[S35] cystine and DL-[beta-C14] cystine. The relatively poor conversion of the C-labeled cystine into serine and the almost complete absence of radioactivity in methionine after feeding S-labeled cystine indicates that the formation of cystine from methionine and serine via cystathionine is not reversible to any significant extent. There was no appreciable conversion of the beta-C atom of cystine to the methyl groups of choline or methionine. A similar expt. with DL-[gamma-C14] valine that this amino acid also was not a precursor of methyl groups. The major pathway of cysteine metabolism appears to be to pyruvate as shown by the good incorporation of C14 from dietary DL-[beta-C14] cystine into alanine, aspartic acid and glutamic acid of the visceral protein and into the acetyl group of alpha-acetamido-gamma-phenylbutyric acid excreted in the urine. A synthesis of DL-[beta-C14] cystine from C14H3OH is descr.Keywords
This publication has 27 references indexed in Scilit:
- The effect of cobalamin on the quantitative utilization of serine, glycine and formate for the synthesis of choline and methyl groups of methionineBiochemical Journal, 1953
- Evidence for a three-carbon acid intermediate in the metabolism of valineArchives of Biochemistry and Biophysics, 1952
- Fractionation of the nitrogenous water-soluble constituents of liver. 1. The isolation of glycerylphosphorylethanolamine and of taurineBiochemical Journal, 1952
- Intermediary metabolism of cysteinesulfinic acid in cell-free extracts of Proteus vulgarisBiochimica et Biophysica Acta, 1952
- Synthesis of purines and methyl groups from carbon atom of histidineArchives of Biochemistry and Biophysics, 1951
- Some aspects of the metabolism of d- and l-serine by the ratBiochemical Journal, 1951
- The conversion of l-valine to glucose and glycogen in the ratArchives of Biochemistry and Biophysics, 1951
- Appendix 2. Preparation of solid samples for assay of 14CBiochemical Journal, 1950
- CHROMATOGRAPHIC DETERMINATION OF THE AMINO ACID COMPOSITION OF PROTEINSCold Spring Harbor Symposia on Quantitative Biology, 1950
- Studies in the sulphur metabolism of the dogBiochemical Journal, 1932