A study of the sulphur amino acids of rat tissues

Abstract

In a study of the metabolism of L-[35S]methionine in vivo, the labelled sulphur compounds of rat liver and brain were separated first by ion-exchange chromatography into two fractions containing free sulphur amino acids such as methionine, cystathionine, cyst(e)ine and homocyst(e)ine and glutathione. Two-dimensional paper chromatography with butan-1-ol-acetic acid or propionic acid-water in the first direction and 80% acetone or acetone-ethyl methyl ketone-water in the second direction was found superior to other solvent systems for separating the sulphur amino acids. At 10 min. after in-jection of [35s]methionine only a small part of the S35 was found com-bined in free methionine or other free sulphur amino acids. Evidence was obtained of the presence of adenosyl[35S]methionine and adenosyl [S35]homocysteine in perchloric acid extracts of rat liver and brain. The trans-sulphuration pathway was active in brain as well as in liver.