The metabolism of glycyl-L-serine O[35-S]-sulphate in the rat.

It is now well established that mammalian tissues contain an enzyme system that can desulphate L-serine 0-sulphate both in vivo (Tudball, 1962) and in vitro (Dodgson & Tudball, 1961). Information about the precise nature of the system is very limited and it is still not clear whether a simple hydrolase is involved. However, the localization of the enzyme system in the high-speed supernatant fractions of tissue homogenates shows that it cannot be identified with any of the known mammalian sulphatase enzymes. To obtain further information on this desulphating system, studies have been extended to include simple peptides containing sulphated L-serine residues. The present paper deals with the preparation and the metabolism in the rat of glycyl-L-serine 0[35S]-sulphate. A preliminary account of some of this work has already been published (Noda, Tudball & Dodgson, 1963).