Isolation and distribution of 1-methyl-5-thiol-L-histidine disulfide and a related metabolite in eggs from echinoderms

Unfertilized eggs of Paracentrotus lividus contained, in addn. to glutathione, large amts. of 1-methyl-5-thiol-L-histidine disulfide. The same amino acid was also isolated from eggs of the sea urchin Arbacia lixula, the holothuroid Holothuria tubulosa, and the asteroids Marthasterias glacialis and Astropecten aurantiacus. Unfertilized eggs of Sphaerechinus granularis contained a related metabolite identified as Nα,Nα,1-trimethyl-5-thiol-L-histidine disulfide on the basis of its spectral and chem. properties.