The cell-free biosynthesis of the glycoprotein of membranes from Ehrlich ascites carcinoma cells.

Abstract

The incorporation of glucosamine and galactose into soluble and membrane glycoproteins is described. The enzymes which incorporate glucosamine and galactose (from UDP[uridine diphosphate]-galactose) into TCA[trichloroacetic acid]-insoluble glycoproteins were found to reside in a postmicrosomal particulate fraction. It was postulated that the oligosaccharides, synthesized by this fraction, are attached to a protein receptor at the membranes bearing microsomes as a step in the eventual buildup of the surface membrane. The incorporation of monosaccharides was stimulated by ATP[adenosine triphosphate] and other monosaccharides, but not by UTP[uridine triphosphate], GTP[guanosine triphosphate], CTR [cytidine triphosphate], RNase[adenosine triphosphate], and puromycin. The incorporation of monosaccharides was contrasted with the incorporation of amino acids into soluble and membrane fractions.