GLYCOPROTEIN STRUCTURE OF YEAST INVERTASE

Invertase in yeast appears to exist in two forms. One is intracellular and devoid of carbohydrate. The other is localized externally to the cell membrane in the cell wall and, unlike the internal enzyme, is a glycoprotein which contains approximately 50% carbohydrate. An estimate of both the number and sizes of the carbohydrate units in the enzyme has been obtained by an examination of glycopeptides obtained after proteolytic digestion of the enzyme by Streptomyce griseus protease. The results indicate that approximately 30 chains of polysaccharide of varying size are present per molecule of enzyme. The nature of the carbohydrate-protein linkage has been examined and appears to involve a glucosylaminyl-asparagine bond. © 1969, American Chemical Society. All rights reserved.