Carbohydrate Peptide Complex from Egg Albumin

Abstract

ONE of us described in 1938 the preparation from crystalline egg albumin of a polysaccharide containing mannose and glucosamine and a small amount of an unidentified nitrogenous substance¹. On the basis of hexose and amino-sugar estimations on the intact protein and the molecular weight of 40,000 then accepted for hen's egg albumin, it was concluded that one albumin molecule contains four mannose and two glucosamine residues. Since the method of isolation involved acetylation, no information could then be obtained as to whether the glucosamine residues were originally present in the N-acetylated form. Since there were no suitable chromatographic methods available in 1938, the work was discontinued and many problems concerning this carbohydrate were left unanswered, particularly the nature of the linkage of the polysaccharide with the peptide chain.