Über das Vorkommen neuraminsäurehaltiger Glykoproteide in Körperflüssigkeiten

Abstract

Neuraminic acid estimations, using a modification of the Bial reaction, were carried out on a wide range of biological materials. The substance is present in the serum of normal humans to the extent of 40-65 mg %, of which about 70% is present in the alpha-globulin fraction, 20% in the beta-globulin, and 10% in gamma-globulin; that is, alpha-globulins contained over 2% neuraminic acid, and beta-globulins almost 1%. The substance was also found in the sera of 15 species of animals (i.e. in all the ones tested) in similar amounts to those in human serum. It was also present in transudates, urine, cerebrospinal fluid, milk and saliva. Haemoglobin contained only traces; the neuraminic acid contents of very pure serum protein fractions obtained by electrophoresis are given.