Oligosaccharides released by hydrazinolysis from Tamm-Horsfall protein of various human donors contain similar high-mannose glycans.

As pathophysiological functions claimed for Tamm-Horsfall protein (THP) are related to its sugar moiety, we examined influence of pregnancy and various diseases on high-mannose chains. Hydrazinolysis was used to liberate oligosaccharides from THP polypeptide backbone. After HPLC separation of fluorescently labelled glycans similar profiles of neutral oligosaccharides were observed in THP of healthy subjects, pregnant women, patients with Bartter's syndrome, patients with acute lymphoblastic leukemia and a patient with carbohydrate deficient glycoprotein syndrome. THP contains Man-5, Man-6 and Man-7 glycans, with the preponderant amount of Man-6 glycan (about 7% of total THP oligosaccharides). No statistically significant differences were found in THP high-mannose glycans profiles between control subjects and pregnant women or patients. It is likely that neither pregnancy nor the pathological conditions examined affect high-mannose chains. In our opinion hydrazinolysis as a method of oligosaccharides liberation, in contrast to enzymatic deglycosylation, is more appropriate for analysis of the sugar moiety of THP.